Possible pulmonary gas embolism associated with localized thermal therapy of the liver.

EXTERNAL heating by conventional electric cautery or by laser provides coagulation of the tissue by conducting the heat from the surface to the inside of the tissue. Conversely, internal heating is the method for necrotizing tumor and hemostasis by means of a dielectric heating electrode, which is inserted into the tissue or tumor. The two methods of administering localized internal thermal therapy of the liver are microwave coagulation therapy (MCT) and radiofrequency ablation (RFA). A venous air embolism, a potential complication of surgery in the sitting position or of laparoscopy, is unlikely to occur during laparotomy in a horizontal position. However, we experienced a case with abrupt decreases in end-tidal carbon dioxide partial pressure (PETCO2) and hemoglobin oxygen saturation (SpO2) during laparotomic MCT in the left lateral recumbent position, probably due to pulmonary gas emboli. We believe that the case discussed below is the first detailed report of a pulmonary gas embolism caused by localized thermal therapy of the liver.