Staged stent-assisted angioplasty for symptomatic intracranial vertebrobasilar artery stenosis

Abstract

Object. Medically refractory symptomatic vertebrobasilar atherosclerotic disease has a poor prognosis. Studies have shown that longer (≥ 10 mm), eccentric, high-grade (> 70%) stenoses portend increased procedure-related morbidity. The authors reviewed their experience to determine whether a staged procedure consisting of angioplasty followed by delayed (≥ 1 month later) repeated angioplasty and stent placement reduces the morbidity associated with endovascular treatment of symptomatic basilar and/or intracranial vertebral artery (VA) stenoses. Methods. The authors retrospectively reviewed the medical records in a consecutive series of eight patients who underwent planned stent-assisted angioplasty for medically refractory, symptomatic atherosclerotic disease of the intracranial posterior circulation between February 1999 and January 2002. Staged stent-assisted angioplasty was planned for these patients because the extent and degree of stenosis of the VA and/or basilar artery (BA) lesion portended an excessive procedure-related risk. The degree of stenosis, recent onset of symptoms (unstable plaque), vessel tortuosity, and lesion length and morphological features were contributing factors in determining procedure-related risk. Patient records were analyzed for location and degree of stenosis, preprocedural regimen of antiplatelet and/or anticoagulation agents, devices used, procedure-related complications, and clinical and radiographic outcomes. Among the patients in whom staged stent-assisted angioplasty was planned, vessel dissection, which necessitated immediate stent placement, occurred during passage of the balloon in one of them. In a second patient, the stent could not be maneuvered through the tortuous VA. In a third patient, the VA and BAs remained widely patent after angioplasty alone, and therefore stent placement was not required. Significant complications among the eight patients included transient aphasia and hemiparesis in one and a groin hematoma that necessitated surgical intervention in another; there was no permanent neurological morbidity. The mean stenosis before treatment was 78%, which fell to 54% after angioplasty, and the mean residual stenosis after stent placement was 30%. At the last follow-up examination, none of the treated patients had further symptoms attributable to the treated stenosis. Conclusions. The novel combination of initial angioplasty followed by delayed endoluminal stent placement may reduce the neurological morbidity associated with endovascular treatment of long, high-grade stenotic lesions. Attempting to cross high-grade stenoses with higher-profile devices such as stents may result in an embolic shower. Furthermore, neointimal proliferation and scar formation after angioplasty result in a thickened fibrous layer, which may be protective during delayed stent deployment. Larger-scale studies involving multiple centers are needed to elucidate further the lesion morphological characteristics and patient population most likely to benefit from staged procedures.