Universal External Carotid Artery to Proximal Middle Cerebral Artery Bypass With Interposed Radial Artery Graft Prior to Approaching Ruptured Blood Blister-Like Aneurysm of the Internal Carotid Artery -Technical Note-

Abstract

Blood blister-like aneurysms are dangerous aneurysms with fragile walls arising from the supraclinoid internal carotid artery (ICA). Primary treatment of these aneurysms in the acute stage is challenging, due to the substantial risk of periprocedural bleeding. We describe a series of 4 patients who presented with ruptured blister-like aneurysm of the ICA and were treated with completion of extracranial-intracranial high-flow bypass followed by inspection and trapping of the aneurysm. All patients were treated in the acute stage, within 48 hours of bleeding. External carotid artery to proximal middle cerebral artery bypass with interposed radial artery (RA) graft was established followed by approach to the lesion and trapping of the parent vessels. The aneurysms in 3 patients ruptured during dissection of the lesion from the surrounding structures, but bleeding was easily controlled. RA grafts were patent in all patients and no postoperative symptomatic ischemic or hemorrhagic complications were encountered, resulting in excellent outcomes with modified Rankin scale scores of 0 at follow up after 3 months. Our present strategy for surgical treatment of blister-like aneurysms completely avoided the risk of devastating intraoperative hemorrhage, offering a most cautious strategy associated with minimal risk of intraoperative massive bleeding.Key words: blister-like aneurysm, internal carotid artery, trapping, subarachnoid hemorrhage, external carotid artery to proximal middle cerebral artery bypass with interposed radial artery graft

The importance of preoperative diagnosis of blister aneurysms

“…Elevated IOR rates likely derive from inherent vessel fragility coupled with the technical difficulties of securing small, broadbased aneurysms with surgical clips [2,19]. BA are believed to involve only thin vascular adventitia, lacking well developed intimal and medial layers [6,21]. As BA typically arise in regions remote from vessel branching points, high shear stress is not believed to be the principal pathogenic mediator.…”

“…Meticulous operative planning is required. Multiple surgical modalities have been utilized, yet no consensus exists regarding the optimal treatment methods [3,6,13,21,22]. Similar principals apply to endovascular paradigms.…”

“…These lesions account for approximately 0.3-2.1% of all ruptured intracranial aneurysms and 2.2-7.3% of ruptured internal carotid artery aneurysms [1][2][3][4][5]. BA morphology is characterized by arterial wall defects in the internal elastic lamina and media layers [6]. Due to their small size and characteristically broad necks, most BA are not amenable to primary endovascular coil embolization [7].…”

“…Clip ligation is associated with higher morbidity and mortality rates than those reported for saccular aneurysms [2,8]. Less conventional operative paradigms including extracranial-intracranial bypass with aneurysm trapping and parent vessel sacrifice have been utilized [3,6,7,[9][10][11][12][13][14]. Recently, endovascular flow diversion techniques have been reported [9,14].…”

Morphological aspects of blister aneurysms and nuances for surgical treatment

“…16,21,22,47,55 However, occlusion of a major vessel in an acute stage following subarachnoid hemorrhage is associated with poor prognosis. 33 Also, a balloon test occlusion may be difficult to assess when the patient is suffering from the neurological effects of a ruptured aneurysm.…”