Clinical and Technical Review of Percutaneous Transhepatic Portal Vein Islet Cell Transplantation

1. Review clinical scenarios for pancreatic islet cell transplantation (ICT)


2. Describe the Interventional Radiology (IR) related technical aspects of pancreatic ICT, focusing on liver track embolization


3. Present the clinical outcomes of pancreatic ICT

Percutaneous ICT is an emerging therapy for patients with type 1 diabetes. ICT may restore euglycemia, increase insulin independence, and reduce incidence of severe hypoglycemic episodes. The procedure involves percutaneous transhepatic portal venous access, venography, delivery of harvested islet cells, measurement of portal venous pressures, and liver track embolization. The most common adverse event after ICT is bleeding associated with transhepatic portal venous access. Thus, informed selection of embolic material and deployment in the liver track is of critical importance when performing this procedure. This review aims to educate practicing Interventional Radiologists and trainees on the clinical and technical aspects of ICT, and reviews multiple agents available for liver track embolization.

Clinical Findings/Procedure Details: The preferred site for ICT is the portal venous system. Prior to ICT, recipients undergo liver color Doppler ultrasound to assess portal vein anatomy, and patency. A portal venous pressure < 20 mm Hg is required to minimize risk of thrombotic or hemorrhagic events. Following percutaneous portal venous islet infusion, the access track is embolized. Embolization may be performed using several available materials, such as metallic coils, gelatin sponge, tissue fibrin glue, and microfibrillar collagen paste. Various studies have compared the technical effectiveness of each of these agents for closure and prevention of post-procedure bleeding; outcome of these studies will be reviewed in detail. After pancreatic ICT, 1- and 2-year insulin independence achievement rates approximate 65% and 75%.

Conclusion and/or Teaching Points: Percutaneous ICT shows promise as a therapeutic intervention for patients with type 1 diabetes and involves multi-disciplinary teams to improve patient outcomes. Because percutaneous transhepatic portal venous access is a procedure long performed by Interventional Radiologists, IR serves a critical role in the delivery of pancreatic ICT therapy. Firsthand knowledge of pancreatic ICT indications, approach, and outcomes can help optimize procedure success, but can also help pave the way for future cellular based therapies.