Editing Meckel's diverticula

== Epidemiology ==

* Incidence 2%
* Equal incidence men and women


== Pathophysiology ==

* Remnant of proximal vitelline (omphalomesenteric) duct (connects embryonic midgut to the yolk sac). Results from incomplete closure.
* Lined by pluripotent cells - therefore, can find heterotopic tissue inside
** Usually normal ileal mucosa
** Gastric mucosa in 50%
** Pancreatic mucosa in 5%
** Colonic mucosa rarely
* Projects from antimesenteric border 45-60cm from ICV.
* Ranges from a small bump to a long projection communicating with the umbilicus
* Typically about 5cm long and 2cm wide
* Rule of twos:
** 2 feet from ICV
** 2% of population
** Symptomatic in 2% of cases (usually within first 2 years of life)
** Usually less than two inches/5cm in length



== Presentation ==

* Mostly benign and incidentally discovered during autopsy, laparotomy or barium study
* Bleeding - most common presentation
** Can be acute massive bleed, anaemia secondary to occult bleed, or a self-limited recurrent episodic event
** Usual source of bleeding is a chronic acid-induced ulcer in the ileum adjacent to a Meckel diverticulum that contains gastric mucosa
* Obstruction is also common
** Can result from volvulus of small bowel, intussusception, or rarely incarceration of diverticulum in an inguinal hernia (Littre hernia)
** Should resect in all cases
* Diverticulitis (10-20% of symptomatic presentations)
** More common in adults - clinically indistinguishable from appendicitis
** Can lead to perforation
** Should always look for a Meckel's when the appendix is found to be normal
* Neoplasms
** NET (77%)
** Adenocarcinoma (11%)
** GIST (10%)
** Lymphoma (1%)

== Investigation ==

* AXR, CT and USS are rarely helpful
* Sodium 99m-Tc-pertechnetate scintigraphy 
** Especially useful in children
** Molecule is preferentially taken up by mucus-secreting cells of gastric mucosa and ectopic gastric tissue in the diverticulum
** Sensitivity 85%, specificity 95% in children
** Sensitivity 63% in adults due to less presence of gastric mucosa in the diverticulum - also need to pre-treat with cimetidine to increase uptake
**
* Barium contrast imaging
* CT angio - in patients with bleeding

== Management ==

* Symptomatic - resect
* Asymptomatic found on imaging - no intervention
* Asymptomatic, incidentally found at operation on a child - resect
* Asymptomatic, incidentally found at operation on an adult - personalised decision; resect only if high-risk features for future complication
** Age <50yo
** Male sex
** Diverticulum length >2cm
** Ectopic tissue or palpable abnormalities
** Fibrous band to another structure

=== Intervention ===

* Simplest exam answer is for complete resection and anastomosis
* Segmental resection and primary ileoileostomy
** Patients with haemorrhage
* Diverticulectomy
** Non-bleeding Meckel's
* Consider appendicectomy at same time

[[Category:Small bowel]]