Interventional MRI-guided local delivery of agents into swine bile duct walls using MR-compatible needle-integrated balloon catheter system.

The purpose of this study was to investigate the feasibility of interventional MRI-guided local agent delivery into pig common bile duct (CBD) walls using a newly designed MR-compatible, needle-integrated balloon catheter system. We first designed a needle-integrated balloon catheter system that comprised of a 22 G MR-compatible Chiba biopsy needle and a conventional 12 mm × 2 cm balloon catheter. Under fluoroscopy guidance, a custom needle-balloon system was positioned in the target CBD via a transcholecystic access. T1-weighted MRI was used to localize and reposition the needle-balloon system in the target. A 0.5 mL mixture of motexafin gadolinium (MGd) and trypan blue dye as well as 5-fluorouracil was delivered into the CBD wall through the needle-balloon system. Post-infusion T1-weighted MRI was obtained and contrast-to-noise ratios (CNRs) of CBD walls of pre- and post-MGd-blue infusions were compared by a paired t-test. In addition, post-infusion x-ray cholangiography was achieved to evaluate the potential injuries of CBDs by the needle-balloon system. Subsequent histologic analysis was performed to correlate and confirm the imaging findings. A post-infusion cholangiogram did not show any extravasation of contrast agent, indicating no procedure-related damage to the CBDs. MRI demonstrated clear enhancement of the target bile duct walls infused with MGd-trypan blue dye with average penetration depth of 4.7 ± 1.2 mm and an average MGd perfusion length of 21 ± 1.5 mm in the bile ducts and their surrounding tissues. The average CNR of the post-infusion bile ducts was significant higher than that of the pre-infusion bile ducts (110.6 ± 22 versus 5.7 ± 2.8, p < 0.0001). Histology depicted the blue dye staining and red fluorescence of MGd through the target CBD walls, which was well correlated with the imaging findings. It is feasible to use the new MR-compatible, needle-integrated balloon catheter system for intrabiliary local agent delivery into CBD walls under MRI guidance, which may open new avenues for efficient management of pancreatobiliary malignancies using MR-guided interventional oncology.