Abstract: Three trials with 392 participants met the inclusion criteria. Studies were conducted in three European countries (Switzerland, Netherlands, and Germany). The median age of participants ranged from 62 to 66 years; 53% to 64% were female. Inclusion criteria differed among studies. One trial included participants with Hinchey I characteristics as well as those who underwent Hartmann’s procedure; the second trial included only participants with "a proven stage II/III disease according to the classification of Stock and Hansen"; the third trial considered for inclusion patients with "diverticular disease of sigmoid colon documented by colonoscopy and 2 episodes of uncomplicated diverticulitis, one at least being documented with CT scan, 1 episode of complicated diverticulitis, with a pericolic abscess (Hinchey stage I) or pelvic abscess (Hinchey stage II) requiring percutaneous drainage." We determined that two studies were at low risk of selection bias; two that reported considerable dropouts were at high risk of attrition bias; none reported blinding of outcome assessors (unclear detection bias); and all were exposed to performance bias owing to the nature of the intervention. Available low-quality evidence suggests that laparoscopic surgical resection may lead to little or no difference in mean hospital stay compared with open surgical resection (3 studies, 360 participants; MD -0.62 (days), 95% CI -2.49 to 1.25; I² = 0%). Low-quality evidence suggests that operating time was longer in the laparoscopic surgery group than in the open surgery group (3 studies, 360 participants; MD 49.28 (minutes), 95% CI 40.64 to 57.93; I² = 0%). We are uncertain whether laparoscopic surgery improves postoperative pain between day 1 and day 3 more effectively than open surgery. Low-quality evidence suggests that laparoscopic surgery may improve postoperative pain at the fourth postoperative day more effectively than open surgery (2 studies, 250 participants; MD = -0.65, 95% CI -1.04 to -0.25). Researchers reported quality of life differently across trials, hindering the possibility of meta-analysis. Low-quality evidence from one trial using the Short Form (SF)-36 questionnaire six weeks after surgery suggests that laparoscopic intervention may improve quality of life, whereas evidence from two other trials using the European Organization for Research and Treatment of Cancer core quality of life questionnaire (EORTC QLQ-C30) v3 and the Gastrointestinal Quality of Life Index score, respectively, suggests that laparoscopic surgery may make little or no difference in improving quality of life compared with open surgery. We are uncertain whether laparoscopic surgery improves the following outcomes: 30-day postoperative mortality, early overall morbidity, major and minor complications, surgical complications, postoperative times to liquid and solid diets, and reoperations due to anastomotic leak. Results from the present comprehensive review indicate that evidence to support or refute the safety and effectiveness of laparoscopic surgery versus open surgical resection for treatment of patients with acute diverticular disease is insufficient. Well-designed trials with adequate sample size are needed to investigate the efficacy of laparoscopic surgery towards important patient-oriented (e.g. postoperative pain) and health system-oriented outcomes (e.g. mean hospital stay).

Plain-language summary: We identified three trials that compared the efficacy of laparoscopic surgery and open surgery. These studies included 392 participants (195 in the laparoscopic group vs 197 in the open surgery group). The method used to allocate participants based on randomisation, that is, the choice of treatment that participants received, was determined by a method similar to coin tossing, so the two groups were as similar as possible. We found that laparoscopic surgical resection may lead to little or no difference in mean hospital stay when compared with open surgical resection. Operating time was longer in the laparoscopic group by an average of 49 minutes. No important differences were observed in terms of 30-day postoperative mortality, early overall morbidity, major and minor complications, surgical complications, postoperative times to liquid and solid diets, and reoperations due to anastomotic leak. To assess quality of life, researchers used different scales at different periods of time. Although one trial reported that patients who received laparoscopic surgery had better quality of life, the other two trials showed no benefit favouring either laparoscopic surgery or open surgery. The quality of the evidence varied from low to very low owing to risk of bias (i.e. conclusions may overestimate benefits or underestimate harms because of biased study design and conduct) and limitations in the patient population sample. Well-designed trials are necessary to obtain a more accurate estimate of the benefits and safety of laparoscopic surgery over open surgery.