Complicated small bowel diverticular disease: a case series
Executive Summary
Small bowel diverticulosis of the jejunum and ileum is a rare clinical entity, with a prevalence rate ranging from 0.2% to 1.9%. Because the disease often lacks pathognomonic features or specific clinical symptoms, diagnosis is frequently delayed until the onset of life-threatening complications. These complications, occurring in 6.5% to 10.4% of cases, include diverticulitis, perforation, hemorrhage, and intestinal obstruction. While prophylactic resection is not recommended for asymptomatic cases, the established consensus for complicated disease is segmental small bowel resection with primary anastomosis. Maintaining a high index of suspicion is critical when evaluating elderly patients with a history of colonic diverticulosis or connective tissue disorders presenting with occult abdominal symptoms.
Epidemiology and Pathogenesis
Diverticular disease of the small bowel is significantly less common than its colonic counterpart. The condition is primarily identified in the elderly, typically appearing in the sixth and seventh decades of life, and shows a higher prevalence in males.
Prevalence and Distribution
Autopsy findings: 0.2% to 1.3%.
Small bowel studies: 0.3% to 1.9%.
Anatomical Distribution: Two-thirds of affected patients have multiple diverticula. The frequency of diverticula decreases distally, often transitioning to solitary diverticula in the distal small bowel.
Pathogenetic Mechanisms
The exact etiology remains incompletely explained, though most cases are believed to be acquired.
Mechanical Dysfunction: One theory suggests that diverticula develop due to dysfunction in the small muscle or myenteric plexus. This lead to abnormal bowel movements and increased intraluminal pressure, causing the mucosa to herniate.
Anatomical Vulnerability: These are typically "false" diverticula occurring along the mesenteric border. They frequently enter the bowel at the same site as the blood supply, making them particularly prone to hemorrhage.
Associated Conditions: There is a notable correlation with connective tissue and systemic disorders, including Marfan’s disease, cystic fibrosis, and autosomal dominant polycystic kidney disease.
Clinical Presentation and Complications
Most patients with small bowel diverticulosis remain asymptomatic. However, when complications arise, they often present as emergent surgical conditions.
Primary Complications
Diagnostic Challenges
Diagnosis is notoriously difficult because diverticula are often hidden within mesenteric fat. Furthermore, 35% to 75% of these patients also have colonic diverticulosis, which can obscure the true source of perforation or hemorrhage in emergency settings.
Case Study Synthesis: Clinical Progressions
The following cases illustrate the occult nature of the disease and its progression to emergent states.
Case 1 (Perforation): A 69-year-old male with a history of episodic abdominal pain and constipation. Initial CT showed thickening of the terminal ileum and microperforation. Despite antibiotic treatment, he progressed to purulent peritonitis requiring urgent laparotomy and resection of a matted ileal mass and abscess.
Case 2 (Obstruction): An 82-year-old female with multiple hospitalizations for small bowel obstruction (SBO) over six months. Her history of extensive prior abdominal surgeries (colectomies) complicated the diagnosis. Elective laparotomy revealed a mass of thickened jejunoileal loops and mesenteric lymphadenopathy requiring excision.
Case 3 (Hemorrhage): An 80-year-old female presenting with bright red blood per rectum and a hemoglobin drop to 5.2. CT angiogram and push enteroscopy identified multiple jejunal diverticula. Intermittent, unremitting bleeding necessitated a 60 cm resection of the blood-filled proximal jejunum.
Diagnostic Modalities and Imaging
There is no single "ideal" imaging modality; diagnosis often requires a combination of techniques or surgical exploration.
CT Scan: Useful for identifying bowel wall thickening, extraluminal gas (indicating perforation), and inflammatory stranding.
Ultrasound: Can detect small bowel wall thickening and hyperechoic irregular projections.
Enteroclysis and Capsule Endoscopy: Often more effective than standard imaging for identifying the presence of numerous diverticula.
CT Angiography: Primary tool for localizing active hemorrhage.
Diagnostic Laparoscopy: Often the definitive method for identifying inflamed or bleeding diverticula that remain hidden on non-invasive scans.
Treatment and Management Guidelines
The management of small bowel diverticular disease depends entirely on the presence of complications.
Asymptomatic Disease: No prophylactic surgical intervention is recommended.
Complicated Disease: The standard of care is segmental enterectomy (small bowel resection) with primary anastomosis.
Surgical Approach: Both laparoscopic and open techniques are utilized, depending on the patient's stability and the presence of peritonitis. In cases of perforation, "en bloc" resection of the inflamed segment and associated abscess is necessary.
Medical Management: While expectant management with antibiotics can be attempted for minor inflammation, the risk of rapid progression to perforation or peritonitis is high, often requiring prompt surgical intervention.
Summary of Literature Review
Analysis of various case reports confirms the diversity of presentations and the critical role of surgery in management.
