Aspirin After Free Flaps: Does The Addition Of Postoperative Aspirin To Heparin-based Thromboprophylaxis Provide Any Meaningful Benefit?
Year: 2026
Type: conference-paper
Study design: Observational Study
Abstract: PURPOSE: Short-term thromboprophylaxis (unfractionated heparin [UFH] and low-molecular-weight heparin [LMWH]) is the standard of care for postoperative patients. Patients undergoing free flap reconstruction procedures are also often given aspirin to mitigate the risk of venous congestion and subsequent flap loss. No standardized recommendations exist regarding the use of both aspirin and UFH/LMWH. This study compares postoperative complication rates among free flap patients who received postoperative LMWH/UFH alone versus those who also received postoperative aspirin. METHODS: We conducted a retrospective cohort analysis using the TriNetX Research Networka global federated database of de-identified electronic health records. Adult patients (≥18 years) who underwent free flap procedures between 2005 and 2025 were identified using CPT codes. CPT codes with less than 100 entries were excluded from our analyses. These patients were stratified into two cohortsthose who received both LMWH/UFH and aspirin in the first 7 days after their procedure, and those who received LMWH/UFH only. These two cohorts underwent 1:1 propensity score matching for age, sex, body mass index (BMI), nicotine dependence, tobacco use, preoperative anticoagulant use, and preoperative antiplatelet use. Our postoperative outcomes included DVT/PE, hemorrhage/hematoma formation, wound dehiscence, revision of anastomosis, need for incision and drainage (I&D), and overall complication risk within 30 days of the procedure. RESULTS: A total of 26,928 patients who underwent free flap procedures were identified18,154 who received both aspirin and LMWH/UFH postoperatively, and 8,774 who received only LMWH/UFH. Propensity score matching yielded 8,351 matched pairs, which were used for subsequent analyses. The risk of having a DVT/PE within thirty days of the initial procedure was lower in the aspirin cohort (2.7% vs. 3.6%; risk ratio [RR] 0.76; p<0.01). However, the risk of postoperative hemorrhage/hematoma formation was significantly higher in the aspirin cohort (3.7% vs. 2.8%; RR 1.33; p=0.001), as was the risk of wound dehiscence (8.5% vs. 6.9%; p<0.01). The risk of requiring anastomotic revision within thirty days was also higher in the aspirin cohort (2.7% vs. 2.1%; RR 1.26; p=0.02). There was no significant difference in risk for requiring I&D between the two cohorts. Taken together, there was no significant difference in overall risk for postoperative complications between the two cohorts. CONCLUSION: In the setting of free flap reconstruction procedures, postoperative thromboprophylaxis with aspirin in combination with LMWH/UFH was associated with a lower risk of DVT/PE, but an increased risk for postoperative hemorrhage/hematoma formation, wound dehiscence, and need for anastomotic revision compared to LMWH/UFH therapy alone. In addition, the overall risk for postoperative complications was not significantly different between these two groups. This preliminary retrospective data suggests that while DVT/PE prevention was improved with the addition of aspirin to heparin-based thromboprophylaxis, the addition of aspirin may even increase some postoperative risks. Further prospective studies are needed to validate these conclusions and inform postoperative management of patients undergoing reconstruction with free flaps. *Source: https://ps-rc.org/meeting/Program/2026/MS22.cgi*
Institution: University of Utah
Language: English
Subfield: Internal Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7160596679