SLR - November 2015 - Paul A. Osemene

The Impact of Risk Assessment on the Implementation of Venous Thromboembolism Prophylaxis in Foot and Ankle Surgery

Reference: Saragas NP, Ferrao PN, Saragas E, Jacobson BF. The Impact of Risk Assessment on the Implementation of Venous Thromboembolism Prophylaxis in Foot and Ankle Surgery. Foot Ankle Surg. 2014 Jun; 20(2):85-9.

Scientific Literature Review

Reviewed By: Paul A. Osemene, DPM
Residency Program: Englewood Hospital Medical Center

Podiatric Relevance: The incidence of deep-vein thrombosis (DVT) and pulmonary embolism (PE) is thought to be low following foot and ankle surgery, but the routine use of chemoprophylaxis remains controversial. Risk factors have been highlighted in several studies with some factors being more prevalent than others, although it is not yet possible to predict the individual risk of developing VTE in clinical practice. This prospective study was to determine whether the more frequently quoted procedure and patient specific risk factors have any impact in the implementation of venous thromboembolism (VTE) prophylaxis following foot and ankle surgery.

Methods: In the period June 2011 to May 2012, 216, (68 male and 148 female) consecutive patients who met the criteria were included in this prospective study. The predisposing risk factors considered in this study were taken from the “Thrombosis Risk Factor Assessment” form endorsed by the Southern African Society of Thrombosis and Haemostasis (SASTH). The risk level is determined by the sum of the individual risk factors. Each risk factor is assigned points, thus giving a total risk factor score. The higher the total risk factor score, the higher the risk for patient developing a DVT. The inclusion criteria were patients who required foot and ankle surgery with cast immobilization and nonweightbearing status for at least 4 weeks, as well as patients undergoing hallux surgery, which does not require cast immobilization and nonweightbearing status. The exclusion criteria were patients on warfarin, previous VTE or any conditions requiring anticoagulation as well as patients requesting anticoagulation. A variety of operative procedures was carried out with the common denominator being a below knee cast for at least four weeks and nonweightbearing for an average of six weeks in 130 patients. The remainder of the patients had hallux surgery not requiring a cast and were allowed to weightbear. No patient received any form of thromboprophylaxis postoperatively. All patients were subjected to compression ultrasonography for DVT between two and six weeks postoperatively.

Results: There was a 5.09 percent incidence of VTE (0.9 percent pulmonary embolism) overall. No VTE (neither DVT nor pulmonary embolus) developed in the hallux subgroup. The incidence of VTE in the cast/nonweightbearing group was 8.46%. There was no significant difference in number of risk factors and no association between gender in the VTE and non VTE groups. 90.9 percent of patients in the VTE group had a total risk factor score of five or more and 73.7 percent of patients in the non VTE group had a total risk factor score of 5 or more. The average timing to the diagnosis of VTE in this current study was 33.1 days.

Conclusions: The authors recommend the routine use of thromboprophylaxis in foot and ankle surgery requiring nonweightbearing in combination with short leg cast immobilization. In view of the average time to diagnose VTE in this study, the thromboprophylaxis should therefore be continued until the patient regains adequate mobility, either by weightbearing or removal of cast immobilization. Larger prospective randomized clinical studies in foot and ankle surgery are needed to validate this study.

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