Study on myocardial revascularization using laser

1999 Fiscal Year Final Research Report Summary

• Project/Area Number: 09671398
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Thoracic surgery
• Research Institution: Nippon Medical School
• Principal Investigator: NINOMIYA Junichi Nippon Medical School, Associate Professor, 医学部, 助教授 (00112962)
• Co-Investigator(Kenkyū-buntansha): HICHINOHE Kazuhiro Nippon Medical School, assistant Professor, 医学部, 講師 (30096995) ; SUGAMUMA Masumi Nippon Medical School, assistant, 医学部, 助手 (50206215)
• Project Period (FY): 1997 – 1999
• Keywords: laser / myocardial revascularization

Research Abstract

Adult dogs(the Beagle dog, six to 11 kg weight) was used, and the experimental result from the acute term to a chronic term of the myocardial revascularization of fencing by laser has improved the myocardial regional function of a laser irradiation region for postoperative one to three months. In particular, it has improved clearly for three months. However, that whose myocardium of adult dogs which did sacrifice has checked the revascularization of a new blood vessel carried out clearly was 20%. The number of what is considered to be the revascularization of a new blood vessel from time pathology of three cases which carried out sacrifice six months afterward was 1/3cases. What is considered that these views also had continuity clearly and the new blood vessel was reproduced did not have one cases, either. Also in the chronic dog which carried out sacrifice one year after the operation, the clear continuous revascularization (formation) of a new blood vessel was not accepted, but it w as unthinkable that the improvement of the regional myocardium is based on reproduction of the new blood vessel by laser.
On the other hand, although the clinical example was used together with coronary-arteries bypass surgery to the angina after myocardial infarction and enforced laser revascularization so much to it, with these cases, the improvement of the heartbeat with good postoperative was accepted. However, there is width of the grade of an improvement according to a case, and it was not able to be concluded that it was what this improvement depends on laser. From this our research, the myocardial revascularization by laser was not able to prove the effect certainly.
Some of the cause is considered. Since the used laser was Nd-YAG, heat might be generated, and it may have occluded after blood circulation reconstruction. Moreover, a possibility that there is no myocardial revascularization capability to have been stabilized in laser's own effect cannot be denied, either.
Therefore, it is necessary to consider the method of blood circulation reconstruction with a new viewpoint from now on.