Incidence, Risk Factors, and Clinical Implications of Postoperative Hematoma Requiring Reoperation Following Anterior Cervical Discectomy and Fusion

Study Design. Retrospective study of prospectively collected data. Objective. To determine the incidence, timing, risk factors, and clinical implications of postoperative hematoma requiring reoperation after anterior cervical discectomy and fusion (ACDF). Summary of Background Data. Postoperative hematomas requiring reoperation are rare but potentially catastrophic complications after ACDF. However, there has been a lack of large cohort studies investigating these complications in the ACDF population despite increasing outpatient procedure volume. Methods. Patients who underwent ACDF in the 2012 to 2016 National Surgical Quality Improvement Program database were identified. The primary outcome was an occurrence of hematoma requiring reoperation within 30 days postoperatively. Risk factors for this outcome were identified using multivariate regression. Postoperative length of stay, subsequent complications, and mortality were compared between patients who did and did not develop a hematoma requiring reoperation. Results. A total of 37,261 ACDF patients were identified, of which 148 (0.40%) developed a hematoma requiring reoperation (95% confidence interval [CI], 0.33%–0.46%). Of the cases that developed this complication, 37% occurred after discharge. Risk factors for the development of hematoma requiring reoperation were multilevel procedures (most notably ≥3 levels, relative risk [RR] = 3.14, 95% CI = 1.86–5.32, P < 0.001), preoperative international normalized ratio >1.2 (RR = 2.85, 95% CI = 1.42–5.71, P = 0.006), lower BMI (notably body mass index ≤24, RR = 2.11, 95% CI = 1.21–3.67, P = 0.008), American Society of Anesthesiologists classification ≥3 (RR = 2.07, 95% CI = 1.47–2.91, P < 0.001), preoperative anemia (RR = 1.71, 95% CI = 1.12–2.63, P = 0.027), and male sex (RR = 1.67, 95% CI = 1.18–2.37, P = 0.004). In addition, patients who developed a hematoma requiring reoperation before discharge had a longer length of stay. Further, those who developed a hematoma requiring reoperation were at higher risk for subsequent ventilator requirement, deep wound infection, pneumonia, and reintubation. Conclusion. Postoperative hematoma requiring reoperation occurred in approximately 1 in 250 patients after ACDF. High-risk patients should be closely monitored through the perioperative period. Level of Evidence: 3