Arteriovenous Fistulae: Drug-eluting Balloon Angioplasty

Overview

Dysfunctions such as tight stenosis or thrombosis in haemodialysis vascular accesses are the leading cause of hospitalisationand morbidity in chronic haemodialysis patients incurring significant related costs estimated at over one billion dollars in the USA. Dysfunctions of these vascular accesses are generally treated by conventional angioplasty as this is the least invasive procedure, the alternative being revision surgery. Angioplasty uses an inflatable balloon of various diameters. Different types of angioplasty balloons may be needed to break fibrous venous stenosis, in particular high-pressure balloons or cutting balloons. These angioplasty procedures which are often painful during dilation have a high technical success rate but a poor 1-year patency rate. These invasive repeated procedures impair the quality of life of these patients with end-stage renal disease who are on permanent dialysis or awaiting a kidney transplant and for whom vascular access patency is vital. Due to their traumatic effect on the vessel wall, these procedures induce cell proliferation processes that retrigger neointimal hyperplasia the very act of preserving the haemodialysis access is the key factor in development of a new stenosis and hence a vicious circle of stenosis-angioplasty. For the past few years, angioplasty balloons delivering anticancer drugs have been developed. These drugs, generally used in high doses for cancer chemotherapy, are released in small doses on the medical angioplasty devices. During inflation, the local release of the anticancer molecule through the different layers of the vessel wall confers local antiproliferative action without the systemic toxic effects associated with high-dose chemotherapy. These medical devices have demonstrated their efficacy in terms of increase in primary and secondary patency rates on procedures such as coronary artery angioplasty, femoro-popliteal or sub-popliteal artery angioplasty. These drug-eluting balloons (DEBs) are also CE marked with the recommendation of being indicated for AVF anticancerangioplasties, but no randomised multi-centre clinical trial has proven their medical effectiveness, and in particular their contribution in terms of patency rate improvement. However, studies on animal models show significant results regarding efficacy against neointimal hyperplasia and the first single-centre clinical trials on a small sample size appear promising. The key assessment criterion is primary patency of the dilated stenosis at one year defined by patients efficaciously dialysed at one year without re-intervention on the dilated lesion after initial angioplasty. The delay of occurrence of dilation will be considered. Patients that will be non-evaluable for the primary endpointwill be censored at the date of the latest news.

Dysfunctions such as tight stenosis or thrombosis in haemodialysis vascular accesses are the leading cause of hospitalisation (20%) and morbidity in chronic haemodialysis patients incurring significant related costs estimated at over one billion dollars in the USA. Dysfunctions of these vascular accesses are generally treated by conventional angioplasty as this is the least invasive procedure, the alternative being revision surgery. Angioplasty uses an inflatable balloon of various diameters. Different types of angioplasty balloons may be needed to break fibrous venous stenosis, in particular high-pressure balloons (20 atm) or cutting balloons. These angioplasty procedures which are often painful during dilation have a high technical success rate (90-97%) but a poor 1-year patency rate, varying between 26 and 64% depending on the team and a mean rate estimated at 40% for the studies including the larger number of patients, some of whom requiring several procedures. These invasive repeated procedures impair the quality of life of these patients with end-stage renal disease who are on permanent dialysis or awaiting a kidney transplant and for whom vascular access patency is vital. Due to their traumatic effect on the vessel wall, these procedures induce cell proliferation processes that retrigger neointimal hyperplasia the very act of preserving the haemodialysis access is the key factor in development of a new stenosis and hence a vicious circle of stenosis-angioplasty. For the past few years, angioplasty balloons delivering anticancer drugs (Paclitaxel, Sirolimus, Everolimus) have been developed. These drugs, generally used in high doses for cancer chemotherapy, are released in small doses on the medical angioplasty devices. During inflation, the local release of the anticancer (antimitotic) molecule through the different layers of the vessel wall (Paclitaxel is lipophilic and hydrophobic) confers local antiproliferative action without the systemic toxic effects associated with high-dose chemotherapy. These medical devices have demonstrated their efficacy in terms of increase in primary and secondary patency rates on procedures such as coronary artery angioplasty, femoro-popliteal or sub-popliteal artery angioplasty (treatment of angina or lower limb arteriopathy). These drug-eluting balloons (DEBs) are also CE marked with the recommendation of being indicated for AVF anticancerangioplasties, but no randomised multi-centre clinical trial has proven their medical effectiveness, and in particular their contribution in terms of patency rate improvement. However, studies on animal models show significant results regarding efficacy against neointimal hyperplasia and the first single-centre clinical trials on a small sample size appear promising. The key assessment criterion is primary patency of the dilated stenosis at one year defined by patients efficaciously dialysed at one year without re-intervention on the dilated lesion after initial angioplasty. The delay of occurrence of dilation will be considered (censored criteria). Patients that will be non-evaluable for the primary endpoint (death, lost to follow-up…) will be censored at the date of the latest news.