Venous thromboembolism following SCI is a source of significant morbidity and mortality. The majority of the research is focused on prophylaxis of venous thromboembolism in this very high-risk population. Guidelines, based on best available evidence for DVT prophylaxis in SCI, include use of sequential compression devices for two weeks and anticoagulant for 8-12 weeks after injury (Maxwell et al. 2002). There is evidence in the literature that 5000 IU subcutaneously of unfractionated heparin delivered every 12 hours in this population may not be sufficient to provide adequate protection. LMWH with enoxaparin (primary drug studied), appears to be more effective and should be considered the new standard of care, given the added benefit of lower risk of bleeding complications. Physical or mechanical prevention methods, in particular gradient pressure stockings and intermittent pneumatic compression, are designed to reduce the impact of stasis due to prolonged immobilization of the lower extremities and have been shown to have a limited impact. There is an intuitive benefit to combining treatment (i.e., pharmacological with mechanical treatment) although the evidence suggests pharmacological measures are the more important of the two for the purpose of prophylaxis.
Deep venous thrombosis is common in SCI patients not receiving prophylactic treatment.
There is level 2 evidence (from 2 RCTs and 1 prospective controlled trial; Merli et al. 1988; Agarwal & Mathur 2009; Frisbie & Sasahara 1981) that 5000 IU of low-dose unfractionated heparin is no more effective than placebo in the prophylaxis of venous thrombosis post SCI.
There is level 1b evidence (from 1 RCT; Green et al. 1988) that adjusted (higher) dose unfractionated heparin is more effective in prophylaxis of venous thromboembolism than 5000 IU low-dose unfractionated heparin but has a higher incidence of bleeding complications.
There is level 1a evidence (from 2 RCTs, 1 prospective controlled trial, 1 pre-post, and 1 case series; SCI Thromboprophylaxis Investigators 2003a, 2003b; Green et al. 1990, 1994; Maxwell et al. 2002) that low-molecular-weight heparin, in particular enoxaparin, is more effective in reducing venous thromboembolic events, when compared to the standard subcutaneous heparin prophylaxis. Moreover, the incidence of bleeding complications was less in the LMWH group.
There is level 4 evidence (from 1 case control study; Hebbeler et al. 2004) that 40 mg daily enoxaparin is no more effective than 30 mg twice daily enoxaparin in reducing the incidence of deep venous thrombosis or bleeding complications when used prophylactically.
There is level 1b evidence (from 1 RCT and 1 case control study; Chiou-Tan et al. 2003; Slavik et al. 2007) that enoxaparin is no more effective than dalteparin in reducing the risk of deep venous thrombosis or bleeding complications although enoxaparin is more expensive.
There is level 3 evidence (from 1 case control study; Marciniak et al. 2012) that enoxaparin is no more effective than tinzaparin in reducing the risk of deep venous thrombosis or bleeding complications.
There is level 4 evidence (from 1 pre-post study and 1 case series; Chung et al. 2011; Winemiller et al. 1999) that sequential pneumatic compression devices (SCD) or gradient elastic stockings (GES) were associated with a reduced risk of venous thromboembolism post SCI.
There is level 1b evidence (from 1 RCT; Becker et al. 1987) that rotating treatment tables reduce the incidence of venous thrombi in acute SCI patients.
There is level 3 evidence (from 1 case control study and 1 case series study; Merli et al. 1992; Maxwell et al. 2002) that a comprehensive prophylactic treatment of external pneumatic compression, gradient pressure stockings and low dose unfractionated heparin reduces venous thrombosis post SCI.
There is level 4 evidence (from 1 pre-post study; Aito et al. 2000) that a comprehensive prophylactic regimen of pharmacological and physical measures is more effective in preventing venous thrombosis post SCI when instituted earlier rather than later.
There was a trend (from 1 RCT; Green et al. 1982) that pneumatic compression plus antiplatelet agents (ASA and Dipyridamole) was more effective than pneumatic compression alone; the trend was not statistically significant (p<0.100).
There is level 3 evidence (from 2 case control studies, 2 case series studies, and 1 pre-post study; Roberts et al. 2011; Gorman et al. 2009; Kinny et al. 1996; Wilson et al. 1994; Jarrell et al. 1983) that inferior vena cava filters significantly reduce the risk of pulmonary emboli in high-risk SCI patients.
There is level 4 (from 1 case series study; Tomaio et al. 1998) evidence that subcutaneous enoxaparin is a safe, cost-effective and less labour-intensive compared to intravenous heparin for acute DVTs post SCI.