Embolization of ruptured flow-related aneurysms arising from basilar artery perforators feeding lateral pontine arteriovenous malformations: a case series.

INTRODUCTION: It is worthwhile to evaluate the safety of endovascular treatment (EVT) for ruptured flow-related aneurysms on basilar artery (BA) perforators that supply lateral pontine arteriovenous malformations (AVMs). PRESENTATION OF CASES: From July 2017 to March 2024, five patients (1 male and 4 females) aged 54-68 years (mean age, 61.4 years) were enrolled, all presenting with subarachnoid hemorrhage. Angiography identified five lateral pontine AVMs accompanied by six flow-related aneurysms on BA perforators, five of which were ruptured. EVT was successfully performed for all aneurysms using the following approaches: coil embolization alone (n = 2), combined coil embolization with Onyx casting (n = 1), and Onyx casting alone (n = 3). Notably, none of the AVMs received direct treatment during these interventions. Postoperatively, the patients had no procedure-related complications. One patient developed acute hydrocephalus, which was effectively managed with external ventricular drainage. Among the five patients, two underwent angiographic follow-up at 4 and 6 months post-procedure, with both showing complete aneurysm occlusion and stable AVM status. Long-term follow-up, ranging from 8 months to 7 years, revealed a modified Rankin Scale score of 0, with no rebleeding or recurrence of neurological symptoms. CLINICAL DISCUSSION: Flow-related aneurysms in BA perforators supplying lateral pontine AVMs present unique challenges. The primary concern is brainstem ischemia resulting from occlusion of these perforators. In this case series, occlusion of the BA perforators was not associated with complications. CONCLUSION: This small series demonstrates that embolization of ruptured flow-related aneurysms on BA perforators that supply lateral pontine AVMs can be safe. A larger series is expected in the future.