Granulomatous Phlebitis of the Hepatic Vein Tributaries after Portal Venous Embolization

Background & Aims: Granulomatous phlebitis of hepatic vein is a rare disease and its exact etiopathogenesis remains unknown. Recently, we experienced granulomatous phlebitis of small hepatic veins in a patient who underwent hepatic resection for metastatic liver cancer after preoperative portal venous embolization (PVE). Methods: We surveyed such phlebitis in the patients who underwent PVE (2008 August – 2014 August). A total of 62 patients underwent PVE followed by hepatectomy for hepatocellular carcinoma (HCC), peripheral cholangicarcinoma (pCCA), or metastatic liver tumor (MLT) during this period. As a control, 20 cases of surgically resected livers without a history of preoperative PVE for liver tumors of comparable age and sex distribution in recent 2 years in the same hospital, were used. Results: Granulomatous phlebitis of small hepatic veins was found in 10 patients with a history of PVE (16.1% of 62 cases) but not in control cases. No microbial agents were identified in these granulomatous lesions. Interestingly, the presence of embolic materials containing sponge gel with inflammation and foreign body reaction in the portal veins in the embolized livers were independently associated with granulomatous phlebitis. Conclusions: It was suggested that sponge gel used for PVE might have be directly or indirectly related to the occurrence of granulomatous phlebitis. This is the first report of granulomatous phlebitis related to PVE.