BRAVO I: A pilot study of vascular brachytherapy in polytetrafluoroethylene dialysis access grafts

Abstract

Hemodialysis vascular access dysfunction owing to stenosis and thrombosis in polytetrafluoroethylene dialysis access grafts is a huge clinical problem for which there are currently no long lasting durable therapies. Vascular brachytherapy has been used successfully for the prevention of coronary restenosis following angioplasty and stent placement. The Beta Radiation for Treatment of Arterial-Venous Graft Outflow I study was a pilot study of vascular brachytherapy in hemodialysis patients with patent but dysfunctional grafts. Twenty-five patients were randomized to receive either radiation therapy (a single dose of 18.4 Gy) or sham radiation, following angioplasty. The primary efficacy end point of the study was target lesion primary patency at 6 months. The primary safety end point was a composite of death, emergency surgery on the graft, venous rupture, or aneurysm formation. Forty-two percent of the radiated grafts achieved the target lesion primary patency end point at 6 months as compared to 0% of the control group (P = 0.015), but this did not translate into an improvement in secondary patency at either 6 or 12 months. Radiation therapy was found to be safe in the setting of hemodialysis vascular access dysfunction. Our results suggest that vascular brachytherapy is an intervention that is worthy of further examination in the setting of non-thrombosed dialysis access grafts.

Diagnosis and Treatment of Insufficient Dialysis Vascular Access

“…Endovascular brachytherapy and external radiation are additional interventional methods that have not yet been able to be proven to be superior and are thus not used in the clinical routine [69]. With the goal of preventing neointimal hyperplasia, brachytherapy was examined in a pilot study including 25 patients [15]. For ultrasound-guided PTA, there is currently only an insufficient number of studies of insufficient dialysis vascular access [70,71].…”

“…To prevent recurrent stenoses, the use of drug-coated balloons is increasingly being reported [12,13]. There are currently no randomized studies or even larger case series showing a superior long-term patency rate for endovascular brachytherapy [14,15] and cryoplasty [16]. In addition to thrombolysis via medication, thrombosed AV fistulas and vascular access grafts can be treated in a combined pharmacomechanical manner or purely mechanically with thrombectomy catheters [17] or hydrodynamic systems [18].…”

Current Management of Vascular Access

“…How can the benefit of angioplasty be enhanced? A pilot study suggested that vascular brachytherapy increases the primary patency of grafts after angioplasty (83). Two retrospective studies suggested that stents, by creating a rigid scaffold for the vessel, prolong graft patency after thrombectomy and angioplasty (84,85).…”

Novel Therapies for Hemodialysis Vascular Access Dysfunction

“…At 1 year, the stenosis rate in the brachytherapy group was 56% compared with 37% in the control group (60). A multicenter clinical trial (Beta Radiation for Treatment of Arterial-Venous Graft Outflow) recruited 25 patients with a single stenosis at the vein-graft anastomosis of AVG for randomization to either radiation (18.4 Gy) after PTA or sham intervention after PTA alone (61). At 6 months, target lesion primary patency was significantly improved in the brachytherapy group (41.6% versus 0%; PTA alone); but 1-year thrombosis and patency rates were the same.…”