Symptomatic Basilar Artery Stenosis with Pontine Perforator Ischemia; Avoiding the Snowplow Phenomenon Through Implantation of a Solitaire Stent Without Balloon Angioplasty and Dissolution of the Atherosclerotic Plaque with Excellent Long-Term Outcome

A 69-year-old man with a past medical history of prostate carcinoma was brought by his family to the emergency department with acute onset of right-sided weakness and sensory disturbances, partial right facial nerve paralysis, dysarthria, and word-finding difficulties with fluctuating symptomatology. A National Institutes of Health Stroke Scale (NIHSS) score of 1 was documented on hospital admission. Magnetic resonance imaging (MRI) revealed diffusion restriction in the left paramedian pons and a similar lesion in the right occipital lobe. Time-of-flight and contrast-enhanced MR angiography revealed moderate stenosis in the proximal course of the basilar artery (BA). Subsequent angiography studies confirmed stenosis of the BA and documented the origin of the anterior inferior cerebellar arteries (AICAs) bilaterally at the level of the stenosis. The right AICA was hypoplastic with stenosis in the initial segment. Collectively, these findings suggested that balloon angioplasty might be associated with an increased risk of developing complications. Thus, a conservative management strategy with dual antiplatelet therapy (DAPT; acetylsalicylic acid and ticagrelor) was initiated. Three weeks later, the patient presented with new onset dizziness, gait unsteadiness, and dysarthria. A MRI study performed at that time revealed no changes to the pons lesion or BA stenosis. However, because transient ischemic attacks had recurred under adequate DAPT, the patient was likely to be at an increased risk of stroke. The risks associated with balloon dilatation of the BA and the possibility that this procedure might result in the occlusion of the pontine branches remained. Therefore, the decision was made to implant a Solitaire stent into the BA without balloon dilatation with the center of the stent shaft covering the stenotic region. The procedure was well tolerated, although follow-up studies revealed transient weakness of the right leg and an increase in the size of the preexisting lesion in the pons. The patient was maintained on the DAPT regimen; complete regression of the BA stenosis was observed over the following months to years. No symptoms associated with brainstem ischemia were reported at any time during the nine years since the completion of this procedure. In this report, we focus on parameters associated with endovascular treatment of symptomatic stenosis of the BA via the implantation of a Solitaire stent without balloon angioplasty.