Hybrid Vascular Graft Research Articles

Implantation of Adipose-Derived Mesenchymal Stromal Cells (ADSCs)-Lining Prosthetic Graft Promotes Vascular Regeneration in Monkeys and Pigs

Background:Current replacement procedures for stenosis or occluded arteries using prosthetic grafts have serious limitations in clinical applications, particularly, endothelialization of the luminal surface is a long-standing unresolved problem.Method:We produced a cell-based hybrid vascular graft using a bioink engulfing adipose-derived mesenchymal stromal cells (ADSCs) and a 3D bioprinting process lining the ADSCs on the luminal surface of GORE-Tex grafts. The hybrid graft was implanted as an interposition conduit to replace a 3-cm-long segment of the infrarenal abdominal aorta in Rhesus monkeys.Results:Complete endothelium layer and smooth muscle layer were fully developed within 21 days post-implantation, along with normalized collagen deposition and crosslinking in the regenerated vasculature in all monkeys. The regenerated blood vessels showed normal functionality for the longest observation of more than 1650 days. The same procedure was also conducted in miniature pigs for the interposition replacement of a 10-cm-long right iliac artery and showed the same long-term effective and safe outcome.Conclusion:This cell-based vascular graft is ready to undergo clinical trials for human patients.

Left Main Coronary Artery Stenosis following Bentall Procedure: A case report.

Since its introduction, Bentall procedure has remained the standard of care for management of ascending aortic aneurysms with associated aortic valve pathologies. It involves replacement of aortic root, ascending aorta and the aortic valve, using a hybrid vascular graft with built in valves. The openings of the main coronary arteries are then rejoined with the graft. The procedure has satisfactory long term survival rate. However, there are some complications including graft infection, stroke from dislodged plaques and coronary insufficiency due to kinking of the reconnected main coronary arteries.
 Here, we report a rare and life-threatening complication following Bentall procedure. A 76-year-old female developed left main stenosis following Bentall procedure, successfully treated with percutaneous coronary intervention (PCI). We discuss various etiologies and treatment options for this complication. We recommend routine surveillance with coronary angiography at six months post Bentall.

Comparison of sutureless anastomosis with hybrid vascular graft to standard graft for the hypogastric preservation during open aortic surgery

article: Comparison of sutureless anastomosis with hybrid vascular graft to standard graft for the hypogastric preservation during open aortic surgery - Italian Journal of Vascular and Endovascular Surgery 2022 June;29(2):45-51 - Minerva Medica - Journals

A Novel Hybrid Silk Fibroin/Polyurethane Arteriovenous Graft for Hemodialysis: Proof-of-Concept Animal Study in an Ovine Model.

To solve the problem of vascular access failure, a novel semi-degradable hybrid vascular graft, manufactured by electrospinning using silk fibroin and polyurethane (Silkothane), has been previously developed and characterized in vitro. This proof-of-concept animal study aims at evaluating the performances of Silkothane grafts in a sheep model of arteriovenous shunt, in terms of patency and short-term remodeling. Nine Silkothane grafts are implanted between the common carotid artery and the external jugular vein of nine sheep, examined by palpation three times per week, by echo-color Doppler every two weeks, and euthanized at 30, 60, and 90 days (N = 3 per group). At sacrifice, grafts are harvested and submitted for histopathology and/or scanning electron microcopy (SEM). No cases of graft-related complications are recorded. Eight of nine sheep (89%) show 100% primary unassisted patency at the respective time of sacrifice (flow rate 1.76±0.61L min-1 , one case of surgery-related thrombosis excluded). Histopathology and SEM analysis evidence signs of inflammation and pseudointima inside the graft lumen, especially at the venous anastomosis; however, endoluminal stenosis never impairs the functionality of the shunt and coverage by endothelial cells is observed. In this model, Silkothane grafts grant safety and 100% patency up to 90 days.

A hybrid vascular graft harnessing the superior mechanical properties of synthetic fibers and the biological performance of collagen filaments.

Tissue-engineered small caliber vascular grafts have attracted much research attention as a viable alternative to traditional vascular grafts with their biocompatibility and potential to achieve complete healing. However, the major challenge is to fabricate a scaffold with both satisfactory mechanical properties and fast endothelialization. In this study, a hybrid tubular vascular tissue engineered scaffold has been circular-knitted using novel electrochemically aligned collagen (ELAC) filaments plied together with traditional poly(lactic acid) (PLA) yarn. The collagen component was able to promote the recruitment and proliferation of endothelial cells by increasing the initial cell adhesion 10-fold and the eventual cell population 3.2 times higher than the PLA scaffold alone. At the same time, the PLA yarn was able to provide sufficient mechanical strength and structural stability, as well as facilitate scaffold fabrication on high speed textile production equipment. The tubular hybrid scaffold exhibited excellent bursting strength (1.89±0.43MPa) and suture retention strength (10.86±0.49N), and had comparable compliance (3.98±1.94%/100mmHg) to that of the coronary artery (3.8±0.3%/100mmHg) under normotensive pressure. With its excellent mechanical and biological performance, this prototype hybrid scaffold is a promising candidate for the construction of a clinically successful and easily translatable tissue-engineered small caliber vascular graft.

A Novel Hybrid Silk Fibroin/Polyurethane Arteriovenous Graft for Hemodialysis: Proof‐of‐principle Animal Study in an Ovine Model

BACKGROUNDIn an attempt at answering the need for a valuable and durable hemodialysis vascular access, a novel semi‐degradable hybrid vascular graft, manufactured by electrospinning using silk fibroin and polyurethane (Silkothane®), has been developed and characterized in vitro according to standards.OBJECTIVESIn this proof‐of‐principle animal study, we aimed at evaluating the performances of Silkothane® grafts in a sheep model of arteriovenous shunt, with respect to patency and short‐term graft remodeling.MATERIALS AND METHODSNine Silkothane® grafts (6mm inner diameter, ≈7cm long, ≈400μm thick) were surgically placed into the left cervical fossa of nine female sheep, between the common carotid artery and the external jugular vein. During the housing period the animals were treated with an inhibitor of platelets aggregation. Grafts were examined by palpation three times per week, and by duplex ultrasound every two weeks to exclude significant stenosis, dilation, presence of thromboses, neointimal proliferation or other complicating features. The sheep were euthanized at 30, 60 and 90 days (N=3 for each group). At sacrifice, grafts were harvested, fixed, and submitted for histologic, immunohistochemical and Scanning Electron Microscopy examination.RESULTSNo cases of graft‐related complications (e.g. seroma formation, transgraft bleeding, aneurismal dilation, calcification, structural yielding) were recorded in this study. One graft failed due to a thrombotic event likely related to a technical error (11%). One sheep had post‐operative wound infection, surgically resolved (11%). Four out of nine sheep (44%) showed post‐operative edema, usually disappearing in 7 days. Eight of nine sheep (89%) showed 100% primary unassisted patency at the respective time of sacrifice, as confirmed by palpation and ultrasound evaluation (average flow rate 1.76 ± 0.61 l/min). Histological, immunoistochemical and SEM analysis evidenced signs of inflammation and formation of neointimal hyperplasia at the venous anastomosis, as it typically happens with arteriovenous fistulae and synthetic grafts.CONCLUSIONSIn our ovine model of arteriovenous shunt, Silkothane® grafts provided evidences of safety and efficacy in granting 100% patency up to 90 days. Further studied need to be conducted in order to directly compare the novel grafts with commercially available synthetic grafts.

Comparison of Hybrid Vascular Grafts and Standard Grafts in Terms of Kidney Injury for the Treatment of Thoraco‐Abdominal Aortic Aneurysm

We present a comparison of renal function outcomes during HTAR with the use of a new hybrid vascular graft (GHVG) or standard graft. It is a multicenter, retrospective, observational study. Between January 2015 and March 2019, 36 patients were treated with HTAR. We compared HTAR performed with the use of the GHVG and with the use of standard bypass graft. Primary outcome measures were hospital mortality, acute kidney injury (AKI) at 30days and GHVG patency. Mean GHVG ischemia time was significantly lower for both renal arteries (right: GHVG, 4 ± 2 vs. standard graft, 15 ± 7min; 95% CI 2.23-6.69, P < 0.001; left: GHVG, 3 ± 2 vs. standard graft, 13 ± 7min; 95% CI 2.44-5.03, P < 0.001). Hospital mortality was 17% (6/36); while mortality did not differ between the two groups, postoperative acute kidney injury rate was 30.5% (11/36 patients) and was more common in the standard graft group (7% vs. 29%; OR 3.2, P = 0.074). Estimated primary patency was 92% ± 2 (95% CI 79.5-97%) at 36months and was not different between the two groups (GHVG 94% ± 6 vs. standard graft 91% ± 6; log-rank χ2 = 0.260, P = 0.610). In our experience of HTAR, ischemia time was significantly shorter and postoperative AKI occurrence was lower with GHVG if compared to standard graft bypass, with satisfactory midterm patency rate comparable to that of standard graft bypass.

Carotid Bypass with Gore Hybrid Vascular Graft as a Rescue Technique for on Table Failed Carotid Endarterectomy: A Five Years Follow-up

Introduction: Carotid endarterectomy (CEA) remains the gold standard for stenotic lesions involving the carotid bifurcation. Carotid bypass grafting is a suitable alternative technique especially in challenging and on table failed endarterectomy. We report our five years' experience using the Gore Hybrid vascular graft (GHVG) as a rescue technique when standard CEA failed. Methods: Between November 2014 and November 2018 nineteen GHVGs were used in patients undergoing CEA. All patients were scheduled for a routine endarterectomy and patch plasty. Pre-operative detailed duplex imaging was undertaken in all patients to measure the proximal and distal diameter of the internal carotid artery (ICA). The GHVG was used in eleven cases in which the plaque extended beyond the surgical exposure resulting in an unsatisfactory distal end point. Five patients had penetrating atherosclerotic ulcers causing a disruption of the posterior wall. Two cases had a significant wall thinning after the endarterectomy and in one case the bypass option was selected for a post-radiation induced stenosis. All patients were discharged on day 3 on dual antiplatelets and were followed up at 1 , 3, 6 ,12 months with duplex and CT angiogram . After one year the follow up continued regularly every six months using only duplex scan. CT angiogram was requested to monitor a severe restenosis. Kaplan Meir analysis was used for assessing the long term patency. Results: Procedural success was achieved in all cases. All patients made a good post-operative recovery with no perioperative stroke or death. The total operative time and cerebral ischaemic time was reduced because the avoidance of creating two sutured anastomosis. In six patients the external carotid artery (ECA) was re- implanted in an end to side fashion. Four GHVGs occluded during the follow-up at 6, 12,24 and 39 months completely asymptomatic. Five patients developed restenosis without any neurological events at 12, 13,15 20 and 28 months. Two patients underwent a carotid angioplasty and stenting for asymptomatic severe restenosis. The primary patency rate at 50 months was 78.9% Conclusion: The GHVG is a new promising technology in patients with extensive carotid atherosclerotic disease when conventional endarterectomy has failed. Our experience suggests a potential role of this graft in challenging case. Dual antiplatelets and long term follow up are needed to maintain the durability of this graft. Disclosure: Nothing to disclose

Total robotic iliac aneurysm repair with preservation of the internal iliac artery using sutureless vascular anastomosis

ObjectiveInternal iliac artery (IIA) preservation is associated with improved outcomes after both open and endovascular aortoiliac aneurysm repair. Total robotic laparoscopic repair of aortoiliac aneurysms has been reported in the past, but not in combination with sutureless anastomosis applied to the IIAs. The objective of this study was to demonstrate the feasibility of the total robotic laparoscopic technique including a method of deploying the Gore Hybrid Vascular Graft (GHVG; W. L. Gore & Associates, Flagstaff, Ariz) using robotic instruments. MethodsBetween June 2015 and December 2016, four patients underwent total robotic laparoscopic repair of isolated common iliac artery (CIA) aneurysms. Two patients had unilateral aneurysms and two had bilateral aneurysms. Unilateral CIA aneurysms were treated with a graft from the proximal CIA to the proximal external iliac artery, and bilateral CIA aneurysms were treated with a bifurcated graft between the distal aorta and both proximal external iliac arteries. The nitinol reinforced section of the GHVG was then inserted and deployed into the corresponding IIA, and the nonreinforced segment was sewn in an end-to-side fashion to the iliac graft. ResultsThe median age of patients was 55.5 years (range, 48-64 years); median body mass index was 24.9 kg/m2 (range, 23-26.4 kg/m2). All four cases were technically successful. Operative times were 325 and 332 minutes for unilateral cases and 491 and 385 minutes for bilateral cases. For the entire series, median proximal clamping time was 143 minutes (range, 110-163 minutes), and the median time to deploy the GHVG was 15 minutes (range, 8-27 minutes). The median estimated blood loss was 1800 mL (range, 800-2100 mL). Intraoperative cell salvage was used in all cases. No intraoperative or postoperative complications occurred. No patient required blood transfusion. All patients tolerated a regular diet on postoperative day 2 and were discharged on postoperative day 4. Patients returned to work and full physical activity within 6 weeks (range, 2-6 weeks). At 6-month follow-up, computed tomography angiography demonstrated 100% patency of iliac artery grafts as well as of the GHVGs. ConclusionsTotal robotic laparoscopic CIA aneurysm repair is feasible in both unilateral and bilateral cases in carefully selected patients. The GHVG can be successfully deployed using robotic technique for IIA preservation during total robotic CIA aneurysm repair.

Hybrid arteriovenous graft for hemodialysis vascular access in a multicenter registry

ObjectiveThe aim of our study was to identify patients' characteristics that predicted a higher chance of arteriovenous graft patency in patients undergoing Gore Hybrid Vascular Graft (GHVG; W. L. Gore & Associates, Flagstaff, Ariz) implantation for hemodialysis access. The GHVG is a polytetrafluroethylene (PTFE) prosthesis with a nitinol-reinforced section (NRS) at the venous end. MethodsAll consecutive patients undergoing GHVG implantation for hemodialysis access at 10 tertiary referral centers between December 2013 and January 2018 were included in the study and compared with a control group of patients undergoing standard PTFE graft implantation. Selection of patients for hybrid graft implantation was based on the impossibility of autogenous vascular access creation. ResultsThere were 145 patients included in the GHVG group and 218 in the PTFE group. In the GHVG and the PTFE groups, the mean age was 67 ± 13 years and 65 ± 13 years, and male patients totaled 52% and 46%, respectively. The technical success was 99%. The mean duration of the intervention was 100 minutes (median, 95 minutes; interquartile range, 80-120 minutes). The brachial-axillary configuration was used in the majority of cases (n = 78 [54%]). The 5-cm NRS length was prevalent (n = 108 [75%]). The median NRS oversize was 14% (interquartile range, 0%-21%). Mean follow-up was 13 months (range, 0-55 months). Seventy-one patients (49%) underwent at least one reintervention. Primary, assisted primary, and secondary patency estimates at 12 months were 44% ± 5%, 47% ± 5%, and 65% ± 4% for the GHVG group and 41% ± 4%, 53% ± 4%, and 75% ± 3% for the control group, respectively (P = NS). One-year survival was 90% ± 3%. On multivariable Cox regression analysis, hypotension (P < .001; hazard ratio [HR], 5.8; confidence interval [CI], 2.6-13) and diabetes (P = .024; HR, 1.9; CI, 1.1-3.2) were significant predictors of GHVG loss. A larger graft size was protective against GHVG loss (P = .042; HR, 0.73; CI, 0.54-0.99). The 10-cm-long graft showed a tendency toward improved patency but did not reach statistical significance (P = .074; HR, 0.48; CI, 0.21-1.07). ConclusionsDiabetes and hypotension were predictors of loss of hybrid arteriovenous access. Smaller diameters of NRS were more prone to thrombosis, whereas the 10-cm length seemed to perform better than the 5-cm one.

Three-layer collagen-based vascular graft designed for low-flow peripheral vascular reconstructions.

The aim of this study was to develop a prototype of an artificial blood vessel which has similar mechanical properties to a human saphenous vein graft and to experimentally verify the function of the prosthesis via ovine carotid bypass implantation. The prototype of an artificial graft prosthesis for low flow was developed and manufactured from a collagenous matrix and reinforcing polyester mesh. We compared the results of both the pressurisation and the mechanical stress evaluation tests of VSM with four types of hybrid vascular graft. The most similar graft (type II) was chosen for the first ovine model implantation. Dominant behavior e.g. mechanical response of VSM graft in plots of circumferential and axial stress during loading is observed in circumferential direction. Average results of used VSM showed area of ideal mechanical response and the properties of artificial blood vessels were fitted into this area. Developed graft remained patent after 161 days of follow up in ovine model. The mechanical properties of the graft were designed and adjusted to be similar to the behaviour of human saphenous veins. This approach showed promising results and enhanced the final performance of the prosthesis.

Rapid endothelialization and controlled smooth muscle regeneration by electrospun heparin-loaded polycaprolactone/gelatin hybrid vascular grafts.

The bioinert characteristic of polycaprolactone (PCL) remains a major defect when using PCL-based materials as small-diameter vascular grafts for implantation in vivo. To improve the hydrophilicity, cytocompatibility, and biodegradation of PCL vascular grafts, we constructed hybrid vascular grafts from electrospun PCL/gelatin. The PCL/gelatin hybrid vascular graft was further functionalized with the addition of heparin, to improve hemocompatibility. This study investigated the performance of heparin-loaded PCL/gelatin hybrid vascular grafts in vivo. Our results showed that the combination of gelatin and PCL was an effective approach to overcome each individual component's shortcomings, in the context of vascular graft generation. Furthermore, by loading heparin onto the grafts, thrombosis, which could be otherwise induced by gelatin, was prevented. Overall, our electrospun heparin-loaded PCL/gelatin vascular grafts promoted endothelialization and regulated smooth muscle regeneration. The data presented here show PCL/gelatin and heparin-loaded vascular grafts as an effective biomaterial candidate for the generation of artificial small-diameter vascular grafts. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2040-2049, 2019.

VD11 FROZEN ELEPHANT TRUNK BY USING E-VITA PROSTHESES AND BENTALL PROCEDURE IN A GIANT DESCENDING THORACIC AORTA ANEURYSM

We present the case of a 54-year-old male patient with a 12 cm post-decoarctation aneurysm of the descending thoracic aorta with bicuspid aortic valve stenosis and ventricular septal defect. Right femoral artery and bicaval cannulation were used for Cardiopulmonary bypass. Antegrade cerebral perfusion with moderate hypotermia (25°C) was achieved with the innominate and left carotid artery cannulation. The aortic arch replacement was performed by using Frozen Elephant Trunk technique with a 40 mm E-Vita Open Plus prosthesis and a separated Plexus 4-branches prosthesis. The reimplantation of the left subclavian artery was performed by a 9 mm Gore hybrid vascular graft. A St.Jude 23 mm mechanical valve conduit was used for the Bentall procedure. The ventricular septal defect was closed with direct suture. Cardiopulmonary bypass, aortic cross-clamp and cerebral perfusion times were 258,186 and 109 minutes, respectively. Post-operative course was uneventful and CT scan showed the good result of the procedure.

Outcomes of a Polytetrafluoroethylene Hybrid Vascular Graft with Preloaded Nitinol Stent at the Venous Outflow for Dialysis Vascular Access

To evaluate outcomes and patency of arteriovenous grafts (AVGs) created using Gore hybrid vascular grafts in hemodialysis patients with limited venous outflow or challenging anatomy. A retrospective review was performed in two academic centers of all patients between July 2013 and December 2016 who underwent surgical AVG creation using a Gore hybrid vascular graft in a brachial artery to axillary configuration. Patient characteristics and comorbidities as well as graft patency, function, and subsequent need for percutaneous interventions were recorded. Forty-six patients including 30 females (65.2%) and 16 males (34.8%) with a mean age of 63±13years were identified. The most common indications for a hybrid vascular graft were limited surgical accessibility and/or revision of existing AVG due to severe stenotic lesions at the venous outflow in 33 patients (72%). One-year primary unassisted and assisted patency rates were 44±8% and 54±8%, respectively, compared with 1-year secondary patency rate of 66±8%. The rate of percutaneous interventions to maintain graft function and patency was approximately one intervention per graft per year. Access created with the hybrid vascular graft in a brachial-axillary (brachial artery to axillary vein) configuration is an acceptable option for patients with limited venous outflow reserve and challenging anatomy. Twelve-month primary and secondary patency rates and need for percutaneous interventions were comparable to traditional AVGs.

In Vivo Performance of Decellularized Vascular Grafts: A Review Article.

Due to poor vessel quality in patients with cardiovascular diseases, there has been an increased demand for small-diameter tissue-engineered blood vessels that can be used as replacement grafts in bypass surgery. Decellularization techniques to minimize cellular inflammation have been applied in tissue engineering research for the development of small-diameter vascular grafts. The biocompatibility of allogenic or xenogenic decellularized matrices has been evaluated in vitro and in vivo. Both short-term and long-term preclinical studies are crucial for evaluation of the in vivo performance of decellularized vascular grafts. This review offers insight into the various preclinical studies that have been performed using decellularized vascular grafts. Different strategies, such as surface-modified, recellularized, or hybrid vascular grafts, used to improve neoendothelialization and vascular wall remodeling, are also highlighted. This review provides information on the current status and the future development of decellularized vascular grafts.

State-of the-art review on the renal and visceral protection during open thoracoabdominal aortic aneurysm repair.

During open thoracoabdominal aortic aneurysm repair (OTAAAR), there is an inevitable organ ischemic period that occurs when the abdominal arteries are being reattached to the aortic graft. Despite various protective techniques, the incidence of renal and visceral complications remains substantial. This state-of-the-art review gives an overview of the current and most evidence-based organ protection methods during OTAAAR, based on the most recent publications and personal experience. An electronic search was performed in four medical databases, using the following MeSH terms: thoracoabdominal aneurysm, TAAAR, visceral protection, renal protection, kidney, perfusion, and intestines. Every publication type was considered. The literature search was ended on August 31st, 2017. The left heart bypass (LHB) is currently the most frequent adjunct to provide distal aortic perfusion (DAP) during aortic clamping. Together with systemic hypothermia, it forms the cornerstone in organ protection during aortic clamping. Further renal protection can be obtained by selective renal perfusion (SRP) with cold blood or cold crystalloid solution, the latter enriched with mannitol. The perfusion should be administered in a volume- and pressure-controlled way and, if possible, by use of a pulsatile pump. Selective visceral perfusion (SVP) is not routinely used, as it does not provide adequate blood flow for visceral protection. The best way to protect the intestines is by minimizing the ischemic time. The preservation of renal and visceral function after OTAAAR can only be obtained with specific strategies before, during, and after the operation. This involves a series of measures, including selective digestive decontamination (SDD), avoidance of nephrotoxic drugs, minimizing the renal and intestinal ischemic time, systemic cooling, avoidance of hemodynamic instability, and regional protective perfusion of the kidneys. Future innovations in catheters, cardiac bypass flow types, mechanical components, hybrid vascular grafts, and pharmaceutical protection measures will hopefully further reduce organ complications.

Strategy of advanced renal protection during open repair of thoraco-abdominal aortic aneurysms: a new solution of perfusion, direct stenting and bypass with Gore hybrid vascular grafts

Strategy of advanced renal protection during open repair of thoraco-abdominal aortic aneurysms: a new solution of perfusion, direct stenting and bypass with Gore hybrid vascular grafts

Small-diameter hybrid vascular grafts composed of polycaprolactone and polydioxanone fibers

Electrospun polycaprolactone (PCL) vascular grafts showed good mechanical properties and patency. However, the slow degradation of PCL limited vascular regeneration in the graft. Polydioxanone (PDS) is a biodegradable polymer with high mechanical strength and moderate degradation rate in vivo. In this study, a small-diameter hybrid vascular graft was prepared by co-electrospinning PCL and PDS fibers. The incorporation of PDS improves mechanical properties, hydrophilicity of the hybrid grafts compared to PCL grafts. The in vitro/vivo degradation assay showed that PDS fibers completely degraded within 12 weeks, which resulted in the increased pore size of PCL/PDS grafts. The healing characteristics of the hybrid grafts were evaluated by implantation in rat abdominal aorta replacement model for 1 and 3 months. Color Doppler ultrasound demonstrated PCL/PDS grafts had good patency, and did not show aneurysmal dilatation. Immunofluorescence staining showed the coverage of endothelial cells (ECs) was significantly enhanced in PCL/PDS grafts due to the improved surface hydrophilicity. The degradation of PDS fibers provided extra space, which facilitated vascular smooth muscle regeneration within PCL/PDS grafts. These results suggest that the hybrid PCL/PDS graft may be a promising candidate for the small-diameter vascular grafts.

Description and early outcomes of the hybrid graft for dialysis.

Long-term dialysis access has become more challenging as patient survival has improved in end-stage renal disease. The GORE® Hybrid Vascular Graft (GHVG) has been designed to improve dialysis access outcomes and provide additional access options for challenging patients. In this article, we will review the design of the graft, unique properties and reported outcomes. We reviewed data available at our institution and performed a Pubmed search on GORE® Hybrid Vascular graft. We found two more studies besides the data published by our department. To date, there have been three papers showing early results of these grafts. All studies report successful placement of the grafts with no unexpected complications. Limb edema has not been a common problem, despite concerns of placing a stent graft into the axillary vein. The papers have shown 70% cumulative patency of the GHVG at 12 months. The comparative studies showed no significant benefit compared to conventional grafts. We see this as an option of continuing with arm access rather than going to more complex access creation such as a chest wall access or going to access creation in the legs. The GHVG has been shown to have comparable performance to standard arteriovenous graft techniques and can expand access options for some patients with challenging anatomy.

Initial clinical experience with a polytetrafluoroethylene vascular dialysis graft reinforced with nitinol at the venous end

ObjectiveThe purpose of this study was to examine the outcomes of a vascular hybrid polytetrafluoroethylene (PTFE) graft, provided with a nitinol-reinforced section (NRS) on one end, in hemodialysis vascular access placement. MethodsA retrospective study was conducted including all the consecutive patients who underwent Gore Hybrid Vascular Graft (GHVG; W. L. Gore & Associates, Flagstaff, Ariz) implantation for hemodialysis access placement between October 2013 and November 2015. A propensity-matched control group was obtained from consecutive patients who underwent standard PTFE arteriovenous graft implantation between January 2010 and July 2013. The selection criteria were inadequate venous material for autogenous arteriovenous fistula placement, patent deep venous circulation, and vein diameter of 4 to 8.5 mm. The implantation technique involves the insertion of the NRS some centimeters into the target vein. Fluoroscopic guidance helps deploy the device in the desired landing zone (ie, position of the proximal end of the NRS), based on anatomic landmarks. Survival, functional patency rates, and complications were compared with a propensity-matched historical control group. Vein diameter, previous vascular access placement, and diabetes were tested as predictors of reintervention with a logistic regression analysis. ResultsThere were 32 patients (14 men; mean age, 69 ± 14 years) who received the GHVG graft. The historical control group included 43 patients. Technical success was 100%. The graft configuration was brachial-axillary (n = 22 [69%]), brachial-basilic loop (n = 5 [16%]), brachial-antecubital loop (n = 3 [9%]), axilloaxillary loop (n = 1 [3%]), and femoral-femoral loop (n = 1 [3%]). Mean NRS oversize was 20% ± 7% (range, 3%-34%; median, 19%). Perioperative complications requiring revision included acute limb ischemia treated with thrombectomy (n = 1 [3%]) and graft infection requiring explantation (n = 2 [6%]). Two patients (6%) died in the hospital of unrelated causes. The mean follow-up was 15 ± 11 months (range, 0-33 months; median, 15.5). The propensity-matched groups included 25 patients each. Survival estimates at 24 months for the GHVG and standard PTFE groups were 91% ± 6% and 82% ± 9% (P > .05), respectively. The 12-month patency estimates were as follows: functional primary patency, 66% ± 10% vs 51% ± 10% (P > .05); functional assisted primary patency, 75% ± 9% vs 51% ± 10% (P > .05); and functional secondary patency, 79% ± 9% vs 67% ± 10% (P > .05). Reduction in vein diameter was associated with reintervention. ConclusionsThe GHVG is a safe and effective alternative to standard PTFE in hemodialysis access surgery. Careful planning for the landing zone is advisable, especially for small outflow veins. Larger studies and randomized trials are needed to define the role for this device. A study including a greater number of centers experienced with this device is currently under way.