CASE REPORTS MUCOSAL DIAPHRAGM OF THE GASTRIC ANTRUM

GASTROENTEROLOGY Copyright 1967 by The Williams & Wilkins Co. Vo!' 52, No.6 Printed in U.S.A. CASE REPORTS MUCOSAL DIAPHRAGM OF THE GASTRIC ANTRUM PETERA. BANKS, M.D., JEROME D. WAYE, M.D., ALBERTM. WAITMAN, M.D., AND ALBERT CORNELL, M.D. Division of Gastroenterology, Department of Medicine, The Mount Sinai Hospital, New York, New York A mucosal diaphragm obstructing the gastric antrum has been reported previously in only 12 adults. 1-12 The diaphragm has been described as a thin, membranous septum projecting into the lumen of the antrum perpendicular to its longitudinal axis. In each case it has been composed of two surfaces of mucosa separated by submucosa. In all instances a small aperture located at or near the center of the septum has been the only channel for gastric contents to pass from proximal antrum to the pylorus. The origin of this membrane is not clear. We would like to report the 13th case, and present clinical and pathological evidence that supports a congenital basis for this condition. A comparison will be made between antral mucosal diaphragms and those located at the pylorus. Case Report F. L., a 62-year-old white woman, gave a 12- year history of epigastric pain and nausea occurring after large meals and relieved by forced vomiting. Each episode was treated symptomatically with a variety of antacids, diets, sedatives, and antiemetics. Relief with these measures was not striking, but the symptoms usually subsided within a few days. Between episodes, she enjoyed relatively good health, sometimes for periods of several months, and in one instance for an interval of 3 years. However, even in these Received December 28, 1966. Accepted January 25, 1967. Address requests for reprints to: Dr. Peter A. Banks, Division of Gastroenterology, The Mount Sinai Hospital, 11 East 100th Street, New York, New York 10029. periods, large meals consistently produced a bloated sensation in the epigastrium. Physical examination and routine laboratory studies were consistently normal. Numerous upper gastrointestinal X-ray series revealed a smooth antral contraction thought to be consistent with an inflammatory process or spasm. Evidence of gastric retention was occasionally found. Because of the increasing frequency and severity of symptoms, her X-ray studies were reviewed in September 1965. A constant linear defect was seen in the distal antrum, which suggested the possibility of a mucosal diaphragm (fig. 1). Gastroscopy was then performed. A tiny oval aperture was identified in the distal antrum, which provided the only egress from the stomach. The size of this opening remained constant throughout the period of observation. The mucosa surrounding this aperture appeared normal, save for a tiny erosion which was not present 1 week later. There were no inflammatory changes in the mucosa proximal to the aperture. The gastroscopic findings were consistent with a diaphragm occluding the antrum. The patient initially refused surgery, but because of increased discomfort requested an operation in April 1966. By this time she was vomiting after every meal, and even baby food was unable to pass freely. On physical examination, the only positive findings were minimal tenderness in the epigastrium and the presence of a succussion splash. Laboratory evaluation was completely normal. At laparotomy, the duodenal bulb was normal. The serosal aspect of the stomach suggested moderate gastric dilation. At first, no abnormality could be palpated in the antrum, but the aperture of the diaphragm was then felt between the surgeon's fingers. An antrectomy and Billroth I gastroduodenostomy were performed. The specimen was opened along the greater 1003

IOO:! CASE REPORTS Vol. 52, No.6 FIG. 1. Upper gastrointestinal roentgenogram performed in February 1960. The linear defect of the diaphragm remains unchanged, as a normal peristaltic wave approaches it from the proximal antrum. The portion of the antrum distal to the diaphragm distends fully. In other views the pyloric channel is seen to enter the bulb symmetrically, and the duodenal bulb distends fully. curvature of the antrum (fig. 2). A thin, membranous septum was seen approximately 2 em from the pylorus. There was no ulceration or fibrosis. The lumen of the diaphragm consisted of an aperture that was almost pinpoint in size, measuring only 2 mm in diameter. A thin probe could be introduced through this opening to the prepyloric region and the pylorus. The mucosa proximal to the diaphragm did not appear dilated or inflamed. When the diaphragm was incised, it contracted and collapsed into the surrounding antral tissue, making it impossible to obtain a histological section that demonstrated the projecting ridge of the diaphragm (fig. 3A). A higher magnification of the collapsed diaphragm is shown in figure 3B. Histologically, the diaphragm was covered with normal gastric mucosa on both sides. The submucosa was devoid of inflammatory cells and fibrosis. The only significant finding was a slightly hypertrophied muscularis mucosa. These findings were consistent with a congenital antral diaphragm. The patient made an uneventful recovery and has been asymptomatic, eating a normal diet and gaining weight. Discussion This is the 13th case of an antral mucosal diaphragm reported in an adult. 1-12 Seven have occurred among women, ages 29 to 74 years (average age, 49) ; 6 among men, ages 32 to 70 (average age, 57). In all but 1 patient the classical symptom has been epigastric discomfort or pain after eating relieved by vomiting. Antacids and bland food have characteristically been ineffective in relieving the discomfort. Several patients found they could tolerate a liquid diet at a time when food, and especially large portions, caused discomfort. Physical examination was in general unrevealing, save for an occasional patient with loss of weight and others with either abdominal tenderness or a succussion splash in the epigastrium. Symptoms recurred intermittently, with variable periods of well-being interspersed with days or weeks of disability. Most patients were symptomatic for a total of 3 to 10 years be-

June 1967 CASE REPORTS 1005 fore the correct diagnosis was made, one for as little as 4 months,5 and another as long as 20 years.12 Despite the chronicity of the disorder, complications have been rare. Three patients have had gastric ulcers probably due to stasis of gastric contents ;1, 3, 6 one of these developed significant gastrointestinal bleeding. 1 One patient became dehydrated from persistent vomiting. 12 No other congenital anomalies have been reported. The only related condition has been a duodenal ulcer in 1 patient. 6 A preoperative X-ray diagnosis of antral diaphragm was reported in 9 of the 12 patients who have come to surgery. The diaphragm was described as a linear, knifelike defect in the antrum, which persisted in all projections. Usually, the segment of antrum between diaphragm and pylorus filled completely. A "double bulb" effect was thereby produced, one "bulb" consisting of the outpouching of the distal antrum between the constriction of the diaphragm proximally and the pyloric channel distally; the other, the normal duodenal bulb. In 3 instances the diaphragm was not diagnosed prior to surgery; it was, however, clearly present on the preoperative barium study.l, 5, 6 The correct diagnosis was made in these patients either at the time of surgery or when the surgical specimen was opened. Although the primary symptoms have been related to obstruction, in only 5 patients was there radiological evidence of gastric retention, as shown either by the presence of gastric FIG. 2. Surgical specimen. The antrum has been opened along its greater curvature. The incised edges of the greater curvature are reflected back and are displayed along the top and bottom of the photograph. The proximal edge of the specimen is at the right. The pylorus is hidden beneath the membranous diaphragm at the left. The aperture of the diaphragm is 2 mm in diameter. FIG. 3A. Photomicrograph of a section through the antrum. The contracted antral diaphragm is seen projecting slightly from the wall of the antrum.

LUUo CAl:3JiJ HJiJJ'UH'l 'l:3 Vol. 52, No. 0 FIG. 3B. Higher magnification of the mucosa of the antral diaphragm shown in figure 3A. Normal histological details are seen (H & E, X 100). secretions in the stomach or by retention of barium for prolonged periods. Even in these instances peristalsis was normal, and there was no discernible delay of barium through the diaphragm. Gastroscopy has been performed in 3 patients. In one,7 the septum was not visualized; in the case described by Sokol et aly and the present one, it was clearly seen and appeared to be composed of normal mucosa. At the time of surgery, the stomach appeared somewhat dilated in several patients. In only 1 instance could the site of the diaphragm be anticipated by the presence of a circumferential depression of the serosa. 1 The diaphragm was usually located 1.5 to 2.5 cm proximal to the pylorus; in 1 instance it was 4 cm 5 and in another, 7 cm proximal to it.4 The thickness was estimated as 2 to 3 mm in 1 case 2 and 4 mm in another.4 The aperture varied from 1 mm to 1 cm in diameter, with the majority 1 to 3 mm. The aperture could usually be dilated a few additional millimeters. The procedures that have been performed have included simple excision of the diaphragm in 1 patient,9 partial gastrectomy in 6, and pyloroplasty with excision of the diaphragm in 5. All patients showed complete remission of symptoms after surgery. The gross appearance of the diaphragm has been well described. There is general agreement that the diaphragm is a soft, thin membrane, somewhat pliable when indented by a finger, but resisting marked distortion. 2, 4, 6, 7, 11 Evidence of fibrosis and ulceration has invariably been absent. An occasional patient has shown slight inflammation of the margin of the aperture, thought to be due to stasis of gastric content.! The histological appearances of the diaphragm have not been described in detail. All authors agree that the diaphragm is composed of two surfaces of mucosa enclosing a layer of submucosa and at times muscularis mucosae, and that the muscular coat of the stomach does not participate in the structure of the diaphragm. In the reports in which photomicrographs have been shown, no ulceration or fibrosis of the diaphragm was seen, and normal histological findings were described. 7, 9, 10 When histological features were described but not shown, the diaphragm was thought to contain normal mucosa and submucosa in 1

June 1967 CASE REPORTS 1007 case;1 the submucosa was thought to contain dense collagenous tissue without appreciable inflammatory reaction in another;4 and features suggesting chronic inflammation were described in a third.12 There is considerable evidence that the diaphragm is not a result of peptic ulcer disease. A history suggestive of peptic ulcer disease is conspicuously absent in all but the 1 patient who was found to have both a duodenal ulcer and an antral diaphragm. Clinically, the symptoms are those of obstruction and do not respond to an antacid program. Furthermore, barium studies and surgical palpation have consistently shown a normal duodenal bulb in all but the 1 p atient in whom the two conditions coexisted. Finally, examination of the diaphragm has in general shown no fibrosis or significant inflammatory changes. For these reasons, most authors have favored a congenital origin for this condition. The development of the diaphragm may take place in the fifth or sixth week of embryological life. 13 At t his time the epithelium of the intestine proliferates actively, transforming the patent lumen into a solid core. Normally, vacuoles then appear which coalesce, thus restoring a tubular structure. Should coalescence be incomplete, a diaphragm would then remain. If this explanation is correct, t he location of the diaphragm would be subject to change from patient to patient. Some variation of position in the antrum has already been described. Moreover, there are in addition 20 case reports of mucosal diaphragm located at the pylorus in adults.6, 14-22 Half of these patients displayed symptoms of obstruction throughout their period of medical supervision. Among these patients the diaphragm was thought to show normal histological features in some,15, 16 but to have an increase in fibrous tissue and lymphocytic infiltration in another.14 The remaining half of the patients displayed symptoms suggestive of peptic ulcer disease. Among these, the diaphragm was described as inflammatory in many,6, 17, 20 and normal in another.19 It would appear that the patients with mucosal diaghragm at the pylorus represented a mixed population; in some it Was congenital in origin and in others related to peptic ulcer disease. The importance of this mixed group of patients is that the complication rate was high (9 had associated gastric ulcers, and several were dehydrated). Furthermore, the proximity of the diaphragm to the pylorus prevented its visualization on barium studies; as a result surgery was usually performed for gastric obstruction of unknown cause. Even after the diaphragm had been diagnosed at surgery, its presence could not be detected on retrospective study of preoperative X-rays. If this defect in the antrum or pylorus is congenital in origin, it should produce symptoms early in life in some instances. To date, in the pediatric population, 4 patients with a diaphragm located in the antrum and 15 with its location at the pylorus have been reported. 23 It should also be mentioned that there have been at least 100 reports of congenital duodenal diaphragm in the pediatric population and 15 among adults. 24 It is not completely clear why many patients do not have symptoms until adult life. It is possible that the aperture gradually narrows and becomes less distensible as part of the aging process. Also, with advancing years, food may not be chewed as thoroughly. In at least 2 instances, obstructive symptoms started with the removal of teeth ;15, 18 in 1 patient,15 the histological evaluation suggested a congenital diaphragm. Surgical treatment has cured all patients with an antral diaphragm and most of those with a pyloric diaphragm. Antral diaphragms are in general amenable to simple excision. A pyloroplasty can be included to insure patency by extending the longitudinal incision across the pylorus and closing the incision transversely. The diaphragm located at the pylorus is best treated by gastric resection and vagotomy, since many appear to be caused by peptic ulcer disease. Summary The 13th case of antral mucosal diaphragm in an adult is reported. Clinical and pathological features are described which suggest that the defect may be congenital in origin. The 20 instances of mucosal diaphragm located at the pylorus are discusf>ed.

1008 CASE REPORTS Vol. 52, No. (] Some appear to be congenital in origin, and others secondary to peptic ulcer disease. Suggestions are made concerning diagnosis and treatment of this condition. REFERENCES 1. Sames, C. P. 1949. A case of partial atresia of the pyloric antrum due to a mucosal diaphragm of doubtful origin. Brit. J. Surg. 37: 244-246. 2. Gross, K. E., and M. W. Durham. 1953. Pyloric antral mucosal diaphragm. Radiology 61: 368-372. 3. Albot, G., and F. Magnier. 1955. Mucosal diaphragm of pyloric antrum. Arch. Mal. Appar. Dig. 44: 1162-1166. 4. Swartz, W. T., and R D. Shepard. 1956. Congenital mucosal diaphragm of pyloric antrum. J. Kentucky Med. Assn. 54: 150-161. 5. Bariety, M., J. Poulet, and M. Courtois Suffit. 1957. Diaphragme muqueux prepylorique et cancer bronchique primitif. Presse Med. 65: 785-787. 6. Rhind, J. A. 1959. Mucosal stenosis of pylorus. Brit. J. Surg. 46: 534-540. 7. Rowling, J. T. 1959. The prepyloric septum; a rare anomaly. Brit. J. Surg. 47: 162-166. 8. Popesco-Urluieni, M., L. Bacalou, and S. Mayer. 1962. Syndrome du diaphragme muqueux antro-pylorique. Arch. Mal. Appar. Dig. 51: 1535-1541. 9. Munro, A. 1. 1963. Prepyloric mucosal diaphragm. Brit. J. Surg. 50: 981-982. 10. Browning, R W. 1964. Prepyloric antral mucosal diaphragm or "web." Amer. Surg. 30: 73-76. 11. Sokol, E. M., M. A. Shorofsky, and J. L. Werther. 1965. Mucosal diaphragm of the gastric antrum. Bull. Gastroint. Endosc. 12: 20-21. 12. Schwartz, 1. R, E. Hirsch, J. E. Mule, and L. Bluestone. 1966. Antral mucosal diaphragm; clinical and roentgen characteristics, with first reported case of vibrio fetus in human bile. Amer. J. Gastroent. 45: 366-373. 13. Patten, B. M. 1953. Human embryology, p. 474. The Blakiston Company, Inc., Division of McGraw-Hill Book Company, Inc., New York. 14. Rota, A. N. 1953. Pyloric obstruction due to mucosal diaphragm. Arch. Path. 55: 223-226. 15. Passalacqua, L. A., and C. A. Romero. 1955. Partial obstruction of the pylorus due to a mucosal diaphragm of congenital origin. Bol. Asoc. Med. P. Rico 47: 211-215. 16. Chamberlain, D., and N. V. Addison. 1959. Adult pyloric obstruction due to a mucosal diaphragm. Brit. Med. J. 2: 1381-1384. 17. Spencer, S. L. 1961. Adult pyloric obstruction due to a mucosal diaphragm. Med. J. Aust. 48: 816-817. 18. Young, H. B. 1961. Addisonian pigmentation due to extreme pyloric stenosis by a mucosal diaphragm. Brit. J. Surg. 49: 104-107. 19. Kenny, P. J. 1962. The adult pyloric diaphragm. Aust. New Zeal. J. Surg. 32: 270-273. 20. Stahl, W. M., Jr. 1963. Unusual pyloric obstruction in an adult. J. A. M. A. 186: 1173-1175. 21. Bergeron, A., and G. Bourdeix. 1963. Stenose du pylore par diaphragme muqueux. Arch. Mal. Appar. Dig. 52: 575-580. 22. Pulsifer, L., F. L. Jedd, and T. F. Van Zandt. 1965. Pyloric obstruction by a mucosal diaphragm. Amer. J. Gastroent. 43: 30-34. 23. Gerber, B. C. 1965. Prepyloric diaphragm, an unusual abnormality. Arch. Surg. (Chicago) 90: 472-480. 24. Kazmers, N. 1966. Duodenal diaphragm in the adult. Amer. J. Gastroent. 45: 342-347.