The right becomes the superior mesenteric artery that supplies a terminal branch to the diverticulum, while the left involutes. Having its own blood supply, Meckels diverticulum is susceptible to obstruction or infection. Meckels diverticulum is located in the distal ileum, usually within 60–100 cm (2 feet) of the ileocecal valve. This blind segment or small pouch is about 3–6 cm (2 inch) long and may have a greater lumen diameter than that of the ileum. It runs antimesenterically and has its own blood supply. It is a remnant of the connection from the yolk sac to the small intestine present during embryonic development. It is a true diverticulum, consisting of all 3 layers of the bowel wall which are mucosa, submucosa and muscularis propria.As the vitelline duct is made up of pluripotent cell lining, Meckels diverticulum may harbor abnormal tissues, containing embryonic remnants of other tissue types. Jejunal, duodenal mucosa or Brunners tissue were each found in 2% of ectopic cases. Heterotopic rests of gastric mucosa and pancreatic tissue are seen in 60% and 6% of cases respectively. Heterotopic means the displacement of an organ from its normal anatomic location. Inflammation of this Meckels diverticulum may mimic appendicitis.
A Meckels diverticulum, a true congenital diverticulum, is a slight bulge in the small intestine present at birth and a vestigial remnant of the omphalomesenteric duct (also called the vitelline duct or yolk stalk). It is the most common malformation of the gastrointestinal tract and is present in approximately 2% of the population, with males more frequently experiencing symptoms. Meckels diverticulum was first explained by Fabricius Hildanus in the sixteenth century and later named after Johann Friedrich Meckel, who described the embryological origin of this type of diverticulum in 1809. Signs and symptoms
The majority of people with a Meckels diverticulum are asymptomatic. An asymptomatic Meckels diverticulum is called a silent Meckels diverticulum. If symptoms do occur, they typically appear before the age of two years. The most common presenting symptom is painless rectal bleeding such as melaena-like black offensive stools, followed by intestinal obstruction, volvulus and intussusception. Occasionally, Meckels diverticulitis may present with all the features of acute appendicitis. Also, severe pain in the epigastric region is experienced by the person along with bloating in the epigastric and umbilical regions. At times, the symptoms are so painful that they may cause sleepless nights with acute pain felt in the foregut region, specifically in the epigastric and umbilical regions. In some cases, bleeding occurs without warning and may stop spontaneously. The symptoms can be extremely painful, often mistaken as just stomach pain resulting from not eating or constipation.