Background: Treatment of long coronary lesions with bioresorbable scaffolds is currently limited to overlapping implantations only due to lack of long devices. Additionally, vascular response to long versus regular scaffolds is unknown. Therefore, for the first time we compare long vs. regular scaffolds with 100 micrometer struts (MeRes100) in the porcine coronary restenosis model.
Methods: In total 26 scaffolds, including 17 regular (3.0 x 16 mm) and 9 long (3.0 x 33 mm) were implanted with 120% overstretch with optical coherence tomography (OCT) guidance in 12 domestic animals for 1, 7, 28 and 90 days. At terminal follow-up terminal imaging with OCT was performed and long scaffolds evaluated in pathology.
Results: At all time-points stent areas and the neointimal hyperplasia as expressed as % Area Stenosis was comparable at all time points between long and regular scaffolds (Figure). Healing and endothelialisation was complete already at 28 days in the long scaffold groups.
Conclusions: Implantation of long bioresorbable scaffolds was feasible. At mid-term their integrity remained intact and neointimal response comparable to regular size scaffolds, which is contrary to historical data with metallic stents.