Abstract: A total of 1831 participants were randomised to drain (915 participants) versus 'no drain' (916 participants) in 12 trials included in this review. Only two trials including 199 participants were of low risk of bias. Nine trials included patients undergoing elective laparoscopic cholecystectomy exclusively. One trial included patients undergoing laparoscopic cholecystectomy for acute cholecystitis exclusively. One trial included patients undergoing elective and emergency laparoscopic cholecystectomy, and one trial did not provide this information. The average age of participants in the trials ranged between 48 years and 63 years in the 10 trials that provided this information. The proportion of females ranged between 55.0% and 79.0% in the 11 trials that provided this information. There was no significant difference between the drain group (1/840) (adjusted proportion: 0.1%) and the 'no drain' group (2/841) (0.2%) (RR 0.41; 95% CI 0.04 to 4.37) in short-term mortality in the ten trials with 1681 participants reporting on this outcome. There was no significant difference between the drain group (7/567) (adjusted proportion: 1.1%) and the 'no drain' group (3/576) (0.5%) in the proportion of patients who developed serious adverse events in the seven trials with 1143 participants reporting on this outcome (RR 2.12; 95% CI 0.67 to 7.40) or in the number of serious adverse events in each group reported by eight trials with 1286 participants; drain group (12/646) (adjusted rate: 1.5 events per 100 participants) versus 'no drain' group (6/640) (0.9 events per 100 participants); rate ratio 1.60; 95% CI 0.66 to 3.87). There was no significant difference in the quality of life between the two groups (one trial; 93 participants; SMD 0.22; 95% CI -0.19 to 0.63). The proportion of patients who were discharged as day-procedure laparoscopic cholecystectomy seemed significantly lower in the drain group than the 'no drain' group (one trial; 68 participants; drain group (0/33) (adjusted proportion: 0.2%) versus 'no drain' group (11/35) (31.4%); RR 0.05; 95% CI 0.00 to 0.75). There was no significant difference in the length of hospital stay between the two groups (five trials; 449 participants; MD 0.22 days; 95% CI -0.06 days to 0.51 days). The operating time was significantly longer in the drain group than the 'no drain' group (seven trials; 775 participants; MD 5.00 minutes; 95% CI 2.69 minutes to 7.30 minutes). There was no significant difference in the return to normal activity and return to work between the groups in one trial involving 100 participants. This trial did not provide any information from which the standard deviation could be imputed and so the confidence intervals could not be calculated for these outcomes. There is currently no evidence to support the routine use of drain after laparoscopic cholecystectomy. Further well designed randomised clinical trials are necessary.

Plain-language summary: A total of 1831 participants received drain (915 patients) versus 'no drain' (916 patients) in 12 trials included in this review. The decision of whether the patients received drain or not was determined by a method similar to toss of a coin. Only two trials including 199 patients were of low risk of bias (free from errors in study design that can result in wrong conclusions, leading to overestimation of benefits and to underestimation of harms of the drainage or no drainage). Nine of the 12 trials included patients who underwent planned operations. The average age of participants in the trials ranged between 48 years and 63 years in the 10 trials that provided this information. The proportion of females ranged between 55.0% and 79.0% in the 11 trials that provided this information. There was no significant or clinically important differences in the short-term mortality, serious complications, quality of life, length of hospital stay, operating time, return to normal activity, or return to work in the trials that reported these outcomes. The proportion of patients who were discharged as day-procedure laparoscopic cholecystectomy seemed significantly lower in the drain group than in the 'no drain' group in one trial of high risk of bias involving 68 participants. Currently, there is no evidence to support the use of drain after laparoscopic cholecystectomy. Further well-designed randomised clinical trials are necessary.