Meckel’s diverticulum Flashcards
Define Meckel’s diverticulum.
Outpouching of the ileum along the antimesenteric border containing heterotopic tissue of the stomach (acid secreting parietal cells), pancreas or normal intestinal mucosa.
Explain the embryological aetiology of Meckel’s diverticulum.
During embryogenesis the vitelline duct runs between the terminal ileum, the umbilicus + the yolk sac; usually regresses by 7/40.
Failure to atrophy; can cause either a remaining fibrous band running from the diverticulum to the umbilicus, an umbilical cyst, an ileo-umbilical fistula or MD.
MD is the most common + is formed when the entire duct except the portion adjacent to the ileum is obliterated.
Explain the general aetiology of Meckel’s diverticulum.
Partial or incomplete involution of vitelline duct (omphalomesenteric duct) during embryogenesis. True diverticulum containing all 3 layers of intestinal wall + its own blood supply.
What is the “rule of 2s” with Meckel’s diverticulum?
2% of the population
2 inches (3–5 cm) long
2 feet (60 cm) from the ileocaecal valve
2% are symptomatic
2 types of ectopic tissue (gastric or pancreatic)
clinical presentation commonly aged 2
males 2–3X more likely to be affected.
Summarise the epidemiology of Meckel’s diverticulum.
2% of population
M > F
What are the signs and symptoms of Meckel’s diverticulum?
Most children asymptomatic. 4.2–16% of children with MD estimated to be symptomatic.
Intermittent painless rectal bleeding: Secondary to ulceration of ileal mucosa by ectopic acid production. Characteristically bright red blood. Normal abdo examination.
Signs + Sx of anaemia: Lethargy, pallor + failure to thrive.
Intussusception: MD may be a lead point.
Meckel diverticulitis: Characterised by peritoneal irritation which may localise to the RIF; may be identical presentation to acute appendicitis.
What are appropriate investigations for Meckel’s diverticulum?
Bloods: FBC for anaemia.
Microbiology: Stool sample for foecal occult blood with MC+S.
Imaging: Meckel Scan – radionucleotide scan with IV technetium-99m (binds to gastric mucosa is pre-scan H2- antagonist provided, e.g. ranitidine). Only positive scans are helpful.
What is the general management for Meckel’s diverticulum?
If incidentally found during surgery, removal not recommended due to associated surgical morbidity. Only remove pathological.
What is the surgical management for Meckel’s diverticulum?
Ileal resection + primary anastomosis.
Laparoscopic approach involves delivery of the MD via the umbilicus with extracorporeal anastomosis. Laparoscopy is also recommended for the Ix of PR bleeding possibly secondary to MD.
What are complications associated with Meckel’s diverticulum?
Anastomotic complications (stricture, leak) with surgical intervention. Rarely may contain sarcomas/carcinoid/adenocarcinoma tumours.
What is the prognosis of Meckel’s diverticulum?
Excellent
