Meckel's Diverticulum
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1- Introduction
2- Anatomical Overview
3- Causes
4- Treatment
Introduction
is a congenital anomaly representing a persistent portion of the vitello intestinal duct. It occurs in 2%
of patients, is located about 2 ft (61 cm) from the ileocolic junction, and is about 2 in. (5 cm) long. It can become ulcerated or cause intestinal obstruction.
Anatomical Overview
Anatomy and Development
- Origin: Meckel’s diverticulum arises from the remnants of the vitelline duct (also known as the omphalomesenteric duct), which connects the yolk sac to the midgut during fetal development. Normally, this duct is obliterated by the seventh week of gestation.
- Structure: It is a true diverticulum, meaning it contains all layers of the intestinal wall (mucosa, submucosa, and muscularis propria).
Causes
Meckel’s diverticulum is caused by an incomplete obliteration of the vitelline duct (also known as the omphalomesenteric duct) during fetal development. Here is a detailed explanation of the cause:
Embryological Development
- Vitelline Duct: During early fetal development, the vitelline duct connects the yolk sac to the midgut, providing nutrients to the developing embryo.
- Normal Regression: By the 7th week of gestation, the vitelline duct typically regresses and is absorbed into the developing intestine.
- Incomplete Obliteration: If the vitelline duct does not completely obliterate, remnants can persist. Meckel’s diverticulum is the most common remnant, which forms as a pouch on the antimesenteric border of the ileum (the side opposite to where the mesentery attaches).
Factors Influencing Development
- Genetic Factors: There is no specific gene identified for Meckel’s diverticulum, but the condition is believed to be related to normal variations in embryological development rather than a specific genetic mutation or hereditary condition.
- Developmental Anomalies: Other remnants of the vitelline duct, aside from Meckel’s diverticulum, can include fibrous cords (which can lead to intestinal obstruction), vitelline cysts, or complete vitelline fistulae.
Treatment
- Asymptomatic cases: Generally do not require treatment unless discovered incidentally during surgery for other conditions and are considered at high risk for complications.
- Symptomatic cases: Surgical resection (diverticulectomy) is the treatment of choice. If the diverticulum is inflamed, perforated, or causing obstruction, emergency surgery is indicated.