No long-term repercussions with antibiotic omission in uncomplicated acute diverticulitis
Noninclusion of antibiotics in the management of uncomplicated acute diverticulitis is feasible and fairly safe, with long-term follow-up data from the DIABOLO study showing that such a strategy does not result in increased incidence of complicated or recurrent diverticulitis or sigmoid resections over 2 years.
Short-term data from DIABOLO have initially demonstrated the noninferiority of an observational strategy to a 10-day course of amoxicillin-clavulanic acid for a first episode of uncomplicated acute diverticulitis. The primary outcome of time to recovery during 6 months’ follow-up did not significantly differ (14 vs 12 days, respectively), suggesting that antibiotics can indeed be omitted. [Br J Surg 2017;104:52-61]
The present analysis included 468 patients assigned to an observational (n=227) or an antibiotic treatment strategy (n=241) who completed the 24-month follow-up. Compared with the antibiotic group, the observation group had similar rates of secondary outcomes such as recurrent diverticulitis (15.4 percent vs 14.9 percent; p=0.885), complicated diverticulitis (4.8 percent vs 3.3 percent; p=0.403) and sigmoid resection (9.0 percent vs 5.0 percent; p=0.085) at 24 months. [Am J Gastroenterol 2018;113:1045-1052]
Significant factors associated with a heightened risk of complicated or recurrent diverticulitis were younger age (<50 years; adjusted odds ratio (OR), 1.86; 95 percent CI, 1.05–3.32) and a visual analogue pain score of ≥8 (adjusted OR, 1.89; 1.06–3.35). Treatment type was not a risk factor.
With respect to sigmoid resections, the rate was slightly higher in the observational vs antibiotic group (7.7 percent vs 4.2 percent). Indications for surgery were mostly similar.
Although not significant, the slightly higher proportion of patients undergoing elective sigmoid resection in the observational group may have several explanations, according to the investigators.
For one, patients in the observation group probably felt that they did not receive treatment (ie, antibiotics) during their initial episode and demanded therapy, regardless of being more invasive, when disease recurred. It is also possible that the observational group had a slightly less favourable disease course, as evidenced by minor disadvantages (longer time to recovery and higher rates of ongoing and complicated diverticulitis), accumulating into a disease status that leaned more towards sigmoid resection.
“As the DIABOLO trial was not powered for [the] secondary outcome measures, some uncertainty remains whether small, nonsignificant differences could be true associations,” the investigators said.
“If future research would show any beneficial effect of antibiotics for a subset of long-term outcome parameters, these should be compared with the disadvantages of antibiotics as reported in the initial DIABOLO paper,” they added.
Specifically, 8.3 percent of patients given antibiotics developed treatment-related morbidity, whereas patients without antibiotic treatment could be treated as outpatients in 13.0 percent of cases and, if admitted, length of hospital stay was significantly shorter compared with antibiotic patients.
In an accompanying commentary, Dr Anne Peery from the University of North Carolina in the US pointed out that while the present analysis provides useful insights into the natural history of acute uncomplicated diverticulitis, it might be too soon to abandon antibiotics for treating the disease. [Am J Gastroenterol 2018;113:949-950]
“Every patient with a history of acute uncomplicated diverticulitis is at risk for chronic sequelae. If antibiotics reduce the risk of developing chronic sequelae, then we should continue to treat acute uncomplicated diverticulitis with antibiotics, especially if the alternative is an increased risk of surgery [ie, sigmoid resection],” Peery wrote.
“It seems clear [that] the authors began this study with the goal of proving that withholding antibiotics is safe in this patient population. Ironically, their work ultimately suggests important new areas of concern that call for further study,” she added.