Effect of Chronic Anticoagulation on Outcomes of Endovascular Treatment for Unruptured Intracranial Aneurysms – a Propensity Matched Multi-center Study

Introduction: Endovascular treatment (EVT) of unruptured intracranial aneurysms (UIA) in patients receiving anticoagulant medications has not been well studied. Whether long-term anticoagulation (AC) use affects aneurysmal obliteration rates and treatment-related complications is unclear. We aimed to compare occlusion rates and complications following EVT of UIAs in patients who are on anticoagulant therapy with those who are not.

Methods: Patients with endovascular treatment for UIA from four academic centers were identified and divided into AC and non-AC groups. Data was collected prospectively and analyzed retrospectively. Peri-procedural complications, radiographic and clinical outcomes, permanent morbidity, and retreatment rates were compared between the two groups before and after propensity score matching.

Results: Before propensity score matching, there were 70 patients in the AC group, and 355 in the non-AC group with significant difference in patient demographics, aneurysm characteristic and follow-up duration. After propensity adjustment, 38 pairs of patients were compared for periprocedural complications. The total number of complications were higher in the AC group yet not significant (18.4% vs 5.3%, p=0.15). After adding imaging follow-up duration to propensity matched variables, 36 pairs were obtained. There was no significant difference in Raymond-Roy occlusion rate between the two groups (p=0.74). However, retreatment rate trended higher in the AC group compared to the non-AC group (22.2% vs 5.6%, p=0.09). When replacing imaging follow-up duration with clinical follow up duration and adjusting for propensity score, 26 pairs of cases were obtained for long-term clinical outcomes. There was no significant difference in mRS score between the two groups(p=0.61).

Conclusion : Use of anticoagulants does not affect occlusion rates or long-term outcome in endovascular treatment of UIAs. Retreatment rates were higher in the AC group, however this was not statistically significant. These results indicate that anticoagulated patients should be considered for endovascular procedures with less concern for a lower efficacy.