End-stage vascular access failure: can we define and can we classify?

Renal replacement therapy using dialysis has evolved dramatically over recent years with an improvement in patient survival. With this increased longevity, a cohort of patients are in the precarious position of having exhausted the standard routes of vascular access. The extent of this problem of failed access or 'desperate measures' access is difficult to determine, as there are no uniform definitions or classification allowing standardization and few studies have been performed. The aim of this study is to propose a classification of end-stage vascular access (VA) failure and subsequently test its applicability in a dialysis population.

Using anatomical stratification, a simple hierarchical classification is proposed. This has been applied to a large dialysis population and in particular to patients referred to the complex access clinic dedicated to patients identified as having exhausted standard VA options and also those dialysing on permanent central venous catheters (CVC).

A simple classification is proposed based on a progressive anatomical grading of (I) standard upper arm options exhausted, (II) femoral options exhausted and (III) other options exhausted. These are further subdivided anatomically to allow ease of classification. When applied to a complex group of patients (n = 145) referred to a dedicated complex access clinic, 21 patients were Class I, 26 Class II and 2 Class III. Ninety-six patients did not fall into the classification despite being referred as permanent CVC.

The numbers of patients who have exhausted definitive access options will continue to increase. This simple classification allows the scope of the problem and proposed solutions to be identified. Furthermore, these solutions can be studied and treatments compared in a standardized fashion. The classification may also be applied if patients have the option of transplantation where iliac vessel preservation is desirable and prioritization policies may be instituted.