Marijianowski M M, Crocker I R, Styles T, Forestner D M, Waksman R, Cipolla G D, King S B, Robinson K A
The Andreas Gruentzig Cardiovascular Center, Department of Medicine (Cardiology), Emory University School of Medicine, Atlanta, GA, USA.
Int J Radiat Oncol Biol Phys. 1999 Jun 1;44(3):633-41. doi: 10.1016/s0360-3016(99)00038-3.
Endovascular radiation has reduced postangioplasty restenosis in preclinical and early clinical studies. External radiation treatment may have advantages over endovascular therapy. We examined vascular and perivascular tissue responses to endovascular and external irradiation in pig coronary arteries.
Ninety-one animals received endovascular or external radiation following balloon injury and were sacrificed at 14, 30, or 180 days. Injured segments of coronary vessels including perivascular and myocardial tissues were evaluated with histochemistry.
Endovascular radiation was associated with delayed arterial wound healing as late as 6 months, evidenced by paucity of smooth muscle alpha-actin in neointimal cells compared to control. External treatment was associated with increased collagen in neointima and adventitia, and focal interstitial necrosis in adjacent myocardium.
These investigations showed whole-heart 14 Gy external radiation treatment following coronary injury exacerbated certain aspects of arterial healing. In addition focal myocardial necrosis and fibrosis was observed following external but not endovascular irradiation. Endovascular radiation has some advantages over external irradiation; however the persistence of a synthetic smooth muscle cell phenotype in the neointima at 6 months suggests ionizing radiation in general may have profound effects on vessel architecture over the long term.
在临床前和早期临床研究中，血管内放射治疗已减少血管成形术后再狭窄。外照射治疗可能比血管内治疗具有优势。我们研究了猪冠状动脉对血管内照射和外照射的血管及血管周围组织反应。
91只动物在球囊损伤后接受血管内或外照射，并在14天、30天或180天时处死。对包括血管周围和心肌组织在内的冠状动脉损伤节段进行组织化学评估。
血管内放射治疗与长达6个月的动脉伤口愈合延迟有关，与对照组相比，新生内膜细胞中平滑肌α-肌动蛋白缺乏可证明这一点。外照射治疗与新生内膜和外膜中胶原蛋白增加以及相邻心肌中的局灶性间质坏死有关。
这些研究表明，冠状动脉损伤后进行14 Gy全心外照射治疗会加剧动脉愈合的某些方面。此外，外照射后观察到局灶性心肌坏死和纤维化，而血管内照射后未观察到。血管内放射治疗比外照射具有一些优势；然而，6个月时新生内膜中合成型平滑肌细胞表型的持续存在表明，一般来说，电离辐射可能长期对血管结构产生深远影响。
