PEPTIC ULCER: DUODENAL ULCERS DISTAL TO DUODENAL BULB; MULTIPLE ULCERS
Peptic ulcers in a region distal to the duodenal bulb are rare, and their frequency, altogether probably less than 5% of all duodenal ulcers, decreases with their distance from the pylorus. Ulcers in the second portion of the duodenum give rise to the same symptoms and are beset with the same dangers and complications as are ulcers of the bulb. The acute clinical picture and later significance, however, may be far more complex because of the functional and anatomic implications for the adjoining structures. By the edema of its margin and surroundings, by penetration or by shrinkage, such an ulcer may cause obstruction and eventually stenosis of any one of several structures (the papilla of Vater, the lower part of the common bile duct, and one or both of the pancreatic ducts), so that chronic pancreatitis and/or biliary obstruction with jaundice may result. Deep penetration may give rise to a choledochoduodenal fistula. The presence of duodenal ulcers distal to the duodenal bulb should raise concern for the presence of Zollinger-Ellison syndrome, or gastrinoma, in which excessive gastrin is secreted, leading to excessive secretion of gastric acid.
Multiple chronic ulcers of the duodenum, surprisingly, are not uncommon. Their frequency is 10% to 20%, according to statistical data obtained from cases coming to autopsy. As a rule, the number is restricted to two; only in rare instances have more than two been found. When ulcers develop on both adjacent anterior and posterior walls, they are referred to as “kissing” ulcers. Only a very small percentage of patients with an active duodenal ulcer have also an active gastric ulcer.
A great variety of anatomic changes and roentgenologic deformities of the duodenum can be associated with an ulcer or can develop during the course of its extension or involution. One of the most typical duodenal deformities occurring with the ulcerative process is the prestenotic pseudodiverticulum. Seen from the
lumen, it represents a relatively flat, sinuslike indentation, located usually between the pylorus and the site of the ulcer or proximal to a duodenal stricture resulting from a cicatricial (scarring) remnant of an ulcer. Although all layers of the duodenal wall participate in the formation of such a pouch, the situation differs from that of a true duodenal diverticulum, in that the mucosa has not evaginated through a small muscular gap. The pseudodiverticula need not cause any clinical symptoms, but they produce quite characteristic radiographic pictures, which have been described as a “typical bulbus deformity” in cases of chronic peptic ulcer, though, at times, their differentiation from an active duodenal ulcer niche may be difficult. Although the prestenotic diverticulum is usually single, the development of multiple pouches is not rare. Often two pseudodiverticula may appear symmetrically in the upper and lower parts of the duodenal bulb, and a third one may deform the bulb into what has been called roentgenographically the “cloverleaf bulbus.”