Table 1. Baseline characteristics of patients undergoing arteriovenous fistula angioplasty...

Table 2. Type of fistula and stenosis location

Table 3. Procedural results and follow-up (n=70).

Table 4. Follow-up..

Image 1. Diagnostic fistulography. Severe juxta-anastomotic stenosis.

Image 2. Angioplasty using a coronary system.

Image 3. Angioplasty with 4.0 and 5.0 balloons.

Image 4. Final result.

Introduction

The incidence of patients with chronic kidney disease (CKD) requiring renal replacement therapy by means of hemodialysis has increased over recent decades, due to population aging, improved survival of these patients, and the high prevalence of cardiovascular risk factors. Arteriovenous fistulae (AVF) are the vascular access of choice for hemodialysis, and their proper functioning is essential for patient quality of life and survival. The process ranges from the creation and preservation of vascular access to the treatment of its complications, and it poses a challenge for decision-making because of the complexity of the underlying pathology and the diverse specialties involved (nephrology, vascular surgery, nursing, hemodynamics). 

AVF dysfunction is a frequent complication that requires timely diagnosis and treatment. Percutaneous angioplasty is the first-line treatment in these cases. Its success depends on multiple technical and clinical factors, and its long-term effectiveness varies across different series. The aim of this study was to analyze in-hospital outcomes, providing local data on procedural effectiveness and safety. During follow-up, the study also sought to observe long-term evolution, the need for new procedures, the type of reinterventions required, and prognostic factors in patients with CKD and AVF dysfunction undergoing angioplasty.

Materials and methods

This was an observational, retrospective, single-center study. Enrollment included all patients (n=70) who consecutively underwent AVF angioplasty between January 2013 and March 2024 at the Department of Hemodynamics and Interventional Cardiology of Clínica San Jorge, Ushuaia. Exclusion criteria only featured reinterventions on the same fistula, as they were considered events during follow-up.

Defining fistula dysfunction required the use of clinical and hemodynamic criteria, including decreased pulse, inability to cannulate, venous pressures >200 mmHg, flow < 200 mL/min, recirculation >15%, and unexplained reduction in dialysis adequacy.

Stenotic areas were divided into 3 groups: arterial stenoses, which include vascular lesions located in the arterial tree supplying the vascular access; arteriovenous anastomotic or juxta-anastomotic stenoses, located in an area extending from the anastomosis to 5 cm post-anastomosis, and, finally, venous stenoses. This last group was subdivided into puncture tract stenosis, cephalic vein arch stenosis, and central vein stenosis.

All patients were assessed with diagnostic fistulography. Access for this was obtained by puncturing with an 18–20 Abbocath the hemodialysis puncture area; if the patient had no pulse, the afferent artery was punctured. In cases of ad hoc angioplasty, if the stenosis was located in the juxta-anastomotic zone, roadmapping-guided retrograde puncture was the alternative of choice. Conversely, if it was located in the puncture tract, cephalic vein arch, or central vein, the Abbocath was exchanged for a 6-Fr introducer.

Significant stenosis was defined as any stenosis >50% assessed by angiography. In this center, systematic pre- and post-procedural Doppler ultrasound is not used, although its usefulness is acknowledged.

A successful procedure was defined as angiographic resolution of the stenosis, with residual stenosis of less than 30% of the reference segment, restoration of flow, and absence of immediate complications.

Follow-up was performed through medical records and by telephone for up to 36 months. Events assessed included repeat angioplasty, thrombectomy, creation of a new AVF, and death. Statistical analysis was conducted using automated natural language processing tools.

Results

During the study period, 70 AVF angioplasties were performed. Mean patient age was 59±11 years, and 68% of subjects were men. There was a high prevalence of hypertension (87%) and diabetes (68%) (Table 1). Regarding the type of fistula, 39 were brachiocephalic, 21 brachiobasilic, and 10 radiocephalic. The most frequent obstruction types were venous stenoses (51%), mainly in the puncture tract, followed by juxta-anastomotic stenoses (30%) (Table 2).

Procedural success was 86%. There were no complications during the intervention. All patients had been previously assessed with diagnostic fistulography. In over 80% of cases, the angioplasty was performed ad hoc. Deferred angioplasties were mainly due to central vein stenosis or arteriovenous anastomosis.

Stent use was limited to 8.5% of cases (6 patients), 5 of whom had central vein stenosis, while 1 had stenosis along a prosthesis (Table 3). In the remaining patients, semi-compliant balloons without drug elution were used. Drug-coated balloons and cutting balloons were not employed. Successive dilations were performed, increasing balloon diameter until reaching a 1:1 ratio in relation to the non-diseased segment. For juxta-anastomotic lesions, the balloons used were between 2.5 and 5 mm, and for venous stenoses, between 4.0 and 12 mm. Depending on the tightness of the lesion, angioplasty was initiated with a 0.014" coronary system and then exchanged for a 0.035" wire, or it was initiated directly with a 0.035" system.

As an example, we present the clinical case of a 65-year-old man with hypertension, diabetes, and a history of smoking. He had dialysis-dependent CKD with a brachiocephalic fistula created 16 months earlier. The Department of Nephrology reported that he presented with a severe reduction in pulse and thrill, so he was referred for urgent fistulography. Puncture was performed at the level of the humeral artery with an 18 Abbocath. Diagnostic fistulography showed significant juxta-anastomotic stenosis (Image 1). A decision was made to conduct an ad hoc fistula angioplasty. An antegrade, roadmapping-guided venous puncture was performed, and a 6-Fr introducer was placed, initially using a 0.014" PT2 wire. The stenotic segment was successfully crossed, and successive dilations were conducted with 2.0 × 30 mm and 2.5 × 30 mm balloons up to 16 atm (Image 2). The wire was then exchanged for a 0.035" wire, and dilations were performed with 4.0 × 40 mm and 5.0 × 40 mm balloons up to 16 atm (Image 3). Control projections showed improved flow with mild residual stenosis (Image 4). The patient tolerated the procedure well; the introducer was removed, an X stitch was placed at the site, and a semi-compressive dressing was applied. After achieving this result, the procedure was concluded. The study was performed on an outpatient basis, with follow-up at 24 hours at the Department of Nephrology and suture removal at 7 days.

During follow-up (achieved in 96% of patients), 55% of subjects required a new intervention: 16 repeat angioplasties, 8 thrombectomies, and 13 new fistulae. Only one patient died (Table 4). In subgroup analysis, dysfunction within the first year was associated with a greater need for reintervention (86% vs. 32.5%, p < 0.00001; odds ratio [OR]: 13.5; 95% confidence interval [95% CI]: 3.9-47.0). Another comparison showed that all patients with a failed procedure required a new fistula, compared with 10% of those who had a successful angioplasty.

Discussion

The outcomes of this study confirm that AVF angioplasty is a safe and effective procedure, with a high initial technical success rate (86%) and no intraprocedural complications. These findings are consistent with previous series that describe good immediate results of percutaneous angioplasty in vascular access for hemodialysis3-5, 8.

The high rate of reinterventions (55% during follow-up) reflects the progressive nature of vascular disease in this population and is also consistent with the literature, which reports frequent need for new angioplasty or complementary procedures to maintain access functionality2-3, 7-8.

Such data underscore that angioplasty, while effective, should be understood as part of a dynamic access maintenance strategy rather than a definitive solution.

The finding that early dysfunction (< 1 year) was associated with a higher risk of new intervention (OR: 13.5) allows for the identification of a high-risk subgroup that could benefit from closer surveillance protocols, including systematic clinical assessment, functional monitoring of access, and eventually a more widespread use of Doppler ultrasound, in line with guideline recommendations1, 6, 9. Additionally, the fact that procedural failure is almost always linked to a need for a new fistula supports the importance of optimizing the technique from the first attempt, preferably in centers with experience and multidisciplinary teams, as suggested by previous studies regarding the effectiveness and safety of procedures performed by specialized teams4, 7-8. While pharmacological balloons and specific devices were not routinely used in this series, their role in prolonging the patency of certain stenotic segments is subject of research and could be considered in selected scenarios according to emerging evidence and future recommendations3, 7-8.

Finally, these outcomes uphold the need for comprehensive vascular access planning even from pre-dialysis stages, as proposed by the KDOQI guidelines and Spanish guidelines, with the aim of reducing catheter dependence, prolonging the lifespan of AVF, and improving the quality of dialysis therapy1, 6, 9.

The results of this study are consistent with international literature, showing that AVF angioplasty is a safe procedure, with a high technical success rate and low risk of immediate complications. The high prevalence of reintervention reflects the complexity of patient monitoring in this setting and the natural progression of vascular disease. The finding that early dysfunction is associated with a higher risk of reintervention allows for the identification of a higher-risk population that could benefit from stricter follow-up. Early nephrology consultation in the pre-dialysis stage is essential, as it allows for the planning of renal replacement therapy, avoiding catheters in central veins, and providing sufficient maturation time for AVFs.

Furthermore, initial technical success seems to have a strong impact on the need for a new fistula, which supports the importance of an effective interventional strategy from the start. The absence of routine Doppler may have limited the early detection of subclinical restenosis.

Conclusions

Angioplasty of hemodialysis fistulae proved to be a safe and effective procedure, with a high success rate and low incidence of complications. However, over half of the patients required new interventions during follow-up. Early dysfunction and initial procedure failure were markers of reintervention. Achieving a successful initial outcome can significantly reduce the need for a new fistula.

1. Ibeas J, Roca-Tey R, Vallespín J, et al. Guía Clínica Española del Acceso Vascular para Hemodiálisis. Nefrología. 2017;37:1-191.

2. Quarchioni EM, Riccobelli N, Gluz DI, Birollo O, Licheri A. Complicaciones estenóticas de fístulas arteriovenosas y su resolución mediante angioplastia percutánea. Revista Argentina de Cardioangiología Intervencionista. 2023;1:18-22.

3. Bountouris I, Kritikou G, Degermetzoglou N, Avgerinos KI. A Review of Percutaneous Transluminal Angioplasty in Hemodialysis Fistula. International Journal of Vascular Medicine. 2018;2018:1420136.

4. Beathard GA, Litchfield T. Effectiveness and safety of dialysis vascular access procedures performed by interventional nephrologists. Kidney International. 2004;66(4):1622-32.

5. Trerotola SO, Stavropoulos SW, Mondschein JI, et al. Hemodialysis graft patency: effect of percutaneous balloon angioplasty on long-term access survival. Radiology. 2004;232(2):489-96.

6. KDOQI Clinical Practice Guidelines and Clinical Practice Recommendations for Vascular Access. American Journal of Kidney Diseases. 2006;48(Suppl 1):S176-47.

7. Lok CE, Rajan DK. Prevention and management of hemodialysis access thrombosis. Clinical Journal of the American Society of Nephrology. 2006;1(4):888-98.

8. Vesely TM. Endovascular management of the failing hemodialysis access. Techniques in Vascular and Interventional Radiology. 2004;7(1):2-7.

Para descargar el PDF del artículo
In-hospital outcomes and follow-up of patients undergoing angioplasty in hemodialysis fistulas

Haga click aquí