No consensus on physicians' preferences on vascular access management after kidney transplantation: Results of a multi-national survey.

OBJECTIVE:: Arteriovenous fistulas for hemodialysis vascular access are a burden for the cardiovascular system. After successful kidney transplantation, prophylactic arteriovenous fistula ligation may improve cardiac outcomes; however, evidence is scarce. This survey investigates physicians' preference for management of arteriovenous fistulas and identifies the factors associated with preference for either arteriovenous fistula ligation or maintenance. MATERIALS AND METHODS:: A survey was sent to members of eight national and international Nephrology and Vascular Surgery societies. The survey comprised eight case vignettes of asymptomatic patients with a functioning arteriovenous fistula after kidney transplantation. Characteristics possibly associated with treatment preferences were arteriovenous fistula flow, left ventricular ejection fraction, and patient age. Respondents were asked to state preference to maintain or ligate the arteriovenous fistula. Linear mixed-effects models were used to investigate the association of treatment preference with case characteristics. RESULTS:: A total of 585 surveys were returned. A reduced left ventricular ejection fraction of 30% (beta 0.60, 95% confidence interval 0.55; 0.65) and a high flow of 2500 mL/min (beta 0.46, 95% confidence interval 0.41; 0.51) were associated with a higher preference for arteriovenous fistula ligation. Disagreement among respondents was considerable, as in four out of eight cases less than 70% of respondents agreed on the arteriovenous fistula management strategy. CONCLUSION:: Although respondents recognize a reduced left ventricular ejection fraction and a high flow as the risk factors, the high disagreement on management preferences suggests that evidence is inconclusive to recommend arteriovenous fistula ligation or maintenance after kidney transplantation. More research is needed to determine optimal arteriovenous fistula management after successful kidney transplantation.

Supervised preoperative forearm exercise to increase blood vessel diameter in patients requiring an arteriovenous access for hemodialysis: rationale and design of the PINCH trial.

BACKGROUND: Failure of maturation occurs in 30%-60% of arteriovenous fistula (AVF) creation for hemodialysis, with highest rates in distal radiocephalic fistulas. This is partly due to initial small blood vessel size with limited blood flow capacity. Forearm exercise has shown potential as stimulus for increasing blood vessel size in patients with end-stage renal disease (ESRD) and may promote maturation of AVFs in the upper limb when applied postoperatively. However, it is unknown if forearm exercise increases blood vessel size pre-operatively, which may contribute to more distal AVF creation and raise success rates of AVF surgery. This study will investigate these issues. METHODS AND RESULTS: The PINCH trial (refers to 'pinching') is an investigator-initiated, multicenter, single-blinded, randomized controlled trial with 1:1 randomization to perform supervised forearm exercises compared to no exercise 6 weeks pre-operatively before creation of an AVF. Forty patients receiving an AVF will be included. The main study endpoints are blood vessel diameter (cephalic or basilic vein and radial and ulnar artery), AVF surgical plan (radiocephalic or brachiobasilic/cephalic), and three-month (assisted) maturation rate. The burden of the performed forearm exercises will be evaluated using Kidney Disease Quality of Life (KDQOL-SF Dutch version 1.2) and exercise specific questionnaires. The PINCH trial is planned to start in November 2017. Enrollment is expected to be completed at the end of 2019. CONCLUSIONS: The PINCH study is the first trial to evaluate the effect of pre-operative, supervised forearm exercises on vein diameter and fistula maturation in hemodialysis patients. TRIAL REGISTRATION: NTR6382.