Prospective Randomized Trial Comparing DEB Versus Conventional PTA for the Treatment of Hemodialysis AVF or AVG Stenoses

Introduction:

Neointimal hyperplasia is the main cause of hemodialysis access [arterio-venous fistula (AVF) or graft (AVG)] dysfunction and thrombosis. Although endovascular techniques like percutaneous transluminal angioplasty (PTA), catheter directed thrombolysis, mechanical thrombectomy or bare metal stenting, may salvage the access, long term patency remains dismal due to recurrent stenosis from neointimal hyperplasia.

Drug Eluting Balloon (DEB) is effective in inhibiting neointimal hyperplasia for treatment of coronary in-stent restenosis since 2006 and more recently in femoropopliteal arteries, reducing restenosis rates and prolonging patency.

Specific Aim:

To determine the efficacy of DEB in reducing restenosis rates and prolonging the patency of AVFs/AVGs compared to PTA.

Hypothesis:

DEB is superior to PTA in reducing late luminal loss and restenosis rates, while prolonging primary and secondary patencies.

Methodology:

Prospective, randomized clinical trial with study population comprising of patients with dysfunctional AVFs/AVGs due to underlying stenoses. The patients will be randomized to receive either DEB or PTA.

The 6-month late luminal loss will be primary endpoint. The secondary endpoints of restenosis rate, primary and secondary patencies, will also be determined.

Major Clinical Significance:

Hemodialysis access failures constitute significant morbidity and costs to patient and healthcare system. Maintaining access patency consumes significant resources and constitutes a significant portion of the work of vascular surgeons, nephrologists and interventional radiologists.

Any strategy that reduces access failure or prolonging access lifespan will be beneficial. If DEB is proven to be superior to PTA, there will be a paradigm shift in management of hemodialysis access failures from restenosis - similar to how DEB has changed practice in managing coronary artery in-stent restenosis.

Inclusion criteria

• Upper limb or groin AVF/AVG
• The AVF/AVG is > 3 months old.
• Native vessel measures between 4 to 7 mm diameter (corresponding to the sizes of available DEBs).
• The fistula or graft must not be thrombosed.
• Able to cross with guide wire
• Platelet count >50,000/l (platelet infusion if <100,000/l)
• PT/PTT not more than 3 seconds above normal (FFP infusion for abnormal PT/PTT)

Exclusion criteria

• Uncorrectable coagulopathy (despite transfusion) or hypercoagulable state.
• Evidence of systemic infection or a local infection associated with the fistula or graft.
• The patient is < 21 years of age.
• The patient is pregnant.
• Patient is enrolled in another investigational study
• Patient has comorbid conditions that may limit their ability to comply with the follow-up requirement.
• Life expectancy < 6 months