The incidence of hemodynamically relevant dialysis fistula stenoses/obstructions after 1 year is between 60-90% (from 62.5 to 91% radiocephalic, brachiocephalic 70-84%, PTFE shunts 62-87%), necessitating a therapeutic measure to preserve dialysis access during this period in 1/3 of the patients. This therapeutic measure is a dilatation of the stenosis using a standard PTA balloon (POBA, plain old balloon angioplasty with a primary technical success rate of 50-79% [2-4].In turn, in 21-50% of the cases an insufficient PTA result is obtained (so-called POBA-resistant stenosis). In these cases, predilatation with a so-called cutting balloon (carrying with small knives on its surface) is performed, leading to a success rate of 89%. However, a problem is the high incidence of restenosis, which is about 40% for recurrent stenosis and over 10% in de novo stenosis.

The use of drug-coated balloon (DCB) in non-POBA resistant stenoses lead to a reduction in the restenosis rate of 35% to 5%. However, the effect of DCB in POBA resistant stenoses is unknown.

Therefore, the aim of this study is to evaluate the clinical benefit of the combined use of a cutting balloon and a drug-coated balloon in POBA resistant dialysis fistula stenoses compared to the sole use of a cutting balloon.

Inclusion Criteria:

• dialysis fistula dysfunction requiring cutting balloon angioplasty

Exclusion Criteria:

• missing informed consent or unable to consent
• age < 18 years
• pregnancy