Have we found an answer to DVT prophylaxis in Neurosurgical patients

Deep Vein Thrombosis is a well recognized complication amongst hospitalized patients. Providing prophylaxis against DVT is acknowledged as a high impact intervention. Neurosurgical patients ( cranial and spinal) constitute a special cohort. On the one hand the incidence of DVT amongst this population is as high as 40%. On the other hand, use of chemical prophylaxis is viewed with caution and with the fear of producing a major hemorrhage. Mechanical prophylaxis has been used as an alternative. But the relative risk reduction with mechanical prophylaxis is not very high. Several attempts have been made in the past to review literature related to this aspect. But the results have been ambiguous.
Khan et al have carried out the latest meta analysis to answer the question of safety of chemical prophylaxis in relation to neurosurgical patients.

Chemical venous thromboembolism prophylaxis in neurosurgical patients: an updated systematic review and meta-analysis
Nickalus R Khan et al J Neurosurg 129:906–915, 2018


The authors carried out a search of literature to identify studies which evaluated the efficacy and safety of chemical prophylaxis among patients undergoing cranial and spinal surgery. Studies which didn't have a control or placebo arm were not included. The funnel plot of the overall study list appears symmetrical excluding publication bias. A total of 9 studies withstood the methodological scrutiny and were eligible for the meta analysis.
The chemical prophylaxis used in six of the studies included was enoxaparin.
The total patient base for this study was 1232. Chemical prophylaxis showed a significant benefit in preventing DVT when compared to placebo with an OR of 0.51. The absolute risk reduction was 42%. The number needed to treat (NNT) for prevention of DVT was 11. The heterogeneity I2 statistic was 0%.
The incidence of major Intra Cranial Hemorrhage in the treatment group was 2.7% compared to 1.6% in the control group. The OR was 1.42, 95% CI 0.61–3.30 which was not statistically significant. The Forrest plots of both these data is shown below.

The rates of major extra cranial bleeds and overall minor bleeds were also not significantly different.
This study seems to conclude that there is a significant benefit in using chemical prophylaxis in prevention of DVT amongst neurosurgical patients with no significant increase in the incidence of major intra cranial hemorrhage.

My opinion: DVTpharmaco prophylaxis amongst Neurosurgical patients may now be approached with a little more confidence. However, close monitoring is needed.