Functional outcomes of patients with stroke treated with thrombectomy by aspiration

Purpose: To determine the time of procedure, the value of modified Thrombolysis in Cerebral Infarction and National Institute Health of Stroke Scale as predictors of the functional results of patients with stroke treated with mechanical thrombectomy by aspiration.Methods: Observational, analytical, and retrospective case series analysis of consecutive patients with internal carotid and cerebral media branch occlusions. Clinical outcome was measured with the modified Rankin Scale at 90 days after stroke. To analyze the differences between groups, the Chi² test was used for the qualitative variables.Results: The sample size was 58 patients treated with thrombectomy by aspiration. We observed that the thrombectomy time determines the recanalization results; meanwhile, modified Thrombolysis in Cerebral Infarction is a predictor of modified Rankin Scale at discharge but not after 3 months. National Institute Health of Stroke Scale was determinant for modified Rankin Scale result.Conclusions: Mechanical thrombectomy by aspiration proves to be an effective treatment of acute stroke, improving the patient's vital and functional prognosis. The thrombectomy time is a predictor of the result in relation to the degree of recanalization determined by the modified Thrombolysis in Cerebral Ischemia. Also, the degree of recanalization predicts functional outcome at discharge but not at 3 months.

Experimental Direct Measurement of Clot-Capturing Ability of Stent Retrievers

BACKGROUND

Stent retrievers (SRs) can be used to perform mechanical thrombectomy for the treatment of acute major arterial occlusion. Recanalization is faster, and outcomes are better with treatment involving these devices than with internal treatment. Although several SRs are available, their clot-capturing abilities are unclear. Therefore in the present study, we numerically evaluated the clot-capturing abilities of SRs in an experimental vascular model.

METHODS

A sham clot (urethane foam) was fixed with sutures at the middle of a vascular model (polyvinyl chloride tube). One end of the tube was connected to a measuring instrument. From the other end, an SR was inserted and deployed over the sham clot. The delivery wire of the stent was then withdrawn at a constant velocity using an automatic withdrawal machine. The maximum frictional force before the stent left the clot was measured. Five stents (Trevo ProVue [2 sizes], Revive, and Solitaire [2 sizes]) and three stent-deployment techniques (standard, push-and-fluff, and wire-push techniques) were evaluated.

RESULTS

The clot-capturing ability (maximum withdrawing force [N: newton]) was greater for large-diameter stents than for small-diameter stents (mean 0.39 ± 0.11 vs. 0.56 ± 0.18). For Trevo and Revive, the clot-capturing ability was highest with the push and fluff technique (mean 0.43 ± 0.05). For Solitaire, the ability was the highest with the simple wire-push technique (mean 0.705 ± 0.16).

CONCLUSIONS

We successfully numerically evaluated the clot-capturing abilities of SRs. The clot-capturing ability differed among SRs and among stent-deployment techniques.

Efficacy and Safety of REVIVE SE Thrombectomy Device for Acute Ischemic Stroke: River JAPAN (Reperfuse Ischemic Vessels with Endovascular Recanalization Device in Japan)

REVIVE SE (REVIVE) is a closed-ended, self-expanding stent retriever used in the RIVER JAPAN study. We present our early experience with REVIVE for revascularization of acute ischemic stroke (AIS) in patients who have failed or are ineligible for intravenous recombinant tissue plasminogen activator treatment. This prospective, single-arm, non-randomized, multicenter registry study followed up patients undergoing mechanical thrombectomy with REVIVE for 90 days. The primary endpoint was a post-procedure Thrombolysis in Cerebral Infarction (TICI) score ≥2a. Secondary endpoints were clot migration/embolization; recanalization without symptomatic intracranial hemorrhage (ICH) at 24 h; symptomatic ICH; good neurological outcome (modified Rankin Scale score ≤2 National Institute of Health Stroke Scale (NIHSS) score decrease ≥10) at day 90; device- or procedure-related serious adverse events (SAEs) and mortality at day 90. To confirm non-inferiority of REVIVE, results were compared with historical data of the Merci Retriever. About 49 patients were enrolled (median age 73 years; males 46.9%; middle cerebral artery (MCA) occlusion 83.7%; median NIHSS score 17). A post-procedure TICI score ≥2a was observed in 73.5% (36/49, 95% confidence interval [CI] 58.9–85.1) of patients. No post-procedural clot migration/embolization events occurred. Successful recanalization without symptomatic ICH was observed in 62.5% (30/48, 95% CI 47.4–76.0). The good neurological outcome was achieved in 66.7% (32/48) patients. Symptomatic ICH and device- or procedure-related SAEs were reported in 6.3% and 12.2% of patients, respectively. Two deaths were reported. REVIVE demonstrated equivalent efficacy and safety as the Merci Retriever. Results suggest that REVIVE is effective and safe in recanalizing occluded intracranial arteries in AIS.

Experimental evaluation and training of stent clot retrieval: the confront clot scrambling method

The introduction of stent retrievers has changed the methods used for acute intracranial thrombectomy, but the training approach has not been discussed enough. We, therefore, aimed to establish a simple skill up method which can be used to train anytime and anywhere with low costs. Also, we introduce our experimental confront clot scrambling method (CCSM) which makes a profitable visualization in how the stent retriever works. The CCSM involved a sham clot set in the middle of a polyvinyl chloride tube, after which two stent retrievers were navigated from each side before being simultaneously withdrawn with the same force. The stent that removes the sham clot is determined to have stronger clot retrieval ability. Several adjunctive techniques were also compared. The push and fluff adjunctive technique was the most effective among all the stents. Generally, the former deployed stent was stronger than later one. Therefore, the later deployed stent with the push and fluff technique lets us know whether the physician's maneuver worked well or not. CCSM could directly evaluate the ability of adjunctive techniques with each stent retriever and demonstrate the physicians' skills. Because the actual endovascular clot retrieval requires extreme fine maneuvers against invisible vessels, repeat training is very important especially in beginners.