From Peripheral to Coronary Dynamic Angioplasty: Analysis of Resulting Particles

Abstract

The factors that could reduce the size of particles generated by peripheral (8 Fr) and coronary (5 Fr) Kensey catheters (KC) in calcified and noncalcified atheroma were investigated. Fresh endarterectomy specimens (72 calcified, 72 noncalcified) were inserted in a flow circuit and randomized to undergo simulated dynamic angioplasty using 5 Fr or 8 Fr KC at a range of predetermined cam speeds (20,000–80,000 rpm) and flow rates (18–60 mL/min). Atherectomy as measured by weight loss from the specimen was greater in noncalcified lesions, 21.4 ± 4.5 mg and 14.9 ± 3.8 mg, respectively (P < 0.001). In calcified atheroma, the atherectomy was asymmetrical in 38 out of 72 specimens but in only 12 of 72 noncalcified lesions (P < 0.01). Overall, 65%± 3.9% of collected particles were smaller than 5 μm and 86.8%± 9.1% were smaller than 35 μm. In the remaining 13.2%± 8.9% of particles larger than 35 μm, significant differences were detected between the maximum particle size in each group. Larger particles were generated from calcified atheroma. In noncalcified lesions, increasing cam speed reduced maximum particle size from 890 to 170 μm (P < 0.001). Although a higher flow rate and the use of 5 Fr catheter have also significantly reduced the particle size, their effect was less than that exerted by cam speed. In calcified atheroma, cam speed was the only factor observed to influence the maximal particle size, reducing it from 1,260 to 381 μm (P < 0.001). In conclusion, although the majority of particles resulting from the use of KC were small, a proportion of large particles was also detected. Their size could be significantly reduced by careful adjustment of the operating parameters. These results are important for future application of KC in coronary dynamic angioplasty. However, the impact of reducing particle size on the risk of embolism in vivo requires further study.