Stent Retriever Device Shows Promise in Acute Ischemic Stroke

Download this article's Factoid (PDF & PPT for Gold Subscribers)

Use of a mechanical revascularization device in patients with acute ischemic stroke is associated with good clinical outcome and low risk of procedure- and device-related complications, according to a prospective study published online August 1, 2013, ahead of print in Stroke.

For the Solitaire Flow Restoration Thrombectomy for Acute Revascularization (STAR) study, investigators led by Jan Gralla, MD, MSc, of the University of Bern (Bern, Switzerland), enrolled 202 patients at 14 comprehensive stroke centers in Europe, Canada, and Australia. All patients presented with acute ischemic stroke due to anterior circulation proximal occlusions and were treated with the Solitaire device (ev3, Plymouth, MN).

The Solitaire features an expandable stent that captures clot and removes it as the device is retrieved from the vessel.

High Revascularization, Low Adverse Events

Median time from symptom onset to groin puncture was 238 minutes. Mean procedural time was 29 ± 27 minutes. The mean number of passes with the device was 1.5. Prior to the mechanical procedure, 59% of patients received IV rtPA.

Successful revascularization (thrombolysis in cerebral infarction ≥ 2b after 3 or fewer passes), the primary endpoint, was achieved in 79.2% of patients. Rescue therapy was required in 9% of unsuccessful procedures.

The most common complication was vasospasm, detected in 23% of patients, although it was symptomatic in only 0.5%.

At 90 days, 57.9% of patients had favorable neurological outcomes, defined as 0-2 on the modified Rankin Scale. The frequency of total adverse events was low overall (7.4%) regardless of whether or not patients received rtPA prior to thrombectomy (table 1). The rate of all-cause mortality in the entire cohort was 6.9%.

Table 1. Primary and Secondary Adverse Events at 90 Days

Importantly, good collateral circulation correlated with good outcome (P = 0.034). Patients who required rescue therapy, however, had a lower rate of favorable outcome compared with those who did not (33.3% vs. 60.3%; P = 0.043).

Results Better Than in Earlier Trial

According to the study authors, the rate of favorable outcome in STAR is higher than that seen with the Solitaire retriever in the SWIFT trial, which compared the Solitaire device with the earlier-generation Merci retriever (Stryker, Kalamazoo, MI). This may be attributed, they note, to a higher revascularization rate, as well as selection of patients with exclusively anterior circulation stroke, prestroke modified Rankin Scale scores of 0-2, and comprehensive patient management after treatment. Furthermore, the rate of intracranial hemorrhage seen in STAR was low and within the range seen in SWIFT. This is important, the authors note, given the higher rates of this complication seen with the Merci retriever.

They conclude that the Solitaire device is safe and effective when used “by comprehensive and experienced stroke centers,” noting that the “data support further investigation of this device in randomized controlled trials against best medical treatment alone.”

Study Details

Patients’ median age was 72 years, and their median National Institutes of Health Stroke Scale score at admission was 17; 60% were women.

 

---

Source:
Pereira VM, Gralla J, Davalos A, et al. Prospective, multicenter, single-arm study of mechanical thrombectomy using Solitaire Flow Restoration in acute ischemic stroke. Stroke. 2013;Epub ahead of print.

 

 

Related Stories:

• Novel Clot Retrieval System Superior to Older Device in Acute Stroke Patients
• Small Study Supports Thrombectomy Devices in Large Strokes
• Endovascular Treatment Costs High for Acute Stroke