Meckel's diverticulum pathophysiology
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sudarshana Datta, MD [2]
Overview
During embryonic life, the vitelline duct or the omphalomesenteric duct is the connection between the midgut and the yolk sac responsible for providing nutrition to the midgut. In the period between the fifth and the sixth weeks of gestation, the vitelline duct involutes and disappears, while the bowel is rapidly pulled into the abdominal cavity. Failure of duct involution may lead to persistence of the omphalomesenteric duct with variable morphology: Vitelline fistulae draining through the umbilicus Vitelline cysts Fibrous bands connecting the umbilicus to the diverticulum that may twist to cause intestinal obstruction Meckel’s diverticulum: True diverticulum (comprising of all layers of intestinal wall i.e. mucosa, submucosa and muscularis propria) Arises from the antimesenteric border of the ileum, extends into the umbilical cord Supplied by the vitelline artery, branch of the Superior Mesenteric Artery (SMA), prone to torsion and subsequent ischemia, infarction and obstruction Bears ectopic tissue due to the following reasons: Presence of a pluripotent cell lining Faulty association between endodermal and neural crest cells Absence of inhibitory effect of the mesoderm on the local endoderm may also be responsible
Pathophysiology
- During embryonic life, the vitelline duct or the omphalomesenteric duct is the connection between the midgut and the yolk sac responsible for providing nutrition to the midgut.
- In the period between the fifth and the sixth weeks of gestation, the vitelline duct involutes and disappears, while the bowel is rapidly pulled into the abdominal cavity.
- Failure of duct involution may lead to persistence of the omphalomesenteric duct with variable morphology:
- Vitelline fistulae draining through the umbilicus
- Vitelline cysts
- Fibrous bands connecting the umbilicus to the diverticulum that may twist to cause intestinal obstruction
- Meckel’s diverticulum:
- True diverticulum (comprising of all layers of intestinal wall i.e. mucosa, submucosa and muscularis propria)
- Arises from the antimesenteric border of the ileum, extends into the umbilical cord
- Supplied by the vitelline artery, branch of the Superior Mesenteric Artery (SMA), prone to torsion and subsequent ischemia, infarction and obstruction
- Bears ectopic tissue due to the following reasons:
- Presence of a pluripotent cell lining
- Faulty association between endodermal and neural crest cells
- Absence of inhibitory effect of the mesoderm on the local endoderm may also be responsible
- Types of ectopic tissue: