Jejunal and Ileal Diverticula

Definition

• Acquired, thin-walled (false diverticulum) out-pouchings on the mesenteric border
• Jejunal more common and larger than ileal

Incidence

• Approx 1%

Pathophysiology

• 1. Nature of the diverticula
  • False diverticula (pulsion)
    • Composed of mucosa and submucosa herniating through the muscularis propria
    • Occur on the mesenteric border of the small bowel
  • Most common in the jejunum, followed by the ileum
• 2. Underlying mechanism
  • Disordered intestinal motility or segmental dyskinesia
    • Leads to increased intraluminal pressure
    • Promotes mucosal herniation through points of relative weakness (e.g. entry points of blood vessels – vasa recta)
  • Believed to be acquired, usually in older adults
• 3. Associated factors
  • Age-related weakening of the intestinal wall
  • Abnormal smooth muscle or myenteric plexus dysfunction
    • Impaired peristalsis → segmental stasis and distension
  • Often associated with:
    • Connective tissue disorders (rare)
    • Scleroderma
    • Intestinal pseudo-obstruction

Clinical Presentations

• Usually incidental findings
  • CT, Laparotomy, Upper GI study
• Majority asymptomatic
• Symptoms
  • Vague abdo pain
  • Malabsorption
  • Ileus
  • Iron def anaemia due to occult bleeding
  • Blind loop syndrome
    • Bacterial overgrowth caused by stasis leading to deconjugation of bile salts
    • Uptake of B12 by flora and megaloblastic anaemia and steatorrhea

Complications

• Perforation
• Massive haemorrhage (UGI scope, angiography)
• Intestinal obstruction

Management

• Nonoperative: Vast majority
  • Blind-loop syndrome = Antibiotic treatment
• Operative:
  • Limit contamination
  • Lavage
  • Resection with end-to-end anastomosis