Rationale and objectives: To evaluate the efficacy of a self-expanding metal stent seeded with autologous endothelial progenitor cells (EPCs) for preventing in-stent stenoses in transjugular intrahepatic portosystemic shunt (TIPS) in a swine model.
Materials and methods: TIPS was performed in 18 young adult pigs, using a self-expanding nitinol stent (control, n = 8) and an autologous EPC-seeded stent (treatment, n = 10). All pigs were sacrificed at 2 weeks post-TIPS procedure. Portography was performed immediately before the euthanasia. Gross, microscopic, and immunohistochemistry of the TIPS tract specimens were examined. The proliferative response of the shunt was quantified histologically.
Results: TIPS was performed successfully in 16 swine, 2 animals died during the procedure. Another pig died of unknown causes 2 days post-procedure. At day 14 follow-up, portography and necropsy of the 15 remaining swine demonstrated that five shunts occluded and one shunt was stenotic (80%) in the control group (n = 6). Five shunts remained patent, two shunts were stenosed (50%, 70%), and the remaining two shunts were occluded in the treatment group (n = 9). The patency rate was significantly lower in the control group than in the treatment group, 0% versus 55.6% (P = .03). Histological analyses showed a significantly greater pseudointimal hyperplasia in the TIPS track of the control group than that of the treatment group (P < .05). Intact endothelium was documented in the lumina of all the EPC-implanted stent group.
Conclusions: The EPC-seeded metal stent is feasibly fabricated in vitro and improves the patency in TIPS in a porcine model.