Continuous ultrasound navigation for safe and precise anatomic resection of the liver.

Abstract Anatomic resection of the liver is one of the essential techniques in liver surgery. However, parenchymal transection precisely along intersegmental planes is still a technically demanding procedure, and an optimal navigation method is required. Real-time ultrasound monitoring with a probe applied from behind the liver was tried as a means of locating the site where resection was proceeding in the liver and confirming the direction of hepatic parenchymal transection to facilitate anatomic resection of the liver. The ultrasound navigation technique was performed during 11 hepatectomies in 10 patients in whom adequate retrohepatic space could be obtained to position the ultrasound probe. Continuous monitoring of the site in the liver where the resection was being performed was feasible, and the optimal direction of parenchymal transection was easily determined on the basis of the ultrasound images without interrupting the surgical maneuvers. The mean speed of parenchymal transection was faster (2.4cm2/min vs. 1.2cm2/min, p=0.009) and the amount of blood loss per transected area was smaller (4.4mL/cm2 vs. 7.2mL/cm2, p=0.05) in patients treated with the current technique. Continuous ultrasound monitoring of the liver facilitates the safe and precise parenchymal transection during anatomic resections of the liver.