Organ
Meckel's diverticulum
True ileal diverticulum from an embryonic gut connection
High-yield
Antimesenteric position and full bowel-wall layers are more dependable identifiers than the approximate rule of twos. Distance, size, age at presentation and tissue content vary widely.
Overview
A Meckel diverticulum forms when the intestinal end of the vitelline duct persists. It usually projects from the antimesenteric ileal wall and contains the layers of a true bowel diverticulum. Most are silent, but ectopic tissue or associated bands can create clinically significant complications.
Reference facts
- Location
- Usually the antimesenteric surface of distal ileum, at a variable distance proximal to the ileocecal junction.
- Parts
- Contains mucosa, submucosa, muscular wall and outer serosa; some variants retain a fibrous or patent connection toward the umbilicus.
- Blood supply
- An ileal arterial branch, often a persistent vitelline vessel, can supply the diverticulum through a mesodiverticular connection.
- Innervation
- Shares regional ileal enteric and superior mesenteric autonomic pathways.
- Relations
- May contain ectopic gastric or pancreatic tissue; a residual band can create a point around which nearby bowel becomes trapped.
- Function
- Has no established essential digestive role as a remnant, although any ectopic tissue can retain its own secretory activity.
Mnemonic
Recall the vitelline connection: an ileal pouch may retain gastric tissue or a band toward the umbilicus.
Clinical correlation
Acid from ectopic gastric mucosa can ulcerate nearby ileal mucosa and cause bleeding. A diverticulum or attached band may also produce obstruction, intussusception or inflammation resembling appendicitis. A Meckel scan detects ectopic gastric mucosa rather than the pouch itself.
Frequently asked questions
Where is the meckel's diverticulum located?
Usually the antimesenteric surface of distal ileum, at a variable distance proximal to the ileocecal junction.
What does the meckel's diverticulum do?
Has no established essential digestive role as a remnant, although any ectopic tissue can retain its own secretory activity.
What are the parts of the meckel's diverticulum?
Contains mucosa, submucosa, muscular wall and outer serosa; some variants retain a fibrous or patent connection toward the umbilicus.
What is the blood supply of the meckel's diverticulum?
An ileal arterial branch, often a persistent vitelline vessel, can supply the diverticulum through a mesodiverticular connection.