Risk factors analysis of anastomotic leakage after low anterior resection of rectal cancer

Abstract

Objective To analyze the risk factors for anastomotic leakage after low anterior resection(LAR) for rectal cancer. Methods The retrospective study of 1 336 patients with rectal cancer who underwent LAR from Jan. 2013 to Dec. 2017 in the Department of Colorectal Surgery, First Affiliated Hospital of Nanjing Medical University was conducted. There were 838 male and 498 female patients. The median age was 62 (53, 70) years. Observation indicators: ①intraoperative conditions, including the performance of preventive enterostomy, the preservation of left colic artery, the placement of transanal decompression tube; ②postoperative conditions, for example, postoperative clinical symptoms and physical examination, postoperative hospital stay. Anastomotic leakage patients were graded according to the grading system of anastomotic leakage following anterior resection of the rectum proposed by the International Study Group of Rectal Cancer in 2010. Measurement data with non-normal distribution were described as median, and comparison between groups was done using Mann-Whitney U test. Ranked data were compared with rank sum test. Comparison of count data between groups were analyzed using the Chi-square test or Fisher exact test. Potential risk factors for anastomotic leakage were further analyzed with multiple logistic regression. Results Anastomotic leakage was noted in 138(10.4%) of 1 336 patients with 93 patients (7.0%) of Grade B and 46 patients (3.4%) of Grade C respectively.The occurrence of Grade C anastomotic leakage was on the 3th day postoperatively, which was earlier than Grade B anastomotic leakage [5(3, 7) d, Z=2.746, P=0.006]. There were significant differences in sex, BMI, placement of transanal decompression tube and tumor location between anastomotic leakage cases and non-anastomotic leakage cases by Chi-squared test(χ2=10.897, 9.033, 6.343, 6.34, Z=-2.380, P<0.05). On multiple logistic regression analysis, male sex(OR=1.840, 95%CI: 1.210-2.799, P=0.004), BMI≥24 kg/m2(OR=1.573, 95%CI: 1.088-2.274, P=0.016), placement of transanal decompression tube(OR=2.418, 95%CI: 1.196-4.888, P=0.014), middle rectal cancer(OR=1.536, 95%CI: 0.836-2.822, P=0.167), low rectal cancer(OR=1.989, 95%CI: 1.068-2.822, P=0.03), ultralow rectal cancer (OR=2.908, 95%CI: 1.289-6.560, P=0.01) were independent risk factors of anastomotic leakage. Conclusion Male sex, high BMI, placement of transanal decompression tube and low rectal tumor were independent risk factors of anastomotic leakage for patients receiving LAR. Key words: Retrospective studies; Rectal neoplasms; Risk factors; Low anterior resection; Anastomotic leakage