Risk Factors for Venous Thromboembolism following Thoracolumbar Surgery: Analysis of 43,777 Patients from the American College of Surgeons National Surgical Quality Improvement Program 2005 to 2012

Study Design Retrospective clinical study of a prospectively collected, national database. Objective Determine the 30-day incidence, timing, and risk factors for venous thromboembolism (VTE) following thoracolumbar spine surgery. Methods The American College of Surgeons National Surgical Quality Improvement Program Participant Use File identified 43,777 patients who underwent thoracolumbar surgery from 2005 to 2012. Multiple patient characteristics were identified. The incidence and timing (in days) of deep vein thrombosis (DVT) and pulmonary embolus (PE) were determined. Multivariable regression analysis was performed to identify significant risk factors. Results Of the 43,777 patients identified as having had thoracolumbar surgery, 202 cases of PE (0.5%) and 311 cases of DVT (0.7%) were identified. VTE rates were highest in patients undergoing corpectomy, with a 1.7% PE rate and a 3.8% DVT rate. Independent risk factors for VTE included length of stay (LOS) ≥ 6 days (odds ratio [OR] 4.07), disseminated cancer (OR 1.77), white blood cell count > 12 (OR 1.76), paraplegia (OR 1.75), albumin < 3 (OR 1.73), American Society of Anesthesiologists class 4 or greater (OR 1.54), body mass index > 40 (OR 1.49), and operative time > 193 minutes (OR 1.43). LOS < 3 days was protective (OR 0.427). Conclusions We report an overall 30-day PE rate of 0.5% and DVT rate of 0.7% following thoracolumbar spine surgery. Patients undergoing corpectomy were at highest risk for VTE. Multiple VTE risk factors were identified. Further studies are needed to develop algorithms to stratify VTE risk and direct prophylaxis accordingly.