Background and purpose

High periprocedural complication rate is a key limitation of endovascular treatment of intracranial atherosclerotic disease (ICAD), despite potential risk reduction of recurrent stroke. Taking lessons from the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Arterial Stenosis (SAMMPRIS) trial, targeting a selected patient population, we prospectively evaluated the feasibility and safety of tailored angioplasty and/or stenting for patients with ICAD.

Methods

From November 2011 to October 2012, 158 patients with symptomatic ICAD caused by hypoperfusion combined with poor collateral flow were consecutively recruited into a prospective single center study. Patients were divided into three groups based on arterial access and lesion morphology: balloon mounted stent group (group BS) for smooth access and Mori A lesion, angioplasty plus self-expanding stent group (group AS) for tortuous access and Mori B or C lesion, and angioplasty group (group AG) for tortuous access and Mori A lesion. The primary endpoints were successful procedure rate and any vascular event within 30 days.

Results

Overall technical success rate was 96.3% (154/158). There were significant differences in the technical success rate: 89.7% (35/39) in group AG compared with 97.5% (79/81) in group BS and 100% (38/38) in group AS (p=0.042). The 30 day composite stroke, myocardial infarction, or death rate was 4.4% (7/158). Stroke within 30 days occurred in four patients in group BS and in three patients in group AS.

Conclusions

Individualized treatment of ICAD using tailored devices according to arterial access and lesion morphology was feasible and safe in symptomatic patients caused by hypoperfusion with poor collateral flow.

PURPOSE: Current studies on endovascular intervention for intracranial atherosclerosis select patients based on luminal stenosis. Coronary studies demonstrated that fractional flow measurements assess ischemia better than anatomical stenosis and can guide patient selection for intervention. We similarly postulated that fractional flow can be used to assess ischemic stroke risk. METHODS: This was a feasibility study to assess the technical use and safety of applying a pressure guidewire to measure fractional flow across intracranial stenoses. Twenty patients with severe intracranial stenosis were recruited. The percentage of luminal stenosis, distal to proximal pressure ratios (fractional flow) and the fractional flow gradients across the stenosis were measured. Procedural success rate and safety outcomes were documented. RESULTS: All 20 patients had successful crossing of stenosis by the pressure guidewire. Ten patients underwent angioplasty, and 5 had stenting performed. There was one perforator stroke, but not related to the use of the pressure wire. For the 13 patients with complete pre- and postintervention data, the mean preintervention stenosis, fractional flow and translesional pressure gradient were 76.2%, 0.66 and 29.9 mm Hg, whilst the corresponding postintervention measurements were 24.7%, 0.88 and 10.9 mm Hg, respectively. Fractional flow (r = -0.530, p = 0.001) and the translesional pressure gradient (r = 0.501, p = 0.002) only had a modest correlation with the luminal stenosis. CONCLUSION: Fractional flow measurement by floating a pressure guidewire across the intracranial stenosis was technically feasible and safe in this study. Further studies are needed to validate its use for ischemic stroke risk assessment.