He presented results of a study aiming to demonstrate that the Caprini Risk Assessment Model effectively risk-stratifies plastic surgery patients.
Patients with a Caprini score >8 are at significantly increased risk to develop venous thromboembolism. A separate “maximum” risk level may be warranted for these patients in future risk assessment models, Pannucci said. “In contrast to other surgical subspecialties, the plastic surgery literature demonstrates a paucity of research regarding the efficacy of chemoprophylaxis in venous thromboembolism prevention,” he added.
As a result, researchers created a consortium of five tertiary referral centres with demonstrated expertise in plastic and reconstructive surgery to perform a prospective cohort study with historic controls to examine the efficacy of low molecular weight heparin prophylaxis for venous thromboembolism prevention in plastic surgery patients.
A mid-term analysis of the study’s control group was conducted to evaluate the incidence of risk assessment model when chemoprophylaxis is not provided and to validate the predictive ability of the Caprini risk assessment model for venous thromboembolism.
Medical record review for patients undergoing plastic surgery between March 2006 and June 2008 was conducted. All patients with Caprini scores ≥3 having surgery under general anaesthesia with post-operative hospital admission were included.
Patients who received any form of chemoprophylaxis were excluded.
Outcomes of interest included symptomatic deep vein thrombosis or pulmonary embolism (confirmed with imaging) within the first 60 postoperative days.
At present, 1,126 patients meeting inclusion criteria have been identified. Venous thromboembolism occurred in 1.7% of patients (deep vein thrombosis incidence 1.26%, pulmonary embolism incidence 0.89%). However, when stratified by Caprini score, significant variation in venous thrombolism incidence was seen. Among patients with Caprini score >8, 11.3% had a post-operative venous thromboemboilsm within 60 days of surgery if no chemoprophylaxis was provided.
Patients with Caprini scores >8 were significantly more likely to develop venous thromboembolism when compared to those with Caprini scores of 3–4 (OR 20.9, p<0.001), Caprini scores of 5–6 (OR 9.9, p<0.001), and Caprini scores of 7–8 (OR 4.6, p=0.015).
A time-series analysis challenged prior dogma that venous thromboembolism events occurred soon after surgery. Particularly among high-risk groups (Caprini score of 7–8 and >8), venous thromboembolism events were not limited to the immediate post-operative period. In these high-risk groups, approximately 50% of venous thromboembolism events occurred between post-operative days 30 and 60.
“Although many high-risk patient subgroups have been identified in aesthetic and reconstructive surgery, there is not much data on venous thromboembolism prophylaxis or prevention. The Centers for Medicare and Medicaid Services (CMS) is working toward making venous thromboembolism a “never event.” If plastic surgery does not create data driven guidelines for venous thromboembolism risk stratification and prophylaxis, such guidelines may be created and mandated for us by CMS,” Pannucci said.
