WSES guidelines for the management of acute colonic diverticulitis in the emergency setting (2020)
Sartelli, M., Weber, D. G., Kluger, Y., Ansaloni, L., Coccolini, F., Abu-Zidan, F., Augustin, G., Ben-Ishay, O., Biffl, W. L., Bouliaris, K., Catena, R., Ceresoli, M., Chiara, O., Chiarugi, M., Coimbra, R., Cortese, F., Cui, Y., Damaskos, D., De' Angelis, G. L., Delibegovic, S., … Catena, F. (2020). 2020 update of the WSES guidelines for the management of acute colonic diverticulitis in the emergency setting. World journal of emergency surgery : WJES, 15(1), 32. https://doi.org/10.1186/s13017-020-00313-4
Executive Summary
This document synthesizes the 2020 updated guidelines from the World Society of Emergency Surgery (WSES) for the management of acute colonic diverticulitis. The guidelines, developed by an international multidisciplinary panel using the GRADE methodology, reflect significant shifts toward more conservative management for uncomplicated cases and provide nuanced, evidence-based recommendations for complicated disease.
Key takeaways include a strong recommendation against the routine use of antibiotics in immunocompetent patients with uncomplicated diverticulitis, as evidence from major trials like the DIABOLO study shows no benefit. Outpatient treatment is endorsed as a safe, effective, and cost-saving approach for selected patients with uncomplicated disease. For diagnosis and staging, contrast-enhanced CT remains the gold standard, with the WSES proposing a practical, CT-based classification system to guide clinical management. C-reactive protein (CRP) is highlighted as a crucial biomarker for assessing severity, with levels above 150-175 mg/l indicating a higher risk of complications.
In cases of complicated diverticulitis, the guidelines offer specific strategies. For diffuse peritonitis, primary resection with anastomosis is now favored over Hartmann’s procedure in stable patients due to significantly higher stoma reversal rates. Hartmann's procedure remains the standard for critically ill or highly comorbid patients. The use of laparoscopic lavage is not recommended as a first-line treatment, based on results from the SCANDIV, LADIES, and DILALA trials showing high failure rates. For high-risk groups, such as immunocompromised patients, the guidelines stress a high index of suspicion for treatment failure and the frequent need for surgical intervention. The principles outlined for left-sided diverticulitis are also deemed applicable to right-sided disease.
Introduction and Epidemiology
Acute colonic diverticulitis is a prevalent clinical condition in emergency surgery. While traditionally more common in elderly populations in Western countries, its incidence is rising globally and seeing a dramatic increase in younger age groups (under 50 years).
Acute Left-Sided Colonic Diverticulitis (ALCD): Common in Western countries, with the sigmoid colon being the most frequently involved segment. The lifetime risk of developing ALCD among individuals with diverticulosis is estimated at approximately 4%.
Acute Right-Sided Colonic Diverticulitis (ARCD): Rarer than ALCD in the West but more common in non-Western populations. It typically presents as a solitary diverticulum and has a lower rate of complication.
Diagnosis and Staging
The guidelines recommend a comprehensive diagnostic approach that combines clinical evaluation, laboratory markers, and radiological imaging, cautioning against reliance on clinical examination alone due to its low accuracy.
Diagnostic Approach and Key Biomarkers
A combination of the following is suggested for diagnosis:
Clinical Assessment: History and signs, such as acute pain or tenderness in the left lower quadrant.
Laboratory Markers: White blood cell count (WBC) and C-reactive protein (CRP) are key inflammatory markers.
Radiological Findings: Imaging is crucial for confirming the diagnosis and staging severity.
C-Reactive Protein (CRP) has been identified as a particularly useful biomarker for predicting the clinical severity of acute diverticulitis.
A CRP cutoff of 170 mg/l was found to significantly discriminate between severe and mild diverticulitis with high sensitivity (87.5%) and specificity (91.1%).
Another study found a cutoff of 149.5 mg/l to distinguish complicated from uncomplicated cases.
A CRP value over 150 mg/l and old age were identified as independent risk factors for complicated disease.
In one prospective study, a CRP cutoff of 173 mg/l was the optimal value for predicting severe disease (Hinchey > Ib) with 90.9% sensitivity and specificity.
Caution: The expert panel notes that CRP levels may be low in the first 6-8 hours of symptom onset and peak at 48 hours, so a low initial value should be interpreted with care.
Imaging Modalities
Contrast-Enhanced CT Scan: Recommended as the first-choice imaging technique. It is the gold standard for both diagnosis and staging due to its excellent sensitivity and specificity. CT can identify colon wall thickening, fat stranding, abscess formation, extraluminal gas, and free fluid.
Ultrasound (US): Suggested as a viable initial evaluation tool, especially when performed by an expert operator, due to its accessibility. A step-up approach, where a CT scan is performed after an inconclusive US, is considered a safe and effective strategy.
Classification Systems
While several classification systems exist (e.g., Hinchey, Neff, Ambrosetti), none has been proven superior. The guidelines highlight the WSES classification, a simple system based on CT findings, as a practical tool for guiding management.
WSES CT-Guided Classification of Acute Left-Sided Colonic Diverticulitis
Management of Uncomplicated Diverticulitis
The guidelines advocate for a significant shift towards conservative and less invasive management for uncomplicated diverticulitis in appropriate patient populations.
Antibiotic Therapy
Recommendation: Antibiotics are not recommended for immunocompetent patients with uncomplicated diverticulitis who show no signs of systemic inflammation (Strong recommendation, high-quality evidence).
Evidence: Multiple randomized controlled trials, including the DIABOLO trial, have shown that antibiotic treatment neither accelerates recovery nor prevents complications or recurrence compared to observational management.
Exceptions: Antibiotic therapy covering Gram-negative bacilli and anaerobes is still suggested for high-risk patients (e.g., immunocompromised, elderly, significant comorbidities) or those with systemic signs of infection. If antibiotics are required, oral administration is preferred when possible.
Outpatient Management
Recommendation: Outpatient treatment is suggested for patients with uncomplicated ALCD who have no significant comorbidities and are able to tolerate oral fluids (Weak recommendation, moderate-quality evidence).
Evidence: Multiple studies, including the DIVER trial, have demonstrated that outpatient management is safe and effective for the vast majority (over 94%) of selected patients. This approach significantly reduces healthcare costs without negatively impacting quality of life. The overall failure rate in an outpatient setting is low, at approximately 4.3%.
Follow-up: Patients managed as outpatients should be re-evaluated within 7 days, or earlier if their clinical condition deteriorates.
Colonic Evaluation After Treatment
Recommendation: Routine colonic evaluation (e.g., colonoscopy) is not recommended for patients after a CT-proven episode of uncomplicated diverticulitis (Weak recommendation, moderate-quality evidence).
Rationale: The risk of underlying colorectal cancer (CRC) in this population is low (approximately 1.16%), which is comparable to screening populations.
In Contrast: Early colonic evaluation (4-6 weeks) is suggested for patients treated non-operatively for a diverticular abscess, as the risk of an underlying malignancy mimicking complicated diverticulitis is significantly higher (11.4% in one study).
Management of Complicated Diverticulitis
For complicated disease, management is stratified based on CT findings and the patient's clinical stability.
Abscesses and Pericolic Gas
Pericolic Gas: For patients with CT findings of pericolic extraluminal gas, a trial of non-operative treatment with antibiotics is suggested, but requires a high index of suspicion for clinical deterioration.
Small Abscess (< 4-5 cm): An initial trial of non-operative treatment with antibiotics alone is suggested. This approach is considered safe and effective, with a pooled failure rate of 20%.
Large Abscess (≥ 4-5 cm): The suggested treatment is percutaneous drainage combined with antibiotic therapy. If drainage is not feasible, antibiotic therapy alone may be attempted in stable patients, with careful clinical monitoring and a low threshold for surgical intervention.
Surgical Management of Diffuse Peritonitis
Surgical intervention is required for patients with generalized peritonitis. The choice of procedure depends on the patient's physiological state.
Laparoscopic Lavage: This is not considered a first-line treatment for diffuse peritonitis from diverticular perforation (Weak recommendation, high-quality evidence). Major trials (SCANDIV, LADIES, DILALA) showed that while mortality was comparable to resection, lavage was associated with a higher rate of treatment failure, need for reoperation, and intra-abdominal abscess formation.
Hartmann’s Procedure (HP) vs. Primary Anastomosis (PA):
HP is recommended for managing diffuse peritonitis in critically ill (unstable) patients and those with multiple comorbidities (Strong recommendation).
Primary Resection with Anastomosis (with or without a diverting stoma) is suggested for clinically stable patients without comorbidities (Weak recommendation). Evidence from the DIVERTI and LADIES trials shows that while short-term morbidity and mortality are similar, PA results in a significantly higher rate of stoma reversal (96% vs. 65% in one trial).
Laparoscopic Resection: Emergency laparoscopic sigmoidectomy is considered feasible in experienced centers for selected stable patients, but low-quality evidence precludes a general recommendation over open surgery.
Damage Control Surgery (DCS): This strategy, involving an initial source-control operation followed by resuscitation and a planned second-look surgery for reconstruction, is suggested for hemodynamically unstable patients in physiological extremis.
Special Populations and Considerations
Immunocompromised Patients
These patients are at high risk for complicated ALCD and failure of non-operative treatment.
They often require urgent surgical intervention, which is associated with significantly higher mortality (31.6% post-operative mortality in one study).
Chronic corticosteroid therapy is a notable risk factor.
Elective Resection After Conservative Treatment
The decision to perform an elective sigmoid resection should be made on a case-by-case basis, considering patient-related factors like ongoing symptoms, disease complexity, operative risk, and patient preference.
The indication is no longer based on a fixed number of recurrences, as the risk of a complicated recurrence after an uncomplicated episode is rare (<5%).
Elective resection is suggested for high-risk patients, such as the immunocompromised.
Acute Right-Sided Colonic Diverticulitis (ARCD)
ARCD differs clinically from ALCD (often solitary, occurs in younger patients), but the principles of diagnosis and treatment are considered similar.
Non-operative management should be the preferred initial approach in the absence of diffuse peritonitis.
Antibiotic Therapy in Complicated Diverticulitis
Regimen Selection: Empiric antibiotic therapy should be chosen based on the patient's clinical condition, presumed pathogens (Gram-negatives and anaerobes), and risk factors for resistant organisms, such as ESBL-producing Enterobacteriaceae.
Duration: For complicated cases where adequate surgical source control has been achieved, a 4-day course of postoperative antibiotics is suggested. The STOP IT trial demonstrated this duration is non-inferior to longer courses.
