ACP: Most Diverticulitis Cases Can Be Treated in the Outpatient Setting

Most patients with uncomplicated cases of acute diverticulitis can be managed in an outpatient setting and antibiotics can be avoided in some, while the use of mesalamine to prevent recurrence should be avoided, according to a pair of new guidelines from the American College of Physicians (ACP).

The first guideline from Amir Qaseem, MD, PhD, of the ACP in Philadelphia, and members of the organization’s clinical guidelines committee, focuses on diverticulitis diagnosis and management, while the second offers recommendations on preventing recurrence and the role of colonoscopy for the diagnostic evaluation of colorectal cancer (CRC) in patients with suspected cases of diverticulitis.

Both were published in Annals of Internal Medicine.

Diagnosis and Management

Based on a systematic review of randomized trials and observational studies, ACP included three recommendations for clinicians regarding the diagnosis and management of acute left-sided colonic diverticulitis:

1. Use abdominal CT in cases of diagnostic uncertainty (conditional recommendation based on low-certainty evidence)
2. Manage most uncomplicated cases in an outpatient setting (conditional recommendation based on low-certainty evidence)
3. Initially manage select immunocompetent patients with uncomplicated diverticulitis without antibiotics (conditional recommendation based on low-certainty evidence)

“Select patients can be managed without antibiotics,” Qaseem told MedPage Today, adding that “physicians need evidence-based guidance for timely and correct diagnosis to ensure appropriate management.”

Regarding diagnosis, the review found moderate-certainty evidence that CT imaging with contrast had a pooled sensitivity and specificity of 94% and 99%, respectively, versus follow-up diagnosis, clinical data, laboratory reports, and operative and histologic reports in surgical patients. In addition, low-certainty evidence “showed that misdiagnoses with CT may not be associated with downstream adverse sequelae, although the effect on patient outcomes is unclear.”

Abdominal ultrasound may be substituted if CT is not feasible, followed by abdominal MRI, if only inconclusive results are provided by ultrasound, the group noted.

“Clinicians should err on the side of imaging in patients with predictors of progression to complicated diverticulitis,” such as “a symptom duration before clinical presentation of longer than 5 days and signs of perforation, bleeding, obstruction or abscess,” according to the guideline.

Uncomplicated cases involve localized inflammation from large intestinal diverticula, while complicated cases involve inflammation linked to “an abscess, a phlegmon, a fistula, an obstruction, bleeding or a perforation,” Qaseem and colleagues noted.

For the recommendation on outpatient management, ACP pointed to the “absence of evidence suggesting a benefit of routine hospitalization for patients with acute uncomplicated diverticulitis.”

On initially avoiding antibiotics in “select” patients, the review of examined studies found that “antibiotics did not reduce the risk for any critical or important outcomes,” and that initial management should include “watchful waiting.” But this recommendation was reserved for patients without “systemic inflammatory response or immunosuppression, who are not medically frail, do not require hospitalization, and can follow up as an outpatient under medical supervision.”

Diagnostic Colonoscopy and Preventing Recurrence

The second set of guidelines focused on the role of colonoscopy for diagnostic evaluation of CRC, as well as the prevention of recurrent diverticulitis, and also includes three recommendations:

1. Refer patients with complicated left-sided colonic diverticulitis for colonoscopy, after an initial episode, if they have not had one recently (conditional recommendation based on low-certainty evidence)
2. Avoid using mesalamine to prevent diverticulitis recurrence (strong recommendation based on high-certainty evidence)
3. Discuss elective surgery to prevent diverticulitis after initial treatment for complicated cases or for uncomplicated cases that remain persistent or recur frequently (conditional recommendation based on low-certainty evidence)

The guideline committee noted that a CRC diagnosis at 1 or 2 years follow-up after an acute diverticulitis case “may not differ between patients who did or did not have a colonoscopy within about 2 to 12 months” (OR 1.77, 95% CI 0.79-3.99).

However, “the identified CRC cases and high-risk colonic neoplasia in the included studies occurred mostly in patients with complicated diverticulitis,” the authors wrote, and other research showed those with complicated cases “had higher prevalence of CRC, advanced colonic neoplasia and advanced adenomas.”

For their second recommendation, the group found that use of aminosalicylate (5-ASA) mesalamine resulted in no difference in recurrent diverticulitis risk versus placebo (absolute difference 2.7%, 95% CI -1.6% to 7.5%), may not improve symptoms, and was associated with more discontinuation due to adverse events.

ACP also recommended a “team-based approach” to elective surgical decisions in patients with persistent, uncomplicated diverticulitis or complicated diverticulitis.

While high-certainty evidence showed that recurrence rates were lower among patients with “smoldering” symptoms (persisting more than 3 months) or frequent recurring symptoms (three or more episodes in 2 years) who underwent surgery, the “evidence was very uncertain (insufficient) on the effect of elective surgery compared with conservative management on mortality, length of hospital stay, total serious adverse events, and quality of life, and to evaluate predictors of surgery-related adverse events.”

According to the guideline, “the informed decision whether or not to undergo surgery should be personalized based on a discussion of potential benefits, harms, costs, and patient’s preferences.”