Department of Vascular Surgery, Mount Sinai School of Medicine, New York, NY 10029, USA.
J Vasc Surg. 2010 Feb;51(2):317-22. doi: 10.1016/j.jvs.2009.08.063. Epub 2009 Dec 14.
Extracranial carotid stenoses exhibit significant variance in embolic potential, with restenotic lesions having a particularly low propensity for embolization. This study sought to identify characteristics associated with increased generation of embolic debris during carotid angioplasty and stenting (CAS).
Captured particulate was available for analysis in 56 consecutive patients. Demographics were mean age, 74 years (range, 60-94 years); mean stenosis, 88% (range, 70%-99%); symptomatic, 27%; prior carotid endarterectomy (CEA), 27%; prior radiotherapy, 7%. Plaque echogenicity, heterogenicity, ulceration, and irregularity were assessed with B-mode duplex ultrasound analysis. Gray scale median (GSM) was calculated from normalized B-mode VHS video recordings. Calcification and degree of stenosis were determined angiographically. Captured particulate debris was evaluated for total number; number >200 microm, >500 microm, >1000 microm; mean and median size. Hematoxylin and eosin, trichrome, and von Kossa stains were used for histologic analysis of captured material.
Restenotic carotid stenoses after prior CEA generated minimal embolic debris compared with primary stenoses. Four of 15 patients (27%) with restenotic lesions demonstrated embolic particles; all debris was <500 microm. All 41 patients with primary stenoses had some embolic debris; particulate size was >200 microm in 91%, >500 microm in 72%, and >1000 microm in 43%. In primary lesions, the number and size of captured particulate correlated with GSM and with the combined ultrasound findings of echogenicity, heterogenicity, and luminal irregularity/ulceration (P < .02, 95% confidence interval, 4.5-27.6). None of these ultrasound factors correlated independently with embolic particulate (P = NS). Patients aged >70 years exhibited more total particles (8.1 vs 2.3, P = .008) and increased mean particle size (370 vs 157 mum, P = .02). No significant correlation was observed between the number and size of captured embolic particulate and any other variable (stenosis percentage, prior radiotherapy, preprocedural symptoms, periprocedural symptoms, and calcification). Histologically, the embolic debris consisted of extensive amorphous, acellular proteinaceous material. Calcium debris in the embolic particulate was associated with heavily and moderately calcified lesions.
Considerable variation exists in the number and size of embolic particles generated during CAS. Embolic potential is positively correlated with lesion GSM and the combination of lesion echogenicity, heterogenicity, and irregularity. Restenosis after prior CEA is associated with minimal embolic particulate generation, suggesting that embolic protection may not be necessary for CAS of restenotic lesions.
颅外颈动脉狭窄的栓塞潜能存在显著差异，再狭窄病变的栓塞倾向特别低。本研究旨在确定与颈动脉血管成形术和支架置入术（CAS）过程中产生更多栓塞碎片相关的特征。
56 例连续患者的捕获颗粒可用于分析。人口统计学数据为平均年龄 74 岁（范围 60-94 岁）；平均狭窄程度为 88%（范围 70%-99%）；有症状的占 27%；颈动脉内膜切除术（CEA）史占 27%；放射治疗史占 7%。斑块回声、异质性、溃疡和不规则性采用 B 型双功能超声分析评估。从归一化 B 型 VHS 视频记录中计算灰度中位数（GSM）。钙化和狭窄程度通过血管造影确定。捕获的颗粒碎片评估总数量；数量>200 µm、>500 µm、>1000 µm；平均和中位数大小。捕获材料的苏木精和伊红、三色和 von Kossa 染色用于组织学分析。
与原发性狭窄相比，先前 CEA 后再狭窄颈动脉狭窄生成的栓塞碎片极少。15 例再狭窄病变中有 4 例（27%）患者出现栓塞颗粒；所有碎片均<500 µm。41 例原发性狭窄患者均有一定的栓塞碎片；91%的颗粒>200 µm，72%的颗粒>500 µm，43%的颗粒>1000 µm。在原发性病变中，捕获颗粒的数量和大小与 GSM 以及回声、异质性和管腔不规则/溃疡的联合超声发现相关（P<.02，95%置信区间，4.5-27.6）。这些超声因素均与栓塞颗粒无独立相关性（P=NS）。年龄>70 岁的患者产生的颗粒总数更多（8.1 比 2.3，P=.008），平均颗粒尺寸更大（370 比 157 µm，P=.02）。捕获的栓塞颗粒的数量和大小与任何其他变量（狭窄百分比、先前的放射治疗、术前症状、围手术期症状和钙化）之间无显著相关性。组织学上，栓塞碎片由广泛的无定形、无细胞蛋白物质组成。栓塞颗粒中的钙碎片与重度和中度钙化病变有关。
在 CAS 过程中产生的栓塞颗粒的数量和大小存在很大差异。栓塞潜能与病变 GSM 呈正相关，并与病变回声、异质性和不规则性相结合。先前 CEA 后的再狭窄与栓塞颗粒的产生量少有关，提示在 CAS 治疗再狭窄病变时可能不需要栓塞保护。
