ePTFE Vascular Grafts Research Articles

MT5 Comparison of Outcomes of ePTFE Vascular Grafts With Heparin End-Point Covalent Bond and Alternative Autologous Vein for Below-Knee Surgical Bypass Procedures in Critical Limb Ischemia Patients

MT5 Comparison of Outcomes of ePTFE Vascular Grafts With Heparin End-Point Covalent Bond and Alternative Autologous Vein for Below-Knee Surgical Bypass Procedures in Critical Limb Ischemia Patients

Design and Synthesis of P(AAm-co-NaAMPS)-Alginate-Xanthan Hydrogels and the Study of Their Mechanical and Rheological Properties in Artificial Vascular Graft Applications.

Cardiovascular diseases (CVDs) are the number one cause of mortality among non-communicable diseases worldwide. Expanded polytetrafluoroethylene (ePTFE) is a widely used material for making artificial vascular grafts to treat CVDs; however, its application in small-diameter vascular grafts is limited by the issues of thrombosis formation and intimal hyperplasia. This paper presents a novel approach that integrates a hydrogel layer on the lumen of ePTFE vascular grafts through mechanical interlocking to efficiently facilitate endothelialization and alleviate thrombosis and restenosis problems. This study investigated how various gel synthesis variables, including N,N'-Methylenebisacrylamide (MBAA), sodium alginate, and calcium sulfate (CaSO4), influence the mechanical and rheological properties of P(AAm-co-NaAMPS)-alginate-xanthan hydrogels intended for vascular graft applications. The findings obtained can provide valuable guidance for crafting hydrogels suitable for artificial vascular graft fabrication. The increased sodium alginate content leads to increased equilibrium swelling ratios, greater viscosity in hydrogel precursor solutions, and reduced transparency. Adding more CaSO4 decreases the swelling ratio of a hydrogel system, which offsets the increased swelling ratio caused by alginate. Increased MBAA in the hydrogel system enhances both the shear modulus and Young's modulus while reducing the transparency of the hydrogel system and the pore size of freeze-dried samples. Overall, Hydrogel (6A12M) with 2.58 mg/mL CaSO4 was the optimal candidate for ePTFE-hydrogel vascular graft applications due to its smallest pore size, highest shear storage modulus and Young's modulus, smallest swelling ratio, and a desirable precursor solution viscosity that facilitates fabrication.

EE4 Hospital Resource Use in below-Knee Surgical Bypass Procedures with Eptfe Vascular Grafts with Heparin End-Point Covalent Bond in Critical Limb Ischemia Peripheral Arterial Disease (PAD) Patients

PAD is mainly caused by atherosclerosis that reduces blood flow to the limbs. Prosthetic vascular grafts are frequently used in lower limb bypass procedures in occluded or stenosed arteries. This study reviewed the hospital resource use reported in published literature for below-knee surgical bypass procedures using the GORE® PROPATEN® Vascular Graft with heparin end-point covalent bond.

EE306 Cost-Consequence Analysis of EPTFE Vascular Grafts With Heparin End Point Covalent Bond Compared to Standard EPTFE Vascular Grafts in Below-Knee Surgical Bypass for Critical Limb Ischemia Pad Patients in Germany

EE306 Cost-Consequence Analysis of EPTFE Vascular Grafts With Heparin End Point Covalent Bond Compared to Standard EPTFE Vascular Grafts in Below-Knee Surgical Bypass for Critical Limb Ischemia Pad Patients in Germany

EE577 Cost-Consequence Analysis of EPTFE Vascular Grafts With Heparin End Point Covalent Bond Compared to Standard EPTFE Vascular Grafts in Below-Knee Surgical Bypass for Critical Limb Ischaemia Pad Patients in Portugal

EE577 Cost-Consequence Analysis of EPTFE Vascular Grafts With Heparin End Point Covalent Bond Compared to Standard EPTFE Vascular Grafts in Below-Knee Surgical Bypass for Critical Limb Ischaemia Pad Patients in Portugal

BIO13: Comprehensive Results Of Protein Adsorption, Platelets Adhesion, And Blood Clot Formation on the DLC-Coated Surface of ePTFE Vascular Graft

BIO13: Comprehensive Results Of Protein Adsorption, Platelets Adhesion, And Blood Clot Formation on the DLC-Coated Surface of ePTFE Vascular Graft

A Radiation-Crosslinked Gelatin Hydrogel That Promotes Tissue Incorporation of an Expanded Polytetrafluoroethylene Vascular Graft in Rats.

A prosthetic vascular graft that induces perigraft tissue incorporation may effectively prevent serious sequelae such as seroma formation and infection. Radiation-crosslinked gelatin hydrogel (RXgel) mimics the chemical and physical properties of the in vivo extracellular matrix and may facilitate wound healing by promoting tissue organization. Fibroblasts cultured on RXgel actively migrated into the gel for up to 7 days. RXgels of three different degrees of hardness (Rx[10], soft; Rx[15], middle; Rx[20], hard) were prepared, and small disc-like samples of RXgels were implanted into rats. In vitro and in vivo results indicated that Rx[10] was too soft to coat vascular grafts. Thus, expanded polytetrafluoroethylene (ePTFE) vascular grafts coated with RXgel were developed using Rx[15] and Rx[20] gels, and ring-shaped slices of the graft were implanted into rats. Alpha-smooth muscle actin (αSMA) and type III collagen (Col-III) levels were detected by immunohistochemistry. Immunohistochemical staining for αSMA and Col-III demonstrated that RXgel-coated vascular grafts induced more granulation tissue than non-coated grafts on days 14 and 28 after implantation. RXgel-coated ePTFE vascular grafts may provide a solution for patients by reducing poor perigraft tissue incorporation.

Efficacy of Cefepime and Vancomycin in Prevention of Dacron and ePTFE Vascular Grafts Infected with Staphylococcus aureus: A Rat Subcutaneous Model

The objective of the present study was to evaluate systemic and local effects of cefepime alone and/or in combination with vancomycin in the prevention of experimentally implanted Dacron and ePTFE vascular grafts infected with Staphylococcus aureus in rat. Ninety healthy adult male Wistar rats were divided into two groups of 45 animals each. Then, each group was subdivided into nine subgroups of 5 animals each. Following anesthesia, in each rat one cm2, sterile Dacron or ePTFE graft was implanted aseptically into dorso-lumbar subcutaneous pocket. The grafts were infected by inoculation of one ml of (5 × 107 CFU/ml) Staphylococcus aureus suspension. The rats received vancomycin or cefepime locally, intraperitoneally, or in combinations. The grafts were removed seven days after implantation and evaluated by quantitative culture. Combinations of cefepime with vancomycin resulted in enhanced efficiency of antibiotics in bacterial growth inhibition. Local vancomycin was more effective than local cefepime in the reduction of graft contamination. A combination of intraperitoneal vancomycin, as well as local cefepime, was more effective than a combination of intraperitoneal cefepime as well as intraperitoneal vancomycin in the Dacron group. Local vancomycin-intraperitoneal cefepime combination could be suggested to prevent Dacron and ePTFE vascular graft infected with Staphylococcus aureus. Local treatment alone, vancomycin for Dacron graft and cefepime for ePTFE graft, and intraperitoneal treatment alone, vancomycin for ePTFE graft, could also be suggested.

Vascular transplantation with dual-biofunctional ePTFE vascular grafts in a porcine model.

Cardiovascular disease (CVD) poses serious health concerns worldwide. The lack of transplantable vascular grafts is an unmet clinical need in the surgical treatment of CVD. Although expanded polytetrafluoroethylene (ePTFE) vascular grafts have been used in clinical practice, a low long-term patency rate in small-diameter transplantation application is still the biggest challenge. Thus, surface modification of ePTFE is sought after. In this study, polydopamine (PDA) was used to improve the hydrophilia and provide immobilization sites in ePTFE. Bivalirudin (BVLD), a direct thrombin inhibitor, was used to enhance the anti-thrombotic activity of ePTFE. The peptides derived from extracellular matrix proteins were used to elevate the bioactivity of ePTFE. The morphology, chemical composition, peptide modified strength, wettability, and hemocompatibility of modified ePTFE vascular grafts were investigated. Then, an endothelial cell proliferation assay was used to evaluate the best co-modification strategy of the ePTFE vascular graft in vitro. Since a large animal could relatively better mimic human physiology, we chose a porcine carotid artery replacement model in the current study. The results showed that the BVLD/REDV co-modified ePTFE vascular grafts had a satisfactory patency rate (66.7%) and a higher endothelial cell coverage ratio (70%) at 12 weeks after implantation. This may offer an opportunity to produce a multi-biofunctional ePTFE vascular graft, thereby yielding a potent product to meet the clinical needs.

Endothelialization of an ePTFE vessel prosthesis modified with an antithrombogenic fibrin/heparin coating enriched with bound growth factors.

Early and late thrombosis remain the most frequent reasons for the failure of synthetic cardiovascular grafts. Long-term hemocompatibility of implanted synthetic grafts can be achieved if a natural living endothelium is formed over its blood-contacting surface. Here we present a modification of a standard expanded polytetrafluorethylene (ePTFE) vessel prosthesis by a controlled preparation of a fibrin mesh enriched with covalently bound heparin and noncovalently bound vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). Compared to a bare prosthesis, the coated prosthesis showed excellent antithrombogenic properties after contact with heparinized fresh human blood. Human umbilical vein endothelial cells seeded on the inner surface of the coated prosthesis formed a confluent layer in 5 days, whereas only small colonies of cells were scattered on the bare prosthesis. Viability of the cells was promoted mainly by FGF immobilized on the coating. These findings suggest that the coating may prevent acute thrombus formation and support the self-endothelialization of an implanted ePTFE vascular graft in vivo.

Preliminary application of a cell-free mono-layered vascular scaffold in a rabbit model

Of the qualities small caliber artificial vascular scaffolds must possess for application in modified Blalock-Taussig (B-T) surgery, effective anticoagulation and mechanical maintenance take priority over structural bionics. Currently, only the IMPRA® ePTFE vascular graft is available. Here, we designed a mono-layered vascular scaffold by loading heparin (Hep), made up of poly(l-lactide-co-caprolactone) (PLCL) and silk fibroin (SF), through a conjugate electrospinning technique. Three kinds of Hep@SF/PLCL nanofiber membranes containing different SF and heparin contents were produced by adjusting the spinning speed of a Hep@SF mixed solution. Compared to the other two nanofiber membranes, the 1.0Hep@SF/PLCL nanofiber membrane contained the most SF, resulting in suitable radial tensile property, optimal hydrophilicity, cytocompatibility and antithrombotic activity. Therefore, we then prepared a mono-layered artificial vascular scaffold using this design. Finally, orthotopic rabbit carotid artery transplantation was performed to evaluate remodeling effect in vivo. Three months after surgery, the 1.0Hep@SF/PLCL vascular scaffold exhibited satisfactory remodeling in vivo, resulting in a regenerated smooth muscle layer covered by a continuous endothelium.

The effect of Substance P/Heparin conjugated PLCL polymer coating of bioinert ePTFE vascular grafts on the recruitment of both ECs and SMCs for accelerated regeneration

Artificial vascular grafts consisting of ePTFE have been mainly used in clinics for the treatment of cardiovascular disease. However, artificial grafts can become clogged after a long time due to thrombosis, as graft maturation by endothelialization is limited. The strategy introduced in this study is to induce graft remodeling through interaction between the bioinert graft and the body. The Substance P (SP) and heparin were covalently conjugated with PLCL, an elastic biocompatible copolymer and the Substance P-conjugated PLCL (SP-PLCL) and/or heparin-conjugated PLCL (Hep-PLCL) were vacuum-coated onto ePTFE vascular grafts. To assess the effectiveness of the coating, coated samples were evaluated by implanting them subcutaneously into SD-Rats. Coatings allow grafts to be remodeled by creating a microenvironment where cells can grow by infiltrating into the grafts while also greatly enhancing angiogenesis. In particular, a double coating of Hep-PLCL and SP-PLCL (Hep/SP-PLCL) at four weeks showed markedly improved vascular remodeling through the recruitment of mesenchymal stem cells (MSCs), vascular cells (ECs, SMCs) and M2 macrophages. Based on these results, it is expected that when the Hep/SP-PLCL-coated ePTFE vascular grafts are implanted in situ, long-term patency will be assured due to the appropriate formation of an endothelial layer and smooth muscle cells in the grafts like native vessels.

Biofunctional Lubricant-Infused Vascular Grafts Functionalized with Silanized Bio-Inks Suppress Thrombin Generation and Promote Endothelialization.

The ongoing problem with the thrombogenicity and poor tissue integration of synthetic vascular grafts demands the design of new surfaces that simultaneously suppress thrombosis and promote endothelialization. Lubricant-infused surfaces have shown outstanding results in preventing clot formation; however, their innate ability to completely block the surface, averts targeted binding of desired biomolecules. We report a new class of expanded polytetrafluoroethylene (ePTFE) vascular grafts that prevent blood coagulation and concurrently promote endothelial cell adhesion. This is made possible by direct silanization of anti-CD34 antibody with the coupling agent and subsequent conjugation of the silanized antibody to the ePTFE surface. In contrast to the conventional methods, we eliminated the need to chemically modify the ePTFE substrate for attaching the capturing ligand, and as a result preserved the innate surface properties of the ePTFE substrate. This is crucial for infiltrating the fluorine-based ePTFE substrate with a biocompatible perfluorocarbon-based lubricant and ultimately creating a functional and stable lubricant-infused layer. Compared to commercially available ePTFE vascular grafts and the ones coated using conventional methods, our developed ePTFE grafts significantly attenuate thrombin generation and blood clot formation and specifically capture endothelial cells from human whole blood while preventing nonspecific adhesion of undesirable proteins and cells. The developed technology can be applied to other biomarkers and biomaterials and can be tailored toward different biomedical applications where biofunctionality and targeted binding are of importance.

Comparison of Acuseal and Standard ePTFE Vascular Grafts for Hemodialysis: A Retrospective Case Series

Background: Grafts, which allow early cannulation have been increasingly used to avoid starting dialysis via tunneled hemodialysis catheters. As we noted graft failures in patients with early cannulation grafts, we reviewed the outcome of these grafts and compared it to ePTFE grafts. Materials and Methods: We retrospectively analyzed time to first intervention, primary and secondary patency rates as well as the number of interventions needed to maintain patency in patients who received an early cannulation graft (GORE® ACUSEAL, acuseal) or an ePTFE (GORE-TEX®) vascular graft between January 2016 and November 2017 in our medical center. Results: 12 patients who had received an acuseal vascular graft were compared with 13 patients with an ePTFE vascular graft. The mean time to first intervention was similar in both groups. On average 0.33 interventions per graft were needed per month to maintain patency in the acuseal group, and 0.08 in the ePTFE group (p = 0.02). The primary patency rate did not differ significantly between the groups. The secondary patency rate at the end of the observation period was significantly worse in the acuseal group (p = 0.02). Four acuseal grafts were lost after a mean of 202 days, whereas none of the ePTFE grafts was lost. Conclusion: Our data is consistent with our clinical impression of an increased number of interventions and lower longevity of the acuseal vascular graft. These data need conformation in a larger cohort.

Evaluation of Microscopic Structure-Function Relationships of PEGylated Small Intestinal Submucosa Vascular Grafts for Arteriovenous Connection.

Vascular grafts are used as vascular access for hemodialysis, the most common renal replacement therapy to artificially clean blood waste after kidney malfunction. Despite that they are widely used in clinical practice, upon implantation, synthetic vasculars show complications such as thrombogenesis, reduced patency rates, low blood pressure, or even complete collapse. In this study, a C-shaped vascular graft was manufactured with small intestinal submucosa (SIS) and modified on the surface and the bulk of the material via conjugation of polyethylene glycol (PEG) to obtain a biocompatible and less thrombogenic vascular graft than the commercially available polytetrafluoroethylene (ePTFE) vascular grafts. Molecular weight and concentration of PEG molecules were systematically varied to gain insights into the underlying structure-function relationships. We analyzed the chemical, thermal, and mechanical properties of vascular grafts modified with 6 equiv of SIS-PEG 400 as well as cytotoxicity and in vitro platelet deposition. Immune response, patency rates, and extent of regeneration were also tested in vivo with the aid of swine animal models. Results showed that the conjugation levels achieved were sufficient to improve graft compliance, therefore approaching that of native vessels, while platelet deposition was altered leading to a 95% reduction compared with pristine SIS and 92% with respect to ePTFE. H&E staining on explanted samples corroborated SIS-PEG 400 biocompatibility and the ability to promote regeneration. The obtained results set solid foundations for the rational design and manufacture of a regenerative, small diameter vascular graft model and introduce an alternative to ePTFE vascular grafts for hemodialysis access.

Improved endothelialization of small-diameter ePTFE vascular grafts through growth factor therapy.

BackgroundProsthetic vascular grafts in humans characteristically lack confluent endothelialization regardless of the duration of implantation. Use of high-porosity grafts has been proposed as a way to induce endothelialization through transgraft capillarization, although early experiments failed to show increased healing in man.ObjectivesWe hypothesized that transduction of tissues around the prosthetic conduit with vectors encoding VEGF receptor-2 (VEGFR2) ligands would augment transinterstitial capillarization and induce luminal endothelialization of high-porosity ePTFE grafts.MethodsFifty-two NZW rabbits received 87 ePTFE uni- or bilateral end-to-end interposition grafts in carotid arteries. Rabbits were randomized to local therapy with adenoviruses encoding AdVEGF-A165, AdVEGF-A109 or control AdLacZ and analyzed at 6 and 28 days after surgery by contrast-enhanced ultrasound and histology.ResultsAdVEGF-A165 and AdVEGF-A109 dramatically increased perfusion in perigraft tissues at 6 days (14.2 ± 3.6 or 16.7 ± 2.6-fold increases, P < 0.05 and P < 0.01). At 28 days, the effect was no longer significantly higher than baseline. At 6 days, no luminal endothelialization was observed in any of the groups. At 28 days, AdVEGF-A109- and AdVEGF-A165-treated animals showed enhanced ingrowth of transinterstitial capillaries (66.0 ± 13.7% and 77.4 ± 15.7% of graft thickness vs 44.7 ± 24.4% in controls, P < 0.05) and improved luminal endothelialization (11.2 ± 26.3% and 11.4 ± 22.2%, AdVEGF-A109 and AdVEGF-A165 vs 0% in controls, P < 0.05). No increased stenosis was observed in the treatment groups as compared to LacZ controls.ConclusionsThis study suggests that transient local overexpression of VEGFR2 ligands in the peri-implant tissues at the time of graft implantation is a novel strategy to increase endothelialization of high-porosity ePTFE vascular grafts and improve the patency of small-diameter vascular prostheses.

Improved endothelialization of small-diameter ePTFE grafts through growth factor therapy.

Background: Prosthetic vascular grafts in humans characteristically lack confluent endothelialization regardless the duration of implantation. Use of high-porosity grafts has been proposed as a way to induce endothelialization through transgraft capillarization, although early experiments failed to show increased healing in man. Objectives: We hypothesized that transduction of tissues around the prosthetic conduit with vectors encoding VEGF Receptor-2 (VEGFR2) ligands would augment transinterstitial capillarization and induce luminal endothelialization of high-porosity PTFE grafts. Methods: Fifty-two NZW rabbits received 87 ePTFE uni- or bilateral end-to-end interposition grafts in carotid arteries. Rabbits were randomized to local therapy with adenoviruses encoding AdVEGF-A165, AdVEGF-A109 or control AdLacZ and analyzed at 6 and 28d after surgery by contrast-enhanced ultrasound and histology. Results: AdVEGF-A165 and AdVEGF-A109 dramatically increased perfusion in perigraft tissues at 6d (14.2±3.6 or 16.7±2.6- fold increases, P&lt;0.05 and P&lt;0.01). At 28d the effect was no longer significantly higher than baseline. At 6d no luminal endothelialization was observed in any of the groups. At 28d, AdVEGF-A109 and AdVEGF-A165 treated animals showed enhanced ingrowth of transinterstitial capillaries (66.0±13.7% and 77.4±15.7% of graft thickness vs. 44.7±24.4% in controls, P&lt;0.05) and improved luminal endothelialization (11.2±26.3% and 11.4±22.2%, AdVEGF-A109 and AdVEGF-A165 vs. 0% in controls, P&lt;0.05). No increased stenosis was observed in the treatment groups as compared to LacZ controls. Conclusions: This study suggests that transient local overexpression of VEGFR2 ligands in the peri-implant tissues at time of graft implantation is a novel strategy to increase endothelialization of high-porosity ePTFE vascular grafts and improve the patency of small-diameter vascular prostheses.

Our Experience with Paired Kidney Exchange Transplantation

Introduction Paired kidney exchange (PKE) transplantation has gained popularity worldwide as the best alternative for renal recipient candidates who are sensitized to their donors or have ABO incompatible donors. In this study we present our early results of paired kidney exchange transplants. Materials and Methods We started our PKE transplantation programme in July 2015. Various incompatible pairs were matched depending upon the availability of suitable donors and compatible recipients. Matching and donor allocation was done manually. As far as possible, donors were matched for age and glomerular filtration rate. In a meeting before transplantation, all details of the surgery as well as the legal and ethical requirements were given, informed consent was received. Induction was offered to all patients. Antithymocyte globulin induction therapy was administered at the time of transplantation as well as the third day posttransplant; tacrolimus (target level 8-10 ng/mL), mycophenolate mofetil (1g twice a day) and prednisolone were started as immunosuppressive therapy and tacrolimus was maintained with a target level of 6-8 ng/mL 3 months after the operation. All patients were followed up twice weekly for the first 2 weeks, once weekly for the second 2 weeks, once a fortnight for the second and third months. Data were collected from medical records, including demographic data, follow-up serum creatinine, acute rejections, graft, and patient loss and infections. Results Seven pairs were matched from July 2015 to September 2017 and we performed 14 PKE (5 women, 9 men) transplants. Mean recipient age was 49.8±11.5 (range: 23-61) and mean donor age was 50.4± 12.4 (range: 38-64) years. Five of the donors were fathers, one of them was a mother, 3 were husbands and 5 were wives. Mean mismatch ratio was 5±1 (range: 3-6). Reason for exchange was ABO incompatibility for 10 patients and positive crossmatch and presence of donor specific antibodies for 4 patients. All were 2-way donations. Median waiting time for getting suitable donor after registration was 3 months. Two of the recipients were retransplanted and desensitization with plasmapheresis was needed for panel reactive antibody positivity. One patient underwent preemptive kidney transplant. Mean serum creatinine level at one month and at third month after transplant were 1.03±0.37 and 0.97±0.25 mg/dL. There were only 2 early biopsy-not-proven acute rejection episodes treated with pulse steroids and 2 urinary tract infections treated with oral antibiotics. In 1 patient external iliac artery was replaced with ePTFE vascular graft due to complete dissection. All patients are alive with no serious complications. Conclusions ABO incompatibility continues to pose a serious problem for transplantation candidates, especially in kidney and liver transplants. Our small series shows that PKE transplantation is an alternative for patients without a viable living-related donor or deceased compatible donor organ.

Improved Patency of ePTFE Grafts as a Hemodialysis Access Site by Seeding Autologous Endothelial Cells Expressing Fibulin-5 and VEGF.

Small caliber synthetic vascular grafts used for dialysis access sites have high failure rates due to neointima formation andthrombosis. Seeding synthetic grafts with endothelial cells (ECs) provides a biocompatible surface that may prevent graft failure. We tested the use of ePTFE grafts seeded with autologous ECs expressing fibulin-5 and vascular endothelial growth factor (VEGF), as a dialysis access site in a porcine model. We connected the carotid arteries and jugular veins of 12miniature pigs using 7-mm ePTFE grafts; five grafts were seeded with autologous venous ECs modified to express fibulin-5 and VEGF, and seven unseeded grafts were implanted at the same location and served as controls. At 6months, after completion of angiography, the carotid arteries and jugular veins with the connecting grafts were excised and fixed. Autologous EC isolation and transduction and graft seeding were successful in all animals. At 3months, 4 of 5 seeded grafts and 3 of 7 control grafts were patent. At 6months, 4 of 5 (80%) seeded grafts and only 2 of 7 (29%) control grafts were patent. Seeding ePTFE vascular grafts with genetically modified ECs improved long term small caliber graft patency. The biosynthetic grafts offera novel therapeutic modality for vascular access in hemodialysis.

Inhibiting intimal hyperplasia in prosthetic vascular grafts via immobilized all-trans retinoic acid

Peripheral arterial disease is a leading cause of morbidity and mortality. The most commonly utilized prosthetic material for peripheral bypass grafting is expanded polytetrafluoroethylene (ePTFE) yet it continues to exhibit poor performance from restenosis due to neointimal hyperplasia, especially in femoral distal bypass procedures. Recently, we demonstrated that periadventitial delivery of all-trans retinoic acid (atRA) immobilized throughout porous poly(1,8 octamethylene citrate) (POC) membranes inhibited neointimal formation in a rat arterial injury model. Thus, the objective of this study was to investigate whether atRA immobilized throughout the lumen of ePTFE vascular grafts would inhibit intimal formation following arterial bypass grafting. Utilizing standard ePTFE, two types of atRA-containing ePTFE vascular grafts were fabricated and evaluated: grafts whereby all-trans retinoic acid was directly immobilized on ePTFE (atRA-ePTFE) and grafts where all-trans retinoic acid was immobilized onto ePTFE grafts coated with POC (atRA-POC-ePTFE). All grafts were characterized by SEM, HPLC, and FTIR and physical characteristics were evaluated in vitro. Modification of these grafts, did not significantly alter their physical characteristics or biocompatibility, and resulted in inhibition of intimal formation in a rat aortic bypass model, with atRA-POC-ePTFE inhibiting intimal formation at both the proximal and distal graft sections. In addition, treatment with atRA-POC-ePTFE resulted in increased graft endothelialization and decreased inflammation when compared to the other treatment groups. This work further confirms the biocompatibility and efficacy of locally delivered atRA to inhibit intimal formation in a bypass setting. Thus, atRA-POC-ePTFE grafts have the potential to improve patency rates in small diameter bypass grafts and warrant further investigation.