Ultrasound imaging of the retrohepatic vena caval wall by percutaneous endocaval sonography (PECS)

Small-aperture endoluminal ultrasound imaging devices, comprising a 7.5- or 20-MHz transducer placed percutaneously inside the inferior vena caval lumen, were evaluated for the imaging of the retrohepatic vena caval wall, both in normal dogs and hospital patients with hepato-biliary carcinoma. Using 20-MHz systems, a three-layered appearance of the retrohepatic vena caval wall was delineated, both in dogs and humans, although the imaging field was limited. For dogs, the depth of the two complex inner layers measured sonographically coincided with the distance from the luminal surface to the outer surface of the muscular layer as determined in histological sections, while the total depth of the three layers measured sonographically proved to be larger than the distance from the luminal surface to the surface of the hepatic parenchyma determined histologically. Endocaval sonography could also establish a negative diagnosis of carcinomatous infiltration to the retrohepatic vena caval wall in patients. Our results suggest that percutaneous endocaval sonography (PECS) might be useful for diagnosing carcinomatous infiltration to the retrohepatic vena caval wall.