Purpose: To analyze visualization of hepatic lymphatic vessels during transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).
Materials and methods: Retrospective review was conducted of 255 tumors in 161 patients treated by TACE with catheterization of the most distal portion of the tumor-feeding branches. All TACE procedures were performed with use of a mixture of iodized oil and anticancer drugs followed by gelatin sponge particles. Arteriograms and spot radiographs obtained during TACE were reviewed to determine whether hepatic lymphatic vessels appeared. Serial computed tomography (CT) images after TACE were evaluated along with clinical symptoms in cases that exhibited lymphatic vessel visualization.
Results: Hepatic lymphatic vessels were demonstrated in eight tumors (3.1%) in eight patients during TACE. The mean tumor diameter was 1.7 cm +/- 0.7 (range, 1.0-3.3 cm), and mean volume of injected iodized oil was 1.7 mL +/- 1.0 (range, 1-4 mL). Lymphatic vessels were demonstrated followed by marked portal vein visualization (n = 5) or extravasation of a small amount of contrast material (n = 2). In the remaining patient, these were depicted during the early stage of the TACE procedure. On CT after 1 week, iodized oil in the lymphatic systems in the hepatoduodenal ligament was seen in six patients, and it was shown to have been retained in four of these patients on follow-up CT performed 2, 7, 11, and 21 months later, respectively. None of these patients presented any clinical symptom other than postembolization syndrome.
Conclusions: Hepatic lymphatic vessels were demonstrated in 3.1% of tumors treated by ultraselective TACE. Iodized oil in the lymphatic vessels may be retained for a relatively long time without specific symptoms.