Meckel's diverticulum overview: Difference between revisions
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==Causes== | ==Causes== | ||
Persistence of the [[vitelline duct]] due to incomplete involution leads to the formation of Meckel’s diverticula, the most common [[congenital abnormality]] of the [[small intestine]]. | |||
==Differentiating Meckel's diverticulum from Other Diseases== | ==Differentiating Meckel's diverticulum from Other Diseases== | ||
Revision as of 16:47, 8 January 2018
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
A Meckel's diverticulum, a true congenital diverticulum, is a small bulge in the small intestine present at birth. It is a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct), and is the most frequent malformation of the gastrointestinal tract.
Historical Perspective
Meckel's diverticulum was first described by Fabricius Hildanus in the sixteenth century. In 1809, Johann Friedrich Meckel threw light on the embryological origin of Meckel's diverticulum.
Classification
There is no established system for the classification of Meckel's diverticulum.
Pathophysiology
The vitelline duct or the omphalomesenteric duct is the connection between the midgut and the yolk sac responsible for providing nutrition to the midgut, during fetal development. The vitelline duct subsequently undergoes involution,in the period between the fifth and the sixth weeks of gestation while the intestinal loop is rapidly pulled into the abdominal cavity. Failure of duct involution may lead to persistence of the proximal portion of omphalomesenteric duct, which may be referred to as the Meckel's diverticulum. The Meckel’s diverticulum is a true diverticulum (comprising of all layers of intestinal wall i.e. mucosa, submucosa and muscularis propria). It arises from the antimesenteric border of the ileum and extends into the umbilical cord. The blood supply comes from the vitelline artery, which is a branch of the superior mesenteric artery, prone to torsion, ischemia, infarction and obstruction. The diverticulum may contain ectopic tissue due to the presence of a pluripotent cell lining, faulty association between endodermal and neural crest cells and absence of inhibitory effect of the mesoderm on the local endoderm.
Causes
Persistence of the vitelline duct due to incomplete involution leads to the formation of Meckel’s diverticula, the most common congenital abnormality of the small intestine.
Differentiating Meckel's diverticulum from Other Diseases
Epidemiology and Demographics
Meckel's diverticulum is present in approximately 2% of the population, with males more frequently experiencing symptoms.
Risk Factors
Screening
Natural History, Complications and Prognosis
Intestinal torsions around the intestinal stalk may also occur, leading to obstruction, ischemia, and necrosis.
Diagnosis
History and Symptoms
Approximately 98% of people afflicted with Meckel's diverticulum are asymptomatic. If symptoms do occur, they typically appear before the age of two.
Physical Examination
Laboratory Findings
Other Imaging Findings
A technetium-99m (99mTc) pertechnetate scan is the investigation of choice to diagnose Meckel's diverticula. This scan detects gastric mucosa; since approximately 50% of symptomatic Meckel's diverticula have ectopic gastric (stomach) cells contained within them, this is displayed as a spot on the scan distant from the stomach itself.
Other Diagnostic Studies
Tests such as colonoscopy and screenings for bleeding disorders should be performed, and angiography can assist in determining the location and severity of bleeding.
Treatment
Medical Therapy
Iron replacement to correct anemia. In major bleeding, a blood transfusion may be needed.
Surgery
Surgical treatment consists of a resection of the affected portion of the bowel.