Abstract W P16: Quantitative Analysis of Distal Emboli During Mechanical Thrombectomy With Stent-Trievers

Abstract

Introduction: While the use of stentrievers has been shown to improve clinical outcomes compared with previous generation technology in the interventional treatment of stroke, there remains variability in clinical results. One contributor may be distal clot fragmentation during thrombectomy. Our goal is to assess various treatment strategies that can reduce the risk of distal embolization. Materials and Methods: Three different treatment strategies using stentrievers (Solitaire FR) included 1 Proximal flow control with a balloon guide catheter (BGC), 2 Thromboaspiration via a 5Fr distal access catheter (DAC) in the origin of the MCA, and 3 Thrombectomy through a conventional 6Fr conventional guide catheter (CGC). The vascular phantom included collateral circulation via PCom and ACom arteries and two different clot types were used( Stroke 2013;44:1396) . For each strategy and clot type, 8 replicate experiments were performed. Large clot fragments (>1000μm) were separated from the effluent collected at each the ACA and MCA outlets and the longest dimension recorded. Particle size and number (<1000μm) were measured with a Coulter counter. A cumulative distribution of clot fragments was made with a moving average of 10μm-wide bins centered at 0.2μm intervals across a range of 25-1000μm. Exponential decay functions were fit to the data and time-constants were calculated. Results: For visible fragments, >1mm, both the use of the BGC and the DAC techniques produce fewer visible clot fragments (>1000μm) as compared to CGC technique (p<0.05, hard clot). For particulate sizes between 250-1000μm there was a trend towards a lower rate of hard clot embolic particulate with the DAC technique. In the size range of 25-250μm, the BGC produced less clot fragments than the DAC technique (p<0.05, hard clot). In the <25 μm group the BGC technique produced a lower rate of embolic particulates compared to the DAC or CGC technique (p<0.05). All regressions had a coefficient of determination >0.95. The BGC and DAC methods were found to have the shortest time-constants for hard and soft clots, respectively. Conclusion: Use of the BGC during a Solitaire FR thrombectomy is associated with statistically lower rates of distal emboli across a broad range of embolic particle sizes..