The Journal of Japan Society for Laser Surgery and Medicine

A new photoacoustic diagnosis of early pancreatic cancer is proposed. In this method, pancreatic tissue is irradiated with pulsed light via a pancreatic duct, and photoacoustic signals originated from the tumor-localizing drug are detected. The validity of this method was investigated for two-layered gelatin models (top: normal tissue mimicking layer, bottom: tumor mimicking layer) whose optical properties were adjusted to be the same as those of pancreas in rats. With a detector in which an optical fiber and a ring-shaped piezoelectric film were coaxially arranged, photoacoustic signals came from the tumor mimicking layer were measured. It was shown that for a drug concentration ratio (normal tissue : tumor) of 1:3, signals came from 3 mm in depth could be detected, while for a ratio of 1:6, the detectable depth increased to 6 mm. The results suggest that the present method can be applied to diagnosis of deep-located early cancers.

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The object of this paper is to report smooth healing of arterial wall of obstructing arterial disease (ASO) treated with laser angioplasty as well as the general results of laser angioplasty.
The initial success rate of percutaneous transluminal laser angioplasty (PTLA) in our series of 161 procedures was 87%. The 6-year-patency rate by Kaplan-Meier method was 89.8% in total cases, 91.4% for iliac lesions and 85.8% for femoro-popliteal lesions.
In our selected cases of ASO, most of which measured less than 10 cm in length, showed fairly good long-term patency, and the arterial wall healed smoothly after PTLA as the time elapsed. Some of such representative cases were demonstrated with follow-up angiograms.
PTLA expanded the indication of percutaneous translumunal angioplasty by making a tunnel in the obstructing lesion in ASO.
The reason of smooth healing of arterial wall after PTLA seems to be partially due to welding effect of laser.

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