Diverticula of the Forequt

Abstract

Embryologically, the foregut is defined as being that part of the gastrointestinal tract which is proximal to the ampulla of Vater. In other words, the foregut includes the pharynx, the oesophagus, the stomach, and the duodenum. The distal inch of the oesophagus, the stomach, and the duodenum are supplied by the coeliac axis. The workers of the Medical Faculty of the University of Manitoba have always shown an interest in diverticula. Grant (1), while Professor of Anatomy, published the first of his studies on duodenal diverticula, based on cadaver material. MacLean (2) was one of the early operators and was the first to remove a pouch imbedded in the head of the pancreas. The writer) has presented two papers dealing with the radiological aspects, the last report being in 1935. Since 1935, as our experience has increased, we have observed a not inconsiderable number of diverticula of the foregut. The great majority of them have been incidental findings in routine barium examinations. Those at the oesophageal-pharyngeal junction and some of the oesophagus have been demonstrated as the result of an examination specifically directed to that part. The frequent demonstration of these lesions by our group is perhaps attributable to the fact that we are “diverticula conscious.” Despite the large number of papers, many of recent date, dealing with these diverticula, there still exists considerable confusion as to their classification, cause, and clinical importance. The descriptive term used by one author has apparently an entirely different meaning when used by a second. Odgers (4) divides all diverticula into primary and secondary and I consider this to be the simplest and the best classification. The primary diverticula are those which occur without obvious cause. Their walls are formed by the mucosal and submucosal coats. Secondary diverticula are those having an obvious cause, with walls consisting of all coats of the bowel. Synonymous terms used by various authors for primary diverticula are “false” and “congenital” forsecondarydiverticula, “true” and “acquired.” The terms “pulsion” and “traction,” as applied to diverticula, only confuse the issue, as it makes little if any difference clinically whether the sac has been pushed out or pulled out. I shall consider diverticula in the following order: (i) oesophageal-pharyngeal diverticula; (ii) diverticula of the thoracic oesophagus; (iii) diverticula of the stomach; (iv) duodenal diverticula. Oesophageal-Pharyngeal Diverticula Raven (5) has presented an excellent study on oesophageal-pharyngeal diverticula and I am indebted to him for the anatomical details. These diverticula are usually situated posteriorly. They have been erroneously described as oesophageal. Actually the pouch is a prolapse of the pharyngeal mucous membrane between the two different sets of musculature comprising the cricopharyngeus.