DOES ANTICOAGULANT THROMBOPROPHYLAXIS INCREASE BLEEDING COMPLICATIONS IN SPINAL SURGERY AND SPINAL CORD INJURY? A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

This study is a systematic review and meta-analysis. The routine use of anticoagulants for the prevention of venothromboembolism in spinal patients is controversial and the risk benefit analysis is poorly described. The objective of this study is to collate the current evidence and quantify the risk of bleeding associated with anticoagulant thrombophylaxis in the spinal patient, both in the elective and trauma settings. Medline, Embase, Cochrane Trial Register databases and the grey literature were searched. Data were pooled via a meta-analysis from randomized trials and cohort studies comparing the rates of spinal epidural haematoma and wound haemorrhagic complications in spinal surgery patients receiving low molecular weight and low dose unfractionated heparin (LMWH/UFH) thromboprophylaxis and those not anticoagulated. The risk of bias within individual studies and across all the studies was assessed using the Cochrane risk of bias tools and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool, respectively. The meta-analysis included 10 studies of 96,042 patients with 1,007 relevant bleeding complications. A significant increase in the risk of extra-spinal wound haemorrhage was found in patients receiving peri-operative LMWH/UFH thromboprophylaxis compared to controls (OR 1.56, 95% CI 1.18-2.06, p=0.002, I2=8%). The same comparison revealed no significant increase in the risk of spinal epidural haemorrhage (OR 1.20, 95% CI 0.65-2.22, p=0.56, I2=0%). The quality of evidence for both outcomes was low. There was insufficient data to conclude about the risk of haemorrhagic complications in spinal trauma and in patients receiving non-heparin thromboprophylaxis agents. In conclusion, the results of this study raise concern about a possible increased risk of extraspinal wound haemorrhage associated with LMWH/LDUFH thromboprophylaxis in spinal surgery. Level of evidence: Therapeutic level III.

Keywords

• spine
• surgery
• spinal cord injury
• trauma
• thromboprophylaxis
• anticoagulant
• bleeding
• epidural spinal haematoma
• wound
• complication