SLR - August 2012 - Bindu Mathew
Reference: Griffiths JT, Matthews L, Pearce CJ, Calder JD. Incidence of venous thromboembolism in elective foot and ankle surgery with and without aspirin prophylaxis. J Bone Joint Surg Br. 2012 Feb; 94(2): 210-4.
Scientific Literature Review
Reviewed by: Bindu Mathew, DPM
Residency Program: Pinnacle Health, Harrisburg, PA
Podiatric Relevance:
Thromboprophylaxis following elective foot and ankle surgery is a controversial topic without definitive recommendations, possibly because the incidence of a deep vein thrombosis is thought to be low in this situation. The purpose of this study was to establish the incidence of clinically significant thromboembolic events in patients undergoing elective foot and ankle surgery with and without the use of low dose aspirin as a form of chemical thromboprophylaxis.
Methods:
The study design consisted of a retrospective analysis on all patients who underwent elective foot and ankle surgery under the care of the senior author between 2003 and 2010. Once daily 75mg aspirin was given to patients between 2003-2006, starting on the first post-operative day (two weeks for forefoot surgery, six weeks for midfoot/rearfoot surgery). No pharmacologic prophylaxis was given to patient between 2007 and 2010. The majority of patients were followed for a minimum of three months post-operatively. Patients considered high risk for DVT or receiving anticoagulation or aspirin therapy for pre-existing medical conditions were excluded. Out of 2654 patients included in the study, 1078 received aspirin post-operatively and 1576 received no form of pharmacologic thromboprophylaxis.
Results:
Apart from the 27 patients that were lost to follow up, 11 out of 2627 patients (0.42 percent) had a symptomatic post-operative thromboembolic event: 7 (0.27 percent) DVTs and 4 (0.15 percent) non-fatal PEs. The incidence was slightly higher in the aspirin group but chi-squared testing showed no statistical difference (p = 0.985) between the two groups. DVT was more common than PE in the aspirin group. No statistical significance noted between both groups from time of surgery to diagnosis of DVT or PE (p= 0.082) or between incidence of PE versus DVT between males and females. If the 27 patients were included, and assuming they developed a VTE event as a worst case scenario, the overall VTE rate was 1.43 percent.
Conclusions:
Based on the results of this study, the authors concluded that the incidence of VTE following elective foot and ankle surgery is low and doesn’t necessitate the use of routine prophylaxis in patients who aren’t at high risk for VTE. In the worst case scenario, the overall VTE rate was 1.43 percent. In this study aspirin therapy didn’t appear to have considerable protection against symptomatic VTE. Therefore, an alternative means of VTE prophylaxis should be taken into account for high risk patients.