Chronic Animal Experimant Using Transmycardial Laser Revascularization (TMLR)

经心肌激光血管重建术（TMLR）使心肌通过创建微孔来增加血液供应。虽然TMLR能改善心绞痛的临床症状，但其确切机制和远期效果尚不清楚。本研究的目的是研究TMLR对组织血流量（TBF）和神经受体破坏的慢性影响。[方法]本研究选用14头猪。在所有动物中，通过TMLR在左前降支和第一对角动脉（D1）周围建立30个微通道。1组结扎D1 (n=7)， 2组完整结扎D1 （n=7）。术后12个月，2组动物D1结扎。两组均测量局部壁运动（RWM）和TBF。此外，将缓激肽注射到TMLR周围的心肌中，评估其对交感神经受体的反应，免疫组织化学证实了这一点。<结果> 1组TMLR区RWM严重减少或与TBF差相关，组织学显示明显纤维化。2组RWM也有所减少，但优于1组，TBF大幅恢复。第2组对缓激肽的反应维持，第1组反应较差。两组患者心外膜周围均可见酪氨酸羟化酶。结论> TMLR可提高TBF，但不能改善RWM。由于TMLR未破坏神经受体，推测TMLR后心绞痛的缓解主要是由于TBF的改善而非神经受体的破坏。

Transmyocardial laser revascularization (TMLR) enables myocardium to increase blood supply by creation of micropores. Although the clinical symptom of angina pectoris was improved by TMLR, the precise mechanism as well as long term results are unclear. The purpose of this study is to investigate chronic effects of TMLR on tissue blood flow (TBF) and destruction of neuroreceptors.<Methods> Fourteen swine were used in this study. In all animals, 30 microchannels by TMLR were created around the left anterior descending artery and the first diagonal artery (D1). Then, D1 was ligated in group 1 (n=7), and was intact in group 2 (n=7). Twelve months after operation, D1 of group 2 animals was also ligated. Regional wall motion (RWM) and TBF was measured in both groups. Furthermore, Bradykinin was injected into the myocardium around TMLR area to evaluate response to sympathetic neuroreceptors, which were confirmed by immunohistochemistry. <Results> In group 1, RWM of TMLR area was severely reduced or akinetic in association with poor TBF, and histology revealed marked fibrosis. In group 2, RWM was also reduced, but was better than in group 1 with substantially restored TBF. The response to Bradykinin was maintained in group 2, while it was poor in group 1. Tyrosine hydroxylase was observed around epicardium in both groups. <Conclusion> TMLR increased TBF, but failed to improve RWM. Since neuroreceptors were not destroyed by TMLR, it was speculated that angina pectoris was predominantly relieved after TMLR due to improvement of TBF rather than destruction of neuroreceptors.