ABSTRACT
Techniques and tools for the division of liver parenchyma are still evolving and they will be treated in a specific chapter. Nevertheless of the most recent technical innovations one has found its definitive place in liver surgery history: intraoperative ultrasonography to define vascular anatomy and to identify occult tumor deposits. Liver surgery has been remarkably safer and more accurate in the last few decades because of the development of intraoperative ultrasonography (IOUS), an imag ing modality which has become essential for hepatic resection. Pioneer in the development of this technique has been Masatoshi Makuuchi, who proposed and developed this technique in the early 1980s, when he was chief of surgery at Shinshu University in Matsumoto, Japan. Two are the major roles of intraoperative ultrasonography: the first role is to verify and validate with higher resolution preoperative data, the second role is to guide the direction of the transection plane during hepatic resection. Current advances have been recently reported on the development of contrast-enhanced ultrasonography, the rapid evolution of contrast materials and related detection systems. The progress of three-dimensional ultrasonography has been also anticipated. Clinical applications and evaluations of В-mode IOUS systems started in the late 1970s and early 1980s. IOUS with real-time B-mode imaging was first applied to liver surgery by Makuuchi and his colleagues.58 A small side-viewing probe, consisting of electronic linear-array transducers and dedicated for IOUS scanning of the liver, was invented and quickly became popular in Japan. Through the 1980s, the clinical use of IOUS gradually increased and the benefits of IOUS were defined.59 Using IOUS, the stage and resectability of tumors could be determined more accurately than with preoperative studies. Intraoperative localization of nonpalpable tumors and precise screening for liver metastasis also became possible using IOUS.60
