Incidence and Risk Factors for Venous Thromboembolic Disease in Podiatric Surgery

SLR - December 2009 - Shannon Schnell

Reference:
Felcher A., Mularski R., Mosen D., et al. (2009). Incidence and risk factors for venous thromboembolic disease in podiatric surgery. The American College of Chest Physicians, 135, 917-922.

Scientific Literature Review

Reviewed by: Shannon Schnell, D.P.M.
Residency Program: Botsford Hospital

Podiatric Relevance:
The purpose of this study is (1) to determine which factors significantly increase a patient’s risk of developing a symptomatic venous thromboembolus (VTE) after podiatric surgery, and (2) to categorize a patient’s need for perioperative prophylaxis based upon these risk factors.

Methods: 
A 5-year retrospective analysis identifying patients that had podiatric surgery from a non-profit HMO database in the Pacific Northwest was performed from December 1999 to November 2004.  Patients were identified based upon procedural terminology codes for outpatient procedures, and International Classification of Diseases (ICD 9) codes for inpatient procedures. A positive compression Duplex ultrasound result was defined as the diagnosis of deep venous thrombus. The diagnosis of a pulmonary embolus required documentation of a positive CT angiogram or a high-probability ventilation/perfusion scan.  All patient records were then researched for the presence or absence of VTE risk factors. Risk factors were analyzed with univariant and logistic regression models. Sensitivity analysis for female patients was performed using a stratified model for estrogen-associated risks.

Results:
A total of 16,804 podiatric surgical procedures in 7,264 patients were identified. Twenty-twovenous thromboemboli occurred within 6 months of the procedure(s). Three risk factors were significantly associated with the development of a VTE associated with podiatric surgery. These factors were a history of a prior VTE, use of hormone replacement therapy or oral contraceptives, and obesity. A prior VTE had an incidence rate of 4.6% in this cohort. Hormone replacement therapy or oral contraceptives had an overall incidence of 0.55%, and obesity had an incidence of 0.48%. The remaining risk factors identified in this study had alow overall risk. 

Conclusion: 
Obesity, the use of hormone replacement therapy, oral contraceptives, and a history of prior VTE were all significantly associated with an increase in a patient’s risk of developing a VTE status-post a podiatric surgical procedure.  The authors concluded that perioperative prophylaxis is warranted in individuals with a history of prior VTE, in patients with 2 or more significant risk factors, or in patients with multiple risk factors. Further studies need to be performed to examine the association of VTE with a patient’s severity of illness, as well as, to perform a prospective study investigating VTE prophylaxis in podiatric surgery.