104 - Efficacy and Value of Mechanical Only DVT Prophylaxis in Spine Surgical Patients

Introduction:
Deep Vein Thrombosis (DVT) occurs when a blood clot forms in a deep vein, typically the lower extremity or pelvis. Post-operative patients are at risk of developing DVT due to reduced mobility and induced prothrombotic states. Proposed treatment options include early mobilization, mechanical prophylaxis, pharmacologic agents, and venous filters. The incidence of DVT after spine surgery has been reported ranging 0.3% to 31%. Given the concerns of postoperative epidural hematoma, pharmaceutical prophylaxis carries added risk in spine patients. In addition to morbidity, there is significant cost associated with DVT treatment. This study demonstrates the efficacy and value of mechanical prophylaxis via sequential compression device (SCD) and early mobilization for DVT prevention with spine surgery patients.

Methods:
This study retrospectively reviewed 432 consecutive open spine cases performed at a single facility by a single surgeon. Five patients were excluded given Cardiology recommended pharmaceutical prophylaxis, leaving 427 cases exclusively using knee high elastic compression stockings and SCD for 30 days. Patients were mobilized the day of surgery, and most were discharged that same day. Patients were examined at 6 and 12 weeks post-operatively. Patients were questioned regarding symptoms and examined for signs of DVT such as Homan signs, leg edema and calf swelling and tenderness. Patient histories were used to determine whether DVT was diagnosed or treated at any outside facility.

Results:
Retrospective review of prospectively collected data was performed on 427 spine surgical patients (Table 1). All cases were treated exclusively with mechanical prophylaxis and mobilization. All patients were followed for a minimum of 3 months. No study patients exhibited histories or exams consistent with DVT in the 3 month post operative period. There were no patients diagnosed or treated for DVT.

Conclusion:
Historically, as noted by Vacarro et al, there has been no consensus standard of care for DVT prophylaxis in postoperative spine patients. While pharmaceutical prophylaxis is common in other Orthopedic subspecialties, there are added concerns for bleeding such as epidural hematoma formation after spine surgery that can cause significant morbidity. Utilization of mechanical prophylaxis through pneumatic SCD and early mobilization eliminates the risk associated with pharmaceutical prophylaxis. Cost is an added consideration in healthcare, and DVT has been shown by Ollendorf et al. to cost an estimated additional $8000.00 per case with an average DVT incidence of 3.0%. In our study of 427 consecutive spine surgical cases, mechanical prophylaxis demonstrated a 100% efficacy as no patient developed clinical DVT in the 90 day post-operative monitoring period. In addition to preventing complications for the patient, approximately $100,000.00 was saved in average treatment costs for DVT. While other variables exist that may affect outcomes, our study would suggest that mechanical prophylaxis with patient mobilization can effectively reduce the risk of post-operative DVT and eliminate post-operative bleeding risks associated with pharmacologic prophylaxis in the spine surgery patient.
References
Vacarro et. al “Venous Thromboembolism Prophylaxis in Spine Surgery” JAAOS 2018.
Ollendorf et al. “Cost of Venous Thromboembolism Following Major Orthopedic Surgery in Hospitalized Patients” in Am J Health Syst Pharm. 2002.