Whether and when to refer patients for predialysis AV fistula creation: complex decision making in the face of uncertainty.

Patients who initiate chronic dialysis with a functional arteriovenous (AV) fistula survive longer and experience fewer complications after initiation of dialysis than those who require a catheter. However, more than 80% of patients in this country begin chronic dialysis with a catheter rather than a fistula, either because they do not have a permanent access or their permanent access is not ready for use. Increasing rates of predialysis AV fistula placement is thus considered a priority area for predialysis care in this country. However, achievement of a functional AV fistula by the time of dialysis initiation is not always an easy proposition. We here outline the limitations of currently recommended approaches toward timing of AV fistula placement. We also highlight the potential complexity of patient and clinician decision making in this area. Particularly in the presence of advanced age and a high burden of comorbidity and disability, it is often uncertain whether patients will need, want, or benefit from chronic dialysis. Adding to this uncertainty, it is often not known whether, when, and after how many revisions an AV fistula will be sufficiently mature to support dialysis. We argue that it is important to acknowledge the complexity of medical decision making in this area and the limitations of currently available prognostic tools to guide such decision making. We conclude that initiation of dialysis with a catheter is appropriate for patients in whom the perceived harms of preemptive fistula placement outweigh the expected benefit.