Hepatic Resection by the Cavitron Ultrasonic Surgical Aspirator?? Increases the Incidence and Severity of Venous Air Embolism

Abstract
The Cavitron Ultrasonic Surgical Aspirator (CUSA) is an innovative tool for resecting hepatic parenchyma, which reduces intraoperative blood loss and perioperative morbidity. We designed this study to compare the incidence and severity of venous air embolism (VAE) detected via transesophageal echocardiography (TEE) during hepatic resection by using either the clamp-crushing method or the CUSA method. Fifty patients scheduled for hepatic resection were randomly assigned to receive hepatic resection by the clamp-crushing method (CC group) or by CUSA (CUSA group). After the induction of anesthesia, the TEE probe was inserted into the patient's esophagus. An independent anesthesiologist graded VAE shown in the 4-chamber view of TEE. All patients in the CUSA group showed VAE during hepatic resection and 44% of the patients had air embolism filling more than half the right heart diameter. In CC group, 68% of the patients showed VAE, which filled less than half the right heart diameter. There were no significant differences in hemodynamics and end-tidal CO2 partial pressure between the two groups. In conclusion, hepatic resection by CUSA increases the incidence and severity of VAE. This study demonstrated that venous air embolism during hepatic resection was more frequent and severe when using the Cavitron Ultrasonic Surgical Aspirator. Although we found no evidence of hemodynamic compromise, increased venous air embolism may increase the risk of paradoxical embolism in patients with liver cirrhosis.