A Simple Risk Score to Predict Clavien-Dindo Grade IV and V Complications After Non-elective Cholecystectomy

Background: Non-elective cholecystectomies can lead to severe postoperative complications and mortality. Existing risk prediction tools do not meet the need to reliably predict these complications. Methods: Using the 2011–2016 American College of Surgeons National Surgical Quality Improvement Program datasets, we identified patients undergoing non-elective cholecystectomy with primary ICD 9/10 codes indicating the following diagnoses: symptomatic cholelithiasis, acute cholecystitis, choledocholithiasis, gallstone pancreatitis, and cholangitis. We randomly allocated patients to derivation and validation cohorts (80/20 split). Severe complications (Clavien-Dindo grades IV and V) included unplanned intubation, prolonged mechanical ventilation, pulmonary embolism, acute renal failure requiring dialysis, stroke, myocardial infarction, cardiac arrest, septic shock, and mortality. Logistic regression using backward selection identified predictors of severe complications and a risk score was generated based on this model. Results: Of 68,953 patients in the derivation cohort, 1.7% (N = 1157) suffered severe complications. The final multivariable risk score model included the following predictors: age (0–12 points), preoperative sepsis (5 points), planned open procedure (5 points), estimated glomerular filtration rate (0–13 points), and preoperative albumin level (0–8 points). The associated risk-score model yielded scores from 0 to 43 with 0.1–59.4% predicted probability of severe complications and had a C-statistic of 0.845 (95% CI 0.834, 0.857) in the derivation cohort and 0.870 (95% CI 0.851, 0.889) in the validation cohort. Conclusion: A simple risk-score model predicts severe complications in patients undergoing unplanned cholecystectomy for common indications encountered in an acute care surgery service and identifies high-risk patients.