Efficacy and Safety of a Polytetrafluoroethylene Membrane Wrapped a Single Layer of Sirolimus-Eluting Stent in a Porcine Coronary Perforation Model

Background: Covered stents are effective in treating coronary artery perforation (CAP), however, the high rate of immediate device deployment failure and in-stent restenosis have limited the application of the currently covered stents. Methods: We designed a covered stent system consisting of a single layer of drug-eluting stent and a layer of polytetrafluoroethylene (PTFE) membrane wrapped at the outer layer of the stent. The immediate sealing effect of our novel covered stent was observed by using an Ellis type III CAP model. The device's success was defined as its ability to seal the perforation, assessed by visual estimation and final thrombolysis in myocardial infarction (TIMI) 3 flow. The antiproliferative effect was evaluated in 12 swine, which were randomly assigned to treatment (sirolimus-eluting covered stents) and control (bare metal covered stents) groups. Coronary angiography and optical coherence tomography (OCT) were performed at index procedure, 1- and 6-month after stent implantation. All swine were sacrificed for histopathological analyses at 6-month. Results: The device success rate was 100%. All swine were alive at 6-month follow-up. At 1-month, the treatment group had a larger minimal luminal diameter (MLD) (1.89 +/- 0.29 mm vs. 0.63 +/- 0.65 mm, p = 0.004) and lower late luminal loss (LLL) (0.47 +/- 0.15 mm vs. 1.80 +/- 0.34 mm, p < 0.001) compared with control group. At 6-month, the treatment group had a numerically higher MLD (0.94 +/- 0.75 mm vs. 0.26 +/- 0.46 mm; p = 0.230) and lower LLL (1.43 +/- 0.85 mm vs. 2.17 +/- 0.28 mm; p = 0.215) compared with control group. Histological analyses revealed the mean plaque area was lower in the treatment group (2.99 +/- 0.81 mm(2) vs. 4.29 +/- 0.77 mm(2), p = 0.035) than in the control group. No in-stent thrombosis was observed in either group. Conclusions: In the porcine model of coronary perforation, the PTFE membrane wrapped sirolimus-eluting stent showed a high device success rate in sealing the perforation. The drug-eluting covered stent demonstrated a relatively sustained antiproliferative effect up to 6 months post-implantation.