Thomas William Link BS, Presenter: Nothing to Disclose

Jeff W.M. Bulte PhD, Abstract Co-Author: Nothing to Disclose

Aravind Arepally MD, Abstract Co-Author: Nothing to Disclose

Intraportal delivery of microencapsulated islets presents a promising treatment for diabetes. Despite recent success in human c-peptide levels in swine, long-term therapy is limited by limited space, inadequate blood perfusion, and a onetime injection. Thus, we have developed an implantable stent-pouch vascular device that can be delivered to any vascular bed through interventional, image-guided techniques. Here, we characterize the physical features of the device and test a prototype in vivo.

The device consists of two concentric stents, placed in a telescoped fashion, that are deployed into a vein. It utilizes the compliance of the vessel wall by pushing out against it, creating space for the transplanted cells. Coating the inner stent is a mesh with pore size 250um to trap the microcapsules (350um) within the space but to allow blood to flow through. This allows interaction of the encapsulated cells with the blood stream. The outer stent is deployed first using a catheter, and then the inner stent/mesh is deployed inside of it. Microcapsules are then injected into the space created by the difference in stent diameters (140-160,000 capsules in portal vein of adult swine). Furthermore, capsules can be removed through interventional techniques and replaced with a new batch if necessary. A flow model was developed, pressure was measured using a pressure-sensitive catheter, and flow characteristics were observed using pulse-wave Doppler ultrasound imaging.

There was no additional pressure drop caused by the stent as compared to a control (no stent). Color Doppler imaging showed flow entering and exiting the pouch through the pores of the mesh. A prototype was successfully deployed into the splenic vein of a pig. No complications arose, and pressures remained normal.

The stent-pouch device offers a novel, promising potential improvement to cell therapy for diabetes and other disorders. We have demonstrated the safety, ease of deployment, and biocompatibility of the device, and are currently investigating its functionality in cell therapy.

The stent-pouch could potentially greatly enhance the effectiveness of cell therapy on such diseases as diabetes and offers a safe, replaceable treatment.

Link, T, Bulte, J, Arepally, A, A Novel Vascular Stent-Pouch Device for Enhanced Cell Therapy.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6019640.html