Jejunal and Ileal Diverticula

See Small Bowel Diverticular Disease for the true/false diverticula overview. Content below is from a textbook reference chapter (Sabiston Ch50 - Diverticular Disease & Miscellaneous Problems), not primary literature.

Incidence and cause

Much less common than duodenal diverticula — incidence ranging from 0.1–1.4% in autopsy series and 0.1–1.5% in upper GI studies. Jejunal diverticula are more common and larger than ileal diverticula. These are false diverticula, occurring mainly in an older age group (after the sixth decade of life), usually multiple, protruding from the mesenteric border of the bowel, and may be overlooked at surgery because they are embedded within the small bowel mesentery (Fig. 50.41).

The cause of jejunoileal diverticulosis is thought to be a motor dysfunction of the smooth muscle or myenteric plexus, resulting in disordered contractions of the small bowel — generating increased intraluminal pressure and herniation of mucosa/submucosa through the weakest portion of the bowel wall (i.e., the mesenteric side).

Clinical manifestations

Usually found incidentally at laparotomy or during an upper GI study (Fig. 50.42); the great majority remain asymptomatic. Acute complications — intestinal obstruction, hemorrhage, and perforation — can occur but are rare. Chronic symptoms include vague chronic abdominal pain, malabsorption, functional pseudo-obstruction, and chronic low-grade GI hemorrhage. Acute complications are diverticulitis with or without abscess or perforation, GI hemorrhage, and intestinal obstruction. Stasis of intestinal flow with bacterial overgrowth (blind loop syndrome), caused by the jejunal dyskinesia, may lead to deconjugation of bile salts and uptake of vitamin B12 by the bacterial flora, resulting in steatorrhea and megaloblastic anemia, with or without neuropathy.

Treatment

For incidentally noted, asymptomatic jejunoileal diverticula, no treatment is required. Treatment of complications of obstruction, bleeding, and perforation is usually intestinal resection and end-to-end anastomosis. Patients presenting with malabsorption secondary to blind loop syndrome and bacterial overgrowth can usually be given antibiotics.

Obstruction may be caused by enteroliths that form in a jejunal diverticulum and are subsequently dislodged, obstructing the distal intestine. This condition may be treated by enterotomy and removal of the enterolith, or sometimes the enterolith can be milked distally into the cecum. When the enterolith causes obstruction at the level of the diverticulum, bowel resection is necessary. When a perforation of a jejunoileal diverticulum is encountered, resection with reanastomosis is required — lesser procedures such as simple closure, excision, and invagination are associated with greater morbidity/mortality rates. Laparoscopic bowel resection with reanastomosis is a safe option in minimally contaminated surgical fields; in extreme cases, such as diffuse peritonitis, enterostomies may be required if judgment dictates that reanastomosis may be risky.

Open items / gaps

• No primary literature yet in the wiki on jejunoileal diverticula — entirely textbook-reference-derived.