Choosing the right treatment for the right lesion, part I: a narrative review of the role of plain balloon angioplasty in dialysis access maintenance

Abstract

Background and objective: The majority of patients with end-stage renal disease (ESRD) requiring hemodialysis (HD) do so via an arteriovenous fistula (AVF) or graft. Both of these accesses are complicated by dysfunction related to neointimal hyperplasia (NIH) and subsequent stenosis. Percutaneous balloon angioplasty using plain balloons is the first line treatment for clinically-significant stenosis, with excellent initial response rates, however, with poor long-term patency and need for frequent reintervention. Recent research has sought to improve patency rates utilizing antiproliferative drug-coated balloons (DCBs), however, their role in treatment has not yet been fully determined. In part one of this two-part review, we aim to provide a comprehensive overview of the mechanisms of arteriovenous (AV) access stenosis, the evidence behind their treatment with high-quality plain balloon angioplasty techniques, and treatment considerations for specific stenotic lesions.

Methods: An electronic search was performed on PubMed and EMBASE to identify relevant articles from 1980 to 2022. The highest available level of evidence regarding stenosis pathophysiology, angioplasty techniques, and approaches to treating different types of lesions within fistulas and grafts were included as part of this narrative review.

Key content and findings: NIH, and subsequent stenoses, develop via a combination of upstream events, causing vascular damage, and downstream events, representing the subsequent biologic response. The large majority of stenotic lesions can be treated utilizing high-pressure balloon angioplasty, with the addition of ultra-high pressure balloon (UHPB) angioplasty for resistant lesions and prolonged angioplasty with progressive balloon upsizing for elastic lesions. Additional treatment considerations must be taken into account when treating specific lesions, including cephalic arch and swing point stenoses in fistulas and graft-vein anastomotic stenoses in grafts, amongst others.

Conclusions: High-quality plain balloon angioplasty, performed utilizing the available evidence-basis regarding technique and considerations for specific lesion locations, is successful in treating the large majority of AV access stenoses. While initially successful, patency rates remain non-durable. Part two of this review will discuss the evolving role of DCBs, which seek to improve angioplasty outcomes.

Keywords: Hemodialysis (HD); angioplasty; fistula; graft; stenosis.

Figure 1

Upstream and downstream events leading to arteriovenous access stenosis. Upstream events include (I) baseline vascular dysfunction related to CKD and uremia, (II) surgical trauma at the time of AV access creation, (III) hemodynamic changes including shear stress, compliance mismatch, and nonlaminar flow at within the access, particularly at anastomoses, (IV) vessel/graft injury from repeat needle cannulation during dialysis, and (V) bioincompatability of graft material in. Upstream events occur at various time points, affect different locations within the access to different degrees, and differ slightly for AVFs and AVGs. The resulting downstream events, occurring in response to the aforementioned insults, include migration of various cells into the subintimal vessel layer, including vascular smooth muscle cells from the media, and, as recent research has suggested, fibroblasts and myofibroblasts from the adventitia. The subsequent cellular proliferation and extracellular matrix deposition within the subintima is termed NIH and results in progressive narrowing of the vessel lumen, leading to stenosis (28-32). VSMCs, vascular smooth muscles cells; ECM, extracellular matric; CKD, chronic kidney disease; AV, arteriovenous; AVFs, arteriovenous fistulas; AVGs, arteriovenous grafts; NIH, neointimal hyperplasia.

Figure 2

Distribution and approximate frequency of stenotic lesions in different access configurations. The most common stenotic lesions are highlighted (green) with a representative image example: juxta-anastomotic stenosis in radiocephalic fistulae, CAS in brachiocephalic fistulae, swing point stenosis in transposed brachiobasilic fistulae, and graft-vein anastomotic stenosis in grafts. The frequency of different lesions are rough approximations determined from a conglomerate of sources, meant to provide an estimation of the relative occurrence of these lesions. The reader is referred to the source data in the cited articles for specific numerical data (8,10,12-15,19,34-48). CAS, cephalic arch stenosis.

Figure 3

Clinical indicators of AV access dysfunction are identified on physical exam and during dialysis session. Each clinical indicator is associated with stenotic lesions in particular location within the access. Potential lesion locations for each clinical indicator are colored in, with red = inflow, yellow = intra-access, blue = outflow, and purple = central veins. Treatment is indicated when a stenosis is identified and a matching clinical indicator is present. ^†, greater than 500 mL per minute and/or a 25% decrease from baseline flow; ^‡, low Kt/V is usually due to an inflow stenosis. AV, arteriovenous.

Figure 4

Algorithm for routine arteriovenous access stenosis. This algorithm provides a general decision tree that one can use to approach most stenotic lesions. There are a number of lesions for which evidence supports a more tailored approach, such as earlier use of stent-grafts in graft-native vein anastomotic lesions, and these lesion-specific considerations must be taken into account when applying the above algorithm. Multidisciplinary discussion refers to the patient’s HD treatment team including nephrologists, interventionalists, and surgeons, at which time an access plan for the patient can be discussed. PTA, percutaneous transluminal angioplasty; HD, hemodialysis.