Decreased incidence of venous thromboembolism after spine surgery with early multimodal prophylaxis

Abstract

Object Venous thromboembolism (VTE) represents a significant complication after spine surgery, with reported rates as high as 2%–4%. Published institutional practices for VTE prophylaxis are highly variable. In 2008, the authors implemented a departmental protocol for early VTE prophylaxis consisting of combined compressive devices and subcutaneous heparin initiated either preoperatively or on the same day of surgery. In this study, the authors compared the incidence of VTE in spine surgery patients before and after implementing this protocol. Methods An institutional review board–approved retrospective review of outcomes in patients undergoing spine surgery 2 years before protocol implementation (representing the preprotocol group) and of outcomes in patients treated 2 years thereafter (the postprotocol group) was conducted. Inclusion criteria were that patients were 18 years or older and had been admitted for 1 or more days. Before 2008 (preprotocol), VTE prophylaxis was variable and provider dependent without any uniform protocol. Since 2008 (postprotocol), a new VTE-prophylaxis protocol was administered, starting either preoperatively or on the same day of surgery and continuing throughout hospitalization. The new protocol consisted of 5000 U heparin administered subcutaneously 3 times daily, except in patients older than 75 years or weighing less than 50 kg, who received this dose twice daily. All patients also received sequential compression devices (SCDs). The incidence of VTE in the 2 protocol phases was identified by codes of the International Classification of Diseases, Ninth Revision (ICD-9) codes for deep vein thrombosis (DVT) and pulmonary embolus (PE). Bleeding complications arising from anticoagulation treatments were evaluated by the Current Procedural Terminology (CPT) code for postoperative epidural hematoma (EDH) requiring evacuation. Results In total, 941 patients in the preprotocol group met the inclusion criteria: 25 had DVT (2.7%), 6 had PE (0.6%), and 6 had postoperative EDH (0.6%). In the postprotocol group, 992 patients met the criteria: 10 had DVT (1.0%), 5 had PE (0.5%), and 4 had postoperative EDH (0.4%). This reduction in DVT after the protocol's implementation was statistically significant (p = 0.009). Despite early aggressive prophylaxis, the incidence of postoperative EDH did not increase and compared favorably to the published literature. Conclusions At a high-volume tertiary center, an aggressive protocol for early VTE prophylaxis after spine surgery decreases VTE incidence without increasing morbidity.