Construction Of Clinical Predictive Model For Difficult Laparoscopic Cholecystectomy And Clinical Retrospective Study Of Posterior Wall Sparing Cholecystectomy

Objective:To screen the risk factors affecting difficult laparoscopic cholecystectomy,construct a clinical prediction model and evaluate the model and internal validation,and demonstrate the safety,efficacy and simplicity of laparoscopic cholecystectomy with partial preservation of the posterior wall of the gallbladder in difficult laparoscopic cholecystectomy.Methods:The clinical data of patients who underwent laparoscopic cholecystectomy in the Department of General Surgery 2 of the Second Hospital of Lanzhou University from January 2017 to May 2020 were collected.1.The 75th percentile of operation time(P₇₅)was used as the segmentation point to divide the Conventional Laparoscopic Cholecystectomy（CLC）and Difficult Laparoscopic Cholecystectomy（DLC）group.Logistic regression was used to analyze the risk factors affecting the degree of difficulty in laparoscopic cholecystectomy,the Nomogram prediction model of difficult cholecystectomy was constructed and internally validated using R software.Index of concordance（C-index）,Receiver Operating Characteristic Curve（ROC）,Calibration Plot and Decision Curve Analysis（DCA）were used to evaluate the model and draw the Clinical Impact Curve.2.The clinical data of patients in the laparoscopic cholecystectomy group with partial preservation of the posterior wall of the gallbladder and patients in the laparoscopic total cholecystectomy group were matched 1:2 using the propensity score method to investigate the safety,efficacy,and simplicity of laparoscopic cholecystectomy with preservation of the posterior wall by comparing the preoperative indicators,operation time,intraoperative blood loss,and incidence of complications,and the included cases were followed up for 1 month after surgery.Results:1.A total of 239 patients were included in the prediction model construction,and the operation time P₇₅ was 80 min,including 51 patients in the DLC group,including 1 patient who was converted to laparotomy;2.Multivariate analysis showed that BMI>25 kg/m²,impacted stones in the neck of the gallbladder,combined gallbladder effusion,thickness of the gallbladder wall>0.3 cm,and history of upper abdominal surgery were independent risk factors for difficult laparoscopic cholecystectomy;3.Both constructed clinical prediction models have high discrimination,calibration,and clinical utility,and internal validation results show good predictive ability of the two prediction models;4.A total of 42 patients were included in the study after the application of propensity score,including 28 patients in the laparoscopic total cholecystectomy group and 14patients in the posterior wall preservation group;5.There was no significant difference in blood routine and blood biochemistry before and after operation between laparoscopic cholecystectomy group and posterior wall preservation group.The thickness of gallbladder wall was significantly thicker in posterior wall preservation laparoscopic cholecystectomy group,and the difference had statistical significance（P<0.05）;6.Compared with laparoscopic total cholecystectomy group,laparoscopic cholecystectomy group with partial preservation of posterior wall of gallbladder had operation time（P<0.05）,but there was no statistical difference in intraoperative blood loss and postoperative hospital stay between the two groups.There was no difference in the follow-up observation results at 1 month after operation between the two groups.Conclusions:1.BMI>25 kg/m²,impacted stones in the neck of the gallbladder,combined gallbladder effusion,thickness of the gallbladder wall>0.3 cm,and previous history of upper abdominal surgery are independent risk factors for difficult laparoscopic cholecystectomy;2.The Nomogram clinical prediction model 1constructed by the study has high discrimination,consistency and clinical practicability.3.Laparoscopic cholecystectomy with preservation of part of the posterior wall of the gallbladder is safe and effective,which can significantly reduce the difficulty of complex gallbladder surgery and has great advantages in the management of difficult gallbladders such as significant thickening of the gallbladder wall,difficulty in separating the gallbladder wall into the liver bed too deeply,abnormally short cystic duct,and acute subacute and gangrenous cholecystitis.