Dialysis access intervention: Techniques for the interventional cardiologist

Abstract

Interventional cardiologists who treat malfunctioning hemodialysis accesses play an important role in the life of patients with end-stage kidney disease (ESKD). By collaborating with interventional nephrologists who currently perform the bulk of routine access angiographic procedures, interventional cardiologists can fill an important gap in the care of ESKD patients by performing urgent or emergent procedures that fall outside the schedule of an outpatient interventional nephrology laboratory to ensure that hemodialysis patients will not miss a hemodialysis session or get a temporary catheter. This paper reviews the pathophysiology of dialysis access failure and illustrates the catheter-based approaches used by interventional cardiologists to treat malfunctioning dialysis accesses.

Introduction

Approximately 2 in every 1000 persons in the US have end-stage kidney disease (ESKD), and > 80% of these individuals undergo hemodialysis.¹ Functioning arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) are the lifeline for patients with ESKD. An AVF is surgically created when an artery is directly anastomosed with autogenous vein (Fig. 1).² An AVG is created when a segment of a prosthetic material like PTFE (polytetrafluoroethylene) connects a native artery with a vein (Fig. 1).

Hemodialysis AVFs and AVGs have limited patency. AVFs generally have longer patencies than AVGs but are not feasible for every patient. Accordingly, the “Fistula First” policy of 2006³ has been supplanted by a patient-centered approach that creates an individualized life plan that allows changes in access in response to changing circumstances.⁴ Common modes of failure for hemodialysis AVFs and AVGs are the early appearance of a stenosis at the inflow arteriovenous anastomosis or the late development of an outflow stenosis in the venous limb. When hemodialysis accesses develop a severe stenosis and slow flow, stasis may lead to thrombosis. In non-thrombosed or thrombosed AVFs and AVGs, catheter-based treatments can promptly restore the usability of the access and have the added advantage over surgical revision of saving venous conduit for future accesses.

Although most AV access interventions are performed in outpatient laboratories by interventional nephrologists, some procedures require the urgent scheduling familiar to interventional cardiologists who treat patients with unstable angina or acute myocardial infarction. Many interventional cardiology groups have more than 20-years' experience performing AV access procedures on demand 7 days a week and have maintained a collegial relationship with interventional nephrologists and clinical nephrologists, who provide all the medical care for ESKD patients and much of the critical care for cardiac patients with or without chronic kidney disease (CKD).