Converted laparoscopic colorectal surgery - A meta-analysis

Background: Conversion rates following laparoscopic colorectal surgery vary widely between studies, and the outcome of converted patients remains controversial. Methods: A comprehensive search of the English-language literature was updated until May 1999. Results: Twenty-eight studies on 3232 patients were considered for analysis. The overall conversion rate was 15.38%. Seventy nine percent of the studies did not include a definition for conversion; in these studies, the conversion rate was significantly lower than in the series where a specific definition was considered (13.7% vs 18.9%, chi-square test, p < 0.001). Converted patients had a prolonged hospital stay (11.38 vs 7.41 days) and operative time (209 vs 189 min) in comparison with laparoscopically completed patients (95% confidence interval (CI), 1.70-4.00 and 35.90-37.10, respectively). The factors associated with an increased rate for conversion were left colectomy (Odds Ratio [OR] = 1.061), anterior resection of the rectum (OR = 1.088), diverticulitis (OR = 1.302), and cancer (OR = 2.944) (for each parameter, Wald chi-square value, p < 0.001). Conclusions: In nonrandomized studies, the rate of laparoscopically completed colorectal resections is close to 85%. Because converted patients have a distinct outcome, a clear definition of conversion is required to compare the results of randomized trials. Such trials should also consider a 20% rate of conversion when estimating the sample size for the desired power level. It is likely that converted patients will have a significant impact on the results of future clinical research in laparoscopic colorectal surgery.