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Sacrococcygeal perineal approach to imperforate anus
Sacrococcygeal Perineal Approach to lmperforate Anus The Stephens Procedure RICHARD C. MILLER, MD, Jackson, Mississippi ROBERT J. IZANT, Jr, MD, Cleveland, Ohio
The contributions of Stephens to treatment of infants with imperforate anus cannot be overemphasized. In 1953, basing his conclusions on anatomic dissections and embryologic studies, he stressed the enormous importance of the puborectalis sling to fecal continence, and described a sacrococcygeal approach to imperforate anus repair [1,2]. Additional publications by the same author [3,4] have served to further elucidate his surgical technics and the entire problem of rectal and anal anomalies. Although in more recent years Stephens’ sacrococcygeal approach to the levator sling mechanism has generally been accepted, many surgeons have been reluctant to complete the pullthrough procedure from the posterior view because of difficulties encountered in delineating the urinary fistula and in dissecting the colonic pouch from the bladder and proximal urethra. Although at present there is no unanimity of opinion as to the best Qingle procedure for anorectal agenesis (“high” imperforate anus), most surgeons employ some modification of an abdominoperineal pull-through, with or without a preliminary sacrococcygeal incision to delineate the puborectalis sling. On the other hand, in spite of some minor difficulties encountered during the dissections, we have used the Stephens’ sacrococcygeal approach in all infants with anorectal agenesis and have made a conscious effort to avoid an abdominal incision unless the operation could not be completed through the posterior route. The report concerns our experience during the past six years with sixteen infants with supralevator anorectal agenesis. In fourteen of the infants, the pullthrough procedure was accomplished entireIy through sacrococcygeal and perineal incisions. In the two patients who required an additional abdominal incision, the blind end of the colon was From the Divisions of Pediatric Surgery, Departments of Surgery, The University of Mississippi School of Medicine, Jackson, Mississippi: the Case Western Reserve University School of Medicine; and the University Hospitals, Cleveland, Ohio. Presented at the Eleventh Annual Meeting of the Society for Surgery of the Alimentary Tract, Chicago, Illinois, June 20 and 21. 1970.
62
well above the levator diaphragm and the urinary fistulas were into the bladder rather than into the more common position in the prostatic urethra. Embryologic
and Anatomic
Considerations
Patients with anorectal deformities may be anatomically divided into those in whom the blind colonic pouch ends above the levator diaphragm and into those in whom the pouch has penetrated the diaphragm to an infralevator position. In those patients, principally males, in whom there is a supralevator (“high”) deformity, there is usually a fistula from the colon into the urinary tract, most often at the level of the prostatic urethra. Less often, there will be no fistula at all; or the fistula will enter directly into the bladder, and the tip of the blind rectal pouch will then be at a correspondingly elevated position. The particular type of deformity which is present in a new born infant may be ascertained by close inspection of the perineum and vulva for the presence of a fistula, often of minute size ; by examination of the urine for meconium ; and by the use of inverted lateral x-ray films, as originally described by Wangensteen and Rice [5]. The prostatic urethra in the male, the cervical OS in the female, and levator diaphragm in both sexes lie on the pubococcygeal line as seen on the lateral x-ray film of the pelvis. It is therefore apparent that observation of the blind airfilled rectal pouch in regard to its relation to the pubococcygeal line will in most instances define either a supra- or infralevator deformity. All of the sixteen patients presented herein had supralevator deformities and are not to be confused with those infants with infralevator anomalies for which surgical repair is less difficult. The muscles of fecal continence are those of the internal and external sphincters and the puborectalis portion of the levator ani. In the child with supralevator anorectal agenesis, the internal sphincter, which is embryologically derived from and is continuous with the circular smooth muscle The
American
Journal of Surgery
Sacrococcygeal
TABLE I
Diagnosis
Male RG
Additional
Anorectal agenesis with rectourethral fistula
WA
Anorectal agenesis with rectourethral fistula
JM
Anorectal agenesis with rectourethral fistula Anorectal agenesis with rectourethral fistula Anorectal agenesis with rectourethral fistula
AC
AD BR
MF SM RT ST
ws Female HT TW HH CP
Anorectal agenesis with rectourethral fistula Anorectal agenesis with rectovesical fistula
Anorectal agenesis with rectovesical fistula Anorectal agenesis with restovesical fistula Anorectal agenesis without fistula Anorectal agenesis without fistula Anorectal agenesis out fistula
with-
Anorectal agenesis with rectovestibular fistula Anorectal agenesis with rectovestibular fistula Anorectal agenesis with rectovestibular fistula Anorectal agenesis with rectocloacal fistula
Diagnoses
January
1971
Years of Follow-up Study after Pull-Through at 12-18 Months of Age
Urinary Continence
Yes
Fecal Continence
lmperforate
Anus
4
S-P
...
Down’s
S-P
P/2
Yes
Yes
S-P
2’/2
Yes
Yes
S-P
5
Yes
Yes
S-P
1
Yes
t
Dextrocardia, agenesis of right kidney, right undescended testis, malrotation of colon
S-P-A
3
Yes
Yes
...
S-P-A
2
Yes
Yes
S-P
5
Yes
Yes
S-P
2
Yes
?
syndrome
Intestinal disaccharide intolerance Esophageal atresia with tracheoesophageal fistula Down’s syndrome
S-P
4
Yes
Yes
S-P
‘12
Yes
t
Annular
pancreas
S-P
4
Yes
Yes
...
S-P
4
Yes
Yes
S-P
2112
Yes
Yes
S-P
3
Yes
Yes
Bilateral
hydronephrosis
Unilateral hydronephrosis and hydroureter
Complications
Yes
SP
Hyperchloremic acidosis; died at 2 yr after cardiac procedure Orchitis 1 yr after operation
Anal stenosis requiring revision 1 yr after operation
lleocecal at4mo
intussusception
Prolapsed infarcted tomy at 6 mo Constipation
colos-
to evaluate.
coat of the bowel, is absent. The external sphincter fibers which are skeletal muscle and are embryologically derived on the perineum, are almost always present; and the presence of these muscle fibers may be demonstrated regardless of the level of the rectal pouch. However, the functional ability of the external sphincter in these circumstances is open to question. Although usefulness of the external sphincter may have been underestimated in the past, and although there are some children who seem to have a perfectly normal sphincter after repair, there remain a consider121,
Incisions Required for PullThrough Procedure*
Esophageal atresia with tracheoesophageal fistula; pyloric stenosis Tetralogy of Fallot
*S, sacrococcygeal; P, perineal; A, abdominal. f Follow-up period too short and child too young
Volume
to
Summary of Sixteen Patients with Anorectal Agenesis
Patients
GH
Approach
able number of patients in whom external sphincter function is minimal to nil. Some of the latter undoubtedly have resulted from injudicious manipulation. The puborectalis sling at the level of the pelvic floor is the most important muscle to preserve in the infant with a supralevator deformity. Anatomically, this muscle encircles the most posterior structure in the pelvis and it normally passes posterior to the rectum. When the rectum is absent (anorectal agenesis), the fibers of the puborectalis are displaced forward and are closely applied to 63
Miller and lzant
the posterior aspect of the urethra in the male, and to the vagina (or cloaca) in the female. The pull-through procedure should ensure that the puborectalis sling is carefully dissected and that the bowel is brought down anteriorly inside the sling. The sling thus encircles the new rectum. When the rectal pouch ends at a lower level in the infralevator deformities, the encirclement of the rectum by the puborectalis is already complete and this, in part, accounts for the better functional results which have come to be expected in these children. The motor, sensory, and parasympathetic innervation of areas related to continence are of sacral origin. Not only must an estimation of function of these nerves be made, especially in infants with sacral agenesis or absent sacral segments, but also, every effort should be made to avoid injury to them at the time of operation. As far as possible, dissection should be confined to the midline. To provide anal sensation, it seems important that the anal skin extend upward into the anal canal and that an extra long pull-through of the colon with its attendant prolapse be avoided. Furthermore, there may be sensory receptors in the puborectalis muscle and in the blind rectal pouch. Kiesewetter [6] has therefore suggested that the rectal pouch be preserved and has devised a procedure to avoid dissection of its outer wall by stripping the mucosa from within. The Patients and Their Early Management
Pull-through procedures for anorectal agenesis were performed on sixteen infants at the University Hospitals of Cleveland between 1964 and 1969. Data concerning these patients are summarized in Table I. Of the twelve male patients, six had anorectal agenesis with rectourethral fistulas, three had rectovesical fistulas, and three had anorectal agenesis without a demonstrable fistula. Of the four female patients, three had anorectal agenesis with rectovestibular fistulas, whereas one had a rectocloacal fistula. All of the infants were treated primarily in the neonatal period with diverting colostomies in the sigmoid or left transverse colon. Although sigmoid colostomies have seemed preferable in that the blind rectal loop is shorter and therefore easier to wash out, care should be taken to place the colostomy in the more proximal sigmoid. This insures that an adequate length of colon will be available for the subsequent pullthrough procedure without disruption of the colostomy. One of the sixteen infants continued to have reflux of urine into the colon through the urinary fistula with a resultant hyperchloremic acidosis that necessitated the division of the fistula and the 64
pull-through procedure at six months of age. The remainder of the patients had elective procedures at twelve to eighteen months of age. Nine of the sixteen patients had other congenital anomalies including esophageal atresia, Down’s syndrome, tetralogy of Fallot, complete duodenal obstruction due to annular pancreas, hydronephrosis and hydroureter, unilateral renal agenesis, dextrocardia, and intestinal disaccharide intolerance. All of the children had urinary tract evaluations including intravenous urograms and cystograms. Although several of the patients had sacral deformities in terms of hemivertebra and odd-shaped fragments, none had sacral agenesis, and all seemed to have an adequate sacral nerve supply. All had perineal sensation and functioning continent bladders. Preoperative evaluation of the patients included colography for visualization of the blind rectal pouch, and urethrography in the male infants to aid in the delineation of the urinary fistula. The blind pouch was irrigated to remove all fecal matter, and 1 per cent neomycin solution was instilled into it twelve hours before surgery. Preparation of the proximal colon was unnecessary since the diverting colostomies were left undisturbed. Sacrococcygeal
Perineal Pull-Through
Procedure
The lower abdomen, perineum, and thighs are widely prepared with surgical soap, and in the male infants, a small curved metal urethral sound is passed into the bladder. Then with adequate assistance, the patient is turned face down on to a sterile sheet resting partially on his knees and partially on a sterile rolled sheet placed under the abdomen and pelvis. (Figure 1.) The metal sound rests on the drapes between the patient’s legs. The surgical preparation is then continued by scrubbing the remainder of the back and buttock areas. Sterile towels and drapes are applied, taking care that there is easy access to the urethral sound for manipulation as necessary. Two incisions are used. The first one is in the midline cleft starting over the distal sacrum and continuing downward for 4 or 5 cm stopping well short of the normal position for the anal orifice. The second incision is at the position of the anal orifice. (Figure 2.) The latter is made in the form of an “N” or “Z” so that the points of skin may be interdigitated into the anal canal to provide as much sensation as possible. An incision of this configuration also allows for a maximal length of suture line for dilatations and helps to avoid the problem of a circular contracting scar. Anal skin should not be excised. The sacral incision is carried down to bone exposing the coccyx, which is cartilaginous and can be sepaThe
American
Journal
of
SW&WY
Sacrococcygeal
Approach
to
lmperforate
Anus
Figure 1. Position of the patient for sacrococcygeal perineal pull-through. The urethral sound’has been placed prior to turning the patient over onto sterile drapes. Figure 2. The incisions for the sacrococcygeal perineal approach to imperforate anus. Anal skin should not be excised.
rated
from the sacrum with a transverse incision. Additional exposure may be gained into the pelvis by dividing the coccyx vertically in the midline, letting the two separate pieces fall laterally and inferiorly. There is then immediate access to the blind rectal pouch in the presacral space above the levator diaphragm. Adequate exposure is obtained with the use of a small self-retaining retractor for the skin and with finger retractors for the coccyx. Attention is first directed toward delineation of the puborectalis sling and the dilatation of the tunnel for the subsequent pull-through. Dissection is carried forward bluntly in the midline elevating the blind colonic pouch until the urethral sound can be palpated. It is helpful during this portion of the operation for the surgeon to hold the urethral sound with his left hand while dissection is being carried on with the right. Any approximation of the blunt dissecting instrument to the urethral sound can readily be detected. When the urethra has been reached, a right angle clamp, bluntly dissecting, is directed caudally, parallel to, and just posterior to the urethra. This carries the dissection down inside the puborectalis sling. When the tip of the right angle clamp is felt approaching the perineum, attention is turned to the perineal incision and the external sphincter. Care should be taken to preserve any sphincter fibers which are present and dissection through this muscle should be in a single direction so as to do minimal damage. It is generally better to divide the sphincter fibers at one point than to tear and stretch many parts of the muscle by overly generous blunt dissection When the tip of the clamp from the sacrococcygeal incision is seen below, a I,& inch rubber Penrose drain is pulled through the tunnel and used as a guide for future dilatations. (Figure 3.) Hegar dilators are then passed successively from the perineum, dilating the tunnel only to a diameter which is consistent with the size of the blind rectal stump. Usually this requires about a 12 mm dilator. The next step is the separation of the blind ending colonic pouch from the urinary tract and the division of the urinary fistula. This is the most Volume
121, January
1971
difficult phase of the procedure since the ballooning rectal pouch tends to obscure the plane of dissection. During this dissection, which for the most part is performed bluntly, it is extremely important to be aware of the position of the urethra. It is easily palpated with the metal sound in place. When the majority of the circumference of the blind rectal pouch has been dissected, it is helpful to open the distal end of the colon, to locate the fistula from within, and to guide further dissection with a finger inside the pouch. When the urinary fistula is isolated, it is divided and ligated with fine chromic catgut. When a small urethral fistula is not found, even if one is known to be present by x-ray studies, it is not overly important to search for it, since during the postoperative period, when catheter drainage is employed, the defect should seal spontaneously. At this point, the urethral sound is removed and a Foley catheter inserted. The catheter should be placed prior to closure of the posterior wound to avoid the risk of perforation of the urethral closure. The catheter may be guided directly into the bladder by a finger placed on the urethra. Once the colon has been freed from the urinary tract, upward blunt dissection will usually mo-
Figure 3. The puborectalis sling has been dissected and a rubber drain placed through the tunnel. The mobilized rectum appearing in the sacrococcygeal wound (large arrow) will be pulled-through and sutured to anal skin (smaller arrows). 65
Miller and lzant
bilize enough colon to provide adequate length to reach to the perineum. The dissection remains extraperitoneal. A few silk sutures are placed through the previously opened rectal pouch and are passed through the tunnel to provide traction to deliver the bowel to the perineum. The encircling Penrose rubber drain is used to keep the tunnel open during the pull-through procedure. Care should be taken to provide that there is an adequate length of bowel to reach the perineum without undue tension. Attention is next directed to the perineum where the colon is sutured to the skin, interdigitating the small flaps. Interrupted Number 4-O chromic catgut sutures in full thickness bites are used. The Penrose drain through the tunnel is removed and a short rubber drain is left in the presacral space. The coccyx is reapproximated with Number 3-O chromic catgut sutures in the perichondrium, the subcutaneous tissues are closed with fine catgut and the skin with interrupted silk. As a final procedure, the rectum is calibrated, but not dilated, with the Hegar dilators for future reference. In the event that a sufficient length of colon cannot be mobilized to reach the perineum, or if the colon cannot be dissected free from the urinary tract, it becomes necessary to close the sacral wound, leaving the Penrose drain through the tunnel, and to reposition the patient on his back for an abdominal incision. The abdomen can be rescrubbed and redraped without disturbing the sterility of the perineum or the posterior portions of the baby which are in contact with the sterile drapes. A sufficient length of sigmoid colon may then be mobilized transabdominably, the fistula divided, and the colon brought down through the prepared tunnel to the perineum. During this procedure, care must be taken not only that the colon is of adequate length, but also that it is not so long as to predispose to prolapse, which may require subsequent excision and anoplasty. The retroperitoneal area is closed and peritonealized. It is unnecessary and undesirable to close the colostomy at this stage ; rather the surgeon should await healing of the perineum. The anorectal canal should be gradually and gently dilated. In the female infant, the procedure is identical except that a small Hegar dilator, placed in the vagina, is substituted for the urethral sound. The catheter is left in the bladder for about seven days to ensure healing of the fistula site, and the sacrococcygeal drain is usually removed in three or four days. Dilatations of the rectum are begun on the fourth or fifth postoperative day, gradually increasing the size of the dilators to at least 10 or 12 mm. Closure of the colostomy is ac66
complished in two to three months when the anal canal is completely healed, well dilated, and shows no evidence of residual inflammation. Rectal dilatations should continue as long as there is any tendency toward stricture formation. These dilatations may be accomplished by the mother’s finger once an adequate size has been attained with the metal dilators. Results
The outcome of sixteen patients with anorectal agenesis has been tabulated in the last columns of Table I. In fourteen, the pull-through procedure was accomplished via sacrococcygeal and perineal incisions without the need for an additional abdominal incision, thereby avoiding the morbidity associated with abdominal surgery. Two male infants, who required an abdominal procedure to isolate the urinary fistula and to mobilize the colon, had rectovesical fistulas with the blind rectal pouches ending well above the levator diaphragm. It was simply not possible to complete the dissection from the sacrococcygeal incision in these infants. The period of follow-up has been from six months to five years, and the oldest child is now six years of age. There were no significant surgical complications. One child died at two years of age after cardiac surgery for tetralogy of Fallot; this death occurred eighteen months after the pullthrough procedure. None of the patients have had difficulty with urinary incontinence. Those children who are not yet toilet trained, nevertheless, void intermittently and are dry and without “dribbling” in the intervals. Twelve children, aged three and a half to six years, have been toilet trained and have fecal continence. The mothers of these children report that they do not use diapers and that the children do not have problems with fecal soiling. Although it is too early to predict the ultimate degree of control especially in regard to flatus and liquid feces, the preliminary results are encouraging. Two infants are too young to evaluate, and one three year old boy (RT) may be having difficulty with continence. His progress has been complicated by diarrhea due to a congenital disaccharide intolerance. Further observation of this patient will be needed. All of the infants routinely received postoperative anal dilatations until the anal canal was soft and without induration. In one patient (AC) a progressive anal stricture developed which required revision a year later. He has since been well. The
American
Journal
of
Surgery
Sacrococcygeal Approach to lmperforate Anus Summary
References
Sixteen patients with anorectal agenesis (high, supralevator imperforate anus) have undergone sacrococcygeal perineal pull-through procedures as described by Stephens. In two patients, additional abdominal incisions were needed to mobilize the colon and to divide the urinary fistulas which were into the bladder well above the levator muscle. There were no major complications associated with the surgery. The operative experience and early follow-up results in this modest number of patients are presented and are encouraging.
1.
Volume
121, January
1971
2. 3. 4.
5.
6.
Stephens FD: Congenital imperforate rectum, rectourethral and recta-vaginal fistulae. Aust New Zeal J Surg 22: 161, 1953. Stephens FD: lmperforate rectum: a new surgical technique. Med J Aust 2: 202, 1953. Stephens FD: lmperforate anus. Med J Aust 2: 803, 1959. Stephens FD: Congenital Malformations of the Rectum, Anus, and Genito-Urinary Tracts. Edinburgh and London, E. and S. Livingstone Ltd, 1963. Wangensteen OH, Rice CO: lmperforate anus: a method for determining the surgical approach. Ann Surg 92: 77, 1930. Kiesewetter WB: lmperforate anus: the role and results of the sacro-abdomino-perineal operation. Ann Surg 164: 655, 1966.
67
The contributions of Stephens to treatment of infants with imperforate anus cannot be overemphasized. In 1953, basing his conclusions on anatomic dissections and embryologic studies, he stressed the enormous importance of the puborectalis sling to fecal continence, and described a sacrococcygeal approach to imperforate anus repair [1,2]. Additional publications by the same author [3,4] have served to further elucidate his surgical technics and the entire problem of rectal and anal anomalies. Although in more recent years Stephens’ sacrococcygeal approach to the levator sling mechanism has generally been accepted, many surgeons have been reluctant to complete the pullthrough procedure from the posterior view because of difficulties encountered in delineating the urinary fistula and in dissecting the colonic pouch from the bladder and proximal urethra. Although at present there is no unanimity of opinion as to the best Qingle procedure for anorectal agenesis (“high” imperforate anus), most surgeons employ some modification of an abdominoperineal pull-through, with or without a preliminary sacrococcygeal incision to delineate the puborectalis sling. On the other hand, in spite of some minor difficulties encountered during the dissections, we have used the Stephens’ sacrococcygeal approach in all infants with anorectal agenesis and have made a conscious effort to avoid an abdominal incision unless the operation could not be completed through the posterior route. The report concerns our experience during the past six years with sixteen infants with supralevator anorectal agenesis. In fourteen of the infants, the pullthrough procedure was accomplished entireIy through sacrococcygeal and perineal incisions. In the two patients who required an additional abdominal incision, the blind end of the colon was From the Divisions of Pediatric Surgery, Departments of Surgery, The University of Mississippi School of Medicine, Jackson, Mississippi: the Case Western Reserve University School of Medicine; and the University Hospitals, Cleveland, Ohio. Presented at the Eleventh Annual Meeting of the Society for Surgery of the Alimentary Tract, Chicago, Illinois, June 20 and 21. 1970.
62
well above the levator diaphragm and the urinary fistulas were into the bladder rather than into the more common position in the prostatic urethra. Embryologic
and Anatomic
Considerations
Patients with anorectal deformities may be anatomically divided into those in whom the blind colonic pouch ends above the levator diaphragm and into those in whom the pouch has penetrated the diaphragm to an infralevator position. In those patients, principally males, in whom there is a supralevator (“high”) deformity, there is usually a fistula from the colon into the urinary tract, most often at the level of the prostatic urethra. Less often, there will be no fistula at all; or the fistula will enter directly into the bladder, and the tip of the blind rectal pouch will then be at a correspondingly elevated position. The particular type of deformity which is present in a new born infant may be ascertained by close inspection of the perineum and vulva for the presence of a fistula, often of minute size ; by examination of the urine for meconium ; and by the use of inverted lateral x-ray films, as originally described by Wangensteen and Rice [5]. The prostatic urethra in the male, the cervical OS in the female, and levator diaphragm in both sexes lie on the pubococcygeal line as seen on the lateral x-ray film of the pelvis. It is therefore apparent that observation of the blind airfilled rectal pouch in regard to its relation to the pubococcygeal line will in most instances define either a supra- or infralevator deformity. All of the sixteen patients presented herein had supralevator deformities and are not to be confused with those infants with infralevator anomalies for which surgical repair is less difficult. The muscles of fecal continence are those of the internal and external sphincters and the puborectalis portion of the levator ani. In the child with supralevator anorectal agenesis, the internal sphincter, which is embryologically derived from and is continuous with the circular smooth muscle The
American
Journal of Surgery
Sacrococcygeal
TABLE I
Diagnosis
Male RG
Additional
Anorectal agenesis with rectourethral fistula
WA
Anorectal agenesis with rectourethral fistula
JM
Anorectal agenesis with rectourethral fistula Anorectal agenesis with rectourethral fistula Anorectal agenesis with rectourethral fistula
AC
AD BR
MF SM RT ST
ws Female HT TW HH CP
Anorectal agenesis with rectourethral fistula Anorectal agenesis with rectovesical fistula
Anorectal agenesis with rectovesical fistula Anorectal agenesis with restovesical fistula Anorectal agenesis without fistula Anorectal agenesis without fistula Anorectal agenesis out fistula
with-
Anorectal agenesis with rectovestibular fistula Anorectal agenesis with rectovestibular fistula Anorectal agenesis with rectovestibular fistula Anorectal agenesis with rectocloacal fistula
Diagnoses
January
1971
Years of Follow-up Study after Pull-Through at 12-18 Months of Age
Urinary Continence
Yes
Fecal Continence
lmperforate
Anus
4
S-P
...
Down’s
S-P
P/2
Yes
Yes
S-P
2’/2
Yes
Yes
S-P
5
Yes
Yes
S-P
1
Yes
t
Dextrocardia, agenesis of right kidney, right undescended testis, malrotation of colon
S-P-A
3
Yes
Yes
...
S-P-A
2
Yes
Yes
S-P
5
Yes
Yes
S-P
2
Yes
?
syndrome
Intestinal disaccharide intolerance Esophageal atresia with tracheoesophageal fistula Down’s syndrome
S-P
4
Yes
Yes
S-P
‘12
Yes
t
Annular
pancreas
S-P
4
Yes
Yes
...
S-P
4
Yes
Yes
S-P
2112
Yes
Yes
S-P
3
Yes
Yes
Bilateral
hydronephrosis
Unilateral hydronephrosis and hydroureter
Complications
Yes
SP
Hyperchloremic acidosis; died at 2 yr after cardiac procedure Orchitis 1 yr after operation
Anal stenosis requiring revision 1 yr after operation
lleocecal at4mo
intussusception
Prolapsed infarcted tomy at 6 mo Constipation
colos-
to evaluate.
coat of the bowel, is absent. The external sphincter fibers which are skeletal muscle and are embryologically derived on the perineum, are almost always present; and the presence of these muscle fibers may be demonstrated regardless of the level of the rectal pouch. However, the functional ability of the external sphincter in these circumstances is open to question. Although usefulness of the external sphincter may have been underestimated in the past, and although there are some children who seem to have a perfectly normal sphincter after repair, there remain a consider121,
Incisions Required for PullThrough Procedure*
Esophageal atresia with tracheoesophageal fistula; pyloric stenosis Tetralogy of Fallot
*S, sacrococcygeal; P, perineal; A, abdominal. f Follow-up period too short and child too young
Volume
to
Summary of Sixteen Patients with Anorectal Agenesis
Patients
GH
Approach
able number of patients in whom external sphincter function is minimal to nil. Some of the latter undoubtedly have resulted from injudicious manipulation. The puborectalis sling at the level of the pelvic floor is the most important muscle to preserve in the infant with a supralevator deformity. Anatomically, this muscle encircles the most posterior structure in the pelvis and it normally passes posterior to the rectum. When the rectum is absent (anorectal agenesis), the fibers of the puborectalis are displaced forward and are closely applied to 63
Miller and lzant
the posterior aspect of the urethra in the male, and to the vagina (or cloaca) in the female. The pull-through procedure should ensure that the puborectalis sling is carefully dissected and that the bowel is brought down anteriorly inside the sling. The sling thus encircles the new rectum. When the rectal pouch ends at a lower level in the infralevator deformities, the encirclement of the rectum by the puborectalis is already complete and this, in part, accounts for the better functional results which have come to be expected in these children. The motor, sensory, and parasympathetic innervation of areas related to continence are of sacral origin. Not only must an estimation of function of these nerves be made, especially in infants with sacral agenesis or absent sacral segments, but also, every effort should be made to avoid injury to them at the time of operation. As far as possible, dissection should be confined to the midline. To provide anal sensation, it seems important that the anal skin extend upward into the anal canal and that an extra long pull-through of the colon with its attendant prolapse be avoided. Furthermore, there may be sensory receptors in the puborectalis muscle and in the blind rectal pouch. Kiesewetter [6] has therefore suggested that the rectal pouch be preserved and has devised a procedure to avoid dissection of its outer wall by stripping the mucosa from within. The Patients and Their Early Management
Pull-through procedures for anorectal agenesis were performed on sixteen infants at the University Hospitals of Cleveland between 1964 and 1969. Data concerning these patients are summarized in Table I. Of the twelve male patients, six had anorectal agenesis with rectourethral fistulas, three had rectovesical fistulas, and three had anorectal agenesis without a demonstrable fistula. Of the four female patients, three had anorectal agenesis with rectovestibular fistulas, whereas one had a rectocloacal fistula. All of the infants were treated primarily in the neonatal period with diverting colostomies in the sigmoid or left transverse colon. Although sigmoid colostomies have seemed preferable in that the blind rectal loop is shorter and therefore easier to wash out, care should be taken to place the colostomy in the more proximal sigmoid. This insures that an adequate length of colon will be available for the subsequent pullthrough procedure without disruption of the colostomy. One of the sixteen infants continued to have reflux of urine into the colon through the urinary fistula with a resultant hyperchloremic acidosis that necessitated the division of the fistula and the 64
pull-through procedure at six months of age. The remainder of the patients had elective procedures at twelve to eighteen months of age. Nine of the sixteen patients had other congenital anomalies including esophageal atresia, Down’s syndrome, tetralogy of Fallot, complete duodenal obstruction due to annular pancreas, hydronephrosis and hydroureter, unilateral renal agenesis, dextrocardia, and intestinal disaccharide intolerance. All of the children had urinary tract evaluations including intravenous urograms and cystograms. Although several of the patients had sacral deformities in terms of hemivertebra and odd-shaped fragments, none had sacral agenesis, and all seemed to have an adequate sacral nerve supply. All had perineal sensation and functioning continent bladders. Preoperative evaluation of the patients included colography for visualization of the blind rectal pouch, and urethrography in the male infants to aid in the delineation of the urinary fistula. The blind pouch was irrigated to remove all fecal matter, and 1 per cent neomycin solution was instilled into it twelve hours before surgery. Preparation of the proximal colon was unnecessary since the diverting colostomies were left undisturbed. Sacrococcygeal
Perineal Pull-Through
Procedure
The lower abdomen, perineum, and thighs are widely prepared with surgical soap, and in the male infants, a small curved metal urethral sound is passed into the bladder. Then with adequate assistance, the patient is turned face down on to a sterile sheet resting partially on his knees and partially on a sterile rolled sheet placed under the abdomen and pelvis. (Figure 1.) The metal sound rests on the drapes between the patient’s legs. The surgical preparation is then continued by scrubbing the remainder of the back and buttock areas. Sterile towels and drapes are applied, taking care that there is easy access to the urethral sound for manipulation as necessary. Two incisions are used. The first one is in the midline cleft starting over the distal sacrum and continuing downward for 4 or 5 cm stopping well short of the normal position for the anal orifice. The second incision is at the position of the anal orifice. (Figure 2.) The latter is made in the form of an “N” or “Z” so that the points of skin may be interdigitated into the anal canal to provide as much sensation as possible. An incision of this configuration also allows for a maximal length of suture line for dilatations and helps to avoid the problem of a circular contracting scar. Anal skin should not be excised. The sacral incision is carried down to bone exposing the coccyx, which is cartilaginous and can be sepaThe
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Sacrococcygeal
Approach
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Anus
Figure 1. Position of the patient for sacrococcygeal perineal pull-through. The urethral sound’has been placed prior to turning the patient over onto sterile drapes. Figure 2. The incisions for the sacrococcygeal perineal approach to imperforate anus. Anal skin should not be excised.
rated
from the sacrum with a transverse incision. Additional exposure may be gained into the pelvis by dividing the coccyx vertically in the midline, letting the two separate pieces fall laterally and inferiorly. There is then immediate access to the blind rectal pouch in the presacral space above the levator diaphragm. Adequate exposure is obtained with the use of a small self-retaining retractor for the skin and with finger retractors for the coccyx. Attention is first directed toward delineation of the puborectalis sling and the dilatation of the tunnel for the subsequent pull-through. Dissection is carried forward bluntly in the midline elevating the blind colonic pouch until the urethral sound can be palpated. It is helpful during this portion of the operation for the surgeon to hold the urethral sound with his left hand while dissection is being carried on with the right. Any approximation of the blunt dissecting instrument to the urethral sound can readily be detected. When the urethra has been reached, a right angle clamp, bluntly dissecting, is directed caudally, parallel to, and just posterior to the urethra. This carries the dissection down inside the puborectalis sling. When the tip of the right angle clamp is felt approaching the perineum, attention is turned to the perineal incision and the external sphincter. Care should be taken to preserve any sphincter fibers which are present and dissection through this muscle should be in a single direction so as to do minimal damage. It is generally better to divide the sphincter fibers at one point than to tear and stretch many parts of the muscle by overly generous blunt dissection When the tip of the clamp from the sacrococcygeal incision is seen below, a I,& inch rubber Penrose drain is pulled through the tunnel and used as a guide for future dilatations. (Figure 3.) Hegar dilators are then passed successively from the perineum, dilating the tunnel only to a diameter which is consistent with the size of the blind rectal stump. Usually this requires about a 12 mm dilator. The next step is the separation of the blind ending colonic pouch from the urinary tract and the division of the urinary fistula. This is the most Volume
121, January
1971
difficult phase of the procedure since the ballooning rectal pouch tends to obscure the plane of dissection. During this dissection, which for the most part is performed bluntly, it is extremely important to be aware of the position of the urethra. It is easily palpated with the metal sound in place. When the majority of the circumference of the blind rectal pouch has been dissected, it is helpful to open the distal end of the colon, to locate the fistula from within, and to guide further dissection with a finger inside the pouch. When the urinary fistula is isolated, it is divided and ligated with fine chromic catgut. When a small urethral fistula is not found, even if one is known to be present by x-ray studies, it is not overly important to search for it, since during the postoperative period, when catheter drainage is employed, the defect should seal spontaneously. At this point, the urethral sound is removed and a Foley catheter inserted. The catheter should be placed prior to closure of the posterior wound to avoid the risk of perforation of the urethral closure. The catheter may be guided directly into the bladder by a finger placed on the urethra. Once the colon has been freed from the urinary tract, upward blunt dissection will usually mo-
Figure 3. The puborectalis sling has been dissected and a rubber drain placed through the tunnel. The mobilized rectum appearing in the sacrococcygeal wound (large arrow) will be pulled-through and sutured to anal skin (smaller arrows). 65
Miller and lzant
bilize enough colon to provide adequate length to reach to the perineum. The dissection remains extraperitoneal. A few silk sutures are placed through the previously opened rectal pouch and are passed through the tunnel to provide traction to deliver the bowel to the perineum. The encircling Penrose rubber drain is used to keep the tunnel open during the pull-through procedure. Care should be taken to provide that there is an adequate length of bowel to reach the perineum without undue tension. Attention is next directed to the perineum where the colon is sutured to the skin, interdigitating the small flaps. Interrupted Number 4-O chromic catgut sutures in full thickness bites are used. The Penrose drain through the tunnel is removed and a short rubber drain is left in the presacral space. The coccyx is reapproximated with Number 3-O chromic catgut sutures in the perichondrium, the subcutaneous tissues are closed with fine catgut and the skin with interrupted silk. As a final procedure, the rectum is calibrated, but not dilated, with the Hegar dilators for future reference. In the event that a sufficient length of colon cannot be mobilized to reach the perineum, or if the colon cannot be dissected free from the urinary tract, it becomes necessary to close the sacral wound, leaving the Penrose drain through the tunnel, and to reposition the patient on his back for an abdominal incision. The abdomen can be rescrubbed and redraped without disturbing the sterility of the perineum or the posterior portions of the baby which are in contact with the sterile drapes. A sufficient length of sigmoid colon may then be mobilized transabdominably, the fistula divided, and the colon brought down through the prepared tunnel to the perineum. During this procedure, care must be taken not only that the colon is of adequate length, but also that it is not so long as to predispose to prolapse, which may require subsequent excision and anoplasty. The retroperitoneal area is closed and peritonealized. It is unnecessary and undesirable to close the colostomy at this stage ; rather the surgeon should await healing of the perineum. The anorectal canal should be gradually and gently dilated. In the female infant, the procedure is identical except that a small Hegar dilator, placed in the vagina, is substituted for the urethral sound. The catheter is left in the bladder for about seven days to ensure healing of the fistula site, and the sacrococcygeal drain is usually removed in three or four days. Dilatations of the rectum are begun on the fourth or fifth postoperative day, gradually increasing the size of the dilators to at least 10 or 12 mm. Closure of the colostomy is ac66
complished in two to three months when the anal canal is completely healed, well dilated, and shows no evidence of residual inflammation. Rectal dilatations should continue as long as there is any tendency toward stricture formation. These dilatations may be accomplished by the mother’s finger once an adequate size has been attained with the metal dilators. Results
The outcome of sixteen patients with anorectal agenesis has been tabulated in the last columns of Table I. In fourteen, the pull-through procedure was accomplished via sacrococcygeal and perineal incisions without the need for an additional abdominal incision, thereby avoiding the morbidity associated with abdominal surgery. Two male infants, who required an abdominal procedure to isolate the urinary fistula and to mobilize the colon, had rectovesical fistulas with the blind rectal pouches ending well above the levator diaphragm. It was simply not possible to complete the dissection from the sacrococcygeal incision in these infants. The period of follow-up has been from six months to five years, and the oldest child is now six years of age. There were no significant surgical complications. One child died at two years of age after cardiac surgery for tetralogy of Fallot; this death occurred eighteen months after the pullthrough procedure. None of the patients have had difficulty with urinary incontinence. Those children who are not yet toilet trained, nevertheless, void intermittently and are dry and without “dribbling” in the intervals. Twelve children, aged three and a half to six years, have been toilet trained and have fecal continence. The mothers of these children report that they do not use diapers and that the children do not have problems with fecal soiling. Although it is too early to predict the ultimate degree of control especially in regard to flatus and liquid feces, the preliminary results are encouraging. Two infants are too young to evaluate, and one three year old boy (RT) may be having difficulty with continence. His progress has been complicated by diarrhea due to a congenital disaccharide intolerance. Further observation of this patient will be needed. All of the infants routinely received postoperative anal dilatations until the anal canal was soft and without induration. In one patient (AC) a progressive anal stricture developed which required revision a year later. He has since been well. The
American
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Sacrococcygeal Approach to lmperforate Anus Summary
References
Sixteen patients with anorectal agenesis (high, supralevator imperforate anus) have undergone sacrococcygeal perineal pull-through procedures as described by Stephens. In two patients, additional abdominal incisions were needed to mobilize the colon and to divide the urinary fistulas which were into the bladder well above the levator muscle. There were no major complications associated with the surgery. The operative experience and early follow-up results in this modest number of patients are presented and are encouraging.
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2. 3. 4.
5.
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Stephens FD: Congenital imperforate rectum, rectourethral and recta-vaginal fistulae. Aust New Zeal J Surg 22: 161, 1953. Stephens FD: lmperforate rectum: a new surgical technique. Med J Aust 2: 202, 1953. Stephens FD: lmperforate anus. Med J Aust 2: 803, 1959. Stephens FD: Congenital Malformations of the Rectum, Anus, and Genito-Urinary Tracts. Edinburgh and London, E. and S. Livingstone Ltd, 1963. Wangensteen OH, Rice CO: lmperforate anus: a method for determining the surgical approach. Ann Surg 92: 77, 1930. Kiesewetter WB: lmperforate anus: the role and results of the sacro-abdomino-perineal operation. Ann Surg 164: 655, 1966.
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