Hepatic interstitial laser photocoagulation: demonstration and possible clinical importance of intravascular gas.

PURPOSE: To investigate gas formation during hepatic interstitial laser photocoagulation (ILP). MATERIALS AND METHODS: In vitro, ILP was performed with a neodymium yttrium aluminum garnet laser on a piece of liver in a water bath. In vivo, nine pigs underwent 24 ultrasound (US)-monitored ILP procedures. Fiber tips were more than 1 cm from (n = 16) or adjacent to (n = 8) intrahepatic veins. The gas production seen on US images was graded on a …