Update on laparoscopic ultrasonography.

Ultrasonography has many clinical applications and can be done with both extra- and intracorporeal techniques. Miniaturization of ultrasound transducers has opened the way for intracorporeal use of ultrasound at laparoscopy. The principles of ultrasonography are presented. Laparoscopic intracorporeal ultrasound (LICU) has proven to be useful in the differential diagnosis of liver tumours. In one series, 75 of 85 patients had positive identification of a suspected liver tumour with laparoscopic ultrasound examination. LICU has also been useful for delineation of hepatobiliary anatomy during laparoscopic cholecystectomy in both animal models and patients having cholecystectomy. LICU may detect useful anatomic information prior to dissection of the cystic duct and is accurate in detecting common bile duct stones. LICU may also be useful in the preoperative staging of pancreatic malignancy. Laparoscopic intracorporeal ultrasound may find practical application in other areas as experience evolves.