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Correspondence to Dr Michael J Alexander, Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; [email protected]
Background
The Wingspan stent system (Stryker Neurovascular, Salt Lake City, Utah USA) is a self-expanding, nitinol, intracranial stent that was originally cleared by the Food and Drug Administration (FDA) in the USA in 2005 under the Humanitarian Device Exemption (HDE) classification. The decision was based on the results of the initial approval trial.1 The original indication for use was for patients who had 50–99% intracranial artery stenosis due to intracranial atherosclerotic disease (ICAD), who presented with a stroke, and who were 'refractory to medical therapy'.2 The medical therapy regimen was not well defined at that time. At the time of their qualifying event, 84% of patients were taking one or more antiplatelet agents, 42% were taking anticoagulant therapy, and 27% were taking a combination of antiplatelet and anticoagulant therapy. In the HDE trial, the target vessel for revascularization had to be 2 mm or larger, the patient had to have a moderately functional neurologic status with modified Rankin Scale score of 3 or better, and stenting was performed at 1 week or longer following the qualifying event.
Subsequent registries in the USA3–5 comprised a spectrum of on-label and off-label patients, including patients who presented with transient ischemic attacks, without documented strokes, patients for whom medical therapy had not failed, and patients treated for other intracranial lesions, such as dissection. These studies demonstrated periprocedural complication rates of stroke and death of approximately 6%. Published Wingspan stent series from Asia6–12 with heterogeneous inclusion and exclusion criteria also demonstrated low periprocedural complication rates and relatively reproducible 1-year follow-up stroke and death rates (table 1).
Table 1Table analyzing the major Wingspan stent studies with reference to enrollment criteria, periprocedural events, and 1-year follow-up
| Number of patients stented | Percentage stented per HDE trial indication | Periprocedural complications | Time to stent from stroke or TIA | Cumulative 1-year stroke and death rate | |
| HDE Trial1 | 44 | 93% | 4.5% | 22 days | Not reported |
| NIH Registry3 4 | 160 | 61% | 6.2% | 10 days | Not reported |
| US Registry5 | 158 | 57% | 6.9% | Not reported | Not reported |
| Jiang6 | 100 | 71% | 5.0% | 34 days | 7.3% |
| SAMMPRIS13 | 224 | 8.2% | 14.7% | 7 days | 20.0% |
| Miao |