2117 Matched Cohort Analysis of the Complications and Clinical Outcomes Following Incidental Durotomies During Spine Surgery

INTRODUCTION: Incidental durotomies occur in 1.8% to 17.4% of spine surgeries, and have been reported to increase care costs and prolonged hospitalization. Despite the espoused negative impact on these immediate outcomes, there remains heterogeneity in the reported literature characterizing the resultant complications and clinical outcomes. METHODS: All neurosurgical spine surgeries performed between January 2018 and August 2023 at a large, multicenter academic institution were identified. Data were extracted on patient demographics, operative parameters, perioperative complications, and short-term (30-day, 90-day) outcomes. Univariate and multivariate analyses were performed to determine the difference in baseline risk factors between the cohorts with and without incidental durotomy. Optimal individual matching was performed to create two similar cohorts at a 4:1 ratio on 44 baseline variables. Operative duration, hospitalization duration, perioperative complications (including surgical site infection), and 30-day and 90-day readmission and reoperation were examined. RESULTS: A total of 20,985 spine surgery cases were included, of which 1,133 experienced an incidental durotomy (prevalence 5.3%). The matched 4:1 cohort yielded 3,535 patients (707 with durotomy). Patients with incidental durotomies had significantly longer mean operative time (350 vs. 329 minutes, p<0.01), greater mean blood loss (759 vs. 464 mL, p<0.01), and longer hospitalization duration (6 days vs. 4.9 days, p<0.01). They were also more likely to undergo non-home discharge (27.6% vs 22.8%; p=0.03). Patients experiencing durotomies also had higher rates of postoperative complications at 30 days (13.2% vs 9.0%; p<0.01), including surgical site infections (3% vs 1.1%, p<0.01), venous thromboembolism (2.4% vs 1.2%, p<0.01), as well as 30- and 90-day readmissions (15.4 vs 11.2%; p<0.01 at 30-day; 19.9 vs 14.6%; p<0.01 at 90-day) and reoperations (10.7 vs 8.0%;p=0.02 for both 30- and 90-day). CONCLUSIONS: Durotomies were independently associated with an increased risk of additional postoperative complications and morbidity. Further examination of the financial costs and long-term implications of incidental durotomy are merited.