Adult spinal deformity surgery: a systematic review of venous thromboprophylaxis and incidence of venous thromboembolic events

Venous thromboprophylaxis consisting of chemical and/or mechanical prophylaxis is administered to patients undergoing adult spinal deformity (ASD) surgery to prevent venous thromboembolic events. However, the true incidence of venous thromboembolism (VTE) after these surgeries is unknown resulting in weak recommendations and lack of consensus regarding type and timing of prophylaxis in these patients. A systematic literature review was conducted to examine VTE incidence in addition to optimal type and timing of VTE prophylaxis. A detailed search was carried out on Embase, PubMed, and Cochrane Library databases through October 18, 2017, for studies that evaluated venous thromboembolic outcomes, type, and timing of prophylaxis administration among ASD surgery patients who were on VTE prophylaxis. The randomized study was assessed for risk of bias using the Cochrane tool and the observational studies using the Newcastle-Ottawa scale (NOS). The search yielded 1180 studies, and three articles published between 1996 and 2008 met the inclusion criteria. There were 583 surgeries performed on 537 patients with a mean age ranging from 45 to 52 years. Females dominated the study with percentages ranging from 60 to 94% in the different study populations. VTE prophylaxis was initiated before surgery in 87.7% patients and intraoperatively in 12.3% patients. VTE incidence ranged between 0 and 9.1% among the studies. VTE can occur after ASD surgery regardless of the type of prophylaxis, and incidence may be higher when mechanical prophylaxis alone is initiated intraoperatively. Further studies to examine VTE prophylaxis in patients undergoing ASD surgery should be considered.