Heparin Loading and Pre-endothelialization in Enhancing the Patency Rate of Electrospun Small-Diameter Vascular Grafts in a Canine Model

Abstract

We herein proved that the two commonly used antithrombotic methods, heparin loading and pre-endothelialization could both greatly enhance the patency rate of a small-diameter graft in a canine model. Tubular grafts having an inner diameter of 4 mm were prepared by electrospinning poly(l-lactide-co-ε-caprolactone) (P(LLA-CL)) and heparin through a coaxial electrospinning technique. Seventy-two percent of heparin was found to be released sustainably from the graft within 14 days. To prepare the pre-endothelialized grafts, we seeded endothelial cells isolated from the femoral artery and cultured then dynamically on the lumen until a cell monolayer was formed. Digital subtraction angiography (DSA) and color Doppler flow imaging (CDFI) were used to monitor the patency without sacrificing the animals. Histological analyses revealed that following the direction of blood flow, a cell monolayer was formed at the proximal end of the heparin-loaded grafts, but such a monolayer could be found in the middle or distal region of the grafts. In contrast, the whole luminal surface of the pre-endothelialized graft was covered by a cell monolayer, suggesting the in vivo survival of the preseeded cells. This demonstrated that heparin was a comparatively simple method to achieve good patency, but the pre-endothelialization had better mechanical properties and cellular compatibility.

Effect of immobilized collagen type IV on biological properties of endothelial cells for the enhanced endothelialization of synthetic vascular graft materials

“…S4). Collectively, COL-IV modification successfully augmented HUVECs proliferation that can lead to fast recovery of healthy endothelium in lumen, and subsequently it can guarantee long-term patency of graft by reducing thrombogenesis [50].…”

Early postoperative changes in hematological, erythrocyte aggregation and blood coagulation parameters after unilateral implantation of polytetrafluoroethylene vascular graft in the femoral artery of beagle dogs

“…The number of prosthetic grafts, used for intermittent claudication/critical limb ischemia has fallen. Poor patency rate and the concerns about graft infections are the main reasons for that [1][2][3][4][5][9][10][11][12][13] .…”

“…Late: pseudoaneurysm formation due to suture insufficiency, obstruction of the graft, stenosis caused by neointima formation or occlusion, graft infection [9][10][11][12][13] . The blood flow characteristics change at the anastomoses, the cells may suffer mechanical injury -here the formation of deposits usually leads to another operation 10,[12][13][14] .…”

“…The blood flow characteristics change at the anastomoses, the cells may suffer mechanical injury -here the formation of deposits usually leads to another operation 10,[12][13][14] . Although it is not completely clarified that from which point the flow properties of the altered vascular geometry can lead to thrombotic complications later.…”

Vascular Grafting Strategies in Coronary Intervention

“…As early as 1 week, three of eight P(LLA-CL) grafts had already occluded, and at 3 months, only one graft remained patent. Conversely, three of four preendothelialized grafts remained patent at 3 months, which the authors attributed to greater luminal monolayer coverage of the pre-seeded grafts (Huang et al, 2013). Notwithstanding the improved patency of the cell sodded grafts, the presence of a cell monolayer does not in and of itself prove that the seeded cells survived in the absence of a cell tracker.…”