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Evaluation of the nissen antireflux procedure by esophageal manometry and twenty-four hour pH monitoring
Evaluation of the Nissen Antireflux Procedure by Esophageal Manometry and Twenty-Four Hour pH Monitoring LTC Tom Ft. De&&ester, MC,’ Honolulu, Hawaii LTC Lawrence F. Johnson, MC, Honolulu, Hawaii
The goal of surgical treatment for gastroesophageal reflux is the restoration of cardioesophageal competence. Recently, we have evaluated by a randomized prospective study the ability of the new operative procedures, namely, the Hill, Belsey Mark IV, and Nissen repairs, to achieve this goal. This study showed that the Nissen repair best controlled gastroesophageal reflux as measured objectively with the standard acid reflux test and twenty-four hour pH monitoring of the distal esophagus [I 1. The present study evaluates the ability of the Nissen antireflux procedure to return the cardioesophageal sphincter to normal by comparing its competence in a group of symptomatic patients before and after surgery with normal volunteers who have never experienced symptoms of gastroesophageal reflux. Methods Thirty-one persons were submitted to esophageal manometry studies and twenty-four hour pH monitoring of the distal esophagus. Fifteen of these thirty-one persons formed the control group. They were asymptomatic volunteers who had no history of symptoms of gastroesophageal reflux, antacid therapy, or an upper gastrointestinal radiographic study for digestive symptoms. They were selected from the elective admissions to Tripler Army Medical Center for inguinal hernia repair or other nongastroenterologic illnesses. The sixteen remaining paGents made up the symptomatic group. They had typical symptoms of heartburn and regurgitation unresponsive to medical management and showed endoscopic or histologic evidence of esophagitis. Fourteen of the From the Departments of Surgery and Medicine, Tripler Army Medical Center, Honolulu, Hawaii. * Present address and address for reprint requests: Department of Surgery, The University of Chicago, 950 East 59th Street, Chicago, Illinois 60637. Presented at the Fifteenth Annual Meeting of the Society for Surgery of the Alimentary Tract, San Francisco, California, May 21 and 22, 1974.
94
sixteen patients had a hiatus hernia demonstrated on radiographic examination, and eight had radiographic evidence of gastroesophageal reflux. (Table I.) Each of the symptomatic patients was graded 011 a scale of 0 to 3 for each of the symptoms of heartburn and regurgitation. The grading was carried out prior to any objective study using a reflux questionnaire completed by one of the authors during an interview with the patient. The highest possible score that could be obtained was 6 and would represent a patient with heartburn that interfered with daily activities and episodes of pulmonary aspiration secondary to regurgitation. Both the control and symptomatic groups were compared as to the esophageal manometric values and the results of twenty-four hour pH monitoring of the distal esophagus. Each patient in the symptomatic group had a Nissen antireflux procedure, returned for postsurgical subjective evaluation on an average of four months after surgery, and was restudied with an upper gastrointestinal radiographic examination, esophageal manometry, and twenty-four hour pH monitoring of the distal esophagus. The results of the postsurgical studies were compared with those obtained preoperatively and with those in the control group. At postsurgical subjective evaluation, each patient was evaluated for the presence of reflux symptoms; the duration of postoperative dysphagia, that is, any subjective discomfort during swallowing; the need for dilatation; the ability to vomit and belch; and the presence of increased flatus, diarrhea, and periodic episodes of abdominal distention. Esophageal manometric studies were performed according to the technic of Winans and Harris (21, using a single catheter assembly consisting of three fluid-filled, perfused, polyethylene tubes bonded t.ogether with three distal 2 mm lateral openings placed 5 cm apart. The catheter was passed into the empty stomach and withdrawn in 1 cm increments back Into the esophagus and up to the cricopharyngeus high pressure zone. The distal esophageal sphincter (DES) pressure was measured as the difference in millimeters of mercury be-
The American .lournal of Suraerv
Nissen Antireflux
TABLE
I
Radiographic
Studies on Symptomatic
Before surgery After surgery * Excluding
patients
with
Patients ____
hiatal
14/16 O/16
Radiographic Reflux
Esophagus (cm)
__~~_____
8/16
50%
1.0 f
o*
0%
O/16
0%
4.0 It
1.3
-___
hernia.
Twenty-Four Hour pH Monitoring ____A
Component
Average Intra-Abdominal
81.5%
tween the resting end expiratory gastric pressure and distal esophageal sphincter pressure. The twenty-four hour pH monitoring of the distal esophagus was performed according to a technic that we have previeusly described [3]. It consists of positioning a pH electrode 5 cm above the distal esophageal sphincter previously located by manometry and placing a reference lead on the forearm. Both the pH probe and the reference lead are connected to a strip chart recorder running at 6 inches per hour for twenty-four hours. A normal diet is given during this period, unique only in the absence of food and beverages having a pH value of less than 5. All persons were given a pencil to mark on the strip chart recorder any subjective reflux symptoms that occurred as well as their body position, whether upright or supine. Reflux was defined as an esophageal pH of less than 4. From the twenty-four hour record, the per cent of time that the pH was less than 4 in the distal esophagus could be determined for the total twenty-four hour period and for the time spent in the upright and supine positions. Also, the total number of reflux episodes, the number of episodes five minutes or greater in duration, and the length of the longest reflux episode was obtained from the tracing. This gave six components from the twenty-four hour record in which each patient was measured. A numeric twenty-four hour pH score was calculated for each person and was used to compare the over-all results of the twenty-four hour pH monitoring test. TABLE II
___
Anatomic Hiatal Hernia
Studies
Procedure
Presurgical
Results Esophageal pH Monitoring. Table II shows the results of six different components measured from
the twenty-four hour record and the numeric twenty-four hour pH score. In column A, the preoperative results of the symptomatic patients are compared with those in the controls. Minimal reflux was observed in the normal control subjects in both the supine and upright positions; however, no record of symptoms associated with these reflux episodes was made on the strip chart recorder. Reflux rarely occurred during slumber and commonly occurred during and for a short period after alimentation but was cleared rapidly, with few episodes lasting longer than five minutes. The symptomatic patients had significantly more reflux than did the controls in all categories of the twenty-four hour pH record (p. This was most marked in the supine position, and the number of reflux episodes that were of five minutes’ duration or longer was greater. Comparison of the pre- and postsurgical twentyfour hour pH monitoring results is shown in Table II, column B. The Nissen antireflux procedure resulted in an improvement in all categories of the twenty-four hour pH record over the patients’ pre-
of Distal Esophagus B Control
vs
Presurgical
vs
C
Postsurgical
Postsurgical
vs
Control
11.1 zt 4.6
1.5 f
1.4*
11.1 f: 4.6
0.2 f
11.3
f
6.4
2.3 f
2.0*
11.3 zk 6.4
0.2 xk 0.4*
0.2 zk 0.4
2.3 f- 2*
10.4
+
7.6
0.3 i
0.5*
10.4 f
7.6
0.1 f
0.1 f
0.3 f
Number of reflux episodes during 24 hr period Number of reflux episodes of 5 min or longer
63.5
zk 26.2
63.5 i
26.2
4.4 zk 8.8*
4.4 zk 8.8
0.0 f
*
0.0
Longest reflux episode (min)
28.9
zt 15.6
24 hr pH score
65.2
+
Per cent period Per cent period Per cent period
of pH of pH of pH
total 24 hr <4 upright <4 supine <4
7.8 =k 5.3
24.5
20.6
zt 14.8*
0.6 f
1.2*
3.9 =t 2.7* 12.0
f
4.7*
7.8 A. 5.3
0.3*
0.3*
0.2 *
0.3
0.3
1.5 It 1.4*
20.6 +
0.5 14.8*
0.6 h
1.2
28.9 f
15.6
0.6 f
1.4*
0.6 f
1.4
3.9 f
2.7*
65.2 f
24.5
6.7 f
1.8*
6.7 f
1.8
12.0 * -___
4.7*
* p < 0.001.
Volume 129, January 1975
95
DeMeester
and Johnson
40
3S
CONTROL vs. PK
pt.01
PRE vs. POST
p<.Ga
CONTROL vs POST pcOl I
I
D.E.S. PRESSURE
mm. Hg.
PRE 13.1’49
POST 26.7*8.0
Figure 1. Distal esophageal sphincter (DES) pressure in fitteen contra/ subjects and sixteen patients before and after the Nissen antirefkx procedure.
operative values (p
KX)
CONTROL vs. PRE
p<.Ol
90
PRE vs. POST
p<.Ol
6.
CONTROL vs. POST NS.
60 X OF DES BEUW
R.I.P. 5o 40. 30 20. IO.
RE 590t12.6 LENGTH OF DES.
50*1.2
439W2 49AOB
POW 64.3tl9.2 4.9il.O
(cm.1
Figure 2. Over-all kngth of the distal esophageal sphincter (DES) and the per cent located below respiratory inverskn point (RIP) in fifteen control subjects and sixteen patients before and after Nissen antireflux procedure.
96
position and the number of reflux episodes lasting five minutes or longer, the results remained the same as those in the controls. Esophageal Manometry. Sphincteric pressure (Figure 1): Preoperatively, the symptomatic patients had a distal esophageal sphincter pressure that was less than that of the controls (p
The American Journal of Surgery
Nissen Antireflux
29
1
Procedure
6 pt.02
CLINICAL 3 SCORE 2
25.V1.7
267*2.0
Figure 3. Esophageal length before and after Nissen antirefiux procedure, each of the sixteen patients serving as his own control.
dominal esophagus. the intra-abdominal 3.5 cm.
PRE
POST
Figure 4. Pre- and postsurgical changes in the clinical score. See text for explanation of score.
Postoperatively, the length of esophagus was increased to
Dysphagia (Figure 5): There was a 69 per cent incidence of dysphagia in the preoperative symptomatic patients. After the Nissen antireflux procedure this was increased to 87 per cent during the immediate postoperative period. If the patient experienced postoperative dysphagia, its average duration was sixty-two days. One patient required postoperative dilatation. All patients were free of dysphagia six months after surgery. Morbidity (Figure 6): After the Nissen antireflux procedure 57 per cent of the patients were unable to vomit, which was of minimal concern to most of them. Eighty-one per cent of the patients were able to belch after surgery. There was a temporary increase in the amount of flatus in 63 per cent of the patients and a 44 per cent incidence of temporary postoperative diarrhea. On specific questioning, 25 per cent of the patients reported episodes of mild abdominal distention after eating.
70 60
%
50 40
33 20
I I
ll_-_ E
IO INCIDENCE0
0
l-id
-iG
POST OP 6M3. PRE POST )P SURGERY PERIOD DILATATIONS POST Of?
Figure 5. The effect of the Ntssen antirefiux procedure on symptoms of dysphagia.
IOO-
90. 00. 70. 60. % INclENcE
Comments
The value obtained for each component of the twenty-four hour pH monitoring test after a Nissen antireflux procedure was significantly improved over the preoperative value. The Nissen antireflux procedure restored cardioesophageal competence in both the upright and supine positions, that is, in the upright position, the patient has the aid of gravity to prevent reflux and in the
Volume
129,
January
1975
5040.
5 z
xl. ZQIO.
n
0 ABILITY VOMIT
TO ABILITY -IO UKREA‘XD BELCH FLATUS
lEhl=CRARY DlARRtiEf,
PBDOMINAL DISTENTION
Figure 6. The morbidity of the Nissen antirefiux procedure.
97
Debleester and Johnson
supine position, the encouragement of gravity to effect reflux. We have recently shown that the number of reflux episodes that are of five minutes’ duration or greater are more significant in producing esophagitis than are those that cleared more rapidly [4]. It is pertinent, therefore, that the Nissen antireflux procedure significantly reduced the number of prolonged episodes of reflux to control values. Comparison of the postsurgical values with the control values indicates that the Nissen antireflux procedure significantly improved cardioesophageal competence over that observed in the control patients in four of the six components of the twenty-four hour study. In control subjects, reflux rarely occurs in the supine position; however, it does occur as a rule in the upright position during and for a short period after alimentation and is considered a normal physiologic phenomenon. The Nissen procedure interferes with this physiologic reflux by producing a supercompetent sphincter as indicated by the small amount of reflux in the upright position compared with that in the controls. There is strong evidence to suggest that distal esophageal sphincter pressure is a major deterrent to reflux. Distal esophageal sphincter pressure has been shown to be less than normal in patients with symptoms of reflux and in those in whom reflux has been determined objectively using the standard acid reflux test [2,Fi]. We have previously demonstrated that the incidence and severity of reflux lessened quantitatively with increasing distal esophageal sphincter pressure [5,6]. This would indicate that any surgical treatment that increased the distal esophageal sphincter pressure should be of benefit to the patient. The Nissen antireflux procedure increased the distal esophageal sphincter pressure to a height twice the preoperative levels and significantly greater than that in the control subjects. This was associated with less reflux than that in the control subjects in four components of the twenty-four hour pH record and further supports the finding that increasing sphincter pressure is a major deterrent to reflux. This rise in sphincter pressure is thought to occur when the lower esophagus is placed in the intra-abdominal position where it is in a positive pressure environment [ 71. The manometric studies showed that the Nissen procedure placed 20 per cent more of the sphincter in the positive pressure environment of the abdomen as opposed to that measured preoperatively. This resulted in an equal amount of distal esophageal sphincter being exposed to the positive pressure of the abdomen as that in the control subjects. On the basis of these
98
findings, one would expect a rise in sphincter pressure to a level equal to that in the controls. Indeed, after procedures in which a similar amount of distal esophageal sphincter is anchored within the positive pressure environment of the abdomen and a gastric fundic wrap is not employed, namely, the Hill procedure, we have observed an increase in the sphincter pressure in fifteen patients from 15.3 f 5.5 to 19.8 f 5.8 mm Hg [I J. As can be seen, this is identical to that pressure obtained in the fifteen control subjects. (Figure 1.) The Nissen antireflux procedure, however, increased the sphincter pressure to a level significantly greater than that in the normal controls, This would suggest that the addition of a gastric fundic wrap causes an increase in the sphincter pressure over that pressure obtained by only placing the distal esophageal sphincter within the positive pressure environment, of the abdomen. It should be noted that the amount of distal esophageal sphincter exposed to the positive pressure environment of the abdomen on manometric studies is not identical to that observed on radiographic examination. (Figure 2 versus Table I.) Preoperatively in the presence of a hiatal hernia and therefore without a radiographic intra-abdominal segment of esophagus, an average of 44 per cent or 2.2 cm of the distal esophageal sphincter was exposed to a positive environment. (Figure 2.) This would indicate that the hernial sac allows transmission of positive abdominal pressure up to its insertion around the cardioesophageal junction. Based on manometric studies, the Nissen procedure placed 64 per cent, or 3.2 cm, of the distal esophageal sphincter in the positive pressure environment of the abdomen. Radiographically, however, the Nissen procedure produced an average of 4 cm of esophagus below the diaphragm. When the hernial sac is reduced and an antireflux repair carried out, the creation of a 4 cm intra-abdominal esophagus results in the placement of only an additional 1 cm of distal esophageal sphincter in a functional positive pressure environment. It is also probable that the transmitted positive pressure in the hernial sac is less than the positive pressure in the abdomen and that surgery places that portion of the distal esophageal sphincter exposed t.o positive pressure in an area of stronger positive pressure than that of the hernial sac (81. This stronger positive pressure environment would account for the increase in resting distal esophageal sphincter pressure which is further increased if the intraabdominal portion of the esophagus is buttressed by a gastric fundic wrap so that gastric pressure
The American
Journal Of Surgery
Nissen Antireflux Procedure
can be applied directly to the distal esophageal sphincter. The importance of exposing a portion of the distal esophageal sphincter to the positive pressure of the abdomen has been pointed out by Nagler and Spiro [9]. They have shown that as intragastric pressure rises, the resting pressure of the intraabdominal segment of the distal esophageal sphincter (below the respiratory inversion point) also rises to maintain a pressure gradient between the sphincter and the gastric fundus. The intrathoracic segment of the distal esophageal sphincter (above the respiratory inversion point) is not affected by the increase in intragastric pressure so that the gradient between the intrathoracic portion of the distal esophageal sphincter and the gastric fundus is diminished or lost entirely when extrinsic pressure is applied to the abdomen. They have further noted that intragastric pressure is generally elevated during pregnancy, but all pregnant women do not have gastroesophageal reflux. Those in whom it can be demonstrated invariably fail to show an intra-abdominal segment of the distal esophageal sphincter. After delivery, the intra-abdominal segment reappears and reflux is not demonstrated. Certainly the findings that the symptomatic preoperative patients had signficantly less distal esophageal sphincter exposed to the positive pressure environment of the abdomen than did the asymptomatic control subjects and that the Nissen antireflux procedure corrected this condition and reduced concomitantly the amount of reflux support the concept that as the amount of distal esophageal sphincter located within the intra-abdominal positive pressure environment increases, the effectiveness of the distal esophageal sphincter as a barrier against acid reflux increases. Sixty-nine per cent of the symptomatic patients demonstrated some degree of dysphagia preoperatively. This was aggravated significantly by the Nissen antireflux repair during the immediate postoperative period. This dysphagia was unrelated to the degree and duration of relaxation of the distal esophageal sphincter since both the postsurgical patient and the normal control subject relaxed equally. Dodds and associates [IO] have shown a 1 cm or more oral movement of radiographic markers in the distal esophagus with peristalsis as the esophagus shortens to dilate and engulf a passing bolus. It is pertinent that the Nissen procedure significantly increased the length of the esophagus by 1.6 cm. (Figure 3.) The degree of dysphagia post repair may be related to this stretching of the esophagus rather than to too vig-
Valune
129. Januarv
1975
orous approximation of the crura. This stretching of the esophagus may limit the amount of orad extension of the distal esophagus during peristalsis, thus making it difficult for the esophagus to dilate and accept a bolus of food and giving rise to the symptoms of dysphagia that the patients experienced after the repair. When the tissues were able to accommodate to the new length, symptoms of dysphagia should have disappeared. This, indeed, was the case as all patients were free of dysphagia after six months. The most significant morbidity of the Nissen procedure is the inability of 57 per cent of the patients to vomit after repair. Only a few patients considered this to be a distinct disadvantage. Sixty-three per cent of the patients noted an increase in flatus after the operative repair. We believe that this increase in flatus is secondary to the marked aerophagia that a significant number of the preoperative patients demonstrated. When this habit was broken postoperatively, the amount of flatus decreased. Conclusions The Nissen antireflux procedure appears to control gastroesophageal reflux as measured subjectively on the basis of symptoms or objectively using twenty-four hour pH monitoring of the distal esophagus. Postsurgical patients had less reflux than did asymptomatic control subjects, indicating that the Nissen procedure interferes with physiologic reflux. Surgery produces a competent cardioesophageal sphincter by increasing the amount of distal esophageal sphincter exposed to the positive pressure environment of the abdomen and increasing its resting pressure. This was accomplished with a low morbidity but with temporary, mild, postoperative dysphagia and a 43 per cent chance of being able to vomit after the repair. Summary Fifteen normal volunteers without symptoms of gastroesophageal reflux and sixteen patients with symptoms of gastroesophageal reflux unresponsive to medical management and having endoscopic esophagitis had esophageal manometry and twenty-four hour pH monitoring of the distal esophagus. The symptomatic patients underwent a Nissen antireflux procedure and were restudied at four months. After surgery, patients had less reflux, a higher sphincteric pressure, and an equal amount of sphincter within the abdomen as did asymptomatic control subjects.
99
DeMeester
and Johnson
References 1. DeMeester TR. Johnson LF, Kent AH: Evaluation of current operation for the prevention of gastroesophageal reflux. Ann Surg 180: 511, 1974. 2. Winans CS, Harris LD: Quantitation of the lower esophageal sphincter competence. Gasfroenterology 52: 779, 1967. 3. Johnson LF, De&rester TR: Twenty-four hour pH monitoring of the distal esophagus: a quantitative measure of gastroesophageal reflux. Am J Gasfroenterol in press. 4. Johnson LF, DeMeester TR, Haggitt RC: Esophageal histology correlated to objective measure of gastroesophageal reflux (abstract). Gastroenterology 66: A-70, 1974. 5. Thurer RL, DeMeester TR, Johnson LF: Distal esophageal sphincter and its relationship to gastroesophageal reflux. J
100
Surg Res 16: 418,1974. 6. Johnson LF, DeMeester TR: Advantage of distal esophageal 24-hour pH monitoring over other tests for gastroesophageal reflux (abstract). Gasfroenterology 66: A-70, 1974. 7. Mustard RA: A survey of techniques and results of hiatus hernia repair. Surg Gynecol Obstet 130: 13 1, 1970. 8. Moosa AR, Cooley GR, Skinner DB: lntraluminal and intraperitoneal pressures at the cardia: effects of hormones and surgical intervention. Surg Forum 24: 372, 1973. 9. Nagler R. Spiro HM: Experimental response of the inferior esophageal sphincter to elevated intragastric pressure. Gastroenterology 40: 405, 196 1. 10. Dodds WJ, Stewart ET, Hodges D, Zboralske FF: Movement of the feline esophagus associated with respiration and peristalsis. J C/in invest 52: 1, 1973.
The American Journal
of Surgery
The goal of surgical treatment for gastroesophageal reflux is the restoration of cardioesophageal competence. Recently, we have evaluated by a randomized prospective study the ability of the new operative procedures, namely, the Hill, Belsey Mark IV, and Nissen repairs, to achieve this goal. This study showed that the Nissen repair best controlled gastroesophageal reflux as measured objectively with the standard acid reflux test and twenty-four hour pH monitoring of the distal esophagus [I 1. The present study evaluates the ability of the Nissen antireflux procedure to return the cardioesophageal sphincter to normal by comparing its competence in a group of symptomatic patients before and after surgery with normal volunteers who have never experienced symptoms of gastroesophageal reflux. Methods Thirty-one persons were submitted to esophageal manometry studies and twenty-four hour pH monitoring of the distal esophagus. Fifteen of these thirty-one persons formed the control group. They were asymptomatic volunteers who had no history of symptoms of gastroesophageal reflux, antacid therapy, or an upper gastrointestinal radiographic study for digestive symptoms. They were selected from the elective admissions to Tripler Army Medical Center for inguinal hernia repair or other nongastroenterologic illnesses. The sixteen remaining paGents made up the symptomatic group. They had typical symptoms of heartburn and regurgitation unresponsive to medical management and showed endoscopic or histologic evidence of esophagitis. Fourteen of the From the Departments of Surgery and Medicine, Tripler Army Medical Center, Honolulu, Hawaii. * Present address and address for reprint requests: Department of Surgery, The University of Chicago, 950 East 59th Street, Chicago, Illinois 60637. Presented at the Fifteenth Annual Meeting of the Society for Surgery of the Alimentary Tract, San Francisco, California, May 21 and 22, 1974.
94
sixteen patients had a hiatus hernia demonstrated on radiographic examination, and eight had radiographic evidence of gastroesophageal reflux. (Table I.) Each of the symptomatic patients was graded 011 a scale of 0 to 3 for each of the symptoms of heartburn and regurgitation. The grading was carried out prior to any objective study using a reflux questionnaire completed by one of the authors during an interview with the patient. The highest possible score that could be obtained was 6 and would represent a patient with heartburn that interfered with daily activities and episodes of pulmonary aspiration secondary to regurgitation. Both the control and symptomatic groups were compared as to the esophageal manometric values and the results of twenty-four hour pH monitoring of the distal esophagus. Each patient in the symptomatic group had a Nissen antireflux procedure, returned for postsurgical subjective evaluation on an average of four months after surgery, and was restudied with an upper gastrointestinal radiographic examination, esophageal manometry, and twenty-four hour pH monitoring of the distal esophagus. The results of the postsurgical studies were compared with those obtained preoperatively and with those in the control group. At postsurgical subjective evaluation, each patient was evaluated for the presence of reflux symptoms; the duration of postoperative dysphagia, that is, any subjective discomfort during swallowing; the need for dilatation; the ability to vomit and belch; and the presence of increased flatus, diarrhea, and periodic episodes of abdominal distention. Esophageal manometric studies were performed according to the technic of Winans and Harris (21, using a single catheter assembly consisting of three fluid-filled, perfused, polyethylene tubes bonded t.ogether with three distal 2 mm lateral openings placed 5 cm apart. The catheter was passed into the empty stomach and withdrawn in 1 cm increments back Into the esophagus and up to the cricopharyngeus high pressure zone. The distal esophageal sphincter (DES) pressure was measured as the difference in millimeters of mercury be-
The American .lournal of Suraerv
Nissen Antireflux
TABLE
I
Radiographic
Studies on Symptomatic
Before surgery After surgery * Excluding
patients
with
Patients ____
hiatal
14/16 O/16
Radiographic Reflux
Esophagus (cm)
__~~_____
8/16
50%
1.0 f
o*
0%
O/16
0%
4.0 It
1.3
-___
hernia.
Twenty-Four Hour pH Monitoring ____A
Component
Average Intra-Abdominal
81.5%
tween the resting end expiratory gastric pressure and distal esophageal sphincter pressure. The twenty-four hour pH monitoring of the distal esophagus was performed according to a technic that we have previeusly described [3]. It consists of positioning a pH electrode 5 cm above the distal esophageal sphincter previously located by manometry and placing a reference lead on the forearm. Both the pH probe and the reference lead are connected to a strip chart recorder running at 6 inches per hour for twenty-four hours. A normal diet is given during this period, unique only in the absence of food and beverages having a pH value of less than 5. All persons were given a pencil to mark on the strip chart recorder any subjective reflux symptoms that occurred as well as their body position, whether upright or supine. Reflux was defined as an esophageal pH of less than 4. From the twenty-four hour record, the per cent of time that the pH was less than 4 in the distal esophagus could be determined for the total twenty-four hour period and for the time spent in the upright and supine positions. Also, the total number of reflux episodes, the number of episodes five minutes or greater in duration, and the length of the longest reflux episode was obtained from the tracing. This gave six components from the twenty-four hour record in which each patient was measured. A numeric twenty-four hour pH score was calculated for each person and was used to compare the over-all results of the twenty-four hour pH monitoring test. TABLE II
___
Anatomic Hiatal Hernia
Studies
Procedure
Presurgical
Results Esophageal pH Monitoring. Table II shows the results of six different components measured from
the twenty-four hour record and the numeric twenty-four hour pH score. In column A, the preoperative results of the symptomatic patients are compared with those in the controls. Minimal reflux was observed in the normal control subjects in both the supine and upright positions; however, no record of symptoms associated with these reflux episodes was made on the strip chart recorder. Reflux rarely occurred during slumber and commonly occurred during and for a short period after alimentation but was cleared rapidly, with few episodes lasting longer than five minutes. The symptomatic patients had significantly more reflux than did the controls in all categories of the twenty-four hour pH record (p
of Distal Esophagus B Control
vs
Presurgical
vs
C
Postsurgical
Postsurgical
vs
Control
11.1 zt 4.6
1.5 f
1.4*
11.1 f: 4.6
0.2 f
11.3
f
6.4
2.3 f
2.0*
11.3 zk 6.4
0.2 xk 0.4*
0.2 zk 0.4
2.3 f- 2*
10.4
+
7.6
0.3 i
0.5*
10.4 f
7.6
0.1 f
0.1 f
0.3 f
Number of reflux episodes during 24 hr period Number of reflux episodes of 5 min or longer
63.5
zk 26.2
63.5 i
26.2
4.4 zk 8.8*
4.4 zk 8.8
0.0 f
*
0.0
Longest reflux episode (min)
28.9
zt 15.6
24 hr pH score
65.2
+
Per cent period Per cent period Per cent period
of pH of pH of pH
total 24 hr <4 upright <4 supine <4
7.8 =k 5.3
24.5
20.6
zt 14.8*
0.6 f
1.2*
3.9 =t 2.7* 12.0
f
4.7*
7.8 A. 5.3
0.3*
0.3*
0.2 *
0.3
0.3
1.5 It 1.4*
20.6 +
0.5 14.8*
0.6 h
1.2
28.9 f
15.6
0.6 f
1.4*
0.6 f
1.4
3.9 f
2.7*
65.2 f
24.5
6.7 f
1.8*
6.7 f
1.8
12.0 * -___
4.7*
* p < 0.001.
Volume 129, January 1975
95
DeMeester
and Johnson
40
3S
CONTROL vs. PK
pt.01
PRE vs. POST
p<.Ga
CONTROL vs POST pcOl I
I
D.E.S. PRESSURE
mm. Hg.
PRE 13.1’49
POST 26.7*8.0
Figure 1. Distal esophageal sphincter (DES) pressure in fitteen contra/ subjects and sixteen patients before and after the Nissen antirefkx procedure.
operative values (p
KX)
CONTROL vs. PRE
p<.Ol
90
PRE vs. POST
p<.Ol
6.
CONTROL vs. POST NS.
60 X OF DES BEUW
R.I.P. 5o 40. 30 20. IO.
RE 590t12.6 LENGTH OF DES.
50*1.2
439W2 49AOB
POW 64.3tl9.2 4.9il.O
(cm.1
Figure 2. Over-all kngth of the distal esophageal sphincter (DES) and the per cent located below respiratory inverskn point (RIP) in fifteen control subjects and sixteen patients before and after Nissen antireflux procedure.
96
position and the number of reflux episodes lasting five minutes or longer, the results remained the same as those in the controls. Esophageal Manometry. Sphincteric pressure (Figure 1): Preoperatively, the symptomatic patients had a distal esophageal sphincter pressure that was less than that of the controls (p
The American Journal of Surgery
Nissen Antireflux
29
1
Procedure
6 pt.02
CLINICAL 3 SCORE 2
25.V1.7
267*2.0
Figure 3. Esophageal length before and after Nissen antirefiux procedure, each of the sixteen patients serving as his own control.
dominal esophagus. the intra-abdominal 3.5 cm.
PRE
POST
Figure 4. Pre- and postsurgical changes in the clinical score. See text for explanation of score.
Postoperatively, the length of esophagus was increased to
Dysphagia (Figure 5): There was a 69 per cent incidence of dysphagia in the preoperative symptomatic patients. After the Nissen antireflux procedure this was increased to 87 per cent during the immediate postoperative period. If the patient experienced postoperative dysphagia, its average duration was sixty-two days. One patient required postoperative dilatation. All patients were free of dysphagia six months after surgery. Morbidity (Figure 6): After the Nissen antireflux procedure 57 per cent of the patients were unable to vomit, which was of minimal concern to most of them. Eighty-one per cent of the patients were able to belch after surgery. There was a temporary increase in the amount of flatus in 63 per cent of the patients and a 44 per cent incidence of temporary postoperative diarrhea. On specific questioning, 25 per cent of the patients reported episodes of mild abdominal distention after eating.
70 60
%
50 40
33 20
I I
ll_-_ E
IO INCIDENCE0
0
l-id
-iG
POST OP 6M3. PRE POST )P SURGERY PERIOD DILATATIONS POST Of?
Figure 5. The effect of the Ntssen antirefiux procedure on symptoms of dysphagia.
IOO-
90. 00. 70. 60. % INclENcE
Comments
The value obtained for each component of the twenty-four hour pH monitoring test after a Nissen antireflux procedure was significantly improved over the preoperative value. The Nissen antireflux procedure restored cardioesophageal competence in both the upright and supine positions, that is, in the upright position, the patient has the aid of gravity to prevent reflux and in the
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5040.
5 z
xl. ZQIO.
n
0 ABILITY VOMIT
TO ABILITY -IO UKREA‘XD BELCH FLATUS
lEhl=CRARY DlARRtiEf,
PBDOMINAL DISTENTION
Figure 6. The morbidity of the Nissen antirefiux procedure.
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supine position, the encouragement of gravity to effect reflux. We have recently shown that the number of reflux episodes that are of five minutes’ duration or greater are more significant in producing esophagitis than are those that cleared more rapidly [4]. It is pertinent, therefore, that the Nissen antireflux procedure significantly reduced the number of prolonged episodes of reflux to control values. Comparison of the postsurgical values with the control values indicates that the Nissen antireflux procedure significantly improved cardioesophageal competence over that observed in the control patients in four of the six components of the twenty-four hour study. In control subjects, reflux rarely occurs in the supine position; however, it does occur as a rule in the upright position during and for a short period after alimentation and is considered a normal physiologic phenomenon. The Nissen procedure interferes with this physiologic reflux by producing a supercompetent sphincter as indicated by the small amount of reflux in the upright position compared with that in the controls. There is strong evidence to suggest that distal esophageal sphincter pressure is a major deterrent to reflux. Distal esophageal sphincter pressure has been shown to be less than normal in patients with symptoms of reflux and in those in whom reflux has been determined objectively using the standard acid reflux test [2,Fi]. We have previously demonstrated that the incidence and severity of reflux lessened quantitatively with increasing distal esophageal sphincter pressure [5,6]. This would indicate that any surgical treatment that increased the distal esophageal sphincter pressure should be of benefit to the patient. The Nissen antireflux procedure increased the distal esophageal sphincter pressure to a height twice the preoperative levels and significantly greater than that in the control subjects. This was associated with less reflux than that in the control subjects in four components of the twenty-four hour pH record and further supports the finding that increasing sphincter pressure is a major deterrent to reflux. This rise in sphincter pressure is thought to occur when the lower esophagus is placed in the intra-abdominal position where it is in a positive pressure environment [ 71. The manometric studies showed that the Nissen procedure placed 20 per cent more of the sphincter in the positive pressure environment of the abdomen as opposed to that measured preoperatively. This resulted in an equal amount of distal esophageal sphincter being exposed to the positive pressure of the abdomen as that in the control subjects. On the basis of these
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findings, one would expect a rise in sphincter pressure to a level equal to that in the controls. Indeed, after procedures in which a similar amount of distal esophageal sphincter is anchored within the positive pressure environment of the abdomen and a gastric fundic wrap is not employed, namely, the Hill procedure, we have observed an increase in the sphincter pressure in fifteen patients from 15.3 f 5.5 to 19.8 f 5.8 mm Hg [I J. As can be seen, this is identical to that pressure obtained in the fifteen control subjects. (Figure 1.) The Nissen antireflux procedure, however, increased the sphincter pressure to a level significantly greater than that in the normal controls, This would suggest that the addition of a gastric fundic wrap causes an increase in the sphincter pressure over that pressure obtained by only placing the distal esophageal sphincter within the positive pressure environment, of the abdomen. It should be noted that the amount of distal esophageal sphincter exposed to the positive pressure environment of the abdomen on manometric studies is not identical to that observed on radiographic examination. (Figure 2 versus Table I.) Preoperatively in the presence of a hiatal hernia and therefore without a radiographic intra-abdominal segment of esophagus, an average of 44 per cent or 2.2 cm of the distal esophageal sphincter was exposed to a positive environment. (Figure 2.) This would indicate that the hernial sac allows transmission of positive abdominal pressure up to its insertion around the cardioesophageal junction. Based on manometric studies, the Nissen procedure placed 64 per cent, or 3.2 cm, of the distal esophageal sphincter in the positive pressure environment of the abdomen. Radiographically, however, the Nissen procedure produced an average of 4 cm of esophagus below the diaphragm. When the hernial sac is reduced and an antireflux repair carried out, the creation of a 4 cm intra-abdominal esophagus results in the placement of only an additional 1 cm of distal esophageal sphincter in a functional positive pressure environment. It is also probable that the transmitted positive pressure in the hernial sac is less than the positive pressure in the abdomen and that surgery places that portion of the distal esophageal sphincter exposed t.o positive pressure in an area of stronger positive pressure than that of the hernial sac (81. This stronger positive pressure environment would account for the increase in resting distal esophageal sphincter pressure which is further increased if the intraabdominal portion of the esophagus is buttressed by a gastric fundic wrap so that gastric pressure
The American
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Nissen Antireflux Procedure
can be applied directly to the distal esophageal sphincter. The importance of exposing a portion of the distal esophageal sphincter to the positive pressure of the abdomen has been pointed out by Nagler and Spiro [9]. They have shown that as intragastric pressure rises, the resting pressure of the intraabdominal segment of the distal esophageal sphincter (below the respiratory inversion point) also rises to maintain a pressure gradient between the sphincter and the gastric fundus. The intrathoracic segment of the distal esophageal sphincter (above the respiratory inversion point) is not affected by the increase in intragastric pressure so that the gradient between the intrathoracic portion of the distal esophageal sphincter and the gastric fundus is diminished or lost entirely when extrinsic pressure is applied to the abdomen. They have further noted that intragastric pressure is generally elevated during pregnancy, but all pregnant women do not have gastroesophageal reflux. Those in whom it can be demonstrated invariably fail to show an intra-abdominal segment of the distal esophageal sphincter. After delivery, the intra-abdominal segment reappears and reflux is not demonstrated. Certainly the findings that the symptomatic preoperative patients had signficantly less distal esophageal sphincter exposed to the positive pressure environment of the abdomen than did the asymptomatic control subjects and that the Nissen antireflux procedure corrected this condition and reduced concomitantly the amount of reflux support the concept that as the amount of distal esophageal sphincter located within the intra-abdominal positive pressure environment increases, the effectiveness of the distal esophageal sphincter as a barrier against acid reflux increases. Sixty-nine per cent of the symptomatic patients demonstrated some degree of dysphagia preoperatively. This was aggravated significantly by the Nissen antireflux repair during the immediate postoperative period. This dysphagia was unrelated to the degree and duration of relaxation of the distal esophageal sphincter since both the postsurgical patient and the normal control subject relaxed equally. Dodds and associates [IO] have shown a 1 cm or more oral movement of radiographic markers in the distal esophagus with peristalsis as the esophagus shortens to dilate and engulf a passing bolus. It is pertinent that the Nissen procedure significantly increased the length of the esophagus by 1.6 cm. (Figure 3.) The degree of dysphagia post repair may be related to this stretching of the esophagus rather than to too vig-
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orous approximation of the crura. This stretching of the esophagus may limit the amount of orad extension of the distal esophagus during peristalsis, thus making it difficult for the esophagus to dilate and accept a bolus of food and giving rise to the symptoms of dysphagia that the patients experienced after the repair. When the tissues were able to accommodate to the new length, symptoms of dysphagia should have disappeared. This, indeed, was the case as all patients were free of dysphagia after six months. The most significant morbidity of the Nissen procedure is the inability of 57 per cent of the patients to vomit after repair. Only a few patients considered this to be a distinct disadvantage. Sixty-three per cent of the patients noted an increase in flatus after the operative repair. We believe that this increase in flatus is secondary to the marked aerophagia that a significant number of the preoperative patients demonstrated. When this habit was broken postoperatively, the amount of flatus decreased. Conclusions The Nissen antireflux procedure appears to control gastroesophageal reflux as measured subjectively on the basis of symptoms or objectively using twenty-four hour pH monitoring of the distal esophagus. Postsurgical patients had less reflux than did asymptomatic control subjects, indicating that the Nissen procedure interferes with physiologic reflux. Surgery produces a competent cardioesophageal sphincter by increasing the amount of distal esophageal sphincter exposed to the positive pressure environment of the abdomen and increasing its resting pressure. This was accomplished with a low morbidity but with temporary, mild, postoperative dysphagia and a 43 per cent chance of being able to vomit after the repair. Summary Fifteen normal volunteers without symptoms of gastroesophageal reflux and sixteen patients with symptoms of gastroesophageal reflux unresponsive to medical management and having endoscopic esophagitis had esophageal manometry and twenty-four hour pH monitoring of the distal esophagus. The symptomatic patients underwent a Nissen antireflux procedure and were restudied at four months. After surgery, patients had less reflux, a higher sphincteric pressure, and an equal amount of sphincter within the abdomen as did asymptomatic control subjects.
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References 1. DeMeester TR. Johnson LF, Kent AH: Evaluation of current operation for the prevention of gastroesophageal reflux. Ann Surg 180: 511, 1974. 2. Winans CS, Harris LD: Quantitation of the lower esophageal sphincter competence. Gasfroenterology 52: 779, 1967. 3. Johnson LF, De&rester TR: Twenty-four hour pH monitoring of the distal esophagus: a quantitative measure of gastroesophageal reflux. Am J Gasfroenterol in press. 4. Johnson LF, DeMeester TR, Haggitt RC: Esophageal histology correlated to objective measure of gastroesophageal reflux (abstract). Gastroenterology 66: A-70, 1974. 5. Thurer RL, DeMeester TR, Johnson LF: Distal esophageal sphincter and its relationship to gastroesophageal reflux. J
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Surg Res 16: 418,1974. 6. Johnson LF, DeMeester TR: Advantage of distal esophageal 24-hour pH monitoring over other tests for gastroesophageal reflux (abstract). Gasfroenterology 66: A-70, 1974. 7. Mustard RA: A survey of techniques and results of hiatus hernia repair. Surg Gynecol Obstet 130: 13 1, 1970. 8. Moosa AR, Cooley GR, Skinner DB: lntraluminal and intraperitoneal pressures at the cardia: effects of hormones and surgical intervention. Surg Forum 24: 372, 1973. 9. Nagler R. Spiro HM: Experimental response of the inferior esophageal sphincter to elevated intragastric pressure. Gastroenterology 40: 405, 196 1. 10. Dodds WJ, Stewart ET, Hodges D, Zboralske FF: Movement of the feline esophagus associated with respiration and peristalsis. J C/in invest 52: 1, 1973.
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