Preoperative continuation of aspirin administration in patients undergoing major abdominal malignancy surgery

Purpose In contrast to that in a nonoperative setting, it has been shown that perioperative administration of aspirin did not decrease the rate of death or myocardial infarction but increased major bleeding risk. Since these conflicting results might be due to concurrent use of anticoagulants and a lower thrombotic risk of patients, this cohort study was carried out for patients at a high thrombotic risk without concurrent use of anticoagulants. Methods Medical records for patients who underwent major abdominal malignancy surgery and who were on a preoperative antiplatelet regimen were reviewed. The patients were divided into two groups according to perioperative antiplatelet management: administration of all preoperative antiplatelet agent-suspended (no aspirin) group and only aspirin administration-continued (aspirin) group. The incidence of symptomatic thromboembolic events, frequency of exogenous blood transfusion within 30 days after surgery and the amount of intraoperative bleeding were compared between the two groups. Results After propensity score matching, 105 patients of each group were matched. The incidence of perioperative thromboembolic events in the no-aspirin group was significantly higher than that in the aspirin group [7/105 (6.7%) vs 0/105 (0%), 95% CI 1.44–∞, P = 0.016]. In contrast, neither the frequency of exogenous transfusion [21.0% vs 11.4%, 95% CI 0.88–4.38 P = 0.110] nor the amount of intraoperative bleeding [median (interquartile range), ml: 230 (70–500) vs 208 (50–500), P = 0.325] was different between the two groups. Conclusion Although the sample size is relatively small, our findings suggest that continuation of aspirin administration is likely to reduce the thrombotic risk but unlikely to increase the bleeding risk of patients who undergo major abdominal surgery for malignancy.