Antegrade recanalization of parent artery in proximal occlusion of distal posterior inferior cerebellar artery ruptured aneurysm A case report

Rationale: Distal posterior inferior cerebellar artery (PICA) aneurysms are extremely rare. Herein, we describe a case of PICA pseudoaneurysm with proximal occlusion achieved using detachable coils, but antegrade recanalization, which showed a normal PICA configuration on follow-up angiography. Possible mechanisms of the recanalization and lesions are also discussed. Patient concerns: The patient was an 80-year-old woman with a subarachnoid hemorrhage (SAH) resulting from a distal PICA-ruptured aneurysm, initially misdiagnosed as a non-aneurysmal traumatic SAH. Diagnosis: On hospitalization day 10, the patient developed rebleeding, and brain computed tomography angiography confirmed a distal PICA pseudoaneurysm. Intervention: Endovascular coil embolization was performed. Inevitably, the proximal PICA was occluded using detachable coils, and complete occlusion of the affected PICA was confirmed on the final angiogram. Outcome: Fortunately, the patient recovered fully without any neurological sequelae. One year after the procedure, a follow-up angiography was performed, which revealed recanalization of the previously occluded PICA, with normal configuration and no visible aneurysmal dilatation. Conclusion: Even if the SAH is scanty and predominantly in the perimesencephalic cistern, performing a catheter-based angiography is essential. In the case of proximal occlusion of the parent artery without internal trapping in endovascular treatment of PICA pseudoaneurysm, follow-up examination with a short-term angiography might be crucial.