Analysis Of The Risk Factor Of Postoperative Anastomotic Leakage And Construction Of A Nomogram Prediction Model

Background:Anastomotic leakage is one of the most serious postoperative complications of colorectal cancer patients. It can not only affect the recovery of patients, but also delay the treatment and even lead to a higher mortality. For patients received colorectal surgery, preventive ileostomy is the main approach to prevent anastomotic leakage. However, one thing confuses colorectal surgeons is the risk factor of anastomotic leakage being not clear and difficult to predict Colorectal surgeons always perform the preventive ileostomy by personal experiences which seems to be not scientific enough. The present study is going to build a standard system via the use of Nomogram to objectively predict the risk of anastomotic leakage.Material and Methods:We retrospectively collected colorectal cancer patients from 2007 to 2010 in the department of surgical oncology of the second affiliated hospital of Zhejiang University school of medicine. These patients all received either elective or emergency surgery. Through single factor and multi-factor logistic regression analysis, we selected several related risk factors of anastomotic leakage. These risk factors were used to construct the Nomogram by R studio and then each factor had a Nomo score. The Nomo decisions carried out according to Nomo score were finally compared with clinical decisions.Results:453 patients were enrolled in the study.43 cases had received preventive ileostomy while 410 cases hadn’t. Anastomotic leakage happened in 30 cases (7.3%). Single factor analysis showed that patients whose age< 70 (p= 0.046), surgical site located in rectum (p= 0.006), operation time> 150 min (p= 0.003), and mass from the anus with 7 cm or less (p< 0.001), anastomotic anal distance with 5 cm or less (p= 0.012) are more likely to suffer from anastomotic leakage. Then logistic multifactor regression analysis showed that the operation time> 150 min (p= 0.009, OR= 4.009, CI 1.41211.368), and mass frorrrthe anus from 7 cm OR less (p= 0.001, OR= 7.589, CI 2.21226.037) were independent risk factors of anastomotic leakage. Based on the results of single factor and multiple factors regression analysis we built the Nomogram. According to the Nomogram, each risk factor had a Nomo score, we defined age less than 70 years old 46 points, the surgery time more thanl50 minutes 72 points and the distance of mass from anal less than 7 centimeters 100 points. The Nomo decision were then established which suggested that there was no need to perform preventive ileostomy with patients whose Nomo score was 118 or less while patients with Nomo score more than 118 points should receive a preventive ileostomy.With the Nomo decision, the incidence of anastomotic leakage (3.9%) was lower than that reported in previous paper.Conclusion:In this research we built a more effective, objective and quantitative evaluation system for colorectal surgeon. Nomo score indicator, named as Nomo decision, was used to determine if it was necessary to perform a preventive ileostomy. Nomo decision showed that there was no need to perform preventive ileostomy with patients whose Nomo score was 118 or less while patients with Nomo score more than 118 points should receive a preventive ileostomy. This study also compared Nomo decision with clinical decision and found Nomo decision could significantly reduce the incidence of anastomotic leakage.Nomo decisions may help colorectal surgeons assess the risk of anastomotic leakage much easier, and make preventive ileostomy selection more scientific, which would lead to a significantly reduce the incidence of postoperative anastomotic leakage in colorectal cancer patients.