One needle instead of two: new dialysis trick could save veins and money

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Adult patients (age ≥ 18 years). Diagnosis of end-stage kidney disease (ESKD) requiring maintenance hemodialysis (three times per week). Reliable use of a native arteriovenous fistula (AVF) as the primary vascular access for at least the past 3 months. Willing and able to provide written informed consent to participate in the study. Adequate superficial venous vasculature in at least one lower extremity (e.g., dorsal foot veins, saphenous tributaries) as assessed by clinical evaluation and/or bedside ultrasound, deemed suitable for cannulation as a venous return site. For the experimental (SNDR) group: Expressed willingness to adopt the single-needle distal return cannulation strategy. For the control group: Currently receiving and willing to continue standard two-needle AVF cannulation. Exclusion Criteria: * Active systemic infection or localized infection at the potential cannulation sites (AVF or lower extremity veins). Known severe coagulation disorder or thrombocytopenia (platelet count \< 50 × 10⁹/L) that would pose a high risk of bleeding complications from cannulation. Severe peripheral arterial disease or venous insufficiency in the lower extremities that contraindicates venous cannulation or may compromise limb perfusion. Unstable cardiovascular status (e.g., uncontrolled heart failure, severe arrhythmias) as determined by the treating nephrologist, which would increase the risk associated with any change in dialysis procedure. Documented severe cognitive impairment, psychiatric illness, or any condition that would impair the ability to provide informed consent or adhere to the study protocol. Life expectancy less than 12 months due to non-renal comorbid conditions (e.g., metastatic malignancy). Currently pregnant or breastfeeding. Participation in another interventional clinical trial that could confound the outcomes of this study. Anatomical or pathological condition of the AVF (e.g., extreme depth, aneurysm with overlying skin compromise, complete thrombosis) that precludes safe single-needle cannulation, as judged by the study vascular access team. Inability to comply with the scheduled study visits and follow-up assessments.