High-Flow Bypass and Trapping of a Ruptured Internal Carotid Artery Blister Aneurysm: Operative Principles and Key Lessons.

ABSTRACT

Blood blister-like aneurysms (BBAs) are infrequent but challenging small aneurysms with fragile domes consisting of a thin adventitia layer.1 Flow diversion and microsurgical trapping are acceptable treatment options. While endovascular treatment is becoming the first choice in developed countries, it is prohibitive in most developing countries, where microsurgical treatment is the only feasible option. Microsurgical treatment offers superior obliteration rates at similar neurologic outcomes than endovascular treatment.1-3 Mastering high-flow revascularization and pressure monitoring is necessary to improve outcomes of BBA, especially in the developing world. We present our operative principles, which involve pressure monitoring and a high-flow bypass to ensure sufficient post-trapping cerebral pressure.4 A 53-year-old lady was found to have a modified Fisher 4 subarachnoid hemorrhage after the worst headache of her life. Endovascular flow diversion and trapping and bypass were discussed with the patient and family. A right internal carotid artery BBA was trapped (Video 1). A right superficial temporal artery to M4 middle cerebral artery (MCA) bypass was used to both maintain perfusion during a high-flow bypass and to measure cerebral blood pressure. An external carotid artery to MCA bypass using a saphenous vein graft provided >80% of baseline MCA arterial pressure, which prevents delayed ischemic strokes.4 The patient tolerated the procedure well and was discharged home without deficits on postoperative day 15 after vasospasm watch. The patient consented to the procedure and provided consent to the publication of her images.