Gonschior P, Gerheuser F, Lehr H A, Welsch U, Höfling B
Medical Department I Klinikum Grosshadern, München.
Basic Res Cardiol. 1995 Mar-Apr;90(2):160-6. doi: 10.1007/BF00789445.
Restenosis after angioplasty occurs with an incidence of 20-50% and remains a major drawback. Certain randomized studies suggest that a bigger post-angioplasty lumen predicts a better long-term outcome. Conversely other studies showed a better outcome with limited injury. The present study aimed to investigate the depth of the lesion and relate this to cellular alterations after graded vascular injury.
Vessel segments of 30 pigs underwent injury using a directional atherectomy catheter. Vessels were assigned according to the extent of injury to Group 1 (intima lesion) or Group 2 (media injury). 2 hours to 7 days after injury, 68 arteries showing 41 intimal and 27 media lacerations were excised and processed for histology and transmission electron microscopy.
Immediately after injury, thrombus formation was found at the site of the altered segment. A marked, transient infiltration of polymorphonuclear leukocytes (PMN) occurred only if the media was lacerated, starting within the first hours and increasing up until the 12 hours time point. The cellular infiltration was followed by a transformation of contractile myocytes to a synthetic subtype. The ratio of myofilaments to organelles decreased. A pronounced myoproliferative response was found in Group 2 after 7 days (p < 0.01), whereas only moderate tissue hyperplasia was seen in Group 1.
The data presented provide evidence that the cellular alteration of injured vessels begins immediately. Subsequent to an initial temporary PMN infiltration, an activation of local myocytes occurs at a very early stage. In particular, a myoproliferative response was found only after deep injury with rupture of the internal elastic lamina.
血管成形术后再狭窄发生率为20% - 50%，仍是一个主要问题。某些随机研究表明，血管成形术后更大的管腔预示着更好的长期预后。相反，其他研究显示损伤有限时预后更好。本研究旨在调查病变深度，并将其与分级血管损伤后的细胞改变相关联。
使用定向旋切导管对30头猪的血管段进行损伤。根据损伤程度将血管分为1组（内膜病变）或2组（中膜损伤）。损伤后2小时至7天，切除68条动脉，其中41条内膜撕裂，27条中膜撕裂，并进行组织学和透射电子显微镜检查。
损伤后立即在病变段部位发现血栓形成。仅在中膜撕裂时才会出现明显的多形核白细胞（PMN）短暂浸润，始于最初几小时内，并持续增加直至12小时时间点。细胞浸润后，收缩性心肌细胞转变为合成亚型。肌丝与细胞器的比例降低。7天后，2组出现明显的肌增殖反应（p < 0.01），而1组仅见中度组织增生。
所提供的数据表明，受损血管的细胞改变立即开始。在最初的PMN短暂浸润之后，局部心肌细胞在很早阶段就被激活。特别是，仅在伴有内弹性膜破裂的深度损伤后才发现肌增殖反应。
