False-positive “Cavernous Transformation” Secondary to Lymphatic Filling in Parenchymal Hepatic CO2 Injection for Portal Vein Visualization in TIPS Procedures

• Published in: Journal of vascular and interventional radiology Vol. 20; no. 5; pp. 600 - 605
• Main Authors: Hawkins, Irvin F., MD, Cho, Kyung J., MD, Fiola, Frank, MD, Medina, Julian A., MD, Morelli, Giuseppe, MD, Caridi, James G., MD
• Format: Journal Article
• Language: English
• Published: 01.05.2009
• Subjects: Radiology; transjugular intrahepatic portosystemic shunt; TIPS
• ISSN: 1051-0443
• DOI: 10.1016/j.jvir.2009.01.032

Purpose To determine the frequency and potential importance of findings initially interpreted as portal vein occlusion with ”cavernous transformation” at transjugular intrahepatic portosystemic shunt (TIPS) placement with hepatic parenchymal CO2 injection. Materials and Methods One hundred forty-seven patients underwent hepatic parenchymal CO2 injections in the setting of fine-needle CO2 TIPS procedures. Hepatic parenchymal CO2 injections were retrospectively reviewed for findings suggestive of cavernous transformation in which direct portal venography confirmed portal vein patency. Direct portography was performed by injecting CO2 via the fine needle/guide wire complex or a 5-F catheter in a branch of the intrahepatic portal vein. Results Hepatic lymphatic vessels mimicked cavernous transformation of the portal vein in 29 of the 147 patients (19.7%). One patient with portal vein occlusion showed profuse lymphatic filling without filling the extrahepatic portal vein. Hepatic parenchymal CO2 injections safely permitted targeting of the portal vein in all patients. Conclusions During fine-needle CO2 TIPS procedures, what was believed to represent reversed flow of hilar collateral vessels represented hepatic lymphatic vessels. Despite the lack of visualization of the portal vein in nearly one-fifth of patients, targeting of the portal vein was facilitated by the fact the hepatic lymphatic vessels showed a periportal distribution. The high incidence of hepatic lymphatic filling suggestive of cavernous transformation necessitates direct portography or wedged hepatic venography to verify portal vein patency before the procedure is aborted.