The Effects of Oral Anticoagulant Exposure on the Surgical Outcomes of Patients Undergoing Surgery for High-Risk Abdominal Emergencies

BACKGROUND: In chronic anticoagulant users undergoing surgery, bleeding and thromboembolism are common and serious complications. Many studies on mainly elective or minor emergency surgical procedures with low associated risks have focused on these outcomes. In comparison, patients undergoing high-risk emergency abdominal surgical procedures have not received sufficient attention. This study aimed to compare outcomes between oral anticoagulant users and nonusers who required emergency laparotomy for high-risk abdominal emergencies. METHODS: Patients who underwent surgery for abdominal emergencies at our institution between January 2012 and July 2019 were retrospectively reviewed. RESULTS: There were 875 patients, including 370 anticoagulant users and 505 nonusers. Of the 370 anticoagulant users, 189 (51.3), 77 (20.8%), 45 (12.2%), and 59 (15.9%) were prescribed antiplatelets, a vitamin k antagonist, a direct oral anticoagulant, and a combination drug regimen, respectively. The most common high-risk emergencies requiring surgery in both groups were perforated viscus (25.7% vs 40.9%), mesenteric ischemia with enteric necrosis (27% vs 12.8%), and bowel obstruction (17.6% vs 28.1%). The overall bleeding rate was higher (29.2% vs 22%, p = 0.015) in anticoagulant users than in nonusers, but the major bleeding rate was similar (17.8% vs 14.1%, p = 0.129) between the two groups. The rates of thromboembolic events and mortality were significantly higher in anticoagulant users than in nonusers (25.7% vs 9.7%, p < 0.0001 and 39.7% vs 31.1%, p = 0.01, respectively). Liver cirrhosis, peripheral arterial diseases, reoperation, and blood product transfusion were independent predictors of the overall risk of bleeding or TEEs, according to the multivariate analysis. In this model, liver cirrhosis had the largest overall effect on mortality, followed by pneumonia, thromboembolism, peripheral arterial disease, blood product transfusion, and atrial fibrillation. The use of oral anticoagulants was not an independent predictor of either bleeding or in-hospital mortality. The use of oral anticoagulants was associated with a decreased risk of all-cause in-hospital mortality. CONCLUSION: Based on our results, the continued use of oral anticoagulants is more protective than harmful considering the overall outcomes in this subset of patients.