EP972 - Meta-Analysis of Anastomotic Techniques That Eliminate Dog Ears in Colorectal Surgery: Impact on Postoperative Outcomes

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Purpose/Background: Anastomotic leakage and stricture formation are significant postoperative complications in colorectal surgery, often exacerbated by the formation of "dog ears" at the anastomotic site. Various surgical techniques have been developed to eliminate dog ears and improve anastomotic integrity, yet the overall effectiveness of these methods has not been quantitatively assessed.

Methods/Interventions: A systematic review and meta-analysis were conducted, including seven studies (four randomized controlled trials and three observational cohort studies) with a total of 1,234 patients undergoing colorectal anastomosis. The studies were identified through comprehensive searches in PubMed, Embase, and the Cochrane Library. Pooled odds ratios (ORs) and mean differences were calculated using a random-effects model, and heterogeneity was assessed using the I² statistic.

Results/Outcomes: The pooled analysis demonstrated a significant reduction in anastomotic leakage with dog-ear eliminating techniques (OR = 0.52, 95% CI = 0.38–0.71, p < 0.001) and a reduction in stricture formation (OR = 0.65, 95% CI = 0.45–0.93, p = 0.02). The mean difference in operative time was 8.3 minutes longer with these techniques, but this increase was not statistically significant (95% CI = -2.1 to 18.7 minutes, p = 0.12). Heterogeneity was moderate for anastomotic leakage (I² = 42%) and higher for operative time (I² = 58%), reflecting variations in surgical procedures and patient complexity.The overall odds ratio (OR) was 0.52 (95% CI = 0.38–0.71, p < 0.001), indicating a 48% lower risk of leakage in the intervention group. The heterogeneity among studies was moderate (I² = 42%), suggesting a consistent effect across different surgical methods and patient demographics. The meta-analysis also indicated a significant reduction in the incidence of stricture formation with these techniques. The pooled OR was 0.65 (95% CI = 0.45–0.93, p = 0.02), representing a 35% reduction in stricture formation risk. Heterogeneity was low (I² = 25%), indicating high consistency across the studies. Güzey et al. (5) reported a stricture rate of 1.8% in the bean-shaped doughnut technique group compared to 5.3% in the control group. Kitaguchi et al. (4) also observed a significant decrease in stricture rates with their optimized anastomotic technique.
These results provide strong evidence for the effectiveness of dog-ear eliminating techniques in reducing postoperative stricture formation. Subgroup analyses were conducted to assess whether the effectiveness of dog-ear eliminating techniques varied by study design (RCTs versus observational studies) or patient characteristics (such as age or presence of comorbidities). The reduction in anastomotic leakage and stricture formation was consistent across all subgroups, with no significant interaction effects observed (p > 0.05). A funnel plot of the studies included in this meta-analysis showed no significant asymmetry, suggesting a low risk of publication bias. This was further confirmed by Egger's test (p = 0.43), indicating that the results are unlikely to be influenced by small-study effects or selective reporting

Conclusion/Discussion: Techniques that eliminate dog ears during colorectal anastomosis significantly reduce the risk of postoperative complications such as anastomotic leakage and stricture formation. These techniques offer substantial benefits and should be considered in clinical practice, particularly for patients at higher risk of complications.