激光对兔损伤性血管内膜增殖的抑制作用

Inhibition of Rabbit Traumatic Arterial Intimal Hyperplasia by Laser Irradiation

目的 观察５１０－６ ｎｍ 波长激光对兔损伤性血管内膜增殖的抑制作用。方法 实验用雄性日本大耳白兔１２ 只，用球囊导管剥脱腹主动脉内皮，并将其分成激光照射段和对照段，随后用柱状光导纤维以１００Ｊ／ｃｍ２ 的光剂量对照射段进行照射，于术后１４ 天取材，光镜观察血管形态变化，计算机图像分析确定新生血管内膜的面积。结果 激光照射段和对照段腹主动脉均有明显的新生血管内膜形成，呈同心性增厚，厚度不均一。内膜中细胞形态和排列不规则。激光照射段血管新生内膜的平均面积为５－２ ｍｍ２ ±０－６ ｍｍ２ ；对照段为１８－３ ｍｍ２ ±１－１ ｍｍ２ ，两者差异有非常显著意义（Ｐ＜０－０１）。结论 ５１０－６ ｎｍ 波长激光照射能显著抑制损伤性血管内膜的增殖，有望用于再狭窄的防治。

Objective Apoptosis of vascular smooth muscle cells(SMC) was successfully induced by 510 6 nm laser irradiation with an energy densities of 100 J/cm 2 in vivo in the previous study. In this study, the effect of apoptosis induced by laser irradiation on rabbit arterial intimal hyperplasia caused by balloon injury was evaluated. Methods Rabbit abdominal aortas (n=12) were randomly treated with balloon injury or balloon injury plus laser irradiation in separate zones. Laser irradiation was performed using a laser catheter delivering a single dose generated from 510 6 nm laser. The power density was 100 mW/cm 2, the irradiation time was 1 000 seconds and the energy density was 100 J/cm 2. Fourteen days after treatment, the aortas were harvested, fixed and processed for histology. Morphometric investigation was performed with light microscope and the area of intimal hyperplasia were quantitatively determined with planimetric analysis. Results A myoproliferative response was observed in all injured vessels from both control group and laser group. While the myoproliferative response was markedly inhibited by laser irradiation of 100 J/cm 2. The intimal hyperplasia area was 5 2 mm 2±0 6 mm 2 in the laser group and 18 3 mm 2±1 1 mm 2 in the control group. The difference between two groups was significant (P<0 05). Conclusions The experimental data indicated that apoptosis of SMC induced by laser irradiation could inhibit rabbit arterial intimal hyperplasia caused by balloon injury.