A head to head comparison of XINSORB bioresorbable sirolimus-eluting scaffold versus metallic sirolimus-eluting stent: 180 days follow-up in a porcine model

Li Shen, Yizhe Wu, Lei Ge, Yaojun Zhang, Qibing Wang, Juying Qian, Zhifen Qiu, Junbo Ge

We aimed to investigate the safety and efficacy of XINSORB bioresorbable sirolimus-eluting scaffold in porcine model. XINSORB scaffolds and metallic Firebird2™ stents were randomly implanted into minipigs' coronary arteries. Angiography, optical coherent tomography (OCT) and histopathological analyses were performed at post-procedure and 14-, 28-, 90-, 180-day follow-up. Thirty-two minipigs were enrolled. Eight XINSORB scaffolds and 8 Firebird2 stents were examined at each time point. Quantitative coronary angiography showed that in-scaffold late luminal loss (LLL) of XINSORB scaffold was 0.26 ± 0.13, 0.50 ± 0.16, 0.88 ± 0.29 and 0.43 ± 0.24 mm at 14-, 28, 90-, and 180-day follow-up respectively, and the corresponding diameter stenosis (DS) was 7.3 ± 4.7, 12.0 ± 9.5, 22.1 ± 8.0, and 16.0 ± 9.5%. Neither in-scaffold LLL nor DS of XINSORB scaffold was significantly different in comparison with Firebird2 stent. No difference of luminal area, device area, neointimal hyperplasia, and area stenosis was detected between two devices under OCT. Scaffold area of XINSORB remained steady through the observation. Histopathology revealed the similar findings. The greatest late recoil of XINSORB scaffold was about 4.12% at 90-day follow-up, which was comparable to Firebird2 stent. Both devices showed low injury or inflammation of vessel wall. XINSORB scaffold showed early neointimal coverage on struts within 28 days under scanning electron microscopy. XINSORB scaffold suppressed neointimal hyperplasia as effectively as Firebird2 did without obvious late device recoil during the 180 days follow-up. It is feasible to carry out clinical trial to investigate the safety and efficacy of XINSORB scaffold for patients with coronary artery diseases.