Adam de Havenon, MD

Menon BK, Almekhlafi MA, Pereira VM, Gralla J, Bonafe A, Davalos A, et al. Optimal Workflow and Process-Based Performance Measures for Endovascular Therapy in Acute Ischemic Stroke: Analysis of the Solitaire FR Thrombectomy for Acute Revascularization Study. Stroke. 2014

The ongoing debate of why intra-arterial (IA) thrombectomy for ischemic stroke, after showing benefit in multiple single-arm studies, demonstrated no benefit and potential harm in three randomized trials in 2013  has focused on a number of variables, but the most important is clearly time. Successfully triaging a stroke patient to IA and assemlbing all the health care personnel is a monumental effort and, as we know, time is brain. However, all processes can be streamlined and inefficiencies removed, which also applies to IA therapy, especially considering that the amount of time needed to administer IV tPA ranges from 30 to 60 minutes depending on what country you have your stroke in. 

Bijoy Menon et al. report on a multivariate analysis of standard time intervals in the IA process during the STAR trial, a multicenter, single-arm study of Solitaire Flow Restoration thrombectomy in patients with large vessel anterior circulation strokes. STAR enrolled 202 patients and reported excellent outcomes, with an mRS of 0-2 in almost 58% of patients and almost 80% achieved TICI 2b/3 recanalization. The time intervals from stroke onset to groin puncture and final angiogram were substantially lower than IMS-3. The authors report several interesting findings: time from baseline imaging to puncture was prolonged in patients receiving IV tPA by 32 minutes and in patients with MR-based imaging at baseline by 18 minutes. Extra-cranial carotid disease delayed puncture to first stent deployment time by 25 minutes and for each one-hour increase in stroke onset to final angiogram, odds of good clinical outcome decreased by 38%. General anesthesia increased the amount of time from groin puncture to final angiogram by 13 minutes, 
This data confirms and quantifies several longstanding assumptions about why IA treatment can be delayed. The time required to administer IV tPA can be reduced, but tPA should not be excluded, given that it is the most effective approved treatment for acute ischemic stroke. The same cannot be said for MRI, which does not have tangible clinical benefit at this point, and general anesthesia should be avoided if possible because of adverse effects on both time and brain perfusion after systemic hypotension. These are all worthwhile targets to improve, but the question remains: when will we have a larger, randomized controlled trial (RCT) evaluating the Solitaire device, which appears so promising in these single-arm studies, quite like the MERCI and Peumbra devices did before they were tested in RCTs last year.