Complications after surgery for lumbar stenosis in a veteran population

Study Design. Secondary analysis of the prospectively collected Veterans Affairs National Surgical Quality Improvement Program database. Objective. Determine rates of major medical complications, wound complications, and mortality among patients undergoing surgery for lumbar stenosis and examine risk factors for these complications. Summary of Background Data. Surgery for spinal stenosis is concentrated among older adults, in whom complications are more frequent than among middle-aged patients. Many studies have focused on infections or device complications, but fewer studies have focused on major cardiopulmonary complications, using prospectively collected data. Methods. We identified patients who underwent surgery for a primary diagnosis of lumbar stenosis between 1998 and 2009 from the Veterans Affairs National Surgical Quality Improvement Program database. We created a composite of major medical complications, including acute myocardial infarction, stroke, pulmonary embolism, pneumonia, systemic sepsis, coma, and cardiac arrest. Results. Among 12,154 eligible patients, major medical complications occurred in 2.1%, wound complications in 3.2%, and 90-day mortality in 0.6%. Major medical complications, but not wound complications, were strongly associated with age. American Society of Anesthesiologists (ASA) class was a strong predictor of complications. Insulin use, long-term corticosteroid use, and preoperative functional status were also significant predictors. Fusion procedures were associated with higher complication rates than with decompression alone. In logistic regressions, ASA class and age were the strongest predictors of major medical complications (odds ratio for ASA class 4 vs . class 1 or 2: 2.97; 95% confidence interval, 1.68-5.25; P = 0.0002). After adjustment for comorbidity, age, and functional status, fusion procedures remained associated with higher medical complication rates than were decompressions alone (odds ratio = 2.85; 95% confidence interval, 2.14-3.78; P < 0.0001). Conclusion. ASA class, age, type of surgery, insulin or corticosteroid use, and functional status were independent risk factors for major medical complications. These factors may help in selecting patients and planning procedures, improving patient safety.