Impact of anesthesia modality and mechanical venous thromboembolism prophylaxis on the incidence of symptomatic deep venous thrombosis after TKA.

BACKGROUND: Venous thromboembolic events (VTE) are a common complication of total knee arthroplasty (TKA). Prior studies have discussed the utility of mechanical VTE prophylaxis as a monotherapy for low-risk TKA patients. We assess the incidence of clinically significant deep venous thrombosis (DVT) or pulmonary embolism (PE) in low-risk TKA patients who receive mechanical VTE prophylaxis and undergo spinal, epidural, or general anesthesia for their surgery.
METHODS: A retrospective study was performed on consecutive low-risk patients who received a TKA between July 2002 and June 2015 with spinal anesthesia (n = 65), epidural and general anesthesia (n = 154), or general anesthesia alone (n = 152). Patients with spinal anesthesia had mechanical VTE prophylaxis until 15 h postoperatively, when remobilization was permitted. Patients who received epidural or general anesthesia had mechanical VTE prophylaxis for 2 h postoperatively. Notable outcomes included development of clinically symptomatic DVT or PE, patient demographics, and perioperative lab values. Statistical analysis was performed using SPSS 22, with chi-squared and Fisher's exact tests for categorical variables and the Kruskal-Wallis test with Scheffe's method for continuous variables.
RESULTS: No clinically symptomatic DVT or PE was diagnosed. Patient demographics were equivocal. A statistically significant decrease in prothrombin and activated partial thromboplastin times were noted in the general anesthesia group, but all measurements were within the normal range.
CONCLUSIONS: A short course of mechanical VTE prophylaxis may be appropriate for low-risk patients who can immediately mobilize.