Analysis Of Risk Factors Of Anastomotic Leakage After Rectal Cancer Operation And Construction Of Predictive Model

BackgroundAnastomotic leakage is one of the most important complications after anterior resection of rectal cancer.It causes abdominal infection,prolongs hospital stay and increases the cost of treatment.In addition,long-term complications such as anastomotic stricture,defecation dysfunction and chronic pain after anastomotic leakage will cause great harm to patients’ body and mind^[1].At the same time,most scholars believe that anastomotic leakage can lead to the delay of postoperative radiotherapy and chemotherapy,which may affect the local recurrence rate of tumor and reduce the longterm survival rate of postoperative patients^[2].Therefore,it is very important to timely and accurately predict the occurrence of anastomotic leakage and take corresponding measures to reduce the pain,burden and improve the prognosis of patients.At present,there are different opinions on the factors affecting anastomotic leakage after rectal cancer operation and the establishment of anastomotic leakage prediction model,and even some of the research conclusions are different,so there is still a lack of multicenter,large sample research results and high-quality prediction model.The purpose of this study is to analyze the risk factors of postoperative anastomotic leakage in patients with rectal cancer by collecting relevant clinical data,and build a clinical predictive model（CPM）to predict the incidence of postoperative anastomotic leakage,so as to provide reference for clinical diagnosis and treatment of medical staff.MethodsIn this study,by accessing the rectal cancer database of the Department of Gastrointestinal surgery of the first affiliated Hospital of Fujian Medical University,a total of 525 patients with rectal cancer were collected,and 382 patients were included according to the prescribed inclusion and exclusion criteria.According to the existence of anastomotic leakage,the patients were divided into two groups: anastomotic leakage group（ALG）and non-anastomotic leakage group（NALG）.The risk factors of postoperative anastomotic leakage in rectal cancer were obtained by univariate and multivariate analysis.Finally,the line diagram of the prediction model is constructed by using the results of multi-factor analysis.The receiver working curve（Receiver Operating Characteristic Curve）was used to evaluate the prediction ability of the line chart,and the bootstrap test method（Bootstrap）was used for internal verification,and the C-index was calculated to evaluate the accuracy of the prediction model.Finally,the consistency test was carried out by drawing the calibration curve.ResultsA total of 44 of the 382 patients developed postoperative anastomotic leakage,with a probability of 11.5%（44 stroke 382）.Univariate analysis showed that sex,visceral fat area（VFA）,postoperative red blood cell count,postoperative hemoglobin,postoperative hematocrit,distance from tumor to anus ≤7cm,actual hospital stay and postoperative hospital stay were related to anastomotic leakage.Age,body weight,body mass index（BMI）,hypertension,diabetes,smoking,drinking,previous malignant tumors,previous abdominal surgery,preoperative radiotherapy and chemotherapy,carcinoembryonic antigen（CEA）,carbohydrate antigen 199（CA199）,preoperative blood routine level（white blood cell count,neutrophil count,monocyte count,lymphocyte count,hemoglobin count,red blood cell count,hematocrit,platelet count）,preoperative biochemical index level(urea,creatinine,uric acid,glucose,direct bilirubin,total cholesterol,triglyceride,high density lipoprotein,low density lipoprotein,very low density lipoprotein,Apolipoprotein A1（APOA1）,apolipoprotein B（APOB）,indirect bilirubin,total protein,albumin,globulin,glutamic pyruvic transaminase（ALT）,glutamic oxaloacetic transaminase（AST）,prothrombin time（PT）,thrombin time（TT）,activated partial thromboplastin time（APTT）,international standardized coagulation ratio（INR）,fibrinogen（FIB）,ischial interspinous diameter,ischial internodular diameter,subcutaneous fat area（SFA）,operation method（laparotomy or laparoscopy）,operation time,intraoperative blood loss,preventive colostomy,anal decompression tube,intraoperative blood transfusion,ligation of left colonic artery,abdominal drainage volume from 1 to 6 days after operation,the level of blood routine after operation and the days of hospitalization before operation were not related to the final events（P>0.05）.Multivariate logistic regression analysis showed that male（OR=3.645,95% confidence interval: 1.715-7.747）,distance from the lower margin of the tumor to the anus ≤7cm（OR=2.366,95% confidence interval: 1.105-5.06）and visceral fat area（OR=1.009,95%confidence interval: 1.004-1.015）were independent risk factors for postoperative anastomotic leakage in patients with rectal cancer（all P<0.05）.Postoperative hemoglobin level（OR=0.947,95% confidence interval: 0.927～0.967,P<0.001）was an independent protective factor.According to this result,the line chart prediction model is constructed.The AUC of the line chart prediction model is 0.794（95% confidence interval: 0.719-0.869）.After being tested by Bootstrap method,the C-index value of the model is 0.794.The correction curve shows that there is a good correlation between the predicted results and the actual results（Purge 0.863）.The DCA curve shows that the prediction model has high benefit value.ConclusionMale,distance from tumor to anus ≤7cm and visceral fat area were independent risk factors of anastomotic leakage after rectal cancer operation,and postoperative hemoglobin level was independent protective factor.The line chart prediction model can effectively predict the occurrence of postoperative anastomotic leakage.