Chapter 38 (page 191)

The Pyloric Sphincteric Cylinder in Health and Disease

Go to chapter: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39
Chapter 38 (page 191)

In three of our verified cases the size of the defect in the duodenal bulb was seen to be related to the degree of contraction of the pyloric sphincteric cylinder (Keet 1952). In these cases a shallow defect might be visible during relaxation or inactivity of the cylinder. During contraction the duodenal defect became more extensive, reaching its greatest volume with maximal contraction of the cylinder. The same feature was seen in most of our unverified cases as well. It was not unusual for the duodenal bulb to appear normal prior to contraction of the cylinder, with the defect only appearing during contraction.

In contrast, Stiennon (1960) noted that tortuous prepyloric rugae sometimes "prolapsed backward", i.e. in an orad direction, through an advancing peristaltic wave. In most cases a somewhat stronger or tighter wave finally forced the mucosa through the pylorus. A similar phenomenon was described by White et al. (1966), who reported that the hyperaemic and oedematous prepyloric folds pushed back into the stomach as the "sphincter" closed. It was shown in Chapter 13 that orad movement of the mucosa in the pyloric sphincteric cylinder may occur normally during contraction of the cylinder. Furthermore sessile mucosal polyps in the cylinder may move in an orad direction during contraction of the cylinder (Chap. 36).

Levin (l97l) again stated that the duodenal defect of prolapsed gastric mucosa became more prominent during "gastric systole", and that the shape of the bulb reverted to normal during "gastric diastole".

The following are examples of further cases encountered by us:

Case Reports

Case 38.1 J.S., 35 year old male had intermittent, burning epigastric pain apparently related to meals, for the previous 5 years. Large meals occasionally caused vomiting. Clinical examination was negative. Radiology revealed no abnormality in the oesophagus and stomach. During phases of distension or partial contraction of the pyloric sphincteric cylinder, the duodenal bulb appeared normal (Fig. 38.1A). With maximal contraction of the sphincteric cylinder an umbrella- like or mushroom-like defect appeared in the base of the duodenal bulb; it was continuous with longitudinal mucosal folds extending through the fully formed pyloric canal (Fig. 38.1B), and the diagnosis of prolapse of gastric mucosa into the duodenum was made. Gastroscopy showed a few prominent mucosal folds which appeared to be redundant and capable of prolapsing into the duodenum. No evidence of ulceration or other pathology was seen.

Fig. 38.1 A. Case J.S. Partial contraction of pyloric sphincteric cylinder. Base of duodenal bulb normal

Fig. 38.1 B. Case J.S. Maximal contraction of sphincteric cylinder. Umbrella-like defect base of bulb, continuous with longitudinal mucosal folds in pyloric canal

Case 38.2 A.A., 20 year old male, a known case of duodenal ulceration, had received anti-ulcer therapy for the preceding year. Because of a recurrence of symptoms radiographic examination was requested.

Several prominent, tortuous mucosal folds were seen in the pyloric sphincteric cylinder while it was relaxed; the base of the duodenal bulb appeared normal, but there was a possible ulcer near its apex (Fig. 38.2A). During maximal contraction of the pyloric sphincteric cylinder an umbrella-like defect appeared in the base of the duodenal bulb, continuous with longitudinal gastric mucosal folds stretching through the fully formed pyloric canal (Fig. 38.2B). The case was diagnosed as prolapse of gastric mucosa and probable active duodenal ulceration. Control double contrast radiographic examination a month later failed to show the prolapse. At this examination administration of an anticholinergic substance relaxed the gastric walls and insufflation of air caused luminal distension, factors which prevented the sphincteric cylinder from contracting.

Fig. 38.2 A. Case A.A. Prominent, tortuous mucosal folds in relaxed pyloric sphincteric cylinder. Base of duodenal bulb normal. Possible duodenal ulcer

Fig. 38.2 B. Case A.A. Maximal contraction of sphincteric cylinder. Umbrella-like defect base of bulb, continuous with longitudinal mucosal folds in pyloric canal