レーザーを熱源とする短時間加温ホットバルーン血管形成術 (V)

加温パラメーターが慢性期に及ぼす影響

抄録

To prevent chronic restenosis, we experimentally investigated the optimum setting combination of the balloon temperature and heating duration in our laser hot balloon angioplasty in rabbit model. The sufficient energy supply of Nd: YAG laser for our balloon catheter by a thin silica fiber and the irrigation of the laser heated contrast medium in the balloon played key role to attain the rapid temperature rise/fall and uniformity of the balloon. Therefore, the balloon could realize independent control of the balloon temperature and heating duration. In particular, short heating duration (<=15s) was successfully established.
The rabbit femoral arteries were treated by our laser hot balloon of 3mm in diameter with various balloon temperatures and durations ranging 60 to _??_90 deg., and 15 to 30 seconds, respectively. The histological examination showed that relatively high temperature (>70deg.) was necessary to suppress hyperplasia of the vessel in chronic phase. The angiography of preand post- treatment and of 2 months after the treatment showed that relatively high temperature with short heating duration (15s) was the best for chronic patency of the treated vessels. Theoretical calculation regarding to heat conduction reinforced our experimental results.
The laser hot balloon angioplasty with above mentioned parameters might provide excellent chronic patency in clinical treatment.