INTRAPORTAL ENDOVASCULAR ULTRASONOGRAPHY IN THE DIAGNOSIS OF PORTAL-VEIN INVASION BY PANCREATICOBILIARY CARCINOMA

Objective The purpose of this study was to determine the value of intraportal endovascular ultrasonography (IPEUS) in the diagnosis of portal vein invasion by pancreatobiliary carcinoma. The authors reported their experiences with this new technique and compared it with conventional imaging technologies, such as portography and computed tomography (CT). Summary Background Data Pancreatobiliary carcinoma often invades the portal vein. Observation of the echogenic band of the portal vein wall by means of a high-frequency, high-resolution intravascular ultrasound catheter allows for the accurate diagnosis of the portal vein invasion. Methods A prospective study of 30 consecutive patients with pancreatobiliary carcinoma (16 pancreatic carcinomas, 8 bile duct carcinomas and 6 gallbladder carcinomas) was performed. In 23 cases IPEUS was performed intraoperatively from the superior mesenteric venous route with an 8 French, 20 MHz intravascular ultrasound catheter. In 7 cases IPEUS was performed before surgery from the percutaneous transhepatic route with a 6 French, 20 MHz intravascular ultrasound catheter. The finding of IPEUS was confirmed by pathologic examination of resected specimens and surgical exploration. The results of IPEUS were compared to those of portography and CT. Results Intraportal endovascular ultrasonography visualized the portal vein wall as an echogenic band with a thickness of 0.5 mm to 1.0 mm. The diagnostic criterion of portal vein invasion was destruction of this echogenic band. Portal vein invasion was found in 15 of 30 cases. Vascular invasion was confirmed by pathologic examination of resected specimens in 10 patients and operative findings in 5. The sensitivity, specificity, and overall accuracy of IPEUS for diagnosis of portal vein invasion was 100%, 93.3%, and 96.7%, respectively. The values were 80%, 67.7%, and 73.3% for portography and 53.3%, 80%, and 66,7%, respectively, for CT. Conclusions Intraportal endovascular ultrasonography provided precise information about the relationship between the pancreatobiliary tumor and the portal vein wall. It was capable of accurately detecting or excluding early invasion of the portal vein wall by pancreatobiliary carcinoma.