[Analysis of risk factors of anastomotic leakage after laparoscopic intersphincteric resection for low rectal cancer and construction of a nomogram prediction model]

Abstract

Objectives: To examine the risk factors of anastomotic leakage for low rectal cancers undergoing laparoscopic intersphincteric resection (ISR), and to construct a nomogram prediction model for it. Methods: The perioperative data of 302 low rectal cancer patients undergoing laparoscopic ISR by the same surgical team of Department of General Surgery, Peking University First Hospital between January 2012 and January 2019 were retrospectively reviewed. There were 190 males and 112 females, aging 60(14) years (range: 20 to 84 years). χ² test, independent sample t test, U test and Logistic regression analysis were used to analyze the risk factors for anastomotic leakage. R software was used to complete the drawing of the nomogram prediction model, and the receiver operating characteristic curve was used to evaluate the predictive ability of the nomogram prediction model. Results: There were 24 patients (7.9%) had anastomotic leakage among the 302 patients enrolled, including 10 cases of grade A leakage, 9 cases of grade B leakage, and 5 cases of grade C leakage. Out of the 24 patients, 2 patients (8.3%) died, 3 patients (12.5%) received leakage-related reoperation. Median healing time of the anastomotic leakage was 74 (58) days (range: 14 to 180 days). Univariate analysis showed male gender (P=0.009), preoperative serum albumin concentration (P=0.004), neoadjuvant radiochemotherapy (P=0.017), preserving left colonic artery (P=0.002) and performing a diverting ileostomy (P=0.015) were significantly correlated with anastomotic leakage. Logistic multivariate analysis showed male gender (OR=6.052, 95%CI: 1.535 to 23.860, P=0.010), neoadjuvant radiochemotherapy (OR=4.098, 95%CI: 1.318 to 12.821, P=0.015), no preserving left colonic artery (OR=16.699, 95%CI: 3.051 to 91.406, P=0.001) and not performing a diverting ileostomy (OR=21.218, 95%CI: 4.341 to 103.710, P<0.01) were independent risk factors for anastomotic leakage. According to the results of multi-factor regression analysis, the nomogram prediction model was constructed. The area under the curve of the nomogram prediction model was 0.840 (95%CI: 0.766 to 0.914). After internal verification, the concordance index value of the model was 0.840. Conclusion: Male gender, neoadjuvant radiochemotherapy, no preserving left colonic artery and not performing a diverting ileostomy are independent risk factors for anastomotic leakage for low rectal cancers undergoing laparoscopic ISR.