RESUMO
BACKGROUND AND AIMS: Direct injection of chemotherapy into the portal vein for treatment of liver metastases may increase hepatic tissue levels while decreasing systemic levels and toxicities. We aimed to evaluate EUS-guided portal injection chemotherapy (EPIC) by using drug-eluting microbeads or nanoparticles and compare it with systemic injection. METHODS: We conducted a comparative feasibility trial in the acute porcine model (24 anesthetized pigs). Pigs were treated with irinotecan, doxorubicin, or albumin-bound paclitaxel nanoparticles (n = 8/group). Within each group, pigs were treated with EPIC or a systemic intravenous injection of drug and saline solution into the portal vein (n = 4/treatment). Irinotecan or doxorubicin were loaded onto microbeads for EPIC treatment only. We examined drug levels in tissue (1 hour) and plasma (15 minutes). RESULTS: EUS-guided access and injection was successful in all animals. EPIC with irinotecan-loaded microbeads showed nearly double the hepatic concentration compared with systemic injection (6242 vs 3692 ng/g) and almost half the systemic levels. EPIC with doxorubicin-loaded microbeads showed a 5-fold increase in hepatic levels (35,450 vs 6930 ng/g) and a 30-fold decrease in cardiac levels (153 vs 4805 ng/g) compared with systemic administration (P < .05 for both). EPIC with albumin-bound paclitaxel nanoparticles increased hepatic concentrations by 60% and decreased systemic levels by 24% to 32%. CONCLUSIONS: EPIC holds promise as a new treatment for hepatic metastases.