Severity Grading, Risk Factors, and Prediction Model of Complications After Epilepsy Surgery: A Large-Scale and Retrospective Study

Purpose: To report complications after epilepsy surgery, grade the severity of complications, investigate risk factors, and develop a nomogram for risk prediction of complications. Methods: Patients with epilepsy surgery performed by a single surgeon at a single center between October 1, 2003 and April 30, 2019 were retrospectively analyzed. Study outcomes included severity grading of complications occurring in 3-month period after surgery, risk factors and prediction model of these complications. Multivariable logistic regression analysis was used to calculate odds ratio and 95% confidence interval to identify risk factors. Results: In total, 2026 surgical procedures were eligible. There were 380 patients with mild complications, 23 moderate complications, and 82 severe complications. Male (odds ratio 1.29, 95% confidence interval 1.02-1.64), age at surgery (>40 years: 2.58, 1.55-4.31; ≤40: 2.25, 1.39-3.65; ≤30: 1.83, 1.18-2.84; ≤20: 1.71, 1.11-2.63), intracranial hemorrhage in infancy (2.28, 1.14-4.57), serial number of surgery (≤1000: 1.41, 1.01-1.97; ≤1500: 1.63, 1.18-2.25), type of surgical procedure (extratemporal resections: 2.04, 1.55-2.70; and extratemporal plus temporal resections: 2.56, 1.80-3.65), surgery duration (≥6h: 1.94, 1.25-3.00; ≤6: 1.92, 1.39-2.65), and acute postoperative seizure (1.44, 1.06-1.97) were independent risk factors of complications. A nomogram including age at surgery, type of surgical procedure, and surgery duration was developed to predict the probability of complications. Conclusion: Although epilepsy surgery has a potential adverse effect on the patients, most complications were mild and severe complications were few. Risk factors should be considered during the perioperative period. Patients with above risk factors should be closely monitored to identify and treat complications timely. The prediction model is very useful for surgeons to improve the postoperative management.