The True Cost of a Dural Tear Medical and Economic Ramifications of Incidental Durotomy During Lumbar Discectomy in Elderly Medicare Beneficiaries

Study Design. A retrospective database review. Objective. The aim of this study was to identify whether dural tears increase costs and the risk of wound complications and serious adverse events during the postoperative period following primary lumbar discectomy in elderly Medicare beneficiaries. Summary of Background Data. Rates of incidental durotomy during lumbar spine surgery range from 1% to 17%. The full economic and medical burden of this complication remains unclear, particularly as it occurs during lumbar discectomy in elderly patients. Methods. The full set of prospectively gathered Medicare insurance data (2005-2012) was retrospectively reviewed. Patients who underwent primary lumbar discectomy for lumbar disc herniations from 2009 to quarter 3 of 2012 were selected. This cohort (n = 41,655) was then divided into two subgroups: those who were diagnosed with incidental durotomy on the day of surgery ( n = 2052) and those who were not (control population). To select a more effective control population, patients of a similar age, gender, smoking status, diabetes mellitus status, chronic pulmonary disease status, and body mass index were chosen at random from the control population to create a control cohort. In-hospital costs, length of stay, and rates of 30-day readmission, 90-day wound complications, and 90-day serious adverse effects were compared. Results. An incidental durotomy rate of 4.9% was observed. Higher rates of wound infection [2.4% vs. 1.3%; odds ratio ( OR) 1.88; 95% confidence interval ( 95% CI): 1.31-2.70; P<0.001], wound dehiscence (0.9% vs. 0.4%; OR 2.39;95% CI: 1.314.37; P = 0.004), and serious adverse events related to incidental durotomy ( 0.9% vs. 0.2%; OR 4.10; 95% CI: 2.05-8.19; P<0.0001) were observed in incidental durotomy patients. Inhospital costs were increased by over $4000 in patients with incidental durotomy (P<0.0001). Conclusion. Incidental durotomies occur in almost one in every 20 elderly patients treated with primary lumbar discectomy. Given the increased hospital costs and complication rates, this complication must be viewed as anything but benign.