Hemodialysis Fistula Maturation (HFM)

General Description

In patients undergoing hemodialysis for end-stage renal disease, a large number of fistulas fail to mature adequately to support the hemodialysis blood circuit and cannot be used for dialysis. Currently, hemodialysis access using fistulas is hindered by a lack of predictors of and therapies for arteriovenous fistula (AVF) failure. The Hemodialysis Fistula Maturation Study was a prospective, multicenter observational study that was established by the Hemodialysis Fistula Maturation Consortium (HFMC) to identify the clinical and biological factors associated with AVF maturation outcomes. The primary objectives of the study included improving prediction of AVF maturation and exploring the mechanism of AVF failure by examining the relationship between clinical usability and anatomy, biology, clinical attributes, and processes of care.

The study enrolled patients nearing or with end-stage renal disease who are undergoing AVF creation for hemodialysis. Data were collected pre-operatively, peri-operatively, and post-operatively. Medical history, demographics, and physical examination information were collected prior to surgery at baseline. Participants undergone preoperative ultrasound arterial and venous mapping, flow-mediated and nitroglycerin-mediated brachial artery dilation, arterial pulse wave velocity, and venous distensibility; additionally, ultrasounds will be administered at 1 day, 2 weeks, 6 weeks, and prior to fistula intervention and initial cannulation. Information were collected peri-operatively on surgical personnel, surgical procedures, and clinical observations. Outcome data on AVF usability and other dialysis-related data were collected post-operatively. In addition to these measurements, tissue and blood specimens were collected for analyses of histology, morphometry, immunohistochemistry, and gene expression.

Objectives

The primary objective of the study is to identify predictors and underlying mechanisms of AVF clinical maturation by examining the relationship between AVF usability and vascular anatomy, vascular biology, clinical patient-specific attributes, and processes of healthcare.

Outcome Measure

The primary outcome measure is unassisted clinical maturation, defined as successful use of the fistula for dialysis for 4 weeks without maturation-enhancing procedures. Secondary outcome measures include assisted clinical maturation, ultrasound-based anatomical maturation, fistula procedures, fistula abandonment, and central venous catheter use. Clinical, anatomical, biological, and process-of-care factors were correlated with the characterization of subsequent AVF function.

Criteria

Individuals who met the following criteria were eligible for the study:

• Planned single-stage surgery creation of an autogenous upper-extremity AVF by a surgeon participating in HFM
• Currently on chronic dialysis, or expected to be started on chronic dialysis within 3 months of planned AVF creation surgery
• Age < 80 if not yet on chronic hemodialysis; otherwise no upper age limit
• Age allowing legal consent without parent involvement
• Life expectancy ≥ 9 months

Exclusion criteria are documented in the study protocol.

Outcome

This study was completed (end of participant follow-up) in May 2014. As of December 2014, analyses are ongoing. A total of 602 participants were enrolled.