Gonschior P, Gerheuser F, Lehr H A, Welsch U, Höfling B
Medizinische Klinik I, Klinikum Grosshadern, Ludwig-Maximilians-Universität München.
Vasa. 1995;24(4):325-32.
After angioplasty, restenosis remains the major drawback of the procedure with an incidence of between 20-40%. It is a matter of concern whether the cellular alterations start immediately after directional atherectomy (DA) and if they are dependent on the depth of the lesion.
Cellular alterations immediately after DA were investigated using peripheral atherectomy in normal vessels of 30 pigs (A. femoralis, A. carotis communis). DA was used to remove material. The arteries were assigned to two groups according to the depth of vessel injury. (Group 1: lesions to the intima; Group 2: lesions to the media.) 68 arteries with 41 intimal and 27 media lacerations were excised 4 to 24 hours later and processed for transmission electron microscopy, histology and immunohistochemistry.
Immediately after DA, thrombus formation at the site of the altered segment was found. A transient infiltration of polymorphonuclear leukocytes (PMN) occurred, especially if the media was lacerated, followed by the transformation of contractile smooth muscle cells (SMC) into the synthetic subtype. A marked myoproliferative response was found in Group 2 whereas only moderate tissue hyperplasia was seen in Group 1.
The present data provides evidence that cellular alteration of the atherectomized vessel begins immediately after atherectomy. Subsequent to the initial temporary PMN infiltration, an activation of local SMC occurs at a very early stage. These effects and, in particular, a myoproliferative response were found lesions injured the internal elastic membrane, while only minor effects were seen when the lesion affected the intimal layer.
血管成形术后，再狭窄仍然是该手术的主要缺点，发生率在20%至40%之间。定向旋切术（DA）后细胞改变是否立即开始以及它们是否依赖于病变深度，这是一个令人关注的问题。
在30头猪（股动脉、颈总动脉）的正常血管中使用外周旋切术研究DA后立即出现的细胞改变。用DA去除物质。根据血管损伤深度将动脉分为两组。（第1组：内膜损伤；第2组：中膜损伤。）4至24小时后切除68条动脉，其中41条内膜撕裂和27条中膜撕裂，并进行透射电子显微镜检查、组织学检查和免疫组织化学检查。
DA后立即在改变节段部位发现血栓形成。发生多形核白细胞（PMN）短暂浸润，尤其是中膜撕裂时，随后收缩性平滑肌细胞（SMC）转化为合成亚型。第2组发现明显的肌增殖反应，而第1组仅见中度组织增生。
目前的数据提供了证据，表明旋切术后血管的细胞改变立即开始。在最初的PMN暂时浸润之后，局部SMC在非常早期就被激活。这些效应，特别是肌增殖反应，在损伤内弹性膜的病变中被发现，而当病变影响内膜层时仅见轻微效应。
