Impact of circular stapler size on anastomotic complications after low colorectal anastomosis: a systematic review and meta-analysis.

INTRODUCTION Despite advancements in colorectal surgery, anastomotic complications such as leakage and stricture remain significant challenges. The influence of circular stapler size on these outcomes is controversial. This meta-analysis evaluates the impact of stapler diameter on anastomotic morbidity following low colorectal anastomosis. EVIDENCE ACQUISITION A systematic search of PubMed, Google Scholar, and the Cochrane Central Register was conducted in accordance with PRISMA guidelines. Comparative studies that reported outcomes based on circular stapler size were included. Primary endpoints were anastomotic leak, stricture, bleeding, and overall anastomotic morbidity. Secondary outcomes included overall morbidity, major complications, reoperation, readmission, and operative time. Odds ratios (ORs) and standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. The ROBINS-I and GRADE tools were used to assess the risk of bias and quality of evidence. EVIDENCE SYNTHESIS Seven studies comprising 2214 patients (small stapler size (<30 mm): N.=859, large stapler size (≥30 mm): N.=1355) were included. Use of larger staplers was associated with a significantly lower incidence of anastomotic stricture (OR=2.31, 95% CI: 1.48-3.60, P=0.0002), with low heterogeneity (I2=5%). No significant differences were observed in anastomotic leak, bleeding, or overall anastomotic morbidity. Secondary outcomes, including overall and major morbidity, readmission, reoperation, and operative duration, also showed no significant differences between stapler sizes. CONCLUSIONS Larger circular staplers are associated with a reduced risk of anastomotic stricture following low colorectal anastomosis, without increasing other postoperative complications. These findings support the consideration of larger stapler diameters when anatomically feasible. Further high-quality prospective studies are warranted to validate these results and guide surgical decision-making.