Body Mass Index, Age and Gender Have No Impact on Venous Thromboembolism Rates; An Epidemiologic Study of 1434 Foot and Ankle Surgeries Performed at a Single Academic Medical Center

Category: Other Introduction/Purpose: Despite the large volume of foot and ankle orthopaedic procedures performed annually, there is a paucity of data describing the post-operative complications, including venous thromboembolisms (VTE), and the impact of patient characteristics and comorbidities as they contribute to these observed complications. The wide variety of foot and ankle orthopaedic procedures performed presents a challenge for orthopaedic surgeons when counseling patients on the risk of post-operative complications and identifying patients with relevant comorbidities to mitigate risk. Methods: This was a retrospective study of 1434 foot and ankle surgeries performed at a large urban academic medical center by a single surgeon. Patient demographics, pre-operative comorbidities, and VTEs within 90 days postoperatively, defined as either pulmonary embolism (PE) or deep vein thrombosis (DVT), were analyzed using Chi-square test of independence. All patients were given standard prophylaxis of aspirin; enoxaparin or direct oral anticoagulants (DOACs) were given based on preoperative risk factors, such as prior VTE. Preoperative comorbidities recorded included history of myocardial infarction (MI), congestive heart failure, peripheral vascular disease, cerebrovascular disease, dementia, chronic pulmonary disease, rheumatic disease, peptic ulcer disease, mild liver disease, moderate or severe liver disease, diabetes mellitus (DM), hemiplegia/paraplegia, renal disease, malignancy of any kind, metastatic solid tumor of any kind, and human immunodeficiency virus. All patients who smoked were abstinent immediately prior to the procedure. Results: The overall rate of VTE was 1.6% (n=23), with a PE rate of 0.4% (n=6) and DVT rate of 1.3% (n=19); two patients were diagnosed with both. Current smokers had higher rates of PE (1.4% vs 0.0%, p=0.02) than former smokers. Patients who identified as Hispanic had higher rates of DVT than non-Hispanics (4.6% vs 1.2%, p=0.03). Renal disease, MI, and mild liver disease were also associated with higher rates of PE and DVT (p < 0.05). Patients with one or more comorbidities exhibited higher rates of PE than those without comorbidities (0.8% vs 0.1%, p=0.04). Differences in body mass index (BMI), age, DM, gender, race, peri-operative opioid use, and procedure type were not associated with differences in VTE rate. Conclusion: While including both elective and non-elective cases, the results of this study may be used to counsel patients on their anticipated surgical risk based on their demographics and medical comorbidities. Further, these results may help identify areas for targeted mitigation to prevent postoperative VTE. The results of this study indicate that cigarette smoking and preoperative medical comorbidities continue to impact VTE rates while BMI, DM, and age had no significant differences in rate of VTE after foot and ankle surgery. PE and DVT rate by selected patient characteristics Rates of pulmonary embolism (PE) and deep vein thrombosis (DVT) within 90 days of any type of foot and ankle surgery, stratified by age, diabetes (DM) status, smoking status, body mass index (BMI), gender, and self-identified race (AA = African American).