Wingspan Stent Post Market Surveillance Trial
In 2011, the SAMMPRIS trial was stopped prematurely given significantly higher 30 day stroke or death rates of 14.7% in intervention arm compared to 5.8% in medical management arm in patients with severe symptomatic intracranial artery stenosis (ICAS). After panel review in 2012, the FDA approved Wingspan stent use with revised on-label criteria and mandated a new post-market surveillance trial to reassess its peri-procedural safety. In a prospective, single arm design the WEAVE trial intended to enroll 389 consecutive on-label patients. Predetermined interim analysis of the first 100 patients revealed lower event rate than expected when second interim analysis was planned after 150 patients per Bayesian analysis. The enrolled patients were 22 to 80 years old, had baseline mRS ≤3, at least 2 strokes due to symptomatic >70-99% intracranial arterial stenosis and were stented >7 days after most recent stroke. All patients received dual antiplatelet and statin regimen prior to intervention. During balloon angioplasty, under dilation to 60-80% was recommended to avoid arterial dissection, rupture and snowplow effect of compressed plaque into the perforators. Post-stenting angioplasty was discouraged unless residual stenosis was >50%. In 152 enrolled patients, 53% were men and 66% were white. 157 arteries were treated arteries with mean arterial stenosis of 83% and the target artery distribution was MCA (39.5%), ICA (25.5%), Vertebral artery (20.4%), Basilar artery (14%) and PCA (0.6%). Within peri-procedural time window of 72 hours, 2 patients had fatal and 2 patients had nonfatal strokes with cumulative complication rate of 2.6%. Interventionalist with >50 case experience with Wingspan before the trial had 0% event rate compared to 4.8% in those with limited experience of <50 cases. The FDA mandated and Stryker funded WEAVE trial demonstrates excellent safety profile of Wingspan stent system with proper patient selection and in expert hands for the treatment of refractory ICAS.