Acute Colonic Diverticulitis Clinical Practice Guidelines (WSES, 2020)

World Society of Emergency Surgery (WSES)

This is a quick summary of the guidelines without analysis or commentary. For more information, go directly to the guidelines by clicking the link in the reference.

July 29, 2020

Updated recommendations on the management of acute left-sided colonic diverticulitis (ALCD) were released in May 2020 by the World Society of Emergency Surgery (WSES).[1] In addition to including recent changes in the management of ALCD, there is a section about advances in acute right-sided colonic diverticulitis (ARCD), a condition that is more common than ALCD in certain regions of the world.

ALCD Classification

There is no single classification system for ALCD that has been conclusively proven to be superior in predicting patient outcomes. Thus, the WSES does not provide a specific recommendation on which of the many existing classifications should be used in patients with ALCD.

WSES classification: Uncomplicated versus complicated

The WSES classification divides acute diverticulitis into uncomplicated acute diverticulitis, in which the infection only involves the colon and does not extend to the peritoneum, and complicated acute diverticulitis, in which the infectious process extends beyond the colon.

Uncomplicated acute diverticulitis has a single stage, as follows:

  • 0: Diverticula, wall thickening, increased pericolic fat density

Complicated acute diverticulitis is divided into four stages, based on the extension of the infectious process, as follows:

  • 1A: Pericolic air bubbles or a small amount of pericolic fluid without abscess (within 5 cm from inflamed bowel segment)

  • 1B: Abscess ≤4 cm

  • 2A: Abscess >4 cm

  • 2B: Distant gas (>5 cm from inflamed bowel segment)

  • 3: Diffuse fluid without distant free gas

  • 4: Diffuse fluid with distant free gas

ALCD Diagnosis

In patients with suspected ALCD, WSES suggests the following (weak recommendations):

  • Performing a complete patient assessment, including clinical history, signs, laboratory inflammation markers, and radiologic findings

  • Not making the diagnosis on the sole basis of clinical examination

Imaging in Suspected ALCD

Contrast-enhanced abdominal computed tomography (CT) scanning is the suggested imaging modality of first choice for cases of suspected ALCD (weak recommendation).

Ultrasonography (US) performed by an expert operator is suggested in the initial evaluation of suspected ALCD, as it has wide availability and easy accessibility. A step-up approach with CT scanning performed after an inconclusive or negative US may be a safe approach for patients suspected of acute diverticulitis (weak recommendation).

Immunocompromised ALCD Patients

It is suggested that immunocompromised patients with ALCD be considered at high risk for failure of standard, nonoperative treatment (weak recommendation).

Antibiotics in Uncomplicated Acute Diverticulitis

In immunocompetent patients with uncomplicated diverticulitis without signs of systemic inflammation, antibiotic therapy is not recommended (strong recommendation).

In patients requiring antibiotic therapy, oral (PO) administration is recommended whenever possible, primarily, because an early switch from intravenous (IV) to PO therapy may facilitate a shorter inpatient length of stay (strong recommendation).

Outpatient Management

Outpatient management is suggested for patients with uncomplicated ALCD and no comorbidities, with reevaluation suggested within 7 days. Reevaluate patients earlier in the setting of a deteriorating clinical condition (weak recommendation).

Best Treatment for Acute Diverticulitis With CT Findings of Pericolic Gas

In patients with CT scan findings of pericolic extraluminal gas, a trial of nonoperative treatment with antibiotic therapy is suggested (weak recommendation).

Best Treatment for Small (< 4-5 cm) or Large Diverticular Abscesses

For patients with a small (< 4-5 cm) diverticular abscess, WSES suggests an initial trial of nonoperative treatment with antibiotics alone (weak recommendation).

For patients with large abscesses, WSES suggests combination treatment with percutaneous drainage and antibiotics; whenever percutaneous drainage of the abscess is not feasible or not available, it is suggested to initially treat patients with large abscesses with antibiotic therapy alone, clinical conditions permitting. Alternatively, an operative intervention is required (weak recommendation).

Early Colonic Evaluation

In patients with diverticular abscesses treated nonoperatively, planning an early colonic evaluation (4-6 weeks) is suggested (weak recommendation).

In patients with CT-proven uncomplicated diverticulitis treated nonoperatively, routine colonic evaluation is not recommended (weak recommendation).

Role of Nonoperative Treatment When CT Scans Show Distant Gas Without Diffuse Intra-abdominal Fluid

In patients with CT scan findings of distant free gas without diffuse intra-abdominal fluid, WSES suggests a nonoperative treatment in selected patients only if a close follow-up can be performed (weak recommendation).

Diffuse Peritonitis Due to Diverticular Perforation

WSES suggests performing laparoscopic peritoneal lavage and drainage only in very selected patients with generalized peritonitis. It is not considered the first-line treatment in patients with peritonitis from acute colonic diverticulitis (weak recommendation).

A Hartmann procedure is recommended for managing diffuse peritonitis from diverticular perforation in critically ill patients and in selected patients with multiple comorbidities (strong recommendation).

In clinically stable patients with diffuse peritonitis due to diverticular perforation who have no comorbidities, WSES suggests primary resection with anastomosis with or without a diverting stoma (weak recommendation).

In patients with diffuse peritonitis due to perforated diverticulitis, WSES suggests performing an emergency laparoscopic sigmoidectomy only if technical skills and equipment are available (weak recommendation).

Acute Peritonitis Due to Diverticular Perforation

WSES suggests damage control surgery (DCS) with staged laparotomies in selected unstable patients with diffuse peritonitis due to diverticular perforation (weak recommendation).

Planning Elective Resection in Acute Diverticulitis Treated Nonoperatively

WSES suggests evaluating patient-related factors and not the number of previous diverticulitis episodes in planning elective sigmoid resection (weak recommendation).

After an episode of conservatively treated ALCD, WSES suggests planning an elective sigmoid resection in high-risk patients (eg, immunocompromised patients) (weak recommendation).

Optimal Antibiotic Therapy and Duration for Diffuse Peritonitis Due to Diverticular Perforation

Selection of an empirically designed antibiotic regimen is suggested on the basis of the patient’s underlying clinical condition, the pathogens presumed to be involved, and the risk factors for major antimicrobial resistance patterns (strong recommendation).

WSES suggests a 4-day period of postoperative antibiotic therapy in complicated ALCD if source control has been adequate (weak recommendation).

Acute Right-Sided Colonic Diverticulitis: Treatment Principles

All the statements for ALCD are suggested to also apply to ARCD. WSES indicates that although studies have shown that the percentage of complications requiring surgery is higher in patients with ALCD than in those with ARCD, the principles of diagnosis and treatment of patients with ARCD are similar to those of patients with ALCD.

For more information see Diverticulitis and Imaging in Diverticulitis of the Colon.

For more Clinical Practice Guidelines, please go to Guidelines.


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