A NEW ND-YAG LASER-BEARING ANGIOSCOPE IS USEFUL FOR VISUALIZING AND TREATING LESIONS OF THE SUPERIOR VENA-CAVA AND THE RIGHT-SIDED CHAMBERSOF THE HEART - A PRELIMINARY-STUDY IN DOGS

The utility of a prototype Nd:YAC laser-bearing angioscope was evaluat ed for the diagnosis and treatment of neoplastic lesions of superior v ena cava (SVC) and right-sided chambers of the heart in dogs. The angi oscope had a balloon tightly fixed to the tip with heat shrink tubing and suture ligation. Approximately 96% of the Nd:YAG laser energy pene trated the balloon without rupture when the balloon was inflated with saline solution and was in direct contact with the target. The interna l surfaces of the SVC, inferior vena cava, right atrium, tricuspid val ve, right ventricle, and main pulmonary artery were visualized clearly by this angioscopic technique. The Nd:YAG laser was guided successful ly under direct vision and a surgically transplanted neoplasm in the S VC was irradiated. Tumor coagulation was confirmed macroscopically and microscopically. This new angioscope requires further improvement, sp ecifically, to decrease its diameter and improve the durability of the balloon.