Abstract

Background
The resorbable fibrillated scaffold (RFS) is a novel electrospun, polylactide‐based endoluminal scaffold developed for peripheral arterial applications. Its porous microfibre architecture is intended to support host cell infiltration and vascular restoration. Although its near‐wall hemodynamic behaviour has been characterised, its serial anatomical and virtual physiological evolution after implantation has not previously been examined.

Aims
To characterise the serial anatomical changes of the RFS after implantation in peripheral arterial models, and to assess the hemodynamic significance of luminal narrowing during follow‐up using image‐derived virtual flow indices.

Methods
Two preclinical studies were conducted in rabbit and mini‐pig peripheral arterial models. The RFS was implanted bilaterally in the external iliac arteries of three rabbits and in the profunda femoris arteries of six mini‐pigs. Serial follow‐up to 3 months was performed using invasive angiography and intravascular optical coherence tomography (OCT) for anatomical assessment. Virtual physiology was assessed using angiography‐derived Murray‐law‐based quantitative flow ratio (μFR) and OCT‐derived flow ratio (OFR).

Results
Implantation was technically successful in all but one case. In rabbits, between post‐implantation and 3 months, reference vessel diameter increased from 2.08 to 2.54 mm ( p = 0.03), while minimum lumen diameter remained stable; OCT‐derived area stenosis increased from 28.9% to 56.1% ( p < 0.01), scaffold length shortened from 10.40 to 8.63 mm ( p < 0.01), and μFR decreased from 0.99 to 0.92 ( p = 0.04), whereas OFR remained unchanged. In mini‐pigs, the principal changes occurred between post‐implantation and 1 month, with reductions in minimum lumen diameter, minimum lumen area, μFR, and OFR (all p ≤ 0.03), accompanied by increased stenosis and relative stabilization thereafter. Both μFR and OFR declined non‐linearly with increasing OCT‐derived %AS, with similar model fit ( R 2 = 0.57).

Conclusion
This preclinical study supports the feasibility of RFS implantation in peripheral arteries and demonstrates that the device undergoes early structural evolution after deployment. Virtual physiological assessment showed that these anatomical changes were accompanied by measurable reductions in flow indices, though most values remained above the 0.80 reference threshold. Together, these findings provide a basis for further development of the technology and for future studies incorporating both anatomical and virtual physiological assessment.