頭蓋内血行再建術（Ｓｔｅｎｔ．ＰＴＡ）経皮的脳血管形成術の現状と可能性

Abstract

Percutaneous cerebral balloon angioplasty (PTCBA) has been developed. Procedural success and risks or long-term benefits must be anticipated before PTCBA for intracranial atherosclerotic lesions. To estimate them, you have to know angiographic lesions' characteristics appropriate to PTCBA.1) Intracranial balloon angioplasty Forty-two clinically symptomatic patients with 42 hemodynamical1y significant intracranial lesions (% diameter stenosis>70) underwent initial and elective PTCBA between January 1992 and May 1996. Before the angioplasty treatment, the patients were classified into three groups according to the angiographic lesions' characteristics summarized as follows : type A, a short and concentric stenosis ; type B, a tubular lesion, or an extreme eccentric lesion ; and type C, a diffuse lesion. They were followed after PTCBA from one month to six years to compare between the three groups. Primary end points were death, stroke, or bypass surgery. The clinical success rates in type A, B and C groups were 92%, 86% and 33% (p = 0.0032), respectively. Cumulative risks of fatal or nonfatal ischemic stroke/ipsilateral bypass surgery in type A, B and C groups were 8%, 26% and 87% (p<0.0001), respectively. The cumulative risk of 8% in type A group patients appeared to be smaller than in historical studies. PTCBA for intracranial simple (type A) lesions produces a favorable clinical outcome for symptomatic patients.2) Cerebral artery stentingBetween March 1998 and November 1998, 12 intracranial atherosclerotic lesions (type B or C) of the vertebrobasilar artery and the distal internal carotid artery in 10 patients were treated with stenting treatment using flexible balloon-expandable coronary stents. Ten lesions in 8 patients were sufficiently dilated with stents. No complications occurred during or after the procedure and no neurological ischemic events or restenosis have occurred during follow-up since successful CAS. Cerebral angioplasty and stenting may be a safe and effective means to resolve an intracranial atherosclerotic type B or C lesions and yield a favorable arteriographic and clinical outcome. Cerebral artery stenting can increase success rate and reduce risks for lesions inappropriate to balloon angioplasty.3) PTCBA for chronic total occlusionChronic total occlusions younger than 3 months, shorter than 10 mm, are classified into type B lesions. They can be opened.4) PTCBA and stenting for acute stroke patientsClinical outcome of acute stroke patients presenting serious neurological symptoms due to total occlusions of the vertebro-basilar artery (VBA) is poor and direct percutaneous transluminal cerebral balloon angioplasty (PTCBA) and/or cerebral artery stenting (CAS) for recanalization of the VBA is promising.In conclusion, PTCBA and stenting for ntracranial arteries is feasible and safe, and good clinical outcome following PTCBA and/or CAS for ntracranial arteries is expected.