|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1997 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1996 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Improvements of an ultrasonographic probe and a microwave electrode for laparoscopic microwave coagulation therapy of hepatoma were tried. The diameter of the customary used microwave electrode is 1.6mm. The diameter of a newly developed microwave electrode was 2.0mm. The coagulation area was widened to 3cm with this new electrode although it was 2cm width with the customary used microwave electrode. The damages by coagulation with the new electrode to neighboring organs (large blood vessels, gall bladder, stomach, pancreas and kidney) were experimenntally evaluated using dogs. It was confirmed that each safty distance between the newly developed electrode and large blood vessels or gall bladder, between the newly developed electrode and stomch, pancreas or kidney was 1cm and 1.5cm, respectively. The increase of danger of bleeding with the new electrode was not observed.
It was difficult to improve the ultrasonographic probe. But the addition of fine indentations on the surface of microwave electrode and its sheath enabled the ultrasonography to easily catch the location of the microwave electrode in 6cm or more depth, although It was difficult for the ultrasonography to catch it in deeper than 4cm with customary used microwave electrode and its sheath.
Furthermore, the insertion of microwave electrode is more safely done with cutting scales on the surface of the sheath of microwave electrode than without it.