Factors affecting arteriovenous fistula dysfunction: A narrative review

Abstract

Vascular access dysfunction is one of the most important causes of morbidity and mortality in haemodialysis patients, contributing to up to one third of hospitalisations and accounting for a significant amount of the health care costs of these patients. In the past decades, significant scientific advances in understanding mechanisms of arteriovenous fistula maturation and failure have contributed to an increase in the amount of research into techniques for creation and strategies for arteriovenous fistula dysfunction prevention and treatment, in order to improve patient care and outcomes. The aim of this review is to describe the pathogenesis of vascular access failure and provide a comprehensive analysis of the associated risk factors and causes of vascular access failure, in order to interpret possible future therapeutic approaches. Arteriovenous fistula failure is a multifactorial process resulting from the combination of upstream and downstream events with consequent venous neo-intimal hyperplasia and/or inadequate outward remodelling. Inflammation appears to be central in the biology of arteriovenous fistula dysfunction but important triggers still need to be revealed. Given the significant association of arteriovenous fistula failure and patient’s prognosis, it is therefore imperative to further research in this area in order to improve prevention, surveillance and treatment, and ultimately patient care and outcomes.

Arteriovenous access in hemodialysis: A multidisciplinary perspective for future solutions

“…The incidence of non-maturation of an AVF varies between 20% and 60%, 12,[22][23][24] mostly leading to further surgical or catheter interventions in order to attain a VA that enables HD. The main difficulties can be caused by either too low flow or clotting that develops predominantly upon stenosis due to neointimal proliferation.…”

“…23 Vascular dysfunction may arise within the feeding artery and is considered to be related to factors such as age, diabetes mellitus, hypertensive diseases, uremia, tobacco use, and inflammation. 12,23,25 Anastomosis-related problems are considered mainly to be due to surgical measures and once established to wall shear stress and turbulence. 12 Some reports attribute those problems to the angle of the fistula toward the artery, 12 but this hypothesis was not confirmed by others.…”

“…The patient can increase its lower-arm blood flow by repeatedly manually compressing an elastic ball. 4 Besides the possible protective benefits by angiotensin-converting enzyme (ACE)-inhibitors, heparin, and antiplatelet drugs, 12 the illumination using far infrared light supports vascular flow [44][45][46] and helps to increase the vascular diameter. 44,45 Despite all such measures as well as repeated interventions, the venous system may get insufficient as an AVF.…”

“…54,55 As far as blood properties, the underlying diseases, uremic toxic substances, and repeated dialyses lead to an acute inflammation added on to a chronic inflammatory condition. 12 This leads to the activation of immune cells and activation of the coagulation and complement system. These factors contribute to the morbidity of the patients.…”

“…10 Since patient demography can be expected to be similar within the country, this indicates that the reasons for those marked differences depends not only on the conditions of the vessels but also on the preference of the local physician's prescription of type of access and the skills of the local surgeons to place AVF and AVG. 11,12 Puncture techniques may interfere with AV patency. By changing the position of the punctures each time, a "rope ladder" technique is used.…”