Randomised controlled trials (RCT), controlled trials, and case-series (of four or more patients) that evaluated extracranial-intracranial bypass for revascularisation in patients with Hunterian ligation and an otherwise untreatable aneurysm of the anterior cerebral circulation were eligible for inclusion in the review. Aneurysms had to be neuroradiologically documented by intra-arterial and/or computed tomography (CT)/magnetic resonance angiography (MRI) with clinical evidence of transient ischaemic attack. Eligible studies had to report data on the symptoms of occlusive cerebrovascular disease in the carotid territory. Studies were excluded if they had patients with: cerebral ischaemic episodes that affected more than one vascular territory; or large/multiple areas of hypodensity on a CT scan or MRI that caused disabling hemispheric stroke (modified Rankin scale score of more than 3).
Included outcomes were mortality, disability, stroke, haemodynamic parameters, balloon occlusion test, graft failure, modified Rankin scale score (neurological and radiological) and complications.
The mean age of participants in the included studies was 59 years (range 18 to 82); their preoperative mean neurological state score ranged from 1.0 to 2.0, where reported. Most patients had aneurysms of the internal carotid artery (C3: 18%; C4-5: 45%; C6: 2%; C7: 2%); the remainder had aneurysms in the middle cerebral artery (12%) or anterior communicating artery (2%), although the location could not be specifically determined in 19% of patients. The size of the aneurysm was reported in just under half of the included studies; the size was described as ‘giant’ in 42% of patients, ‘large’ in 5%, and ‘small’ in 2% of patients. Most of the patients (79%) had either minimal or no functional impairment, but 21% had some form of abnormality upon neurological examination.
The author did not state how papers were selected for the review.