Intestinal atresia and stenosis

is Associate Professor of Surgery at the University of S o u t h e r n California, l i e received an M.D. from Cornell Llniversity Medical College. Residency training in surgery inchldcd peri{~ds :it The New York Hospital, The tJniversity of California and Boston Children's Hospital, as well as in pathology at the Peter Bent Brigham Hospital, Boston. From 1954 to 1967 lie was on the surgical faculty of the University of California, l.os Angeles. Since that time hc has bt:ell associated with the University of Southern California with teaching and research activity carried out at The Childrens Hospital of l,os Angeles. l)r. f l a y s is a pediatric surgeon with particular interests in congenital m a l f o r m a t i o n s and pediatric neoplasi:l. His research accomplishmcnts have been in the field of hepatic regeneration.

THIS M O N O G R A P H concerns intestinal atresia and stenoses occurring between the py!orus and tile rectum. In the tirst section, duodenal anomalies, which include almost equal numbers of atresia and stenosis, fire reviewed with emphasis on clinical recognition and surgical management. Tile second section concerns jejunal and ileal atresias which are grouped together, although their unique characteristics fire also emphasized. The third section de. cribes the far less frequently encountered colon atresias. In the final section, there is a brief historical review, a summary of embryologic concepts pertinent :~.o atresia, and a summary of laboratory sttldies in which animal models of atresia have been produced. Unless otherwise indicated, statistical information is from a survey of members of tile Surgical Section, American Academy of Pediatrics ( I 9 6 6 - 6 7 ) , including data on over 1,200 infants with atresia, which were reviewed by Drs. Alfred A. deLorimier, Eric W. Fonkalsrud, and the author. "

S

•

"

•

DUODENAL ATRESIA AND STENOSIS GROSS PATHOt.OGY At operation, anomalies of the duodenum in the newborn are ordinarily screened from view by the right colon find mesocolon, which must be completely mobilized to visualize the defect precisely. The prominent features seen in atresia (or severe stenosis) are a bulbous proximal duodenum, which is connected by a wide "isthmus" 3

A BEFZSCTg# COL O N

DILA TED P,eOXIM.4 /.. DUODENL/A4

PANC~EAB

,~ •

.y j~-

¢

a

oesreucnoN itlOilql,.

~-

\

~

:

.....

D/YODE/VO'/,/

Fro. l.~-Duodenal atresia, gross pathology. A illustrates the external appearance found in 85% of infants with atresia, occurring either B, as complete occlu_ sion, or C, with a minute opening in a diaphragm. The d~odenum illustrated is incompletely rotated. (Continued.) to the distended stomach, and the entire distal intestinal tract, including the colon, is minute. The major forms of duodenal atresia and stenosis are illustrated in Figure 1. In duodenal stenosis, the external appearance of the gut may be deceptively normal and the diagnosis may only be made by attempting to pass a catheter through the lumen. In addition to the diaphragms, "'cords" and complete occlusions illustrated, duodenal stenoses may also take the bizarre form of the "windsock" deformity or of an "intralunlinal diverticulum of the diaphragm" (Fig. 2). Ordinarily, the appearance immediately distinguishes duodenal atresia from all other forms of gastroduodenal obstruction seen in the newborn. Two other conditions, "malrotation" and annular pancreas, may present an indistinguishable clinical picture. Incomplete rotation of the colon or duodenum may result in in4

0

,/

(

•

i) cO~,/PzErE

ABSE~/d'E"0/: "CO,eD" TYPE OF A T~ESIA

Fro. I ( c o n t . ) . ~ D and E are two less c o m m o n types of this duodenal anomaly. In D, lhe occlusion consists of a long cordlike segment; in E, the distal duodenum is absent as well as ,some of the jejtmal mesentery. A m o n g infants with alresia (not stenosis), approximately 20% hnve a complete separation of the two du" odenal segments D or E, which is ahray.r postampullary in location.

testinal obstrtictiofl because of bands of tissue which pass over tile duodenum or proxinlal jejunum or because proximal jejunal loops are attached by adhesions to the small intestinal mesentery. Either may be the primary source of obstruction and may produce an appearance superficially similar to atresia. Incomplete rotation is frequently associated with an intrinsic duodenal lesion, i.e., stenosis or atresia, and both may be responsible for the symptoms seen. Annular pancreas may produce symptomatic duodenal obstruction in the newborn, whether it completely encircles the duodenum or not. The embryologie development of the duodenum and of the pancreatic anct biliary ducts and their relationships will be discussed in the final section. From a clinical standpoint, obstruction associated with an annular configuration of the pancreas is almost always combined with secondary (intrinsic) duodenal stenosis. This would make any attempt to free the duodenum from the constricting pancreas unproductive as wel.1 as a menace to the pancreatic duct. Associated biliary ductal abnormalities are common, taking the form of accessory rather than absent ducts. The site of entry of the biliary tract into the intestine, i.e., above or below the site of atresia has been studied with intensity because of the relationship to the presence o]: absence of bile in vomitus. We now know that separate biliary ducts frequently enter botll the proximal and distal segments. The rare gastric antral atresias and stenoses and pyloric atresias are readily distinguished from congenital duodenal obstruction when they are found as single lesions; proximal distention in th~ first group does not extend distal to the pylorus. When occurring as double or corn5

~

"

tl~,

P,4NC~gAS AND STENOTIC

ANIeULA~

)f " ,~i~."

"

~ ,..~:~ "

~,<'

i~ "/'

.... .:::-,:;~:,".~{:/:"

~, ..

,....,,,~.,:. ..

,,,.

•

DUO~ENU/~

-~

C-2

/J

i

.,,,,,,,,..

Flc. 2.--Duodenal stenosis secondary to annular pancreas and unusual! types of intrinsic duodenal stenosis. A, a marked degree of stenosis may be produced by annular p~mcreas. Note that ttle principal pancreatic duct encircles the duodenum. Two additional forms of duodenal stenosis are illustrated: the first, B, is known as an intraluminal diverticulum of the diaphragm. In this instance, the only opening in the diaphragm is adjacent to the neck of the diverticulum. The second, C - l , 2 and 3, is known as the "windsock" deformity. The probable mechanism of its development from a simple diaphragmatic stenosis is diagramed. Both of these anomalies may be difficult to recognize at operation because a catheter may be passed for a considerable distance into the duodenum without detection of the obstruction.

6

.

bined atresias, they may be treacherously confusing ( 1 7 ) . Hypertrophic pyloric stenosis may be present ;it birth but, even at this age, has a characteristic pyloric "tumor." Some cases of duodenal atresia or' stenosis are found with adjacent areas of scar tissue, solid "cord" formation replacing the lumen of the gut (Fig. 1) and shortened total intestinal length, entities usu ally associated with jejunoileal atresia ( 1 5 ) . When present, these are usually found with lesions of the distal duodenum.

CLINICAL FEATURES It is assumed that all patients with duodenal atresia are recognized clinically during the first week of life or die without diagnosis, whe~ea, • s one fourth of those with stenosis may. be recognized later in infancy or childhood. Approximately 9 0 % of newborns with these anomalies are functionally completely obstructed. The distinction between atresia and marked stenosis is difficult and clinically unin> portant. Duodenal atresia (and stenosis) is associated with the highest rate of associated maternal polyhydramnios ( 4 5 % ) and of infant prematurity ( 5 4 % ) found in any group of infants with atresia of the intestinal tract (Table l ) . In the 3d trimester, it is believed that a significant amount of amniotic fluid is returned to the maternal circula-

TABLE

I . ~ I N C I D E N C E OF ~|ATERNAL POLYltYDRAMNIOS AND OF PRFMATURITY IN INFANTS V¢ITtt ATRESIA (ANDSTENOSI3) AT DIFF'ERI:N'r LEVELS 1N THE INTESTINAL TRACT*

LEVEL OF ATRESIA

1. Duodenum 2. Proximal jejunum Distal jejunum Unspecified jejunum Jejunum (total) 3, Proximal ileum Distal ileum

Unspecified ileum Ileum (total) 4.

Multiple mresias

PV.R CENT OF INFANTS WHO ARE PREMATURE BY ~t,~E|GitT

CASES ~vlrll MATERNAI POLYHYDRAMNIOS

PER CENT OF MOTHERS W I T H POt,YtlYDRA MN lOS

342 119 71 7 197 48

154 37 17 4 58 8

45 31 24

34

29

38

121

21

I7 ]7

3 172

2 31

18

25

28

8

30

56

NUMBER OF CASES

(Jejunvm and ileum) *Data from the Survey of Members of the Surgical Section, American Academy of .Pediatrics ( S S , A A P ) (presented 196"/). Comparisons between the total number of infants with duodenal anomalies with the total number of infants with other levels of atresia is invalid, as the former represents a smaller population sample.

7

tion through absorption of swallowed material from the fetal intestine. This pathway is obstrtlcted in high atresia, resulting in polyhydramnios and, probably, subsequently in premature emptying of the uterus. There is no sex preponderance or unusual sibship relationship in single cases of duodenal atrcsia. Families with multiple afflicted siblings have been reported (24). Vomiting is the paramount symptom, occurring in almost all infants in whom it is possible, i.e., excluding those with associated esophageal atie." " sla or in whom the diagnosis is made by an x-ray film taken immediately following birth (because of maternal polyhydramnios). Abdominal distention is localized to the upper portion of the abdomen and is striking.enough to be recognized clinically in one third of these infants. The lower abdomen is often scaphoid, which accentuates the distention of the tipper portion. Meconium is passed per rectum in 50% of these infants, including those with mild stcnosis, severe stenosis or complete occlusion ( ! 5 ) . Thus, almost half of the group emit bile-stained material from both mouth (emesis) and rectum (meconium). The explanation for this will be discussed in the final section. In nonobstructed newborns, the incidental occurrence of bile-stained vomiting has been observed in only 2 of 4,000 consecutive infants (Nixon). All other symptoms and signs in atresia are related to longstanding duodenal" obsti'uction, i.e., dehydration, alkalosis and pulmonary aspiration, or are secondary to the multiple malformations or ottler associated disease states so prevalent in infants with duodenal anomalies. Rupture of the stomach, l)resumably due to distention or vomiting, has been reported but is uncommon. Rupture of the dilated proximal duodenal segment has been encountered in two forms: ( i ) in the fetus, producing (sterile) nleconium peritonitis and (2) in the neonatal period, restllting in nonsteri]e peritonitis, which may be lethal. Perforations of both types are more common in jejunoileal atresia and are described in detail in the second section. In some nurseries for the newborn, an abdominal roentgenogram is taken following the birth of infants delivered by mothers with significan.[ po]yhydrahlnios, which appears suddenly in the 3(I trimester. Distinct signs of Down's syndrome in a newborn infant are an indication for a similar study; but these seem to be rarely recognized. More commonly, x-ray films are taken following the initial vomiting episode, and the presumptive diagnosis of duodenal atresia is made.

ROENTGENOGRAPHIC STUDIES Films (widlout contrast material) taken of the abdomen with the infant in the supine and erect positions, at times supplemented by 8

+/<' i : ,

¢,

)

:(:

..

i

:i

,

,

-.

,

: ] -

.......

..:.-

'

,

Fio. 3 . - - D u o d e n a l atresia. A and B illustrate the classic findings in this anomaly. A, taken with the infant in the supir, e position, shows a single gas shadow with a constric:ked midportion; this is known as the "dumbbell" sign. B, taken with the infant in the erect position, shows a configuration known as the "double bubble" sign. C is the same basic picture, using the lateral decubitus position. Contrast material has been introduced int~ the stomach. Some of this remains in the dependent portion of each of the two saccular segments, that is, the stomach and the distended duodenum.

9

films in the decubitus and inverted positions, will establish a diagnosis of duodenal obstruction and frequently suggest its precise cause. Two air-filled cavities with "fluid levels" in the upper abdomen, representing the dilated stomach and duodenum, are classic signs of duodenal atresia. These may be connected by an "isthmus" producing the ""dumbbell" sign (Fig. 3). The same connected cavities may also be well demonstrated (and the margins delineated) in the lateral or decubitus and the inverted positions (Fig. 3), again appearing either as'the "double bubble" or "dumbbell" sign. If no other evidence of gas can be seen in the abdominal film, the presumptive diagnosis must be duodenal atresia. With the same roentgenographic tindings, however, the diagnosis can also be incomplete rotation ("malrotation") of the intestine or obstruction secondary to annular pancreas. Because of the first possibility, a colon contrast study is helpful during the initial stage in management. The colon is small, but its position can be readily determined. Displacement of the entire colon to the left or the presence of the cecum in the right upper quadrant suggests incomplete rotation. If there are.even minute amounts of intestinal air distal to the two major "bubbles," the operation will usually demonstrate duodenal stenosis or incomplete intestinal rotation as the cause of obstruction. If the volume of gas in the upper intestinal tract seems insufficient for ideal roentgenographic studies, the introduction of 40 cc. of room air through a nasograstric tube may prove helpful. Contrast material is frequently used and provides interesting illustrative material for teaching purposes. It rarely adds significantly to the accuracy of diagnosis and increases the risks of aspiration. If used, the contrast material should be withdrawn and the stomach placed on low ( 3 - 4 cm.) negative pressure after the study.

PREPARATION FOR OPERATION

The possibility of an associated mid-gut volvulus makes this clinical situation a dire emergency Volvulus is statistically rare in the presence of a completely rotated colon. If the abdomen remains scaphoid and the colon is normally rotated, it may be desirable, and is quite justifiable, to spend 24-48 hours in the treatment of associated conditions (hyperbilirubinemia, sepsis and respiratory distress syndrome), assessment of associated anomalies (frequently a problem) and attempts to determine the presence of Down's syndrome, etc. This is quite unlike the situation in more distal forms of atresia where localized volvulus and perforation of the distended proximal segment are common. With the diagnosis of duodenal obstruction established and the •

•

10

6

,

stomach decompressed, the patient must be carefully evaluated with concern for additional problems. The esophagtis must be proved patent by the passage of a tube and the anus examined with a linger (if nacconium has not been noted). The newborn is expected to pass urine before operation. The blood tirea nitrogen is determined, and, if elevated, the urinary tract should be studied by bladder catheterization and an intravenous urogram. Major urinary t r a c t anomalies, such as renal agenesis or posterior urethral valves, are frequent findings. The cardiopulmonary status should be carefully evaluated. Major congenital cardiac lesions are common, and consideration of urgent surgical intervention may be indicated. A considerable group of these patients have the "respiratory distress syndrome" of the newborn or may have aspirated vomitus and have pneunaonia. Anotlaer large group have erythroblastosis fetalis. Exchange transfusions may be required, either prior to or shortly following the abdominal operative procedure. Biliary atresia is rarely, if ever, associated with duodenal atresia; but elevation of the levels of conjugated and unconjugated fractions of serum bilirubin is very, common, due to a variety of causes, many of which are never identiffed. Unexplained elevation of serum bilirubin levels are also found when the site of obstruction is in the proximal jejunum (7). Exchange transfusions or phototherapy may be required to lower bilirubin levels and prevent kernicterus in infants with demonstrated hemolysis and also those without apparent hemolytic disease. A majority of these patients are premature. Many of the unexplained problems associated with prernaturity are found with regularity in infants with atresia (2). In addition to hyperbilirubinemia, these include hypoglycemia, thrombocytopenia and a predilection to sclerema. In summary, the newborn infant with duodenal atresia must be regarded as presenting a wide variety of other diagnostic problems, the recognition of which may be of great help in evaluating his overall status as well as guiding his immediate management.

DOWN'S SYNDROME AND DUODENAL ATRESIA

Almost exactly one third of the infants with duodenal atresia (and stenosis) have Down's syndrome ( 1 5 ) . This high incidence has been long recognized and clearly includes t,he infants with the trisomy'21. Down's syndrome with the translocatioil and mosaicism types of chromosomal defects have not been shown to be involved in this relationship. This represents an associatiofi of a chromosomal abnormality with an anomaly that is not known to be on a chromosomal basis. The association includes not only the neonate, but also those cases of duodenal stenosis which are first recognized later in infancy or child-

11

hood. If, following consultation, it is apparent that one is dealing with Down's syndrome as well as duodenal obstruction, it is the obligation of the surgeon to so inform the parents. As "informed" adults, they do have the right to grant or withhold permission for operation. The Down's syndrome has become a complex of diseases, including some groups with apparently normal mental development, so that decisions should be made only on the basis of expert advice. The presence of this syndrome does not increase the mortality in infants with duodenal anomalies.

COMBINED ATRESIAS IN THE NEWBORN

The concurrence of duodenal atresia (or stenosis) in association with esophageal atresia or imperforate anus-rectal atresia is common and warrants a well-considered operative attack (15). It is not wise to carry out the repair of both the esophagus and the duodenal outlet at the same procedure (21). When duodenal atresia is combined with the usual type of esophageal atresia (Gross type C), i.e., "blind" upper pouch and a distal tracheoesophageal fistula, it is probably best initially to perform a gastrostomy, divide the tracheoesophageal fistula and repair the esophagus. The gastrostomy tube should be large (#1:8 to # 2 2 F.) and kept open and dependent to avoid pressure in the reconstructed esophagus. In 48 hours or more, a laOarotomy to correct the duodenal obstruction is performed. The alternative staging, i.e., performing laparotomy and jejunoduodenostomy initially (always with gastrostomy), may increase the amount of refluxing gastric contents through the fistula and into the tracheobronchial tree. In esophageal atresia without fistula or with upper pouch fistula only (Types A or B), the laparotomy for duodenal obstruction should be the primary operation. The upper esophageal pouch can be maintained on suction for a prolonged period, and the baby can be fed via the gastrostomy. When the associated lesion is rectal atresia, except in those cases where a simple perineal approach will be required, it is advisable to make a colostomy. This should be carried out either prior t o the definitive procedure (under local anesthesia) or in association with the laparotomy for duodenal obstruction, if the latter is to be done without delay. Definitive anorectal reconstruction is always deferred.

OPERATIONS FOR DUODENAL OBSTRUCTION IN THE NEWBORN

Infants with duodenal obstruction may be operated on under local anesthesia, if this seems desirable. The amount used in the small 12

S

"lii

D

~t!yt

, ,<.

"

t

/.

;

REDUE-TION O F

"1411NDSLP6K" DEFO~MITJ FrG. 4 . - - T h e "windsock" deformity. The detection of this type of diaphragmatic duodenal stenosis is difficult. ,However, when a #8 Foley catheter is passed into the jejunum beyond any point of possible obstruction, inflated and withdrawn into the stomach, the "windsock" is readily demonstrated and may be corrected by complete excision of the diaphragm.

13

infant must be carefully measured to prevent toxicity. A total of 3 mg./lb., of Xylocaine (6 m&/lb., of procaine) in 2 hours is well tolerated. The dosage is best conserved by using 1A or ~A% solutions. Because of the lack of distention of the distal intestinal tract, abdominal w:lll closure is usually simple in duodenal atresia. If the infant is strong and crying actively, however, tile absence of a general anesthesia and relaxation may result in considerable trauma te the liver and other viscera during cl'osure. Nevertheless, for the smaller premature or critically ill infant, local anesthesia is recommended. Intubation permits O~ inhalation and prevents aspiration when combined with local infiltration. The abdomeu should be opened through either a long vertical or wide upper transverse incision. If the stomach and proximal duodenum are massively dilated and the entire distal intestinal tract is collapsed, it is apparent that a "bypass" procedure (draining the duodenum) will ordinarily be indicated. Before proceeding with this, however, one must make certain that incomplete rotation of the colon or duodenum does not play a role in this obstruction. It may be possible to do this by inspection of the. area or it may require considerable dissection with division of the obstructing bands as the duodenum is exposed and even mobilized. If some abnormality of intestinal rotation is found, this does not exclude the possibility of intrinsic stenosis. Following the release of obstructing bands, if it is not apparent that fluid passes freely into the-, distal jejunum, it is probable that there is a second anomaly, a congenital diaphragm. This situation is clarified by passing a catheter (Foley) through the duodenum via a gastrostomy opening, intlating the balloon in the jejunum and withdrawing it,. as illustrated in Figure 4. The identification of an annular pancreas is of interest but the surgical therapy is not altered. Identification of the biliary ducts is not required, even in presence of jaundice. If the liver appears abnormal, a biopsy should be performed; this is most easily carried out with a Menghini needle. If the liver is frankly cirrhotic, a cholangiogram should be performed through the gallbladder. Under ordinary circumstances, however, even in the presence of jaundice~ the liver does not appear abnormal, and no operative studies are indicated. A second step which should be carried out before beginning the anastomosis is a search for distal at~esias. When a preoperative colon contrast study has not been obtained, the colon should be included in this examination. This may be accomplished by injecting saline into the lumen (at the site of the proposed anastomosis) and gently forcing it down through the jejunum and ileum. Duodenal atresia or stenosis is ordinarily "by-passed" by a duodenoduodenostomy or duodenojejunostomy performed as a side-to14

side anastomosis (Fig. 5). Other possible procedures will be discussed later. The duodenal anastom,osis may be carried out either through the mesentery of the transverse colon or with the right colon reflected to the left side. In case of malrotation, the colon may already lie to the left of the point where the anastomosis would be placdd. In others, mobilization of the colon during the initial survey of the site of obstruction has been required. There is no reason to replace the right colon in order to use the transmesenteric technic (35), as either approach, i.e., transmesenteric or .extramesenteric, can be utilized. The anastomosis is formed by bringing the first loop of intestine distal to the obstruction to the anteroinferior side or end of the bulbous duodenum. One begins with a posterior row of 5 - 0 interrupted silk sutures, uniting the seromuscular layers. An internal continuous 5 - 0 absorbable suture may be placed (35). (If a distal feeding tube is to be used, it should be positioned at this time with the anastomosis open.) The anterior continuous suture may be completed, and an anterior row of interrupted 5-0 silk sutures placed to unite the seromuscular walls. A one-layer closure with interrupted 5-0, nonabsorbable sutures may be used for both anterior and posterior walls of the anastomosis. A gastrostomy is made in the proximal portion of the anterior gastric wall adjacent to the greater curvature. This should be a Stature, not a Witzel, type, so that the tube can be removed and replaced (if necessary.) without difficulty after its initial fixation (which takes 2 weeks). A # 18 or # 2 0 mushroom catheter is recommended. If a feeding tube is to be used, it is passed down throtlgh the gastrostomy tube, through the duodenal anastomosis and 6-8 era. into the distal jejunal limb (26). A silastic catheter is recommended because of its extreme softness and pliability. It may be more difficult to position accurately than a firmer (polyethylene) tube, and the latter m a y be used if necessary. The operation is completed by bringing the gastrostomy tube.(with the feeding tube inside it, if it is being used) through a separate "stab" incision in the left upper qtmdrant. In performing this maneuver (i.e., placing t h e feeding tube), one should assemble the gastrostomy tube and feeding tube as a unit before positioning it. The proximal end of the feeding tube may be brought through a small opening in the side of the mushroom catheter, which makes it easier to manage during the postoperative period (Fig. 5 ). Other operative approaches may at times be used in duodenal atresia or stenosis. If there is a frank separation of the duodenal end and the distal duodenum or proximal jejunum, it may b e possibte to bring the distal end to the duodenal pouch for an end-to-end (oblique) anastomosis. In this situation, Rehbein exteriorizes the 15

A [ ~ U O D E I V O -d E J U A I O ~ c T O M y TI£A/VS/VlES£1VTE~°IC

) i

.....

~Z~61VO dE, rXTRA -I,4~ -

S: / dEdUNA L FEEPlNG

TUBE

FIG. 5.wAnastomoses for duodenal obstruction; the jejunal feeding tube. A, the traditional retrocolic anastomosis brings the most proximal segment of the jejunum to the distended duodenal segment. The colon is smaller than shown in this.diagram. B, the equally effective extramesenteric duodenojejunostomy. In both anastomosds, the absence of duodenal rotation may make this actually a duodenoduodenostonay. C, the position of a distal jejunal feeding tube. The mushroom catheter and feeding tube are best ~lssembled as ~ unit before placement in the stomach. The feeding tube external opening is separated from the lumen of the mushroom catheter; in this way, decompression and measurement of gastric residual may be carried out without interfering with the feeding regimen.

16

distal opening for a week prior to this anastomosis (46). A portion of the distal segment should be resected as in more distal atresias. Even in this situation, the side-to-side anastomosis is probabl.y preferable. If the anomaly consists of a tlTin, intraluminal diaphragm, it may be possible to resect the diaphragm or carry out a Heineke-Mikulicz procedure at the level of obstruction (46). Such diaphragmatic stenoses, which can be corrected by local procedures, are usually found in older infants or children. In these patients, the opening in the diaphragm has obviously functioned reasonably well for months or even years. In operating on the newborn with duodenal obstruction, one must recognize the "windsock" abnormality, an unusual form of diaphragmatic'stenosis (48). In these infants, the duodenal diaphragm, which has a central perforation, is apparently forced downward by pressure in the proximal gastroduodenal segment. The margins are fixed to the duodenal wall, but the mid-portion stretches distally, eventually assuming the shape of a long "sock," which protrudes through the duodenal lumen (which it distends) for as far as 8 cm. The minute opening is at the distal extremity or tip of the "sock." This distended diaphragm is extremely thin walled, and its recognition may be difficult. The most effective maneuver to demonstrate this anomaly is to pass a Foley catheter ( # 8 ) through a gastrostomy opening, through the duodenum and well down into the proximal jejunum. The small balloon is then inflated with 1 or 2 co. of air, and the catheter is withdrawn into the stomach (Fig. 4). If a marked stenosis is present, the catheter will be obstructed in its passage downward through the duodenum. If the catheter passes through the opening in the "windsock" deformity, the sac wltt be completely inverted and brought up into the gastric lumen as (he catheter is withdrawn. Here it may be resected. A similar anomaly in which the opening in the diaphragm is at the side of the neck of the long pouch (with none at the "tip") is also found (8). This is called an "intraluminal diverticulum of the diaphragm."

GASTROSTOMY There is rio unanimity of opinion regarding the use of a gastrostomy following anastomosis in distal intestinal atresias. In duodenal atresia or stenosis, however, gastrostomy has special merits and is routinely used. During the immediate postoperative period, it provides decompression of the greatly distended gastroduodenal segment. (This proximal segment cannot be excised as in distal atresias.) Further in 17

tile course, it provides an accurate way of measurm= gastric emptying. This results in earlier feeding if patency is demonstrated. Thc gastrostomy is helpful in performing contrast studies if obstruction is suggested. It provides a safe and reliable site of entry for the jejunal feeding tube. If the infant is on a respirator, the gastrostomy (as opposed to a nasal tube) is helpful because it leaves the esophagea:} segment without a firm catheter to produce blceding or even septal necrosis (if combined for a period with ;~n intratracheal tube). The technic for performing'a gastrostomy in the newborn has been well described by several authors (22, 55). When the tube is no longer required, its'removal is usually followed by rapid spontaneous closure of the opening. •

O

°

POSTOPERATIVE MANAGEMENT (DUODENAL ATRESIA) During the postoperative period, infants with duodenal atresia are often the center of professional activity relative to the management of other anomalies or associated diseases. They may require exchange transfusion, prolonged periods on a respirator and even cardiac pacemaker support. The atresia may not appear to be (and actually may not be) amongthe baby's most urgent problems. The gastrostomy should be kept open to decompress the stomach but need not be on suction. Antibiotics with broad-spectrum bacterial coverage are administered during this period. If a jejunal feeding tube is not used, gastrostomy feedings are commenced on the 3d postoperative day and consist initially of aqueous-dextrose solutions. A regimen of frequeni: feedings with periodic emptying of the stomach to determine tile residual should be maintained, and formula feeding should not be commenced until it is apparent that there is adequate emptying. The gastrostomy tube should be kept open and elevated during this period. In this way, no significant gastric pressure can develop which could result in vomiting and aspiration. When aqueous solutions appear to be passing readily from the stomach, a milk substitute such as Nutramigen or meat-base formula, or other formula which forms small curds, should be started. Again, small volumes of feeding should be given frequently, initially hourly, after aspiration of gastric residual. Failure of the stomach to empty readily by the 5th day following surgery is of concern and contrast studies should be performed. Prior to the past several years, it was felt imperative to reoperate on these patients before the 3d week of life if gastric emptying was still inadequate, as a precipitous nutritional decline followed. At present, with the use of a high calorie intravenous alimentation program, this is not required; but the parenteral replacement should be started I8

promptly rather than after repeated changes in formula. High calorie intravenous feeding should be continued until gastric emptying is complete. If reoperation is required, it ca'n be performed on.an adequately nourished inf~mt. i!f a feeding tube has been pa~sed through the stomach to a point in the proximal jejunum, fcedings may be started on the day after operation, with:the initial use of aqueous solutions. To control flow, these are best passed through the dropping chamber of an intravcnous set. The volume of fecdings should be small initially (5 cc. pcr hour or less) to permit accommodation of the small jejunal lumen. The -volume should be gradually increased. The gastrostomy tube is open and elevated with frcquent determinations of gastric residual. Fluid may pass rctrograde from the end of the feeding tube back into the stomach. If' the gastric fluid appears to contain a large part of the solution which has been administered, a contrast study is performed through the feeding tube to see if it is actually in the jejununa. If tube function appears to be adequate, the substitution of a nutritional formula (with small curds or no curds) is made. If the entire caloric requirements of the infant can be met in this manner, it is recommended that the tube be left in place until gastric emptying is clearly demonstrated. Complete lack of residual for several days, with supplementary aqueous feedings per gastrostomy, indicates an open anastomosis. Leaving the fecding tube in place for a prolonged period is quite safe, provided the tube is silastic. If it is a firmer catheter, such as polyethylene, it should not be left in place longer than 6 days. Perforations of the intestinal tract attributed to catheters have been :reported (not with silastic tubes).

LATE RECOGNITION OF DUODENAL STENOSIS

Duodenal stenosis may be recognized clinically late in inf~ncy, in childhood or even in adult life. The clinical picture in this group is often bizarre (20, 3 9 ) . Children in whom a swallowed foreign body ( c o i n ) w i l l not pass through the duodenum, in whom the vomiting initiated by an acute illness (gastroenteritis) persists or in whom there is an unexplained pnet~moperitoneum are examples. At operation, anomalies discovered 8t ~his age may frequently be corrected by a local plastic procedure, i.e., excision of diaphragms or vertical incision with transverse closure. Of particular interest in one study (15) was t h e group of 30 patients in whom stenosis was recognized after the 1st month, but before the 12th year, of life. A review of the history in these patients revealed that ] 6 had been premature infants; ! 1 demonstrated Down's syndrome; 2 had severe congenital heart disease; 1 had esophageal 19

atresia; 3 had colon malrotation; and 4 had other significant anomalies. Although the duodenal obstruction was not recognized until much later in life, this group had the secondary problems that are usually associated in the newborn with duodenal atresia or stenosis.

RESULTS OF THERAPY

Approximately 25% of patients with duodenal atresia (and stenosis) will succumb to conditions associated with other anomalies or diseases. One third.of the survivors will have Down's syndrome. If these two groups are eliminated, the outlook in the remaining infants is relatively good. Complications associated with the direct treatment of the malformation cannot be ignored, but they. are not the major factors in mortality (12, 63). The survival rate in infants with Down's syndrome may actually be greater than in the total group (15). Congenital cardiac lesions associated with duodenal atresia are often severe and include those in which the mortality may be lowered by operations in early infancy. Coexisting duodenal and esophageal atresias have produced an exceptionally high mortality in the past and deserve a separate plan of surgical management as described. The causes Of death in the largest collected series were divided as follow~: associated anomalies ( 3 0 % ) , respiratory complications ( 2 8 % ) ; prematurity ( 2 0 % ) ; anastomotic complications ( 1 6 % ) ; and all other causes ( 6 % ) (Table 2) (15). The over-all survival in this group was 64 %. In an attempt to reduce the mortality in duodenal atresia, the surgeon must direct his efforts toward rapid solution of the problem of duodenal obstruction with a short operative procedure (to reduce pulmonary complications) and early feeding. He will hope to main.

.

.

.

.

.

.

.

.

:

i~,

=l

i

TABLE 2.--MORTALITY, DUODENAL ATRESIA AND STENOSIS (503 I N F A N T S ) *

MAJOR FACTOR I1~ FATALITY~f

1. 2. 3. 4.

Associatedanomalies Respiratory complications Prematurity Anastomotic complications (obstruction and perforation) 5. Miscellaneous causes t l n c l u d i n g late deaths. * D a t a f r o m SS,,~ A P survey.

20

DEATHS

°/b OF TOTAL DEATHS (181 INFANTS) ATTRIBUTED TO FACTOR

54 51 36

30 28 20

29 11

16 6

tain the infant in an adequate nutritional state during the management of the esophageal, cardiac, hepatic and systemic problems which may develop. Prematurity remains a factor in the mortality found in this group and appears to be still uncontrollable, as it is usually the result of duodenal obstruction.

JEJUNOILEAL ATRESIA AND STENOSIS GROSS PATHOLOCY The most common types of this anomaly are illustrated in Figure 6, A, B and C. Stenosis is less frequent!y encountered than in duodenal atresia, accounting for less than 5% of largest collected series (1 l). A clearly recognized V-shaped defect in the mesentery is recognizable in over one third of these patients. Many others have mesenteric scars ( 4 0 % ) , mesenteric shortening or shortened total small intestinal length ( 1 8 % ) . An additional gross variant of atresia is recognized by the extremely wide defect in the mesentery, with almost complete absence of the superior mesenteric axis (Fig. 6, D). The blood supply of the small intestine distal to this defect comes from the superior mesenteric artery by way of collateral vessels, and the blood supply of the proximal segment from several jejunal or celiac branches (60). This may be the maximal extent of vascular occlusion consistent with survival of the fetus. In another gross type, described as "giant abdominal cyst" or "abdominal pseudocyst," the proximal segment has assumed massive proportions, filling the major portion of the abdominal cavity. This frequently infarcts and perforates, producing meconium peritonitis. Its walls are found as fragments of tissue on many intestinal loops. Multiple points of atresia are common in jejunoileal anomalies, giving segments of the intestine the appearance of a "string of beads." Evidence of vascular occlusion and total gut shortening are almost always seen in such cases. Jejunoileal atresia is frequently one factor in a complex of several different intra-abdominal disease processes. It is rarely associated with an intrinsic duodenal anomaly; h9v~ever , incomplete rotation of the colon or of the duodenum is foufid 'in 9 % of these infants and volvulus of the mid-gut in 5% ( 11 ). Nine p e r cent (or more) of jejunoileal atresias occur in infants with meconium ileus. Siblings are frequently affected by this disease combination (6, 27). I n this instance, the gross findings suggest that a disruption of the intestine has occurred, secondary to obstruction by the inspissated intraluminal mass. This has subsequently ,'healed" in a form recognized as intestinal atresia. The diagnosis of meconium 21

ileus is suggested by the characteristic appearance of the contents of the ileum and the colon and often by the family history. Three per cent of cases of intestinal atresia are found during the management of omphalocele or gastroschi~s. Intestinal duplications, intestinal aganglionosis and intussusception have all been found in association with mid-gut atresia (42). The cause-effect relationship in these instances is complex and is reviewed later in this section.

FIG. 6.--Jejunoileal atresia, gross pathology. Three major types of atresia or stenosis are shown in A,'B and C. A illustrates the diaphragmatic obstruction and B shows the connection only by a fibrous cord. (Continued.)

O/APH~A GI~: OBSTRUCTIO!

u,e'u /4NUMB L y

22

C O M P L E T E SEPA,eA TIO N W1174 ~ES6NTEEIC p&".,cFr'T

NESEIVf GR/C D 6 F E ¢ f

FIc. 6 (com.).---C shows complete seraration with mesenteric defect. These are ordinarily designated according to a classification dating from 1889 (Bland Sutton) as type I (diaphragm), type II (cord) and type l l I (complete separation of intestinal ends). The "diaphragm" A is usually complete, although a s m a l l opening is shown here. Mesenteric defects m a y also occur with B, the i"cord" deformity. Many forms o f atresia are combinations of these three basic varieties, D shows more extensive absence of the mesentery in which the distal ileum ac quires its blood supply entireiy from the colon mesentery. This is k n o w n as the "Christmas tree" anomaly.

23

SIGNS AND S Y M P T O M S ; P R E O P E R A T I V E D I F F E R E N T I A L DIAGNOSIS

Jejunal atresia presents little diagnostic difficulty, as the appearance of 3-6 massively dilated intestinal loops in an otherwise opaque abdomen leaves little doubt as to the site or the nature of tile obstruction (Fig. 7). Intestinal atresia (or stenosis) in the newborn, situated in the ileum and proximal colon, presents major diagnostic problems. Included in the differential diagnosis is aganglionosis, meconium ileus, meconium plug syndrome, intestinal duplication o r enteric cyst (usually.located adjacent to the terminal ileum) as well as atresia or stenosis at various levels of ileum and colon. Aganglionosis is probably the most common (56). The syn~ptomatology of these conditions is not distinguishing enough to be significant, all producing abdominal distention, vomiting and, if therapy is delayed, relative failure to pass meconium. Bile-stained emesis is always seen in jejunal atresia and noted in four fifths of the infants with ileal atresia or stenosis (11). Aganglionosis (as it appears in the neonate), meconium ileus and intestinal duplication are also usually associated wtih similar vomiting. Jejunal atresia, because

Fro. 7.--Jejunal ,'itresia. X-ray films taken in the supine, A, and erect, B, positions, demonstrating a limited number of dilated intestinal loops, q'he abdominal cavity is not distended. The diagnosis of jejunal atresia can be made on the basis

24

of the limited number of dilated intestinal loops, may produce strikingly less abdominal distention than the other conditions. Ileal atresia, colon atresia, aganglionosis and meconium ileus, all have a spectrum of severity of distention in which there are no distinguishing features. Although the classic stool passed by infants with atresia is small, gray and mucoid, what appears to be normal meconium is passed per rectum by 27% of the infants with jejunal atrcsia and by 32% of those with ileal atresia (11). Infants with aganglionosis, duplication and the meconium plug syndrome also pass at times small amounts of normal-appearing meconium. The stool of the newborn with meconium ileus (when obtainable) has an olive green "putty-like" character, usually appearing in the form of small spheres. In summary, abdominal distention and bile-stained emesis are common to all of these conditions and passage of apparently normal meconium eliminates only one of them, meconium ileus, from consideration.

ROENTGENOGRAPHIC STUDIES Supine and erect roentgenograms of the abdomen will usually establish a diagnostic probability. A colon contrast study (not upper gastrointestinal series) is helpful. Jejunal atresia presents the roentgenographic picture seen in Figure 7, whereas ileal atresia presents more visible loops as shown in Figure 8. These are of approximately the same caliber, with the exception of one (the most distal loop), which may be larger. In both, a "microcolon'" is seen by barium enema. Similar films in infants with meconium ileus show much greater variation in the size of intestinal loops and a characteristic appearance o£ feces in the terminal ileum, which is described as containing minute "bubbles" or a general "ground glass" appearance. In the movement from supine to erect positions, the appearance of the loops by x-ray is less altered in meconium ileus than in atresia, as the tenacious content does not permit a rapid shift of the air pockets which are seen as "fluid-levels." The caliber of the colon is small in meconium ileus and may simulate the "microcolon" of atresia (Fig. 9). The number and size of small intestinal loops is approximately the same in aganglionosis as in ileal atnzsia. It may be possible to establish a diagnosis of aganglionosis of the distal colon by contrast studies at this ag¢. Frequently, however,, the colon is apparently normal in caliber (distinguishing aganglionosis from atresia). (Aganglionosis is, o£ course, a disease o£ tremendous variation in severity and may not present with the acute intestinal obstruction described here.) In intestinal duplication and the~meconium "plug" syndrome, the distended intestinal loops are similar in appearance to those seen in atresia. The contrast colon study is relatively normal in appearance 25

FI~. 8.--Ileal atresia, abdominal roentgenograms. Lateral, A, and erect, B, views of a newborn infant, revealing n,.ultiple intestinal loops and gross abdominal distgntion. When considered together, these two x-ray films reveal a general similarity in the size of the distended intestinal loops. Differential diagnostic possibilities which must be considered in viewing these x-ray films are meconium ileus, neonatal aganglionosis, duplication of the ileum or colon and the meconiurn plug syndrome, in addition to atresia in either the ileum or colon.

in these two conditions, although in duplications it may suggest Iocalized obstruction in the proximal colon segment and in the"plug" syndrome, a point of irregular (or incomplete) obstruction may be seen in the colon; iThe presence of flecks of calcified material scattered about the abdomen on roentgenographie study indicates meconium peritonitis and suggests that intrauterine intestinal rupture has taken place at least several weeks previously. This :is usually found in atresia or meconium ileus but does not exclude colon aganglionosis or duplication. T I M E FACTOR; THE DECISION TO O P E R A T E ; PREOPERATIVE P R E P A R A T I O N

Jejunoileal atresia is an acute form of intestinal obstruction, and urgent surgical: intervention is mandatory, Only in cases of frank perforation demonstrated by intraperitoneal air, however, i s it necessary to :eliminate the basic :diagnostic studies noted abovel If the colon is normal~in caliber and location, iseveral additional hours may 26

FIG. 9 . ~ " M i c r o c o l o n . " Contrast colon study in a newborn in supine, A, and lateral, B, positions. The minute size of this colon suggests ileal atresia, a!thou'gh meconium ileus is not excluded as a diagnoslic possibility. These x-ray films would eliminate from diagnostic consideration neonatal aganglionosis, intestinal duplication and usually the meconium plug syndrome.

be spent in preparation, further studies or delineation of associated conditions. Acute intestinal obstruction occurring in the neonatal period, secondary to colon aganglionosis may be temporarilyrelieved by warm saline rectal irrigations. If the meconiuna plug syndrome is a serious consideration, several such enemas may produce both diagnosis and cure. In the presence of a frank "microcolon," on the other hand, enemas are not only useless but may be dangerous. The colon volume in such cases is so tiny that perforations have frequently occurred during this maneuver. It is possible that as little as 20 co. of contrast material may rupture such a colon. If the course has been protracted ( 3 - 4 days), it is surely desirable to spend several hours Jn rehydration and the correction of serum electrolyte abnormalities. Maintenance of body temperature in an incubator is..4mportant and continues to be a problem during operation. It is apparent from recent studies that severe metabolic acidosis may result from drops in temperature which occur in the operating room. It has also been demonstrated thaat the newborn cannot be supplied with sufficient heat solely from hi.~;;~posterior skin surface (by a conductive pad) if the surrounding room air is cold. This proble m is accentuated if his abdomen is repeatedly washed with cold solutions. It is important that the operating room be warm (too warm for the surgeon) and that the application of solutions in preparation of the skin be brief in time and small in volume. An iod]nated solution is ideal for preparation, as repeated applications are unnecessary. Once the operative drapes are applied there is less heat !oss. 27

THE OPERATIVE PROCEDURE Local anesthesia alone can often be used in the surgical management of duodenal atresia;, however, in more distal intestinal obstructions, this is rarely possible, except in the smallest premature or moribund infant. The abdomen should be opened through a long paramedian or transverse incision. The immediate operative findings in distal intestinal obstruction of the newborn ate varied and at times very confusing. If the'peritoneal~ surfaces are smooth and free of adhesions, gentle evisceration may readily delineate the problem. The classic finding in intestinal atresia is a bulbous distention of the proximal segment, with dilated intestine above. The distal intestine, including the colon, is minute. The gross appearance of the atresia may take any of the forms noted in Figure 6 or combinations of them. The massively distended loop immediately proximal to the point of atresia frequently appears ischemic, i.e., blue or darker. This may or may not be associated with a volvulus on its mesentery, or torsion resulting from its Weight and size. There may be a series of cystic "beadlike" structures lying in the remnants of the mesentery, which represent small segments of dilated intestine between points of atresia. In contrast, the entire peritoneal cavity may be obliterated by adhesion.s, with many small plaques of calcification seen (meconium peritonitis). In this situation, considerable dissection may be required before the p o i n t of atresia can be found. Other diagnostic possibilities must be constantly kept in mind. If the distal ileum is filled with tenacious meconium, almost solid in consistency, a presumptive diagnos~s of meconium ileus must be made. The content of the obstructed intestinal tract in uncomplicated atresia is liquid and rea~lily displaced upward or downward in the intestine by extraluminal pressure. When the appearance of the ileum (and its contents) or the evidence of meconium peritonitis suggests meconium ileus, although a diagnosis of atresia is made, the basic therapy is that which is dictated by the second diagnosis, i.e., meconium ileus. Exteriorization is more frequently performed, utilizing one of the technics illustrated in Figure 10. If no apparent point of mechanical obstruction can be found, the diagnosis is probably neonatal aganglionosis. A confirmatory biopsy of the most distal sigmoid colon should be carried out, followed by a second biopsy at a point where it is presumed there will be ganglion cells and where a diverting colostomy can be made. If the infant's condition is critical, only the latter is performed. Duplichtions of the intestinal tract are usually found in the mesentery of the terminal ileum or ascending colon and are managedby intestinal resection and anastomosis, as in intestinal atresia, although the extent of resection may be less because vasculai" insufficiency is not a factor.

28

After the establishment of a diagnosis of atresia, a primary step is to locate any possible distal points of obstrtlction (3). This is most easily accomplished by instilling saline with a small ( # 26) hypodermic needle into the proximal portion of the distal segment and' watching this proceed downward to the colon under mild pressure. If the continuity of the lumen of the colon has not been established by a prior contrast study, this examination should be continued, through the large intestine. The most practit:al place to make this injection is immediately distal to the atresia into the tip of the segment which will subsequently be excised. The standard or recommended opcrative procedure for intestinal atresia has progressed historically from exteriorization, through sideto-side anastomoses, to end-to-end (or end-to-side) anhstomoses. Excision of a long segment of the dilated intestine proximal to the atresia had been recommended by surgeons on an empirical or other basis FiG. 10.mExteriorization procedures. A, the classic Mikulicz exteriorization. The proximal and distal intestinal segments should be sutured together for 3-4 cm. to permit early application of the spur-crushing clamp. B. the Santtllli and C, Bishop-Koop exteriorizations have been used extensively in infants with meconjure ileus but are also used in atresia. D, tube enterostomy with a double lumen catheter is employed by Rehbein. This is for both decompression and feeding.

A

B SAtVFUL L I

•;~_.._..221~

. . . . .

•

.......~,i.-~;~',"-::,.,(-','~,,i','~'ill-i''~'~'p'~'~' ~' H ,..~,~

...

.

.

.

.

~r.~im~.l[~i~l~..~

~ . . ~

~

Rel-,'BCJ,,v ENTE/~OST'OA41ES A N D COL O,5"TO/v/IE$ EMPLOYED IN ATRESlA

29

...=~.. ~ ) ~

.

~

l

~

,'¸

:'!: ~ i \. '.,,,

"<::'::;L~.L::~:: "::

..........

~'

(Nixon), before its current rationale was developed (40, 45). Resection of a portion of the distal segment was less commonly performed. At present, on the basis of existing evidence, it is recommended that the proximal segment should be resected back to a point where decompressed intestine no larger than 1 cm. in diameter (and preferably less) cart be utilized in the anastomosis and that several centimeters of the proximal end of the distal intestine should also be resected (32). This decision is influenced by the surgeon's concept of the length of sma~;l intestine that can be removedwith survival of the infant. Jejunoilea~ length in the newborn is between 200 and 300 cm. Infants have survived with as little as 20 cm. It is apparent that with the aid of modern supportive technics an infant with over 50 cm. of small intestine should not succumb to "short gut" complications. It is thus advisable to resect all grossly dilated or questionable viable intestine and. under ordinary, circumstances, to resect portions of intestines between multiple atresias. It is helpful to save the ileocecal valve area, but intestinal growth and development will continue without it (61). The remnant o f small intestine will increase approximately sixfold in length during the first 2 years of life, if nutrition is maintained. Anastomosis is carried out as illustrated in Figure I 1. Incision of the antimesenteric border of the lumen of the distal segment to widen it (Nixon) is now generally used. The anastomosis is ter~:~ed end-toend o~ end-to-oblique. It may be carried out with a single row of inter;upted, inverting, fine silk sutures. An "open" technic is used, with the sutures tied either internally or externally. A continuous internal absorbable suture uniting the mucosa and submucosa has been added by some but does not appear to be necessary and may increase the "'turn-in" and likelihood of anastomotic obstruction. The mesentery is closed with fine interrupted sutures. This may be quite difficult in infants with a very large defect, such as those with the "Christmas tree" anomaly. In such cases, the anastomotic area must be simply sutured to the posterior parietal peritoneum (see Fig. 6, D). If the atresia lies relatively high in the jejunum, it is possible to pass a plastic feeding tube through the anastomosis by way of a gastrostomy tube (as in duodenal atresia). In low ileal atresias, it is possible to pass a tube upward through an appendicostomy to a site proximal to the anastomosis (53). The appendicostomy is formed by simply drawing the appendix through a small stab wound in the abdominal wall. If the anastomotic opening is extremely small or in reresections for suture,line complications, both of these maneuvers may be helpful, although neither is routinely required, A silastic tube is preferable. Exteriorizations are still performed routinely by some surgeons for intestinal atresia~ The traditional Mikulicz procedure functions well in the distal ileum and colon. Excellent results are reported with use of the Bishop-Koop operation (see Fig. 10), which might have great 30

A

bVIDE PB-.OXIMAL ,~AtD DISTAL, RESECTION FO~ AT,eESIA

~ ,

•

; ",

/

y i

,,'x

i

"

.

J

.

C

~, i/-2~:-,~~

i'!'

i

Jk

' ;:.

:

-

¸ ..

j J

~.~.',~3,k~'*(~,\k",k,~s : :..':.;t

WIDENING TttE LUMEN OF THE DISTAL .gEG/VlENT

FI6. l l.--Jejunoileal atresia, wide resection and anastomosis. Striking improvement in survival, associated ,with the elimination of anastomotic problems, has been a~:hieved in jejunal atresia by widely resecting the dilated proximal segment. This is true to a lesser degree in ileal atresia. Sacrifice of a considerable portion of the total intestinal length is justified in order to secure an effectively functioning anastomosis. The antime~enteric border of the small distal lumen is incised (B and C) to minimize the disp~,~rity in size of the two openings.

advantages in more proximal atresias, as the loss of intestinal contents shouldbe reduced andearly closure simplified. In the exteriorization described by Santulli (see Fig. 10), the large, distended proxi, real segment is brought to the skin (a safety factor) while still permitring some distention of the atrophic,distal segment with intestinal contents. The double enterostomy of Rehbein has resulted in an in, creased survival in llatresia (47). For surgeons who carry out these 31

procedures infrequently, the Mikulicz exteriorization is probably preferable. This should be carefully formed so that tile "spur" may be removed with a crushing clamp early in the postoperative course. If intestinal atresia is a complication of meconium ileus, the exteriorizations described above are recommended in place of primary anastomosis. Jejunoileal stenosis, which comprises less than 4% of the total group (11), is ordinarily functionally similar to atresia, and surgical management is the same. Rarely, infants in whom obstruction is not as marked may be treated by local plastic reconstruction of a diaph ragm, etc. Many of the gross findings in infants with intestinal atresia are difficult to explain. The obstruction has been present for many weeks, and the advent of delivery only adds a small volume of air to the contents of the obstructed loops. In some fetuses, these distend relatively conservatively and have a very muscular wall, whereas others have segmental areas in which the muscular layer is thinned to an unrecognizable degree. The "giant abdominal cyst," which fills the major part of the fetus's abdominal cavity, may have a proximal intestinal connection, a distal intestinal connection or be completely isolated. The intestinal wall is frequently thinned to the extent that it may be hardly recognizable as gut. It may be wholly or partially infarcted, liquefied or replaced by pseudomembrane or scar tissue. It is apparent that there are a wide variety of intrauterine diseases, in addition to meconium iletis, which are associated with atresia (44). Aganglionosis may produce obstruction, perforation and intestinal atresia. It has been assumed that fetal intussusception, volvulus and other obstructive lesions, in addition to mesenteric occlusions, can result in atresia (42, 18, 41, 44). On the other hand, atresia (once produced) may be followed by volvulus of the dilated proximal loop, infarction of the twisted segment, perforation and sterile peritonitis. Mechanical obstruction due t o adhesions may develop secondary to meconium peritonitis. This may be followed by volvulus around adhesions and secondary intussusceptions. The surgeon who operates on distal intestinal obstructions of the newborn must be aware that atresia may be a factor (either cause or result) in any one of these processes.

POSTOPERATIVE MANAGEMENT Some surgeons routinely create a gastrostomy in all infants with intestinal anastomoses, and others rarely do it when the seg~ment con cerned is below the duodenum. In the hands of those who do it and who have a nursing staff trained in its use, it provides a simplified form of management. During the first several days following anastomosis, the gastrostomy is maintained ondependent drainage (not on suction). :32

Gastrostomy feedings of aqueous-dextrose solutions are then begun. Small volumes of fluid, repeatedly administered, with frequent determinations of the volume of gastric residual is the recommended regimen. In this way, there will be no vomiting and no aspira'tion. In patients without a gastro~tomy, it may be necessary to maintain nasogastrie suction for several days to prevent vomiting. The tube is then removed, and small dextrose solution feedings are begun by mouth. Formula feedings are commenced when a stool has bcen passed per rectum or-~per enterostomy. The infant is maintained on "broad-spectrum" antibiotics because of the possibility of perforation and sepsis. Standard parenteral feedings for the newborn (750-1,000 ml./in'-') are given. If intestinal complications occur or additional anomalies create secondary feeding problems, a high calorie parenteral alimentation schedule should be promptly considered.

HIGH CALORIE PARENTERAL ALIMENTATION PROGRAMS The development of "total" parenteral feeding programs, made feasible by recognition of the relative ease of using catheters in the larger veins or right auricle, was initially directed toward adults and children with the "short gut" syndrome (62). The aim in these cases was to maintain life until adaptation of the intestinal remnant occurred. Many infants without a major deficiency of intestinal length may profit from the use of this technic. The mortality in a number of the surgical problems of small infants is largely associated with intestinal complications followed by malnutrition and finally sepsis and pneumonia. The factorof malnutrition may be the ke}' one in this sequence. Some surgeons have felt that infants with gastroschisis, ruptured omphalocele, volvulus with infarction and also multiple atresias of the intestinal tract should be placed on the high calorie parenteral regimen at the time of diagnosis. Infants with standard forms of intestinal atresia, if they have no serious complications, do not need it. If they have major intestinal complications, its use is lifesaving. Oiae must institute the program without delay if evidence of obstruction, perforation, etc., develops in distal atresias. If exteriorization of the intestine is required as a secondary operation, as, for example, in postoperative disruption of a jejunal anastomosis (for atresia), it is possible to maintain infants with a fistula in a much better nutritional state with this regimen. Descriptions of the technics of placing central venous catheters and of the solutions administered should be reviewed by surgeons interested in atresia (62). This program has been pioneered by surgeons rather than pediatricians. The latter may take an unduly optimistic view of the prognosis in the infant with atresia and postoperative intestinal complications, resulting in delays in resorting to the use of this technic. 33

POSTOPERATIVE COMPLICATIONS Anastomotic perforation, which may or may not be associated with obstruction, is common after operation for distal intestinal atresia. This group of complications makes the largest contribution to the mortality in all series (Table 3). The appearance of a perforation rarely occurs before the 3d postoperative day or after the 10th day. In more acute perforations, the infant develops the generalized picture of sepsis, frequently with shock. The abdomen does not become rigid but develops a "doughy" feeling on palpation, with distention and a lack of audible peristalsis. Vomiting is noted if the infant has been o n oral feedings, or gastric retention if he is maintained with an open gastrostomy. In this situation, immediate abdominal roentgenograms are carried out and blood cultures made. l.ntraperitoneal air should d i s a p p e a r from the abdominal cavity w i t h i n 2 days after laparotomy in the neonate, so that the presence of any considerable volume of "free" air should be l:egarded as direct evidence of a perforation. After restoration of a homeostatic state by massive antibiotic therapy and colloid replacement, emergency laparotomy is required. Anastomotic perforation in the ileum is usually best managed by exteriorization~ :,Ifit i s in the proximal jejunum, however, wider resection,and reanastomosis should be carried out if possible. A proximal tube:enterostomy with a silastic tube passed through the anastom o s i s into t h e distal segment o r a Similar t u b e passed through a gastrostomy (see Fig. 5, C) should be considered in secondary procedures for complications associated with proximal intestinal anastoTABLE 3.,,,, JEJUNOILEALATRESIA(576 CASES) RELATtVECONTRIBU'rlONOF MAJOR COMPLICATIONS AND ASSOCIATED DISEASES TO MORTALITY* J EJ UNAL ATItESIA

ILEAL ATRESIA

avlULTIPLE ATRESIAS

106 DEATHS)

(80 DE~'rrts)

(20 DEATHS)

1. Anastomotic obstruction 2, Respiratory complications 3. Peritonitis-sepsis-anastomotic separation 4. Prematurity 5. "Short gut:' sequelae 6, Intestinal infarction; voivulus and adhesions 7. Associated anomalies 8. Miscellaneous

24 (23%) 20 (19%)

9 (I1%) 16 (20%)

5 (25%') 4 (20%)

I8 (1,7%)

29 (36%)

3 (15%)

9. Total intra-abdominal and nutritional complications (1, 3~,!5and 6 above)

PRINCIPAL CAUSE OF FATALITY

9(8%) 9 (8%) 5 (5%)

3 (4%) 2 (2.5%) 2 (2.5.%)

2 (10%) 1 (5%) I (5%)

3 (3%)

-! (9%)

2 (10%)

18 (17%)

12 (15%)

2 (I0%)

56 (53%)

42 (53%)

10 (50%)

*Data from SS,AAP survey. v .

.

.

.

i

n

.

.

.

.

.

.

.

.

3,t

moses. It is important to consider that the perforation may be associated with a distal obstruction due to adhesions, l)rainagc of areas in which collections of intestinal contents arc found is recommended. Perforations are often subacute, forming small intraperitoneal abscesses or fistulas through the abdominal incision with minimal interference with intestinal function.' These may be managed expectantly if the general condition of the infant remains good. Intestinal obstruction without perforation is also common and is usually at the anastomotic site, although postoperative adhesions muy form rapidly. Delayed paralytic ileus is not seen in the neonatc, except when associated with frank peritonitis. After the initial 48 hours following operation, obstruction must be assumed to be mechanical. In anastomotic obstruction without perforation, which is particularly prevalent following jejunal resections (Table 3), re-resection and anastomosis is usually feasible. Exteriorization should be strongly considered in distally placed lesions.

UNIQUE ASPECTS OF JEJUNAL ATRESIA

Although considered with ileal atresia in this monograph, there are clinical aspects peculiar to this site of congenital obstruction. Jejunal atresia was at one time thought to be a very rare anomaly with a particularly high mortality. It may actually occur more frequen.tly than atresias in the ileum (11). Infants with jejunal atresia have a higher rate of prematurity than infants with ileal atresia. In respect to its association with maternal polyhydramnios and to unexplained elewltion of the infants' indirect serum bilirubin, this group of newborn infants is similar to those with duodenal atresia. One third of the infants with jejunal atresia have nonhemo!ytic jaundice. Jejunal atresia is less frequently a complication of meconium ileus than is ileal atresia. It is in the treatment of jejunal atresia that wide resection of the proximal dilated bowel has produced the most striking improvements in survivak~~-In one series, the mortality was apparently reduced by almost 50% in comparable groups by using this technic (11). Anastomotic complications are more likely to be obstructive in procedures for jejunal atresia. Exteriorization procedures-produce a greater (tcpletion..If exteriorization is requir,~d in this area, the Bishop,Koop procedure.would seem preferable to the Mikulicz enterostomy.

RESULTS OF ]"HERAPY

During the past I0 years, several remarkable:series have been :reported which illustrate the striking improvement:which has occurred 35

in the surgical management of mid-gut obstructions (33, 57). These appear to be associated with wider resections at the site of atresia and improved anastomotic technics. They undoubtedly also reflect the improvements in anesthetic management, maintenance of a more acceptable state of hydration (and nutrition) by parenteral fluid therapy and an increased willingness to reoperate on these infants in the early postoperative period if complications develop. Unlike the situation in duodenal atresia, associated problems in these infants are usually intra-abdominal. The. incidences of prematurity, extra-abdominal malformations of significance and the associated diseasc states found with duodenal lesions are all relatively smaller factors in infants with jejunoileal atresia. This indicates that cot~tinued improvement is possible by employing factors already at our disposal. It would appear that approximately 90% of these infants can be salvaged (Tables 4, 5 and 6). The long-range results are also more encouraging in this form of atresia. Down's syndrome is uiacommon, and, if the intestinal problems can be managed, these infants develop normally. The length of their intestinal tracts is undoubtedly greatly reduced both by the original process of atresia formation and later wide resections. Significant "short gut" problems, however, have been uncommon, contributing only 3% t o the over-all mortality in the largest collected series (1 1). These remarks do not refer to that group of infants with atresia and meconium ileus, who frequently, demonstrate the later intestinal and ultimately pulmonary problems which are life-limiting complications in this disease. Causes of death following the treatment of jejunoileal atresia are listed in Table 3. The over-all mortality in this series was 41.7% in jejunal atresia and 28% in ileal atresia (11). This included many infants who were treated prior to the present decade. Infants with multiple points of atresia occurring in both the jejunum !

,,

,

l

,,

.

.

.

.

.

.

.

__

.j

~ ,

,

T A B L E 4 , - - G R o s s PATHOLOGIC CLASSIFICATION OF DUODENAL AND JEJUNOILEAL ATRESIA AND STENOSES: RELATIVE FREQUENCY OF DIFFERENT TYPES* DUODENUM

(50I CAs~s) Number

1. Stenosis (extrinsic constriction) 2. Diaphragm (type I atresia) 3. "Cord" anomaly (typeIl

atresia) 4. Completeseparation (type III atresia)

Per Cent

50

10

4

104

19

9

172

31

I1

258

46

29

206 perforated

41

" 44

56

*Excluded are infants with multiple ~oints of atresia or s t e n o s e s .

36

A N D

25

intact

145

JEJUNUM

ILEUM (559 CASES) Number Per Cent

m,

_

TABLE 5.

am

i

MALFORMATIONS AND ASSOCIATED DISEASE STATES FOUND IN INFANTS WITH DUODENAL AND JEJUNOILEAL CONGENI I'AL OBSTRUCTIONS DUODENAL ATRESIA AND STENOS1S

(303 CASES)

A. Extra-abdominal disease states 1. Down's syndrome B. Extra-abdominal malformations 1. Cardiovascular anomalies 2. Esophageal atresia 3. Urinary tract anomalies 4. Imperforate anusrectal atresia 5. Skeletal anomalies 6. Central nervous system anomalies (major) 7. Situs inversus 8. Lung anomalies C. Abdominal malformations and associated disease states 1. Incomplete rotation of colon 2. Meconium ileus 3. Meconium peritonitis (unknown etiology) 4. Meckel's diver, ticulum 5. Intestinal volvulus 6. Om~Shalocelegastroschisis 7. Intestinal duplication 8. A g a n g l i o n o s i s

JEJUNAL AND II.iXAL ATRESIA AND STENOSIS (619 CASES)

Number of Infants with This Malformation or Disease State

Per Cent of Total Group with This Malformation or Disease State

150

30

5

I

86

17

2

2

34 29*

7 6

6 1

I

17

3

6

1

14 7

3 1

3 1

6 6

1 I

0 2

0

98

11

53

9

49 32

8 5

1 It

.2 .2

12

Number of Per Cent of Infants Total Group with This with This Malformation Malformation or Disease or Disease Slate State

.2

.5 .2

.1

2

2

4* 4

1 1

25 15

4 2

0

0

7

1

5

1

6

1

,1

"{'Not including gastric rupture following birth (3 infants). *Cystic disdase ( 7 ) , hydronephrosis (5), horseshoe kidney (3), renal agenesis (3), exstrophy (1), posteriot~urethral valves ( 1 ) a n d miscellaneous (9). :l:Excliiding V'olvulae not recognized at the initial laparotomy.

37

TABLE 6 . ~ W I D E PROXIMAL INTESTINAL RESECTION IN JEJUNAL AND ILEAL ATRESIA: INFLUENCE ON TIlE RESULTS OF END-TO-END* ANASTOMOSES $I~E OF ATRESIA

Jejunum ( 155 cases)

Ileum ( 157 cases)

wm~ wzD~ PltOXIMALRg.'gEcrloN (! 19 Infants.) Survived Died 79 ( 6 6 % ) 40

wm~otrr wzr~ PRORIM,,~L RESECIfO,'~ (36 Infants) Survived Died 14 (39% / 22

( 126 Infants) Survived Died 96 (176%) 30

(31 InfanLs) Survived Died 25 ( 8 0 % ) 6

*Including end-to-oblique and end-to-side (not side-to-side) anastomoses, The superiority of wide proximal resection is demor~trated only for jejunal alresia in this study.

a n d ileum are usually premature males. They have an increased incid e n c e of o t h e r major anomalies and the highest mortality of all ~ o u p s (Table 3 ) . Two areas of atresia, lying in close proximity in. t h e ileum o r jejunum, however, should respond to wide resection with an acceptable survivat rate.

COLON ATRESIA Between 5 and 10% of all atresias distal to the stomach are in some portion of the colon (4). Their etiologic b ~ i s appears to be similar to that ofl jejtmoileal atresia with aI1 types, i.e.. diaphragms. fibrous " c o r d s " and completely separate blind ends, found. Frank obliteration of the inferior mesentefic arterial system and its adjacent mesentery is seen, associated w i t h atresias of the sigmoid colon. Mesenteric "scars" and gross shortening of the remnant colon have been noted frequently. Clinically, the d i a ~ o s t i c possibilities which can be readily confused with this form of congenital obstruction are sirrfilar to those listed in the section on ileal atresia (43). Neonatal agan~__lionosis is a far more prevalent disease than colon atresia and may produce indistin~m~ishable s i ~ and symptoms (56). Atresia of the right colon may resuItin a clinical picture quite similar to that seen in meconium ileus, ileal stenosis, duplication of the terminal ileum or the me.conjure plugs~nadrome, a s we/l as a~an~ionosis. A. roen~eno~aphi~c contrast colon study ~ esta'olish the d i a ~ o s i s k~ tabis situation. This m ~ t be carried out, howe'~er, v~-iththe ~ a t e s t care because ~ffthe possibility o f perforation o f this undistended, minute intestinal segment, that is, thedistal Colon, blind at its proximal end. Atexploratory. laparotomy, the distmc.tion bet~veen colonic atresias and other forms of Obstructaoa, sp~fica tly ~ h s p r t m g , s dis38

¸

ease and meconium ileus, is usually apparent. Duplications, forming "'cysts" in the walls of the terminal ileum and ascending colon, must be recognized. Cases are reported in which the ileocecal valve is apparently competent (30), with the intestinal distention limited or largely confined to the obstructed colon segment. Such lindings would immediately suggest an additional point of atresia. Ordinarily, the entire proximal small k~testine is widely dilated and the possibility of overlooking a proximal atresia .seems remote. Although colon atresias, in contrast to those at other sites, are d~.~cribed by s o p e as not ordinarily associated with other congenital anomalies, the dii~'erence is relative and probably not significant (16, 43 ). Colon atresia associated with rectal atresia was reported by Benson et aL (4) in t968 and Hartman et al. ¢19) in I963. and with aganglionosis, by Hyde axld deLorimier (231~ in i968. This form of atresia has traditionally had a lower mortality than those in. the small intestine (4, 19) This is probably b e c a u ~ historically exteriorization was performed for atresia at all te .~:.t~ and is relatively more effective in the management of the colon lesions. TEis is clearly true: .in those forms beyond the transverse color~. T o s o m e .extent, this preference for exteriorization is still maintained and is justitiabte ~4. 37). The technic has fewer disadvantages in colon atresia than in obstruction at proximal sites and should be carried out when any c~th~-.rconstaerat~on makes the result of an an astomosi.', seem uncertain. The exteriorization may take any of the forms depicted in Figure t0. It may also be. performed as a simpt.e "'loop'" colostomy, if the point of obstruction is in the descending or sigmoRJ

colon (4). Resection of a considerable segment of the dilated colon proximal to the atresia is advantageous, .as in the small intestine ( 16). A sin~elayer anastomosis with interrupted, fine. nonabsorbable sutures is recommended. If exteriorization is elec,~ed, perhaps the best form in colon atresias is the simple double-bar.,eled (see Fig. I0) variety with the walls of the two segments sutured together. This facilitates the use of the spur-crushing clamp .fGmss) When the spu is crushed, tl~" distal segment, which is usually minute, is dilated to some d e ~ e e by the passage of a portion ~of the intestinal contents. "The exteriorized portion may eventually.have to be resected and :an end-toend anastomosis performed, but b21e,disparity of cal * i b e t of the two intestinal segments will have b e ~ '~jeatly reduced during t t~i:~ period of delay. Enlargement of the distal segment is less apparent if the two ends of the smmas are completely separated. JejunoiIea! atresia ,~. rarely associated w i t h d u o d e n a t atrmia or stenosis. Colon atres)a-_ " ' in contrast, is tfften 'seen in infantswith i~trinsic duodenal obstruction, usually stenosis. These infantsrequire a simpIe decompressing cotostomy at the time of their duo~,enaJ pro39

cedure or prior to it (under local anesthesia), if the upper abdominal operation is delayed. Colon atresia is associated with a high rate of perforation of the proximal segment, and its therapy cannot be postponed.

BACKGROUND HISTORY The first survival following an operation for intestinal atresia was achieved by Fockens (Rotterdam) in 1911, and the first successful correction of duodenal atresia (or stenosis), by Ernst of Copenhagcn in 1916 ( 1 3 , 1 4 ) . Reviews of the recognition, early autopsy studies and initial attempts at surgical therapy in intestinal atresia have been made by Cordes; Spriggs; Davis and Poynter; and Webb and Wangensteen. Bland Sutton (1889) proposed the class!fication of gross types of atresia, which is still used (see Fig. 7). He postulated that atresia i:~:! i ! : ~ ; :::L~:::IIII: ?::!:~: :i:?:;:: !: i :~ i::: : i : :: :::~i i : : :

Fro. 12.--Historical recognition of vascular occlusion in association with intestinal atresia. This illustration: appeared in a monograph by Spriggs, published in the Guy's Hospital Reports, 1912. The author belieVed that many etiologic factors, predominantly mechanical, were active in the development of intestinal atresia, including mesenteric vascular occlusion. IThis concept was largely abandoned during the following era, during which atresia was attributed to failure of recanalization of the lumen following the "cord" stage (excessive intraluminal epithelial proliferation) in intestinal development.

40

occurred at the sites of "embryologic events," i.e., the interface of the embryonic gut with other developing or atrophying structures, such as the vitelline duct connecting the intestine to the yolk-sac. The prevalence of esophageal and anorectal anomalies was thus cxplaincd. Ileal lesions were believed to be the result of an excessive obliterarive reaction at the vitellointestinal junction. He correctly suggested that the majority of duodenal anomalies should occur at the point of entry of one (or more) of the biliary ducts. Spriggs' pathologic studies (1912) are of particular merit and include an excellent illustration of a V-shaped mesenteric.defect (Fig. 12). He enlarged Suttons' classification to include all of the types which are recognized today. Spriggs addressed himself to the same problems which have concerned investigators in recent years: the evidences of mechanical factors in many atresias, the presence of bile in a segment separated by atresia from the biliary system, the evidence of vascular interference, etc. He shared with most early investigators the belief that mechanical "accidents," including vascular occlusions, were responsible for intestinal atresia. This consensus was largely supplanted by a concept introduced by the discovery of the "solid stage".in intestinal development. Atresia resulted from failure of "recanalization" of a segment of gut (Tandler, 58), in this view.

EMBRYOLOGIC CONSIDERATIONS It is well established that an undetermined percentage of human embryos (probably a majority) pass through a stage between the 5th and 7th week of gestation in which the lumen of the primitive duodenal segment is filled with proliferating epithelial cells to the extent that its lumen is occluded (25). This appears to be a part of normal development. Proliferation of the epithelium in the intestinal tract distally is much less marked, and complete obliteration of the lumen has not been observed. A minority of students of the subject find less credence in the entire concept of epithelial proliferation, contending that even:in the duodenum complete obliteration of the lumen rarely, if ever, occurs (38). It is apparent that the extension of this hypothesis to explain the occurrence of all intestinal atresia in areas distal to the duodenum was unwarr:ah;ted and probably not the original intent. Regression of the epith~ii~ proliferation in the intestinal lining begins in the 8th week and is completed by the 10th week. In regard to the duodenum, Boyden, Cope and Bill have presented convincing evidence that following the "solid" stage of occlusion of the lumen by epithelial proliferation, vacuolization occurs in a regular fashion. They describe multiple vacuoles coalescing to form two main chambers with the hepatopancreatic system emptying through:a sep41

arate orifice into each of these. The accessory pancreatic duct has a similar double orifice. Streeter demonstrated that these two vacuolizations become fusiform enlargements of the embryonic duodenum, with one lying above and one below the point of entry of the ducts (52). Each vacuolization extends toward the other, but initially they do not meet but form parallel channels. One can thus postulate a stage in nornaal development in which the proximal and the distal duodenal segments have both acquired lumena, with "the intervening segment occluded. The rudimentary choledochus communicates with both structures through a bifid system. The fact that the great majority of duodenal anomalies occur at precisely the area of entry of the major duct has not been widely recognized because the ampullary area is rarely clearly visualized or identified. In those studies in which particular note of this point has been made, this has proved to be true. The first clinical report of biliary ducts entering both above and below duodenal atresia was made in 1901 (Cordes). When this anomaly is searched for specifically (only possible at autopsy), its incidence is high. The general process of recanalization of the duodenum occurs progressively .from proximal to distal (except for the area of the duct), with the final opening occurring at the duodenojejunal junction ~(8). This has been cited as an explanation for the occurrence of duodenal anomalies at this point. It is of interest, however, that the duodenal atresias in this area are those which are associated with fibrous scars, discontinuity of muscular walls, etc., which, when occurring more distally, we associate with infarction. It must be recalled that initially the duodenum does have a me~entery. The development of the pancreas, relative to its annular anomaly, has been described by Lecco and Smetana (29, 50). The principal pancreatic and bile duct has an initial connection with the ventral pancreatic pouch. It migrates around the central axis of the gut (duodenum) from left to right, posteriorly, and then right to left, with~the pancreatic element then forming connections with the dorsal pancreatic anlage to form the pancreatic ducts. Union of the two pancreatic anlagen takes place between the 14-ram. and the 22-ram. stages, so that irrespective of the precise mechanism involved, a ring of pancreatic tissuesurrounds the duodenum in these cases prior to the 8th week of gestation (31). At this stage, the caliber of the lumen of the duodenum is minute, and significant subsequent enlargement of this segment may be restricted.

EXPERIMENTAL ATRESLA Evolution of the concept of fetal ischemic necrosis as tile basic etiologic process in intestinal atresia canlbe divided into three phases 42

chronologically: (1) early clinical descriptions of individual operative and autopsy cases which made this explanation logical to perceptive observers; (2) systematic studies of collections of human autopsy material leading to the same conclusion; and (3) direct experimental attempts to produce the lesion,in animal fetuses. Associated in time and of bearing were the reviews and re-evaluation of the concept of the "solid" stage of the intestinal tract in hunlan embryos (38, 36), and also some additional related experimental work. The studies of Laufman et al., 1949, were of interest (28). They devascularized, isolated and sterilized (relatively) segments of the intestinal tract which were returned to the abdomen. Autolysis and resorption of these segments occurred rapidly, so that little or no gross evidence of their existence remained. Surgeon:s and pathologists have 10ng noted individual hunlan cases in which there was evidence that fetal intussusception, injury at the umbilical opening, internal hernia, torsion or volvulus had produced what could be recognized as intestinal atresia. Early cases were cpllected by Spriggs (1912). Acute clinicians (Louw) noted the presence of bile pigments distal to tile site of totally obstructive human atresia. In the duodenum, this might be explained by tile presence of a double biliary ductal system. More distally, however, this could only be due to the passage of bile through the intestinal tract. As bile secretion in the human fetus is not found until the l l t h week of gestation, this fixed the time of development of atresia in these cases to a period at least 4 weeks after the postulated "solid stage" of the intestine had appeared and resolved. The presence of lanugo hairs and squamous epithelial cells distal to the site of atresia was d e scribed. The swallowing o f such amniotic ituid particles by the fetus is felt to occur only after the 12th wee~:, again indicating late pregnancy as the time of development of atresia. Nixon found meconium within the walls of isolated segments in multiple atresias; squamous epithelial cells and hairs were also found in similarly unconnected segments. The next phase in the development of this concept was initiated by intensive studies of autopsy and surgical specimens from sizable human series with the insight to search specifically for evidence of vascular occlusion or infarction (Nixon, Louw). In Louw's series, he noted V-shaped mesenteric defects (40% of autopsy cases), deficiencies in mesenteric arterial arcades, complete absence of some arterial systems (inferior mesenteric artery) and demonstrated an apparent inadequate blood supply to segrrients immediately proximal to atresia. Contrary evidence was obtained by Nixon, who injected the mesenteric arterial tree i n 4 infants with jejunoileal atresia and found them intact. The surveys of Santulli and Blanc confirmed the observations of 43

Louw (to some degree, Nixon) and added others (49). The frequent association of a major degree of shortening of the total small intestinal length was noted. Microscopic examination of the cordlike segments associated with atresia was made, revealing vascular changes and fibrosis suggestive of healed infarcts. Additional evidence of injury and repair were found in the mesenteries adjacent to atresias. Bile droplets and hair were found in all of the intestinal tracts distal to atresias which they were able. to examine carefully. In one of their specimens, all of the three major types of occlusion, i.e., the "cord," the "blind end" and the diaphragm, were found in a single infant. The third phase of the development of this hypothesis rests principally on the experimental evidence of three laboratories. Louw and Barnard operated on 51 pregnant, dogs between the 45th and 55th day of gestation (34). The fetuses were subjected to (1) ligation of one or more mesenteric vessels or (2) the production of a strangulation obstruction simulating a volvulus. Thirty-eight puppies in file operated on ~ o u p were delivered. Among those that remained in utero for I 2 - 1 4 days following the devascularization procedure, examination of the intestinal tracts revealed all of the types of atresia f o u n d in the human newborn. T h e s e included stenoses, diaphragms, cordlike structures replacing the intestine and complete separations with V-shaped mesenteric defects. The abdominal cavities of puppies delivered prior to the 12th day following the surgical procedure contained intestinal segments in various stages of necrosis and absorption, with the distal and proximal ends wholly or partially sealed. Multiple adhesions were found in those delivered soon after infarction but largely absent in those remaining ~n utero longer. The series included a large enough spectrum of fetal ages (postinfarction) to visualize steps in the development of these atresias. As time in utero lenphened, the ends above and below the infarction became epithelialized, the proximal loops distended, while the distal segments emptied and failed to grow thereafter. Ligations performed close to the ongm of the larger intestinal v ess,.ls produced wide mesenteric defects or "cord" anomalies. Strangulating obstructions which occluded the vessels close t o the intestinal wall resulted in intraluminal diaphragms. Less: extensive occlusions produced stenosis. SantuIli and Blanc duplicated these findings in the dog in 196-I (49) and, in 1966, described observations on 50 rabbit fetuses in which intrauterine ligation of mesenteric vessels or mesenteric avulsion was carried o u t after 20'-27 days of gestation (5). These fetuses were examined 2"8 days after the operative procedure, and again reproductions of the human lesions, including all of its varieties, were observed (Fig. 1 3 ) . They noted that both the extent and the timing of the devascularization were of importance in determining the nature of the infarction produced. The his~ologic response in the areas adjacent to the lesions were found to vary with the actual age of the 42t

FIo. 13.---Human and experimental atresia, A illustrates the findings in a case of multiple ~resias in the human newborn infant:: The forceps points to asite of mesenteric defect. T h e specimen shown in B is from the laboratory of Drs. William A . Blanc and Thomas V, Santulli, :who produced atresia by intrauterine procedures in which the mesenteric vesselsare occluded (see text). A mesenteric defect is noted in this specimen. Disparity in size between intestinal loops above and below the atresic area is similar im~:th'.~:human and animal cases.

fetus, in addition to the duration following the:experimental procedure. In-younger fetuses, i.e., :approximately 20 days a t :the time o f t h e procedure, tliere was a rapid mesenchymal and epithetiM repair :of :the defect: Local vascular dilation was not prominent, and there was a lack of migratory cells in thearea. In contrast, linfetuses which were older at the time of the intrauterine procedure, the me.sen45

chymal and epithelial repair was slower (resulting in fibrosis). A topical vascular response and the infiltration of mast cells into the area were noted. Age of the fetus at the time of injury was established as a third factor in the quality of the response. In 1968, Abrams reported similar experiments in the sheep, an animal with a gestation period of 145 days ( t ) . Between 80 and 100 days after conception, either vascular occlusions or mesenteric avulsions were performed, again producing the complete spectrum of atresias found in the human infant. Avulsioas or "tears" of the mesentery were the most efficient method of producing at~esias, and the mesentery in the lamb fetuses was so delicate that such tears were difficult to prevent at operation. This investigator suggested that such a mesentery might readily be disassociated from the intestine during the return of the gut from the extraembryonic coelom. It is of interest that spontaneous atresia in lambs has been reported with regularity in veterinaxy studies. REFERENCES 1. Abrams, 3. S.: Experimental intestinaI a t t e s t . Surgery 64". 185. 1968. 2. Aitkert, J,: Congenital intHn.sic duodenal obstruction in ~nfancy: A series of 30 cases treated over a 6 year period, Jr Pediat. Surg. ! :546, I966. 3 . Be.~so~ C. D-, and Lloyd, J. R.: Atresia and Steno..,ds of t h e Jejunum and Ileum,. in B e n s o n et at. ( e d s . ) : : Pediatric Surgery (Chicago: Year Book Medic',d Publishers. Inc.. !962 ), vok 2, p. 703. 4. Ben.son. C, D., LorfL M.. W.. and Brough, A. J.: Congenital atresia and stenosis oft.he colon, J. Pedlar. S u r g 3:253, I r.~ 68. ' 5. Blanc. W. A . : N..crosm in t h e fetu~ and congenital malformations. Bull. New York AcacL Med, 42::402. t 966, 6. Blanck. C., Okmian. L., and Robbe, t-L: Mucoviscidosis and intestinal arreSt:a, .Aeza p a e d ~ L S~,~ndinav. >,:. ""- ~""7 ; 1965. 7. Boggs. T. R_, Jr:,, a n d Bkc,hop. H.:: Neonatal hyperbilirubinemia associ.;,ted with hi.gh obstruction of the smMt bowel, J, Pediat. 66: 349. t965. 8. Bo34en. E. A., Cope, J. G., ~ : Bill A. H . , Jr.: .amatomy and embryology of coagenital :intrinsic obstruction of the duodenum, Am. J. Surg. 1 t14:190, 1967. 9. Cs:rdres. L.: Congenital occ!usion of the duodenum, .arch. Pedlar. t8:~01. 1:901. I0, D a ~ s . D. L.~, a n d Poynter. C, W. M . : Congenital occlusions of ~ntestines. ~i~. • report of a case of multiple atresia of jejunum, surg.. Gynec. & Obst. 34:35.2 19 v'~ 1 1 . deLoFtmier. A~ A.. F on-'-'~-" d, E. W.. and H a y s . D.. M..: Congenital atresia and s.~nosis o f ~ e jejunum and ~eum, Surgery 65:8:t9. t969. . . . . . G~, Si,ber, . . . . K.. and ~esew.etter,:W. B,.: Intes-'dnal .aIres~a....rch. D k,. .ua, . . . "~ ~. S ,u~z. 97: :I75~ 1968. I3. Ernst., N: P::: A case o f congeni:t~ atresia of the duodenum treated s~accessN H y b y :operati.on, Brh. M, J: 1.:644:. t 916. 14. Fockens :in Carter, R. F.: :Congenital occtusicm of the d.uodenum and sm',tIl intestine; a ctiniic',d consideration with report of t~'o successful cases. J. PediaL ,..'~-:'192~3._./.. ~"-" •.

.

~

.

. , .

~

.

15. Fonkalsrud, E. W.. deLorimier, A. A., and Hays, D. M." Congenital atresia and steno~is of the duodenum, Pediatrics 43: 79, 1969. 16. Freeman,. N. V." Congenital at resia and ~teno~is of the colon. Brit. J. Surg. 53:595, t966. i7. H~Jer, J. A.. Jr., Cahill, J. L " Combined congenital gastric and duodenal obstruction" Pitfalls in diagnosis and treatment, Surgery 63:503. 1968. 18. Handelsman, J. C., Abrams, S., and Corry, R. J." lmprovem~.nt of therap', for congenital jejuno-ileal atre.~ia, Surg., G~ nec. & ObsL t 17"69I. 1963. 19. Hartman, S. W., Kincannon, W. N.. and Greane.~. K. M.. Jr.: Congenital atresia of the colon, Am. Surg. 29:699. 1963. 20. Hase, O., Shaw, A., and Gould. H. R.: Duodenal diaphragmatic obstruction with pneumoperitoneum pre~enting .in a 13-year-old girt, Surgery 62:530. 1967. 2]. H a~s, D. M., Greaney, E. M., Jr., and Hill. J. T." A n n u l a r pancreas as a cause of acute neonatal duodenal obstruction. Ann. Surg. t 5 3 1 0 3 . 196I. 22. Holder, T. M., and Gross, R. E." T e m p o r a r y gastroatomy in pediatric su:'gery---experience with 187 cases, Pediatrics 26: 36. 1960. _.~. Hyde, G. A., Jr., and deLorimJer, A. A.: Colon atrt.~ia and Hmich.,,prung disem, e, Surgery 64:976, 1968. 24. Hyde, J. S.: C o n g e n i t ~ duodenal atres'~a in four sib,~, J.A.M-A. 19I:146, t965. 25. Johnson, F. P.: The development of the mucus m e m b r a n e of the esophagus. stomach and .~mati inlestine in the h u m a n embryo, Am. J. Anal. t 0 : 5 2 I , 19t0. 26. Knutrud. O., and Eek, S.: Combined intrinsic duodenal obstruction and malrotation, Acta chir. scandinav. 119:506, 1960. 27. Lapeyrie, M., Pages, A., and Pous. J. G.: Atresia of the ~mall intestine and meconium iieus in siblings, Ann. chir. infant 7- 17. 1966, 28. Laufman, H., Martin, W. B., Method, H., Tuell, S. W., and Harding, FI. O ~ e r v a t i o n s in strangulation obstruction. Arch. Su,.g. " ," 59:550, i94.9. ,.~(z). Lecco. T. M." Zur Morphologie des Pankreas annulare, Si~ungsberichte d.er Akademie der Wissenschaften, Mathematischnatur. Wien ! 19: 3 9 1 , 1 9 t 0. 30. Lee, S. S.. Kim, K. Y., and I-tong, P. W.; Congenital at resia of the colon, J.A.M.A. , 0 _ . 1 t 48, 19. :. 31. Lewis, .F.T.- The Embryology of the Pancreas, in Keibe! and Mall (ed~.)" Manual o,¢ Human Embryology (Philadelphia" J, B. Lippincott C o m p a n ) . t912). 32. Louw, J. H." CongenitM at.resia and stenosis of the small intestine: The case for resection and pr.lmary end-to--end anastomosis, South African J. Surg. 4:57, 1966. 33. Louw,,_,J. H.: Re~ection and end-to-end anastomosie, in the managemenl of -atres~a and steno~is of the smah b o w e l Surge,? 62:940. '~9 6/. 134. Louw, J. H , and Barnard. C. N.: Congenital intestinal a t r e s i a ~ o b s e r v a t i o n s • ~;,Z on its origin. Lancet 2:1065.19__. 35. Lynn. H. B.: D u o d e n a l Obstru¢!ic~. Atresia. Stenosis and Annular Pancreas. in Benaon. et aL (eds.)" Pedia~ic Surgery (Chicago: Year Book Medical Pubtishers.~ Inc..,. 1:962 •~v oL "~; p. '66_-3. 36. Lynff. H. B., and Espinas,. E. E.: Intestinal a t r e ~ a ~ a n attempt to relate tocatiQn-to.embryologic processes, Arch. Surg: ~9: 3., 7. 1959. 37. Marion; J:; Picautt, Ch., Michel, C.. R., L a p as, A., a n d Daudet, M..: Some remarks a b o u t 4 a t r e s i ~ o f t h e colon, A n n . chir: infa ~t 6: 233. t.96 5. 38. Mourtsouris, C . : T b e "solid stage'" and congenital intestinal atresia, J. Pedlar. Surg. t:446, 1966. 39. Nelson, T. Y.: DuodezM obstruction in infants and children, M. J. Australia 2:709. 1963. 47

40. Nixon, H. H." Intestinal obstruction in the newborn, Arch. Dis. Childhood 30: 13, 1955. 41. Okmian, L. G., and Kovamees, A.: Jejunal atresia with intestinal aplasia. Strangulation of the intestine in the entraembryonic coelom of the belly stalk, Acta paediat. 53:65, 1964. 42. Parkkulainen, K. V." Intrauterine intussusception as a cause of intestinal atresia, Sttrgery 44"1106, 1958. 43. Peck, D. A., Lynn, H. B., and Harris, L. E.: Congenital atresia and stenosis of the colon, Arch. Surg. 87:86, 1963. 44. Phelan, J. T., Lenamer, K. E., and McDonough, K. B.: Jejunoileal atresia and stenosis, Surgery 46:430, 1959. 45. Pollock, W. F.,'nnd Bergin, W. F." Management of intestinal atresia at the Los Angeles Childrens Hospital, Am. J. Surg. 102:202, 1961. 46. Rehbein, F., and Boix-Ochoa, J." Membranous duodenal atresia, Ptidiat. Fortbild. Prax. 5" ! 03, 1966. 47. Rehbein, F., and Halsband, H." A double-tube technic for the treatment of meconium ileus and small bowel atresia, J. Pediat. Surg. 3"723, 1968. 48. Rowe, M. I., Buckner, D., and Clatworthy, H. W." Wind-sock web of the duodenum, Am. J. Surg. 116:444, 1968. '~r 49. Santulh, T. V., and Blanc, W. A." Congenital atresia of the intestine, Ann. Surg. 154:939, 1961. 50. Smetana, H." Ein beitrag zur kenntnis der missbildunger des pankreas, Beitr. p~th. Anat. 80:239, 1928. 51. Spriggs, N. I.: Congenital intestinal occlusion, Guy's Hosp. Rep. 66:143, I912. 52. Streeter, G. L." Developmental horizons in human embryos. Description of age groups xv, xvi, xvii and xviii. Carnegie Inst. Wash, publication 575, Contr. to Embryol., No. 211, 32, 133, 1948. (pp. 162 and 177 cited). 53. Suruga, K., Tsunoda, A., Masuda, H., Fukuda, A., and Yoshino, M.: Some problems of congenital intestinal atresia, Ztschr. Kinderh. 3 : 29, 1966. 54. Sutton, J. B.: Imperforate ileum, Am. J. Med. Sc. 98:457, 1889. 55. Swenson, O." Congenital /Vlalformations of the Esophagus, in Swenson, O. (ed.)" Pediatric Surgery (New York: Appleton-Century-Crofts Ed. Div. Meredith Corp., 1969), vol. 1, p. 456. 56. Swenson, O., and Davidson, F. Z.: Similarities of mechanical intestinal obstruction and aganglionic megacolon in the newborn infant, New England .1. Med. 262:64, 1960. 57. Swenson, O., and Fisher, H. H.: Small bowel atresia: Treatment by resection ~n
48