21 - Congenital Anomalies

Congenital Anomalies #

Congenital anomalies of the pyloric region of the stomach are rare (Thompson et al. l968; Lamesch and Schneider l973; Korber and Glasson l977). The cause is usually thought to be localized vascular impairment occurring during foetal life (Bremer l944; Louw l959).

Pyloric Atresia #

Almost all cases of gastric atresia occur in the pyloric region (Franken l982). The condition may present as a membrane occluding the lumen, as a gap in continuity, or a fibrous cord intervening between patent portions at the gastroduodenal junction. Some cases have been associated with epidermolysis bullosa (Korber and Glasson l977; Franken l982). Clinically the condition presents as upper abdominal distension in a newborn infant, with bile-free vomiting from birth (Davis and Douglas l961; Thompson et al. l968; Bronsther et al. l97l). Maternal hydramnios occurs in approximately 50 percent of cases (Thompson et al. l968; Bronsther et al. l97l).

Radiographic examination shows the stomach to be distended, with complete absence of gas in the remainder of the gastrointestinal tract. In the erect abdominal film this gives rise to a single air-fluid level in the stomach, topped by a gas bubble (the "single bubble" sign) (Davis & Douglas l961; Becker et al. l963; Bronsther et al. l97l). According to Franken (l982) neonatal gastric hypotonia, which is a much more frequent condition, may give a similar appearance. (In hypotonia gastric inactivity with lack of peristalsis and cyclical contraction of the pyloric sphincteric cylinder may delay gastric emptying as described in Chapter l9).

Discussion #

Gastric atresia usually affects the region of the pyloric sphincteric cylinder; whether it is limited to the cylinder is not known.

References #

  1. Becker JM, Schneider KM, Fischer AE. Pyloric atresia. Arch Surg l963, 87, 413-416.
  2. Bremer JL. Diverticula and duplications of the intestinal tract. Arch Path l944, 38, 132-140.
  3. Bronsther B, Nadeau MR, Abrams MW. Congenital pyloric atresia: a report of three cases and a review of the literature. Surgery l97l, 69, 130-136.
  4. Davis DA, Douglas KR. Congenital pyloric atresia, a rare anomaly. Ann Surg l96l, 153, 418-422.
  5. Franken EA. Gastrointestinal Imaging in Pediatrics. Harper and Row, Philadelphia l982, 2nd ed, p 138.
  6. Korber JS, Glasson MJ. Pyloric atresia associated with epidermolysis bullosa. J Pediatr l977, 90, 600-601.
  7. Lamesch A, Schneider H. Atr‚sie et st‚nose congenitales du pylore. Acta Paed Belgica l973, 27, 169-183.
  8. Louw JH. Congenital intestinal atresia and stenosis in the newborn; observations on its pathogenesis and treatment. Ann Roy Coll Surg l959, 25, 209- 234.
  9. Thompson NW, Parker W, Schwartz S, et al. Congenital pyloric atresia. Arch Surg l968, 97, 792-796.

Duplications #

True or complete duplication of the stomach or any other entire region of the gastrointestinal tract is exceedingly rare. More common (but also rare) incomplete duplications may be defined as spherical or tubular enteric formations which lie in contiguity with the normal alimentary tract and which share with it a common blood supply, and usually a common muscle coat (Abrami and Dennison l961). These cyst-like structures, or duplication cysts, usually do not communicate with the normal lumen. They may have a mucosal lining and may be pedunculated (Kammerer l969). They may occur along the entire alimentary tract, the most common site being the ileum and the least common the stomach (Abrami and Dennison l961; Kremer et al. l970). Over a 21 year period Sieber (l956) encountered 25 cases of gastrointestinal tract duplications, only 4 of which involved the stomach. Duplications of the pyloric region are particularly rare (Grosfeld et al. l970).

Duplication cyst of the stomach is a communicating or non-communicating cyst lined by gastric, intestinal or pancreatic epithelium, and usually located along the greater curvature (Kremer et al. l970). Occasionally it may be situated in the wall of the pyloric region; in such cases encroachment on the lumen may produce gastric outlet obstruction (Grosfeld et al. l970), or an appearance resembling infantile hypertrophic pyloric stenosis (Abrami and Dennison l96l; Kammerer l969). In non-communicating duplication cysts accumulation of acid and pepsin may produce a local inflammatory reaction, perforation, abscess formation and peritonitis; this was seen in 6 of 9 patients described by Kremer et al. (l970).

Discussion #

Gastric duplication does not appear to be related anatomically to the pyloric sphincteric cylinder.

References #

  1. Abrami G, Dennison WM. Duplication of the stomach. Surgery l96l, 49, 794-801.
  2. Grosfeld JL, Boles ET, Reiner C. Duplication of pylorus in the newborn: a rare cause of gastric outlet obstruction. J Ped Surg l970, 5, 365-369.
  3. Grosfeld JL, O'Neill JA, Clatworthy HW. Enteric duplications in infancy and childhood: an l8 year review. Ann Surg l970, 172, 83-90.
  4. Kammerer GT. Duplication of stomach resembling hypertrophic pyloric stenosis. J Amer Med Assoc l969, 207, 2101-2102.
  5. Kremer RM, Lepoff RB, Izant RJ. Duplication of the stomach. J Pediat Surg l970, 5, 360-364.
  6. Sieber WK. Alimentary tract duplications. Arch Surg l956, 73, 383- 392.

Congenital Double Pylorus #

Congenital double pylorus is an extremely rare condition. In reviewing their cases of gastro-intestinal duplications encountered over an l8 year period, Grosfeld et al. (l970) did not mention a single example of this anomaly. A case was reported by Christien et al (l97l), but subsequently doubt was expressed as to the congenital nature of the lesion (Hansen et al. l972). Acquired double pylorus, due to pyloroduodenal fistula, is not nearly as rare and is a well documented condition (Chap. 31).

Sufian et al. (l977) described a case which appears to be of true congenital origin. It concerned a 30 year old female with a long history of epigastric pain and aspirin and ethanol abuse. The radiological examination revealed two pyloric apertures; gastroscopy failed to show any abnormality. Although no evidence of active or previous ulceration was found at operation, a partial gastrectomy was performed. The resection specimen revealed a second pyloric opening 2.0 cm in length and 1.0cm in diameter, adjacent to the normal pylorus. The mucosa and muscularis mucosae of both apertures were normal, but a nodule of ectopic pancreatic tissue was situated in the wall of the second opening.

Gupta and Hollander (l977) described a case of achalasia of the oesophagus occurring in a 56 year old female. During endoscopic examination a double pyloric aperture was an unexpected finding. There was no evidence of peptic ulcer disease and it was considered to be a case of double pylorus of congenital origin.

Williams et al. (l98l) mentioned the case of a 35 year old male who had had duodenal ulcer symptoms for 5 years. Endoscopy showed a duodenal ulcer and a double pylorus proximal to the ulcer. At operation a septum between the 2 apertures was excised. It was composed of normal mucosa with a complete ring of muscularis mucosae, and the case was considered to be a double pylorus of congenital origin.

Discussion #

Congenital double pylorus is extremely rare and cases have not been encountered by us. Acquired double pylorus due to pyloroduodenal fistula is much less rare and is well documented.

References #

  1. Christien G, Branthomme J, Volny L, et al. Pylore double: malformation congénitale. Sem Hôp Paris l97l, 47, 1485-1488.
  2. Grosfeld JL, O'Neill JA, Clatworthy HW. Enteric duplications in infancy and childhood: an l8 year review. Ann Surg l970, l72, 83-90.
  3. Gupta A, Hollander D. Duplication of the pylorus found concomitantly with achalasia: congenital or peptic etiology? Amer J Dig Dis l977, 22, 829-830.
  4. Hansen HO, Kronborg O, Pedersen T. The double pylorus. Scand J Gastroenterol l972, 7, 695-696.
  5. Sufian S, Ominsky S, Matsumoto T. Congenital double pylorus: a case report and review of the literature. Gastroenterology l977, 73, 154-157.
  6. Williams RS, Gilmore IT, Johnson AG. Congenital double pylorus: a case report. Brit J Surg l98l, 68, 65.

Pyloric Membrane, Web or Diaphragm #

Pyloric membrane, web or diaphragm has been defined as a thin, circumferential mucosal septum in the pyloric region, projecting intraluminally perpendicular to the long axis of the "antrum". It is composed of two layers of gastric mucosa, with a central core of submucosa and muscularis mucosae; the external muscular and serous coats do not take part in its formation. In the majority of cases a central or eccentric aperture is present, varying from a pinhole to several millimeters in diameter; in a few cases the membrane was unperforated or complete (Rowling l959; Melamed et al. l960; Gerber l965; Parrish et al. l968; Felson et al. l969; Bell et al. l977; Mitchell et al. l979; Jinkins et al. l980).

Pyloric membrane is generally regarded as a congenital anomaly. It is usually associated with symptoms and signs of gastric outlet obstruction. In incomplete membranes symptoms may only occur in adult life, the aperture preventing obstruction for many years (Cremin l969; Jinkins et al. l980). The condition has been described in premature and newborn infants, in older infants and children (Touroff and Sussman l940; Gerber l965; Farman et al. l968; Cremin l969; Bell et al. l977; Fujioka et al. l980; Jinkins et al. l980), and in adults (Farman et al l968; Felson et al l969; Melamed et al l960; Ghent and Denton l974; Ghahremani l974), the ages in adults ranging from 32 to 85 years.

A typical radiographic sign is a radiolucent line 2.0 to 3.0 mm in width, perpendicular to the long axis of the "antrum", representing the membrane (Felson et al. l969). The region between the membrane and the pyloric aperture may be filled with barium, resembling the duodenal bulb; the "double-bulb" appearance is another chracteristic sign (Parrish et al. l968; Felson et al. l969; Bell et al. l977).

In the great majority of cases described in the literature, the membrane was located 1.0 to 4.0 cm proximal to the pyloric aperture; it could perhaps best be designated a "prepyloric" membrane in these cases (vide infra). In a few instances it was very close to, or at the pylorus ("true pyloric membrane"); one case of Rowling (l959), one of Dineen and Redo (l963), one of Gerber (l965), two of Felson et al. (l969) and one of Mitchell (l979) fall into this category. In isolated instances (one case of Felson et al., and one of Ghahremani), a membrane was seen 7.0cm proximal to the pylorus.

In the prepyloric category, the distance of the membrane from the pyloric aperture varied from 1.0 to 2.0 cm in children (Bell et al. l978), and from 1.5 to 4.5 cm in adults (Ghahremani l974). The majority of membranes in adults were located at a distance of 1.5 to 4.0 cm from the pylorus (Rowling l959; Melamed et al. l960; Parrish l968; Cremin l969; Felson et al. l969; Ghahremani l974; Bell et al. l977; Mitchell et al. l979; Jinkins et al. l980).

Discussion #

We have not encountered reports in which the prepyloric membrane was described in relation to the pyloric sphincteric cylinder. However, in many descriptions and their accompanying illustrations, it was noted that the prepyloric membrane occurred in the location of the left pyloric loop. This is especially well demonstrated in illustrations accompanying the case report of Rowling (l959), that of Melamed et al (l960), the 3 cases of Parrish et al. (l968), the 2 of Cremin (l969), the one of Ghent and Denton (l974), most of the 10 cases of Bell et al. (l977), the 2 cases of Fujioka et al (l980) and the 4 of Jinkins et al. (l980). It appears to us (but it has not been proved) that, in the majority of cases, the prepyloric mucosal membrane occurs on the luminal aspect of the left pyloric loop of the muscularis externa, in the same way as the mucosal and submucosal parts of the pyloric ring are located on the luminal aspect of the right pyloric loop (to form the pyloric ring). It is interesting to note that Parrish et al. (l968) found a definite thickening in the muscularis externa underlying the membrane in one of their cases; this could conceivably be due to the left loop.

Fujioka et al. (l980) also reported 2 cases of pseudowebs, in whom radiographic examination had shown typical signs of prepyloric membranes; at operation and endoscopy no abnormality was found. In these cases the "webs" were probably caused by prominent, circular mucosal folds. It should be possible to differentiate permanent webs from circular mucosal folds by the characteristic movements and change in position of the folds during contraction of the sphincteric cylinder, as discussed in Chapters 2 and 13. However, a circular mucosal fold may occasionally be permanent, simulating a web (Chap. 28).

References #

  1. Bell MJ, Ternberg JL, McAlister W, et al. Antral diaphragm: cause of gastric outlet obstruction in infants and children. J Pediatr l977, 90, 196- 202.
  2. Bell MJ, Ternberg JL, Keating JP, et al. Prepyloric gastric antral web: a puzzling epidemic. J Pediat Surg l978, 13, 307-313.
  3. Cremin BJ. Congenital pyloric antral membranes in infancy. Radiology l969, 92, 509-512.
  4. Dineen JP, Redo SF. Pyloric obstruction due to mucosal diaphragm. Surgery l963, 53, 674-676.
  5. Farman J, Cywes S, Werbeloff L. Pyloric mucosal diaphragms. Clin Rad l968, l9, 95-99.
  6. Felson B, Berkmen YM, Hoyumpa M. Gastric mucosal diaphragm. Radiology l969, 92, 513-517.
  7. Fujioka M, Fisher S, Young LW. Pseudoweb of the gastric antrum in infants. Ped Radiol l980, 9, 73-75.
  8. Gerber BC. Prepyloric diaphragm, an unusual abnormality: a case report. Arch Surg l965, 90, 472-480.
  9. Ghent CN, Denton D. Mucosal diaphragm of the gastric antrum: case report and review of the literature. Canad J Surg l974, 17, 274-278.
  10. Ghahremani GG. Nonobstructive mucosal diaphragms or rings of the gastric antrum in adults. Amer J Roentg Rad Ther Nucl Med l974, 121, 236- 247.
  11. Jinkins JR, Ball TI, Clements JL, et al. Antral mucosal diaphragms in infants and children. Ped Radiol l980, 9, 69-72.
  12. Melamed A, Haukohl RS, Callan E. Pyloric antral mucosal diaphragm with transpyloric mucosal prolapse. Radiology l960, 74, 452-457.
  13. Mitchell KG, McGowan A, Smith DC, et al. Pyloric diaphragm, antral web, congenital antral membrane: a surgical rarity? Brit J Surg l979, 66, 572-574.
  14. Parrish RA, Kanavage CB, Wells JA, et al. Surg Gynaec Obstet l968, 127, 999-1004.
  15. Rowling JT. The prepyloric septum: a rare anomaly. Brit J Surg l959, 47, 162-166.
  16. Touroff ASW, Sussman RM. Congenital prepyloric membranous obstruction in premature infant. Surgery l940, 8, 739-755.

Ectopic Pancreatic Tissue #

Samuel (l955) pointed out that barium-filled ducts in ectopic pancreatic tissue, embedded in the wall of the stomach, may simulate an intramural diverticulum. Moore and Kaplan (l956) found that a small mass of aberrant pancreatic tissue may be loosely attached to the serosal surface of the upper intestine, or it may occur in the subserosal, submuscular or submucosal regions of the gastric walls. Radiographically it usually presents as an elevated mound with a central dimpling and an opening formed by ducts. When the dimpling is filled with barium, it may resemble a polyp with an ulcer at its tip; when the ducts are filled, it resembles a diverticulum.

Besemann et al. (l97l) confirmed that most aberrant pancreatic nodules occurred in the upper gastrointestinal tract, usually in the duodenum, but occasionally in the stomach near the pylorus.

Case Report #

Case 21.1. D.J., 22 year old male, had a long history of dyspepsia not responding to anti-ulcer treatment. Two days before admission there had been an episode of haematemesis. Gastroscopy showed a small orifice on the posterior gastric wall close to the pyloric aperture. It was thought to be either an intramural diverticulum or a double pylorus; radiographic examination was requested for further elucidation. This showed a small, branching, diverticular structure approximately 1.0 cm in length, on the greater curvature side of the pyloric sphincteric cylinder within 1.0 cm of the pylorus (Fig. 21.1). It remained constant in appearance irrespective of the degree of contraction of the cylinder, the contractions being normal. At laparotomy no evidence of ulceration was seen. A nodule of abnormal tissue measuring approximately 2.0 cm in diameter was palpated in the gastric wall at the site indicated by endoscopy and radiology. Gastrostomy revealed a small orifice extending into the nodule, which was removed by local excision. Histology showed it to consist of endo- and exocrine pancreatic tissue located in the muscular coat of the stomach.

Fig. 21.1. Case D.J. Small, branching, diverticulum-like structure (arrow) on greater curvature side of pyloric sphincteric cylinder

Discussion #

In this case a small nodule of ectopic pancreatic tissue in the wall of the greater curvature of the pyloric sphincteric cylinder did not affect the movements of the cylinder to any appreciable extent. Radiographically the lesion mimicked an intramural diverticulum (Chap. 22).

References #

  1. Besemann EF, Auerbach SH, Wolfe WW. Importance of roentgenologic diagnosis of aberrant pancreatic tissue in the gastrointestinal tract. Amer J Roentg Rad Ther Nucl Med l969, 107, 71-76.
  2. Moore MB, Kaplan IW. Heterotopic pancreatic tissue in the stomach. Amer J Gastroenterol l956, 26, 699-705.
  3. Samuel E. Gastric diverticula. Brit J Radiol l955, 28, 574-578.
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