Angiographical Jaggy Sign of Remnant M2 Occlusion during Acute Mechanical Thrombectomy

Area of Science:

• Neurology
• Interventional Neuroradiology
• Vascular Neurology

Background:

• Mechanical thrombectomy is a key treatment for acute ischemic stroke.
• Difficulties arise when one M2 branch of the middle cerebral artery (MCA) is recanalized, but the other remains occluded.
• Understanding the characteristics of these remnant occlusions is crucial for optimizing treatment.

Purpose of the Study:

• To classify angiographical findings of remnant M2 occlusions during mechanical thrombectomy.
• To investigate the clinical features, prognosis, and complications associated with different types of remnant M2 occlusions.
• To evaluate the effectiveness and risks of additional thrombectomy for remnant M2 occlusions.

Main Methods:

• Retrospective analysis of 83 patients undergoing mechanical thrombectomy for acute internal carotid artery or M1 MCA occlusion.
• Identification of 25 patients (30%) with remnant M2 occlusion despite successful recanalization of the contralateral M2 branch.
• Classification of remnant M2 occlusions into stump, round deficit, and jaggy types, with subsequent analysis of clinical data and outcomes.

Main Results:

• Remnant M2 occlusions were classified as stump (40%), round deficit (28%), and jaggy (32%).
• Jaggy type occlusions showed a trend towards association with noncardioembolic stroke (P=0.051).
• Additional thrombectomy had a 50% failure rate for jaggy types versus 6% for nonjaggy types (P=0.023), with higher rates of symptomatic intracranial hemorrhage and poor outcomes in the jaggy group.

Conclusions:

• The "jaggy" angiographical sign in remnant M2 occlusions may suggest underlying atherosclerosis, vasospasm, or arterial dissection.
• Careful consideration is needed before performing additional thrombectomy for remnant M2 occlusions, particularly the jaggy type, due to potential adverse events and poor outcomes.