What is perforated diverticulitis in adults over 50 with diverticular disease?

What is Perforated Diverticulitis?

Perforated diverticulitis is a life-threatening complication of diverticular disease where an inflamed diverticulum ruptures through the colonic wall, releasing intestinal contents into the peritoneal cavity and causing either localized abscess formation or diffuse peritonitis. 1

Clinical Presentation and Pathophysiology

Perforated diverticulitis occurs when the inflammatory process in diverticular disease progresses to full-thickness wall necrosis and rupture. 2 The severity ranges across a spectrum:

• Localized perforation (Hinchey I-II): Pericolic inflammation or walled-off abscess formation where the perforation is contained by surrounding tissues 1
• Purulent peritonitis (Hinchey III): Free perforation with purulent fluid throughout the peritoneal cavity 1, 2
• Fecal peritonitis (Hinchey IV): Free perforation with gross fecal contamination of the peritoneum, representing the most severe form 1, 2

Diagnostic Features

Patients typically present with left lower quadrant abdominal pain, fever, leukocytosis, and signs of sepsis ranging from localized peritonitis to septic shock. 2 The key diagnostic findings include:

• CT imaging findings: Sigmoid wall thickening, pericolonic fat stranding, extraluminal air (either pericolic or distant free air), fluid collections, and abscess formation 1, 2
• Clinical signs: Abdominal guarding, diffuse tenderness, and hemodynamic instability in severe cases 1

Critical Distinction: Localized vs. Diffuse Peritonitis

The presence or absence of diffuse peritonitis fundamentally determines management strategy and prognosis:

• Localized perforation without diffuse peritonitis: May be managed conservatively with antibiotics and percutaneous drainage in clinically stable patients, with success rates of 85-94% for pericolic air but only 71% for distant free air 3
• Diffuse peritonitis (Hinchey III-IV): Requires immediate surgical source control, as non-operative management is contraindicated due to high mortality risk 1

Mortality and Prognostic Factors

Perforated diverticulitis carries significant mortality risk that varies by severity:

• Overall inpatient mortality: 5.4% for patients with perforation compared to 1.5% without perforation 4
• Mortality predictors: Fecal peritonitis, preoperative hypotension, prolonged symptom duration, persistent postoperative sepsis, and delayed surgical intervention 5, 4
• Impact of surgical delay: Each day of delay to surgical intervention increases mortality risk by 31% in patients with perforation requiring surgery 4

Management Implications

The fundamental principle is that diffuse peritonitis (WSES stage 3-4) requires prompt surgical source control and cannot be managed non-operatively. 1 Surgical options include:

• Hartmann procedure: Resection with end colostomy, traditionally used for unstable patients 1
• Resection with primary anastomosis: Associated with 40% lower mortality compared to Hartmann's in appropriately selected stable patients 1, 2
• Damage control surgery: Reserved for patients with severe physiological derangement, involving source control with open abdomen management 1

Laparoscopic lavage alone is not recommended for elderly patients with perforated diverticulitis and peritonitis due to higher rates of inadequate source control, intra-abdominal abscess formation, and reoperation. 1

Antibiotic Management

Broad-spectrum antibiotics covering anaerobes and gram-negative bacteria must be initiated immediately, with the regimen tailored to patient risk factors for resistant organisms (healthcare exposure, immunosuppression, prior antibiotic use). 1 After adequate source control, a 3-5 day antibiotic course is reasonable in immunocompetent patients, extended to 7 days in immunocompromised or critically ill patients. 1, 2

Common Pitfalls

• Attempting non-operative management in patients with diffuse peritonitis: This dramatically increases mortality and is contraindicated 1
• Delaying surgical intervention for complete hemodynamic optimization: Delayed source control increases mortality by 31% per day of delay 4
• Inadequate antimicrobial coverage: Failure to cover resistant organisms in high-risk elderly patients (those with healthcare exposure, immunosuppression, or prior antibiotics) leads to treatment failure 1
• Assuming all perforations require immediate surgery: Stable patients with localized perforation (pericolic air without diffuse fluid) may be managed conservatively with close monitoring 1, 3