Retrieval of an atherosclerotic plaque-vessel wall complex during mechanical thrombectomy: illustrative case.

backgroundRetrieval of an atherosclerotic plaque-vessel wall complex as a single specimen from the middle cerebral artery during mechanical thrombectomy (MT) is exceedingly rare. OBSERVATIONS: A 74-year-old man with atrial fibrillation underwent MT for right M1 occlusion. A red thrombus and a yellowish-white specimen were retrieved, and successful reperfusion was achieved. Histopathological examination of the retrieved specimen revealed an atherosclerotic plaque attached to the arterial wall, consistent with retrieval of the plaque-vessel wall complex as a single specimen. Postoperatively, a subarachnoid hemorrhage was observed around the M2 inferior trunk, where vessel wall retrieval likely induced arterial dissection. Antithrombotic therapy and strict blood pressure control were implemented. Although progressive stenosis of the M2 inferior trunk was noted during follow-up, the vessel diameter eventually normalized without aneurysmal transformation. LESSONS: MT with a stent retriever in vessels harboring atherosclerotic plaque may cause intracranial arterial dissection. Histopathological evaluation of retrieved specimens can help identify iatrogenic dissection. Appropriate selection of antithrombotic therapy, strict blood pressure control, and serial vascular imaging may help prevent progression of an intracranial hemorrhage. https://thejns.org/doi/10.3171/CASE26225.