Abstract: We included eight randomised studies encompassing 850 participants. Five studies compared titanium clips versus ligature, two studies compared an endoscopic stapler device versus ligature, and one study compared an endoscopic stapler device, titanium clips, and ligature. In our analyses of primary outcomes, we found no differences in total complications (OR 0.97, 95% CI 0.27 to 3.50, 8 RCTs, very low-quality evidence), intraoperative complications (OR 0.93, 95% CI 0.34 to 2.55, 8 RCTs, very low-quality evidence), or postoperative complications (OR 0.80, 95% CI 0.21 to 3.13, 8 RCTs, very low-quality evidence) between ligature and all types of mechanical devices. However, our analyses of secondary outcomes revealed that use of mechanical devices saved approximately nine minutes of total operating time when compared with use of a ligature (mean difference (MD) -9.04 minutes, 95% CI -12.97 to -5.11 minutes, 8 RCTs, very low-quality evidence). However, this finding did not translate into a clinically or statistically significant reduction in inpatient hospital stay (MD 0.02 days, 95% CI -0.12 to 0.17 days, 8 RCTs, very low-quality evidence). Available information was insufficient for reliable comparison of total hospital costs and postoperative pain/quality of life between the two approaches. Overall, evidence across all analyses was of very low quality, with substantial potential for confounding factors. Given the limitations of all studies in terms of bias and the low quality of available evidence, a clear conclusion regarding superiority of any one particular type of mechanical device over another is not possible. Evidence is insufficient at present to advocate omission of conventional ligature-based appendix stump closure in favour of any single type of mechanical device over another in uncomplicated appendicitis.

Plain-language summary: We searched for all relevant randomised controlled trials up to 14 June 2017. This systematic review included eight randomised controlled trials involving a total of 850 participants. All trials compared mechanical devices versus ligatures for appendix stump closure. Five of the eight trials compared use of clips versus ligature, two trials compared an automated stapler versus ligature, and one trial compared all three methods. Use of mechanical devices to close the appendix stump during laparoscopic appendectomy did not make a significant difference in the rate of overall complications when compared with use of a ligature, or in the rate of complications that happened during or after the appendectomy procedure. However, mechanical devices did make the operation nine minutes quicker when compared with ligatures. Mechanical devices did not make a substantial difference in overall hospital stay. We did not have enough information to reliably evaluate hospital costs, pain, or quality of life for either of these comparisons. As a result, we have not found enough evidence at present that would lead us to strongly recommend any particular method over another. More research should be undertaken to better compare available newer methods. The evidence used to derive our conclusions was generally of low quality. The studies we included for each analysis were vulnerable to different types of bias and contained inconsistencies and imprecision in their results due to small numbers of participants and events in each included study arm. It is likely that future research will substantially change our conclusions; further studies in this field are needed.