Tissue Ingrowth Markedly Reduces Mechanical Anisotropy and Stiffness in Fibre Direction of Highly Aligned Electrospun Polyurethane Scaffolds.

Purpose: The lack of long-term patency of synthetic vascular grafts currently available on the market has directed research towards improving the performance of small diameter grafts. Improved radial compliance matching and tissue ingrowth into the graft scaffold are amongst the main goals for an ideal vascular graft.

Methods: Biostable polyurethane scaffolds were manufactured by electrospinning and implanted in subcutaneous and circulatory positions in the rat for 7, 14 and 28 days.

Transmural capillary ingrowth is essential for confluent vascular graft healing.

Unlabelled: Spontaneous endothelialization of synthetic vascular grafts may occur via three independent or concurrent modalities: transanastomotic (TA) outgrowth, transmural (TM) ingrowth or fallout (FO) from the blood. The limited TA and FO endothelialization, which occurs in humans, results in poor long-term patency in the small diameter position, where TM ingrowth may offer a clinically relevant alternative. To achieve sequential analysis of each mode of healing, loop grafts comprising anastomotically isolated angiopermissive polyurethane control grafts were abluminally sealed using either ePTFE wraps or solid polyurethane skins and implanted in the rat infrarenal aortic loop model for twelve weeks.

Pusher preventing maximum expansion of transfemoral transcatheter valves.

To report on 2 rare cases of balloon-expandable transfemoral transcatheter aortic valve implantation, where a trapped balloon led to complications requiring acute intervention. Both patients were elderly with increased risk profile and had been discussed by the heart team. After standard positioning of the valves using a transfemoral approach, retrieval of the pusher before deployment of the valve was missed.