New concept of microporous structure in small diameter vascular prostheses

Area of Science:

• Biomaterials Science
• Vascular Surgery
• Polymer Chemistry

Background:

• Developing effective vascular prostheses is critical for treating cardiovascular diseases.
• Optimizing graft properties like surface morphology and porosity influences blood vessel healing and function.
• Polyurethane polydimethylsiloxane (PU-PDMS) and polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) are promising materials for vascular graft fabrication.

Purpose of the Study:

• To investigate the impact of different hydraulic permeabilities (HP) and surface structures on the patency and healing of vascular prostheses.
• To compare the performance of PU-PDMS and PVDF-TrFE based vascular grafts in a rat infrarenal aorta model.
• To determine the relationship between graft porosity, surface characteristics, and early graft outcomes.

Main Methods:

• Fabrication of six types of skinned and microporous vascular prostheses (1.5 mm ID) using spray phase inversion with varying HPs.
• Materials used: PU-PDMS and PVDF-TrFE.
• Implantation of graft segments and one loop graft into the rat infrarenal aorta for evaluation.

Main Results:

• Graft surface morphology and wall porosity (hydraulic permeability) were identified as primary determinants of early patency.
• Complete healing, including endothelialization, was strongly correlated with these surface and porosity characteristics.
• Specific graft types demonstrated varying degrees of success in maintaining patency and promoting healing.

Conclusions:

• Vascular graft design, specifically surface morphology and hydraulic permeability, significantly impacts early graft patency and healing.
• Tailoring these properties is essential for the development of next-generation vascular prostheses.
• The study provides valuable insights into material selection and fabrication techniques for improved vascular graft performance.