Diverticulitis: Questioning Current Practice

Author: Charley Randazzo, MD (Harbor-UCLA Medical Center PGY-3) // Editors: Manpreet Singh, MD (@MPrizzleER) and Alex Koyfman, MD (@EMHighAK)

Background

• Before effective treatments including broad spectrum antibiotics, diverticulitis was a disease with high morbidity and mortality.
• Standard of care has been antibiotics (for complicated or uncomplicated diverticulitis), and often surgery for patients with multiple recurrences.
• Meta-analysis¹ by Morris et al in JAMA in 2014 looks at current practices and asks:

1. What is the known pathophysiology – how do diverticula become inflamed and what are risk factors?
2. What is the natural history, when managed non-operatively?
3. What are medical treatment options (current and future)?
4. What are the indications for surgery?

• Certain advances have changed the thinking about diverticulitis:
  • CT can distinguish complicated (perforation, abscess, phlegmon) from uncomplicated diverticulitis
  • Better follow-up in large populations has allowed for better understanding of natural history
  • Similarities found in pathophysiology among diverticulitis, inflammatory bowel disease, and irritable bowel syndrome
  • Surgeons pursuing less invasive management.

Methods

• Authors looked at articles from 2000-2013.
• Found 1383 abstracts and articles, narrowed to 186.

Pathophysiology

• Prevailing theory for the formation of diverticula is that “altered bowel motility leading to increased luminal pressures causes mucosal outpouching.”
• “Recurrent or chronic diverticulitis displays chemical and histological similarities to inflammatory bowel disease and irritable bowel syndrome.”
  • High levels of histamine, TNF-alpha, and matrix metalloproteinases, as well as granulomas and infiltrating lymphocytes found in all 3 diseases (although unable to show a common pathway).

Risk Factors

• Lower risk for diverticular disease among vegetarians compared to meat eaters (RR 0.69 [95%CI 0.55-0.86]).
• Despite common beliefs, one study showed highest level of diverticulosis among those with the highest fiber intake, and another study showed no relation to nut, corn or popcorn ingestion.
• Diverticulitis risk increased with smoking and obesity, and decreased with physical activity.
• Perforation risk increased with NSAIDs, opioids, and corticosteroids.

Natural History

• Recurrence is relatively rare and usually benign.
• Complications usually during first episode, not during recurrent episodes.

Medical therapies

• Goals: Decrease acute inflammation, prevent recurrence, and manage chronic symptoms

1-Fiber

• Some studies support use for preventing recurrence, others showed no benefit. Most had poor quality evidence.
• 4 studies look at fiber alone vs rifaximin + fiber: rifaximin + fiber had a slight benefit in symptom relief and preventing complications

2-Antibiotics

• A Cochrane review did not support use of antibiotics in acute uncomplicated diverticulitis.
• Good studies have shown no benefit of IV over PO antibiotics, and equal effect of 4-day vs 7-day courses.
• Another systematic review and a retrospective cohort study found that antibiotics did not improve complication rate, need for surgery, or recurrence rate.

3-Probiotics

• Thought that deranged colonic microenvironment contributes to chronic inflammation, so theoretical benefit of probiotics.
• Prospective trial of 83 patients found probiotics after first episode led to less bloating, pain and fever, but equal recurrence rates.

4-Anti-inflammatory meds

• Study comparing the anti-inflammatory medication, mesalamine, with the antibiotic, rifaximin, found significantly reduced symptoms after 6-12 months with mesalamine.

Role of surgery

• Current indications: Sepsis and peritonitis on presentation, or failure to improve with medical therapy or percutaneous drainage. Often done in patients with recurrence to prevent complications or emergent surgery.
• Recurrent diverticulitis – Questioning the need for surgery:
  • Complicated recurrence in only 5% who recovered from uncomplicated diverticulitis
  • Risk of future emergent surgery after uncomplicated diverticulitis was only 4-7%
  • Multiple recurrences did not increase risk of major complications
  • Complications most commonly during first episode
  • 5-25% of patients who underwent surgery had recurrent/unresolved symptoms afterwards anyway
  • Surgery can miss the location of future episodes

Conclusions

• Recent studies suggest a lesser role for aggressive antibiotic and surgical treatments in diverticulitis, and newer treatments such as anti-inflammatory medications (mesalamine) and perhaps probiotics have shown some benefit. However, future research is needed in this area to change the current dogma.

References

1. Morris AM, Regenbogen SE, Hardiman KM, Hendren S. Sigmoid diverticulitis: a systematic review. JAMA Surg. 2014;311:287–297.