Introduction Following the FDA approval trial of the self-expanding Wingspan® Stent System for symptomatic intracranial atherosclerotic disease in which a 4.5% periprocedural complication rate was seen, favorable registry data was reported and subsequently, the prospective randomized SAMMPRIS trial, using the device in an IDE application, not for its original approval, demonstrated poor clinical results with a 14.7% periprocedural complication rate. The WEAVE (Wingspan Stent System Post Market Surveillance Study) Trial is a prospective, consecutive enrollment, single-arm, post market surveillance trial evaluating periprocedural outcomes in patients with the revised FDA indications for use.
Methods Data for the first 50 patients for which completed data is available are included in this report. The primary analysis endpoints included periprocedural stroke or death within 72 h of the stenting procedure in patients who were treated on label. On label indication included patients with 70% or greater intracranial stenosis due to atherosclerotic disease, with evidence of two prior strokes in the target artery territory, with at least one of the events occurring with preventive comprehensive medical therapy which includes medication to control individual risk factors and at least one antithrombotic medication, and stenting greater than 7 days following the most recent qualifying stroke. Half of the participating sites included anti-platelet therapy resistance testing and correction, if needed, in their treatment of the patient. Patient outcomes were separately assessed by an independent stroke Neurologist at 96 (+/- 24) hours for subjects discharged prior to 64 h post procedure.
Results In the initial 50 patients enrolled with completed data, 45 patients were treated on label and are included in the primary analysis, and 5 patients were treated off label. The mean stenosis in the primary analysis group was 83.3% with target artery break down as follows: 41.7% MCA, 18.8% ICA, 16.7% Basilar, 18.8% Vertebral or VB junction. Of the 45 patients in the primary analysis, 2 patients (4.4%) reached a primary endpoint of stroke, or death within 72 h. In the off label group, 3 of the 5 patients reached a primary endpoint within that period.
Conclusions The early interim analysis of the first 50 patients of the WEAVE Trial has demonstrated a very low periprocedural morbidity and mortality of 4.4% for patients treated on label. This is lower than the high periprocedural event rate in the SAMMPRIS trial, and better than the outcomes in the off label group. This early data provides impetus to continue to collect data in this trial, and lends support to the concept that refined patient selection criteria and establishment of best practice techniques and management for these patients can substantially decrease the periprocedural risk of intracranial stenting.
Disclosures M. Alexander: 2; C; Stryker Neurovascular. A. Zauner: 2; C; Stryker Neurovascular. J. Chaloupka: 2; C; Stryker Neurovascular. B. Baxter: 2; C; Stryker Neurovascular. R. Callison: 2; C; Styker Neurovascular. W. Yu: 2; C; Stryker Neurovascular.