Risk Factors Of Early Postoperative Small Bowel Obstruction After Radical Resection Of Rectal Cancer And Establishment Of A Nomogram Prediction Model

Objective: To investigate the incidence and independent risk factors of early postoperative small bowel obstruction(EPSBO)after radical resection of rectal cancer,and to construct an individualized prediction model(nomogram).Methods: This study is a retrospective study.From January 2018 to December 2019,a total of 579 patients with rectal cancer were selected and divided into EPSBO group and non-EPSBO group according to whether small bowel obstruction occurred after operation.The basic clinical data of the two groups were compared and analyzed.SPSS 25.0 statistical software was used to complete the statistical analysis,and the measurement data were compared by independent sample t-test or Kruskall-Wallis test;The enumeration data were tested by chi-square test or Fisher exact probability test;P<0.05 was statistically significant.The significant factors of univariate analysis were included in multivariate logistic regression analysis,and the prediction model of EPSBO after radical resection of rectal cancer was constructed based on the results of multivariate logistic regression analysis by R software.109 patients with rectal cancer treated in the general surgery center of our hospital from January 2020 to December 2020 were randomly selected as external data for verification.And the receiver operating characteristic(ROC)curves of data sets and validation sets were draw,get the sensitivity,specificity and area under the curve(AUC),judge the discrimination of the model;and draw calibration curve to judge the ability of the model to correctly estimate risk;draw the decision curve analysis(DCA)to evaluate the clinical utility of the model,and judge whether the prediction model meets the actual needs of clinical decision-making.Results: 55 of the 579 patients who underwent radical resection of rectal cancer developed EPSBO,52 patients were relieved by conservative treatment,and 3 patients were treated by surgery;The length of hospital stay in EPSBO group(21.93 ± 24.91d)was significantly higher than that in non-EPSBO group(11.96 ± 4.03d);There was no significant difference between the two groups in age(P=0.716),abdominal operation history(P=0.573),hypertension(P=0.772),diabetes mellitus(P=0.565),coronary heart disease(P=0.611),drinking history(P=0.097),ASA grading(P=0.135),BMI(P=0.473),weight loss(P=0.874),tumor distance from the anal border.And there was a significant difference between the groups in gender(P=0.038),preoperative neoadjuvant therapy(P=0.003),smoking history(P=0.003),preoperative total protein(P=0.005),preoperative serum albumin(P<0.001),preoperative prealbumin(P<0.001),operation time(P<0.001),intraoperative blood loss(P=0.013),operation procedure(P=0.022),ileostomy(P=0.004)and combined intraoperative resection of other organs(P<0.001).When the above meaningful factors were taken into multiple logistic regression analysis,the results showed that hypoalbuminemia(OR=0.891,95%CI=0.809～0.982),laparotomy(OR=3.085,95%CI=1.427～6.669),prolonged operation time(OR=1.009,95%CI=1.004～1.014),ileostomy(OR=2.737,95%CI=1.312～5.709)was an independent risk factor for EPSBO after radical resection for rectal cancer;A nomogram to predict the risk of EPSBO occurrence in radical resection of rectal cancer was constructed with R software,the ROC curve was plotted according to the prediction model showed that the model has good discrimination(internal validation AUC=0.788,external validation AUC=0.891),the calibration curve showed that the model had the ability to correctly assess the risk of EPSBO occurrence in radical resection of rectal cancer,and the DCA curve showed that the model has good clinical utility.Conclusions: Hypoalbuminemia,prolonged operation time,ileostomy and laparotomy are independent risk factors for early postoperative small bowel obstruction after radical resection of rectal cancer.The nomogram constructed in this study has excellent discrimination,calibration,and clinical utility,it can individually predict the risk of EPSBO in patients with rectal cancer,and provide prompt clinical intervention for patients with a high predicted risk may help to reduce the incidence of EPSBO after radical resection of rectal cancer.