Endovascular Proximal Forearm Arteriovenous Fistula for Hemodialysis Access: Results of the Prospective, Multicenter Novel Endovascular Access Trial (NEAT).

BACKGROUND: Hemodialysis arteriovenous fistulas (AVFs) are suboptimally used primarily due to problems with maturation, early thrombosis, and patient nonacceptance. An endovascular approach to fistula creation without open surgery offers another hemodialysis vascular access option. STUDY DESIGN: Prospective, single-arm, multicenter study (Novel Endovascular Access Trial [NEAT]). SETTINGS & PARTICIPANTS: Consecutive adult non-dialysis-dependent and dialysis-dependent patients referred for vascular access creation at 9 centers in Canada, Australia, and New Zealand. INTERVENTION: Using catheter-based endovascular technology and radiofrequency energy, an anastomosis was created between target vessels, resulting in an endovascular AVF (endoAVF). OUTCOMES: Safety, efficacy, functional usability, and patency end points. MEASUREMENTS: Safety as percentage of device-related serious adverse events; efficacy as percentage of endoAVFs physiologically suitable (brachial artery flow ≥ 500mL/min, vein diameter ≥ 4mm) for dialysis within 3 months; functional usability of endoAVFs to provide prescribed dialysis via 2-needle cannulation; primary and cumulative endoAVF patencies per standardized definitions. RESULTS: 80 patients were enrolled (20 roll-in and 60 participants in the full analysis set; the latter are reported). EndoAVFs were created in 98% of participants; 8% had a serious procedure-related adverse event (2% device related). 87% were physiologically suitable for dialysis (eg, mean brachial artery flow, 918mL/min; endoAVF vein diameter, 5.2mm [cephalic vein]). EndoAVF functional usability was 64% in participants who received dialysis. 12-month primary and cumulative patencies were 69% and 84%, respectively. LIMITATIONS: Due to the unique anatomy and vessels used to create endoAVFs, this was a single-arm study without a surgical comparator. CONCLUSIONS: An endoAVF can be reliably created using a radiofrequency magnetic catheter-based system, without open surgery and with minimal complications. The endoAVF can be successfully used for hemodialysis and demonstrated high 12-month cumulative patencies. It may be a viable alternative option for achieving AVFs for hemodialysis patients in need of vascular access.

Major Outcomes With Personalized Dialysate TEMPerature (MyTEMP): Rationale and Design of a Pragmatic, Registry-Based, Cluster Randomized Controlled Trial.

BACKGROUND: Small randomized trials demonstrated that a lower compared with higher dialysate temperature reduced the average drop in intradialytic blood pressure. Some observational studies demonstrated that a lower compared with higher dialysate temperature was associated with a lower risk of all-cause mortality and cardiovascular mortality. There is now the need for a large randomized trial that compares the effect of a low vs high dialysate temperature on major cardiovascular outcomes. OBJECTIVE: The purpose of this study is to test the effect of outpatient hemodialysis centers randomized to (1) a personalized temperature-reduced dialysate protocol or (2) a standard-temperature dialysate protocol for 4 years on cardiovascular-related death and hospitalizations. DESIGN: The design of the study is a pragmatic, registry-based, open-label, cluster randomized controlled trial. SETTING: Hemodialysis centers in Ontario, Canada, were randomized on February 1, 2017, for a trial start date of April 3, 2017, and end date of March 31, 2021. PARTICIPANTS: In total, 84 hemodialysis centers will care for approximately 15 500 patients and provide over 4 million dialysis sessions over a 4-year follow-up. INTERVENTION: Hemodialysis centers were randomized (1:1) to provide (1) a personalized temperature-reduced dialysate protocol or (2) a standard-temperature dialysate protocol of 36.5°C. For the personalized protocol, nurses set the dialysate temperature between 0.5°C and 0.9°C below the patient's predialysis body temperature for each dialysis session, to a minimum dialysate temperature of 35.5°C. PRIMARY OUTCOME: A composite of cardiovascular-related death or major cardiovascular-related hospitalization (a hospital admission with myocardial infarction, congestive heart failure, or ischemic stroke) captured in Ontario health care administrative databases. PLANNED PRIMARY ANALYSIS: The primary analysis will follow an intent-to-treat approach. The hazard ratio of time-to-first event will be estimated from a Cox model. Within-center correlation will be considered using a robust sandwich estimator. Observation time will be censored on the trial end date or when patients die from a noncardiovascular event. TRIAL REGISTRATION: www.clinicaltrials.gov; identifier: NCT02628366.

CONTEXTE: De petits essais à répartition aléatoire ont montré que l'utilisation d'un dialysat à basse température réduisait le risque d'hypotension intra-dialytique. De même, certaines études observationnelles ont démontré qu'un dialysat à basse température était associé à un plus faible risque de mortalité toute cause ou d'origine cardiovasculaire. Le temps est venu de procéder à un vaste essai à répartition aléatoire comparant les effets d'un dialysat à basse température et à température standard sur les principaux résultats cardiovasculaires. OBJECTIF: Répartir aléatoirement des centres d'hémodialyse ambulatoire pour qu'ils suivent pendant quatre ans (i) un protocole personnalisé de dialysat à basse température ou (ii) un protocole de dialysat à température standard, et tester l'effet sur les hospitalisations et la mortalité attribuables à des événements cardiovasculaires. TYPE D'ÉTUDE: Un essai clinique à répartition aléatoire en grappes. CADRE: Le 1er février 2017, des centres d'hémodialyse de l'Ontario (Canada) ont été répartis aléatoirement en vue d'un essai qui a débuté le 3 avril 2017 et qui se poursuivra jusqu'au 31 mars 2021. PARTICIPANTS: Quatre-vingt-quatre centres d'hémodialyse qui prendront en charge environ 15 500 patients pendant les quatre ans de suivi. INTERVENTION: Les centres d'hémodialyse ont été répartis aléatoirement (1:1) pour offrir (i) un protocole personnalisé de dialysat à température réduite ou (ii) un protocole de dialysat à 36,5°C. Pour le protocole personnalisé, les infirmières règlent la température du dialysat entre 0,5 et 0,9°C sous la température corporelle du patient mesurée avant la dialyse, jusqu'à une température minimale de 35,5°C. PRINCIPAUX RÉSULTATS: Un ensemble d'hospitalisations attribuables à un événement cardiovasculaire majeur (accident ischémique cérébral non fatal, infarctus du myocarde ou insuffisance cardiaque congestive) et de décès d'origine cardiovasculaire consignés dans les bases de données de santé de l'Ontario. PRINCIPALE ANALYSE ENVISAGÉE: L'analyse primaire adoptera une approche fondée sur l'intention de traiter. Un modèle de Cox servira à estimer le rapport de risque du temps écoulé jusqu'au premier événement. La corrélation intra-centre sera prise en compte à l'aide d'un estimateur sandwich robuste. Le temps d'observation sera censuré à la date de fin de l'essai ou au moment d'un décès non lié à un événement cardiovasculaire.