The combination of mechanical methods and pharmacological agents has been studied for their effect on DVT prophylaxis post SCI.
Various combinations of physical and pharmacological treatments to prevent DVTs post SCI have been studied. Three studies examined LDUH paired with mechanical methods. Merli et al. (1992) studied 36 SCI patients who received either prophylaxis (LDUH 5000 IU) combined with external pneumatic compression and gradient elastic stockings or no treatment for two weeks. The incidence of thrombosis was significantly lower in the treated group (p=0.04). Spinal Cord Injury Thromboprophylaxis Investigators conducted a RCT (2003a) and follow-up prospective controlled trial (2003b) both of which examined the effect of 5000 IU LDUH plus intermittent pneumatic compression versus enoxaparin alone. In the first study (2003a), the authors found no significant difference between the two groups in DVT incidence. However, in the second study the dosage of enoxaparin was increased and they found that high-dose enoxaparin resulted in fewer DVTs than the combined LDUH-IPC treatment (Spinal Cord Injury Thromboprophylaxis Investigators 2003b).
Three types of LMWH (enoxaparin, dalteparin, and Nadroparine) combined with physical methods have also been studied. In a prospective cohort study, Giorgi et al. (2013) found that among 94 individuals receiving either dalteparin or enoxaparin in combination with physical methods, a high rate of DVTs (22%) still occurred. However, the rate of DVTs declined significantly after 3 months post rehabilitation stay. Aito et al. (2000) studied 275 SCI patients, 99 of who were treated within 72 hours of injury while 176 were treated 8-28 days post SCI. The treatment involved permanently dressed gradient elastic stockings, subcutaneous LMWH (Nadroparine), and external sequential pneumatic compression (ESPC) of the lower limbs. There was early mobilization of the lower limbs. The complete prophylactic treatment lasted at least 30 days post SCI; LMWH and ESPC were continued for two more months depending on the patient’s progress. A 2% DVT incidence in the early treatment group compared to a 26% incidence in the later treatment group demonstrated that early treatment was clearly important. In a retrospective study by Deep et al. (2001), the authors reported that just 2.9% of patients developed a DVT/PE between admission and discharge from rehabilitation after being treated with anti-thromboembolic stockings and 40 mg of enoxaparin.
Finally, Green et al. (1982) randomized 27 SCI patients to either external pneumatic calf compression alone, or in combination with 300 mg acetylsalicylic acid twice daily plus 75 mg dipyridamole twice daily. Thrombi developed in 6/15 patients treated solely with EPCC and in 3/12 receiving ASA/Dipyridamole as well as EPCC (p<0.100).
Early application of pharmacological agents, along with mechanical treatments, has been shown to reduce the risk of DVT complications. Maxwell et al. (2002) demonstrated that in comparison to individuals receiving only sequential compression devices, those using compression combined with LMWH developed fewer DVTs and PEs. Given the results by the Spinal Cord Injury Thromboprophylaxis Investigators (2003b) showing better outcomes with high-dose Enoxaparin (alone), future studies comparing LMWH to LMWH plus mechanical methods are warranted.
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).
A combined regiment of pneumatic compression, pressure stockings and low-dose heparin given prophylactically may reduce the incidence of venous thrombosis and this effect is better in early post SCI.