European Journal of Cardiovascular Medicine

Vascular access is the lifeline of patients undergoing maintenance hemodialysis. The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines recommend autogenous arteriovenous (AV) fistulas as the preferred form of vascular access due to their superior long-term patency and lower complication rates compared to central venous catheters [1,2]. However, in many patients, particularly those with unsuitable native vessels like sclerotic veins due to comorbidities such as diabetes mellitus, obesity, or multiple prior failed fistulas, prosthetic grafts become an essential alternative for establishing hemodialysis access [3]. Expanded polytetrafluoroethylene (ePTFE) grafts are most commonly employed for this purpose [4]. Despite higher rates of infection and thrombosis compared to native fistulas, advances in surgical technique, and postoperative care and prosthetic grafts have significantly improved graft outcomes [5].

In this case series, we present six cases of prosthetic AV graft creation performed in a tertiary care centre- Grant Govt Medical College and Sir JJ group of Hospitals, highlighting surgical techniques, outcomes, and complications encountered. The series aims to provide insights into patient selection, graft configuration, and management strategies.

Case 1

A 38-year-old male with end-stage renal disease (ESRD) presented with two prior failed radiocephalic and brachiocephalic fistulas in both limbs. Preoperative duplex ultrasonography also showed small, sclerotic veins unsuitable for native fistula creation. A proximal brachial artery to brachial vein vein loop graft was fashioned using a  ePTFE prosthesis. The graft used was a Goretex standard tapered stretch vascular graft with varying diameters of 4mm on the arterial side and 7 mm on the venous side to allow for more flow into the vein. Furthermore the graft has an additional property of being double layered which acts as a low bleed barrier for cannulation needle holes and prevents hematoma and pseudoaneurysm formation and allows it to be flexible at curves without kinking. The graft was tunneled subcutaneously in the upper arm, and an end-to-side anastomosis was performed to the brachial artery proximally and the brachial vein distally. The graft was strategically paces in the lateral aspect of the arm to allow for easier cannulation access. Postoperatively, graft flow was adequate. Patient had diffuse swelling of the upper arm in the immediate post-operative period. Post operative doppler showed good flow through the graft. The edema was managed with arm elevation and subsequently subsided within 2 days. On 3rd week follow up, the patient presented to the outpatient department with no complaints and a functioning graft. Dialysis through the graft has yet to be initiated for the patient

Case 2

A 59-year-old female with ESRD and exhausted upper extremity veins due to prior multiple central venous catheter placements and sclerotic veins on duplex ultrasonography unsuitable for autogenous AV fistula creation underwent placement of a looped forearm graft. The brachial artery was anastomosed to the basilic vein using a standard tapered stretch ePTFE graft configured in a loop to maximize cannulation area. The patient had uneventful maturation of the graft. However, at 12 months, she developed a venous anastomotic stenosis identified by decreased dialysis flows. Angiography confirmed the diagnosis, and balloon angioplasty was successfully performed. The graft remained functional with no further interventions at 18 months.

Case 3

A 72-year-old male with peripheral vascular disease and a history of multiple failed upper arm autogenous AV fistula bilaterally presented for new access creation. An brachio-brachial loop graft was created using standard tapered stretch ePTFE material. Early postoperative monitoring revealed diminished thrill, and Doppler studies confirmed graft thrombosis within one month. The patient underwent surgical thrombectomy to remove the thrombus. Graft functionality was successfully restored, and he resumed hemodialysis through the graft without further complications for the next 10 months.

Case 4

A 67-year-old morbidly obese female with small-calibre cephalic and basilic veins was planned for a brachial artery to brachial vein loop graft. A tapered stretch ePTFE graft was tunnelled in the upper arm, avoiding areas of high skin tension. Intraoperative flow measurements confirmed good patency. Dialysis through the graft was initiated after 4 weeks. Over a 24-month follow-up, the graft remained functional without thrombosis, infection, or need for reintervention.

Case 5

A 61-year-old male with ESRD and multiple failed upper extremity fistulas underwent brachial artery to brachial vein loop graft placement in the right arm using a standard tapered stretch ePTFE graft. The graft matured uneventfully and provided effective dialysis access. Over a 15-month follow-up, the graft remained functional without thrombosis, infection, or need for reintervention.

Case 6

A 58-year-old female with a history of failed left brachiocephalic fistula with right upper limb venous thrombosis underwent brachio brachial loop graft placement using a heparin-bonded ePTFE graft (Gore Propaten). The surgery involved end-to-side arterial and venous anastomoses with minimal vessel manipulation. Early postoperative duplex sonography showed excellent flow rates. Dialysis was initiated after 2 weeks without any issues. At the 10-month follow-up, the graft remained patent without evidence of thrombosis or stenosis.

Case Series Summary Table

                 TABLE 1: Case Summary

The creation of arteriovenous (AV) access for hemodialysis is critical for patient survival. Although autogenous AV fistulas remain the gold standard due to superior patency and lower complication rates, prosthetic grafts serve as a vital option for patients with unsuitable venous anatomy [1,2]. Our case series involves the follow up of patients up to 24 months operated at Grant Govt Medical College and Sir JJ group of Hospitals and highlights the practical challenges and outcomes associated with prosthetic AV grafts in diverse clinical scenarios.

Patient Selection and Preoperative Evaluation

Preoperative vascular mapping using duplex ultrasonography (DUS) is essential to determine the suitability for autogenous fistula creation [3]. In cases of small, thrombosed, or sclerotic veins, prosthetic grafts become necessary. Our patients typically had multiple comorbidities such as diabetes mellitus, obesity, peripheral vascular disease, and prior failed accesses — all factors known to predict poorer outcomes with both fistulas and grafts [4].

Studies have demonstrated that diabetic patients and those with cardiovascular disease are at higher risk of prosthetic graft failure due to endothelial dysfunction and a higher propensity for thrombosis [5].

Choice of Graft Configuration

The configuration of the graft — whether straight or looped — impacts clinical outcomes. Loop grafts provide a greater cannulation surface area, facilitating better dialysis and offering more flexibility for puncture sites, potentially prolonging graft life [6]. In contrast, straight grafts are technically simpler to implant but may limit cannulation options and predispose to localized stenosis.

A prospective analysis by Schild et al. demonstrated superior functional patency in loop configurations compared to straight grafts at 1-year follow-up [7].

Surgical Techniques and Intraoperative Strategies

Attention to surgical technique, particularly at the arterial and venous anastomoses, plays a critical role in minimizing turbulence, intimal hyperplasia, and subsequent stenosis [8]. The use of meticulous anastomotic suturing with minimal vessel manipulation and intraoperative assessment of flow are associated with improved early patency [9].

Prosthetic grafts also require careful tunnelling through healthy, non-infected subcutaneous tissue, as tunnelling through areas of previous infection or poor skin integrity increases postoperative infection risk.

Complications: Thrombosis, Infection, and Stenosis

Thrombosis remains the most common early complication of prosthetic AV grafts, with reported rates between 20% and 40% within the first year [10]. In our series, early thrombosis occurred in one case (Case 3) and was successfully managed with thrombectomy. Timely intervention is critical and studies show that salvaged grafts have significantly better secondary patency rates compared to newly created accesses [11].

Infection is another major concern, often necessitating graft excision and systemic antibiotic therapy. Infection rates in prosthetic grafts range from 10% to 20% [12]. Factors contributing to infection include repeated cannulations, skin breakdown, and underlying immunosuppression [13]. In our series, we have restricted our graft placements to the upper arm and forearm taking care to avoid the axilla and lower extremities as they are more prone to infections. No case of infected graft has been reported in our series.

The development of peripheral vein stenosis is the primary cause of fistula and graft thrombosis. The formation of stenosis is initiated by endothelial cell injury which leads to smooth muscle proliferation and neointimal hyperplasia. Different factors may lead to endothelial injury including shear stress from turbulent blood flow, mechanical trauma

from venipuncture, and angioplasties. The most common site for stenosis in grafts occurs at the graft-vein anastomosis in 80% to 85% of the time followed by intragraft stenosis 11% to 15% and the graft-artery anastomosis 2% to 5% of the time.[14]. Case 2 in our series developed stenosis at the venous anastomosis which was successfully treated with percutaneous intervention.

Advances in Graft Technology

Innovations such as heparin-bonded ePTFE (HePTFE) grafts aim to reduce thrombosis by decreasing platelet adhesion and fibrin formation. In a study conducted by Samson et al, Propaten HePTFE graft offered significantly better long-term patency over the standard ePTFE graft [15], suggesting it may be used as better alternative to a standard ePTFE graft for AV fistula creation. However, a prospective randomised study by Shemesh et al showed that Heparin-bonded grafts had a significantly lower early thrombosis rate that was sustained only for the first 5 months of follow-up [16].

Emerging biologic conduits, including human acellular vessels (HAVs), show promise in reducing infection and improving integration with host tissue. However, these technologies remain under investigation and are not yet widely available for clinical use [17].

Lower Extremity Grafts

When upper extremity sites are exhausted, femoral-based prosthetic grafts offer a salvage option. IL Geenan et al concluded from a retrospective study which showed that the the patency rates in a large series of prosthetic femoral AV fistula grafts are acceptable, and the complication rates of infection and steal are comparable to those reported in the literature, with a low incidence of lower limb ischemia. This study concluded that femoral AV grafts offer a satisfactory alternative for patients who are not good candidates for upper limb vascular access[18]. However, in our case series we have refrained from placing the prosthetic grafts in the lower extremities and axilla to avoid any risk of infection of the graft.

Careful patient selection and rigorous postoperative surveillance are essential when employing lower extremity access routes.

Comparative Outcomes

Compared to native AV fistulas, prosthetic grafts have lower primary patency rates. Dember et al. reported that the two-year primary patency of grafts is approximately 25%, compared to over 60% for autogenous fistulas [19]. However, for patients with exhausted options, prosthetic grafts remain life-saving and essential.

Aggressive endovascular interventions, advancements in graft materials, and structured surveillance programs can improve the durability of prosthetic access [20].

Prosthetic AV grafts remain an essential tool in vascular access surgery, particularly for hemodialysis patients with unsuitable native vasculature and multiple previously failed autogenous AV fistulas. Our case series demonstrates that with meticulous patient selection, careful surgical technique, aggressive surveillance, and timely intervention for complications, prosthetic grafts can offer acceptable patency and outcomes and are therefore a suitable and reliable alternative to autogenous AV fistula creation. Our case series involved follow up of patients for up to 24 months in order for us to arrive at the most accurate conclusions. With further advancements, the drawbacks of the prosthetic grafts like low patency rate, need for high dose antiplatelet therapy and increased cost can be tackled in the future.  Ongoing innovation in graft materials and access management strategies continues to enhance the prospects for patients dependent on prosthetic vascular access.

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