Venous Thromboembolism in Outpatient Elective Foot and Ankle Procedure Patients Who Is at Risk?

Background: Venous thromboembolism (VTE) is a rare but potentially serious complication following elective foot and ankle (F&A) procedures. The absence of guidelines for thromboprophylaxis in elective procedures underscores the importance of identifying patients at risk. This study aimed to identify key risk factors of VTE in patients who underwent elective foot and ankle (F&A) operations.

Methods: Data was collected from the IBM MarketScan Database (2009-2019) for patients >18 years old without prior VTE who underwent elective F&A procedures. Patients were divided into 3 groups based on region of operation (forefoot, mid/hindfoot, lower leg/ankle). VTE incidence (including deep vein thrombosis and/or pulmonary embolism) was recorded 30 and 90 days postprocedure. Risk factors for VTE were identified through multivariate logistic regression.

Results: Among the 301 256 patients who underwent elective F&A procedures, the overall 90-day incidence of VTE was 0.95%. The findings revealed that 31.9% of VTE incidents occurred within the first 2 weeks after operation, and 29.2% still occurred after 6 weeks. Analysis of the anatomical region of operation demonstrated that the lowest rate of 90-day VTE was amongst patients undergoing forefoot procedures (0.70%). There was a higher risk for VTE in patients undergoing midfoot/hindfoot procedures (1.22%, OR = 1.81) and lower leg/ankle procedures (1.76%, OR = 2.31). Additional risk factors for VTE included thrombophilia (4.02%, OR = 3.37), male sex (1.30%, OR = 1.47), increasing age (1.02% age 65+, OR = 1.41), and a high Charlson Comorbidity Index (1.12%, OR < 0.82 for scores <5).

Conclusion: This study identifies the incidence and timing for VTE after elective F&A procedures. Furthermore, this study defines the risk factors associated with increased odds of VTE after elective F&A procedures. These findings are helpful in educating patients about a continued risk for VTE throughout the 90-day postoperative period and beyond. These results can also be utilized to stratify patients who need thromboprophylaxis based on the individual risk level.

Level of evidence: Level III: Retrospective cohort study.