Abstract
Lasers have been widely applied in the field of medicine and surgery. However laser applications are very rare in the field of cardiovascular surgery through out the world. It is now difficult to keep long-term patency after anastomosis of the conventional fashion with suture materials especially for small-caliber vessels.
First of all, the relationship between output and irradiation time of a CO2 laser was analyzed as well as tissue reaction to the laser in a preliminary experiment. From these preliminary experiments it could be concluded that the optimal laser output was 20-40mW and irradiation time was 6-12sec/mm for vascular anastomosis. of small-caliber vessels in the extremities. Side-to-side, end-to-side, and end-to-end anastomosis at the site of the femoral arteries and veins or the carotid arteries and veins were carried out using a low energy CO2 laser. Diameter of these vessels ranged from 2 to 10mm with a mean of 4mm and laser beam was moved slowly along the anastomic line. Pressure tolerance test and tensile strength test as well as histological examinations were also performed to evaluate the intensity of the laser anastomotic site of the vessels. Consequently, there were no hemorrhages from the sites of laser anastomosis which were effective enough for the site to tolerate high pressures (300mmHg) without bleeding.
On the other hand, the laser anastomotic sites were separated in weights 1,034.2±103.9g, and the sites of anastomosis sutured by 5-0 suture material were also separated into weight 1,103.7±144.8g.
The sites of laser vascular anastomosis were microscopically examined after several time of intervals. Subsequently, good healings of laser anastomotic sites were clearly observed histologically.
From the good experimental studies, laser vascular anastomosis was employed in 111 patients (136 anastomotic sites) with anginal attack, or chronic renal failure and peripheral vascular disorders. Finally, laser vascular anastomosis should be recommended to the reconstructions of small-caliber vessels less than 4mm in diameter.
Finally, current trends of vascular tissue welding were described.
