Laparoscopic surgery may decrease the risk of clinical anastomotic leakage and a nomogram to predict anastomotic leakage after anterior resection for rectal cancer

Anastomotic leakage is still one of the most dreaded complications after anterior resection for rectal cancer. This study aimed to identify risk factors for anastomotic leakage and to create a nomogram for precise prediction of anastomotic leakage after anterior resection for rectal cancer. Two thousand six hundred eighteen consecutive patients who underwent anterior resection for rectal cancer with primary anastomosis, with or without diverting stoma, were retrospectively analyzed as a training dataset. Univariate and multivariable Cox regression analyses were used to determine independent risk factors associated with anastomotic leakage. A nomogram was constructed to predict anastomotic leakage. Data containing 611 patients were prospectively collected as a test dataset. The performance of the nomogram was evaluated by using a bootstrapped-concordance index and calibration plots. The rate of clinical anastomotic leakage was 9.3% in the training dataset. Multivariate analysis identifies the following variables as independent risk factors for anastomotic leakage: gender (male) (odds ratio (OR) = 2.286), distance of tumor to anal verge (OR = 0.791), tumor size (OR = 1.175), operating time (OR = 1.009), diabetes mellitus (OR = 1.704), laparoscopic surgery (OR = 0.445), anastomotic bleeding (OR = 13.46), and diverting stoma (OR = 0.386). We created a nomogram with high discriminative ability (concordance index, 0.722). The area under the curve value, which evaluated the predictive performance of external validation, was 0.723. A protective diverting stoma and laparoscopic surgery significantly decrease the risk of anastomotic leakage. Our nomogram was a useful tool for precise prediction of anastomotic leakage after anterior resection for rectal cancer.