SIR 2024
Interventional Oncology
Barry D. Toombs, MD (he/him/his)
Principal Investigator
St. Luke's Health System, Houston
Financial relationships: Full list of relationships is listed on the CME information page.
Reynaldo Calderon, MD
Co-Investigator
The Methodist Hospital Houston
Disclosure information not submitted.
To evaluate the feasibility of perfusing the liver parenchyma via a retrograde venous approach using a controlled two catheter system allowing segmental infusion and downstream collection.
Materials and Methods: Five domestic swine weighing 48-60 kg were included in this study. Preliminary MR imaging of the liver was performed to assess liver size and hepatic venous anatomy. Sizes of the hepatic vein branches were measured and a suitable lobar venous system was chosen. Procedures were conducted with general anesthesia in a combined cath lab/MR imaging suite. The right jugular vein was accessed. Selective venography was performed in the area chosen based on preliminary MR imaging. Mapping of the vein and its branches along with assessment for anomalous drainage, venous to venous circuits, estimated venous channel volume and venous volume plus parenchymal stain were determined. A dual catheter system was placed with the smaller, balloon-tipped catheter positioned deeper in a segmental hepatic vein and the larger, outer, balloon-tipped catheter terminating downstream in a larger, usually lobar, vein. Further, DSA imaging was performed to optimize the flow rates into the hepatic segment that would maintain parenchymal staining without substantial portal vein reflux. The subject animals were then studied with MR. The segmental catheter was used to infuse the hepatic segment with gadolinium mixture for two minutes while the larger more central catheter was programmed for rapid aspiration. Images were obtained every 30 seconds for 180 seconds. The animals were returned to the cath lab where the segmental catheter was infused over 2 minutes with a vancomycin mixture using a Harvard pump while the downstream catheter aspirated the effluent.
Results:
Homogeneous enhancement of the perfused segment (as seen on MR) was good in most animals. Collateral vein flow and some retrograde filling of the portal vein was occasionally seen. Vancomycin concentrations in the aspirated effluent varied over time, as expected with peak values at the end of segmental infusion. The overall efficiency of vancomycin removal varied between animals, depending on the segmental vein infused, ranging up to 70%. An initial problem with partial thrombosis of the infused veins (from stasis from the balloon inflation and the use of vancomycin) was successfully addressed by more substantive anticoagulation.
Conclusion:
Retrograde venous perfusion with a multicatheter approach offers a promising method of delivering therapeutic agents into the liver parenchyma, with the added benefit of, at least, partial withdrawal.