Venous Drug-Eluting vs. Bare-Metal Stenting: An Experimental Animal Study Using Frequency-Domain Optical Coherence Tomography

Introduction: This protocol was designed to evaluate the safety and feasibility of implanting drug-eluting stents (DES), as well as to compare their long-term results versus bare-metal stents (BMS), in a rabbit venous model, using frequency-domain optical coherence tomography (FD-OCT). Methods: Thirteen New Zealand white rabbits underwent implantation of a zotarolimus-eluting stent in the iliac vein (DES Group) and a BMS in the contralateral iliac vein (BMS Group). The study's primary endpoints included technical success and the comparison of in-stent neointimal hyperplasia in the two study groups, using ex vivo FD-OCT, at 3 months. Results: Thirteen DES and 13 BMS were successfully implanted. The technical success rate was 100% (26/26 stents). Three animals (3/13, 23.0%) died within the first 45 days. The remaining 10/13 animals (77%) were euthanized on the 90th day following stent implantation. The 20 stents were successfully removed. Successful ex vivo FD-OCT was performed in all stent-implanted iliac vein segments, 10 in the DES Group and 10 in the BMS Group. There was no statistically significant difference in the mean neointimal thickness between the two groups (3.02 +/- 1.19 mm(2) in DES Group vs. 2.76 +/- 1.17 mm(2) in BMS Group; p=0.0501). Conclusions: In this experimental protocol, DES implantation in the venous system was safe and feasible. Hyperplasia thickness was similar in both groups after 3 months' follow up.