Reporting Standards for Percutaneous Interventions in Dialysis Access

Results of Stenting for Central Venous Occlusions and Stenoses in the Hemodialysis Patients

Objectives: We aim to investigate the results of stenting for central venous occlusions and stenoses in the hemodialysis patients.

Methods: Twenty-nine cases treated with endovascular recanalization with deployment of bare metal stent (BMS) for central venous occlusions (24 cases) and recurrent stenoses (5 cases) between 2014 and 2018 were retrospectively analyzed. Results of these procedures including success rate, operative time, estimated blood loss, morbidity, primary patency, assisted primary patency and freedom from target-lesion revascularization (TLR) were evaluated.

Results: Nine lesions were in brachiocephalic vein (Occlusion/Stenosis: 8/1) and 20 lesions were in subclavian vein (Occlusion/Stenosis: 16/4). Procedural success was 94% (29/31 cases) and operation time/estimated blood loss was 68±39 min/28±54 g. Symptom were relieved or disappeared in all successful cases. Morbidity (extravasation of contrast medium) was 3% (1/29). During the period of observation, 1 stent fracture with occlusion and 1 stent migration to periphery were recognized. 1-year primary patency, freedom from TLR, and assisted primary patency were 40% (median patent time: 256 days), 67% (median patent time: 524 days), and 77%, respectively.

Conclusion: Stenting for central venous occlusions and stenoses in the hemodialysis patients is safe and durable treatment option. However, considering its off-label use and potential hazard including vessel rupture, stent migration, and stent fracture, the indication for BMS deployment should be conservative, and interventionist should be well acquainted with prevention and measures to these complications. (This is a translation of Jpn J Vasc Surg 2019; 28: 193–198.)

Retrospective Analysis of 77 Hemodialysis Patients Shows No Cases of Steal Syndrome from Graft Taper Reduction

PURPOSE

To review the immediate flow response and incidence of steal syndrome after taper reduction of tapered dialysis grafts.

MATERIAL AND METHODS

This was a retrospective review of a quality assurance database of all hemodialysis access interventions performed between 2005 and 2017. It identified 77 patients who underwent a taper reduction procedure, involving angioplasty of the arterial limb of the graft and the arterial anastomosis for graft thrombosis/poor flow. A subset of patients underwent 5-, 6-, or 7-mm balloon taper reduction angioplasty coupled with intravascular direct flow measurement (n = 15 with 16 dialysis grafts). A two-tailed Wilcoxon matched-pairs signed-rank test was used to compare pre- and post-taper reduction flows. Mean duration of follow-up was 3.5 years (range, 0-12.5 years).

RESULTS

Mean access survival after taper reduction was 20.2 months (range, 0.10-94.4 months). Pre- and post-taper reduction access flows (mean Qb ± standard deviation) were 574 ± 315 ml/min and 929 ± 352 ml/min, respectively (P < .0001). The mean ratio of post- to pre-taper reduction flows was 1.6 (range, 1.1-10.2). No patients developed steal syndrome within 6 months after taper reduction.

CONCLUSIONS

Dialysis graft arterial anastomotic taper reduction did not result in the development of steal syndrome within 6 months. In the subset of patients who underwent flow measurements, taper reduction was associated with nearly a 2-fold improvement in access flow, which is a key predictor of access function.

Cost Analysis of Dialysis Access Maintenance Interventions across Physician Specialties in U.S. Medicare Beneficiaries

Background Dialysis maintenance interventions account for billions of dollars in U.S. Medicare spending and are performed by multiple medical specialties. Whether Medicare costs differ by physician specialty is, to the knowledge of the authors, not known. Purpose To assess patency-adjusted costs of endovascular dialysis access maintenance by physician specialty. Materials and Methods In this retrospective longitudinal cohort study, patients who were beneficiaries of Medicare undergoing their first arteriovenous access placement in 2009 were identified by using billing codes in the 5% Limited Data Set. By tracking their utilization data through 2014, postintervention primary patency and aggregate payments associated with maintenance interventions were calculated. Unadjusted payments per year of access patency gain were compared across physician specialty. A general linear mixed-effects model adjusted for covariates was used, as follows: patient characteristics, access type (fistula vs graft), clinical severity, type of intervention (angioplasty, stent, thrombolysis), clinical location (hospital outpatient vs office-based laboratory), and resource utilization (operating room use, anesthesia use). Results First arteriovenous access was performed in 1479 beneficiaries (mean age, 63 years ± 15 [standard deviation]; 820 men) in 2009. Through 2014, 8166 maintenance interventions were performed in this cohort. Unadjusted mean Medicare payments for each incremental year of patency were as follows: $71 000 for radiologists, $89 000 for nephrologists, and $174 000 for surgeons. Billing for operating room (41.8% [792 of 1895], surgery; 10.2% [277 of 2709], nephrology; and 31.1% [1108 of 3562], radiology) and anesthesia (19.9% [377 of 1895], surgery; 2.6% [70 of 2709], nephrology; 4.7% [170 of 3562], radiology) varied by specialty and accounted for 407% and 132% higher payments, respectively. After adjusting for clinical severity and location, type of intervention, and resource utilization, nephrologists and surgeons had 59% (95% confidence interval: 44%, 73%; P < .001) and 57% (95% confidence interval: 43%, 72%; P < .001) higher payments, respectively, for the same patency gain compared with radiologists. Operating room use and anesthesia services were major drivers of higher cost, with 407% (95% confidence interval: 374%, 443%; P < .001) and 132% (95% confidence interval: 116%, 150%; P < .001) higher costs, respectively. Conclusion Patency-adjusted payments for hemodialysis access maintenance differed by physician specialty, driven partly by discrepant rates of billing for operating room and anesthesia use. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by White in this issue.

Factors affecting patency of arteriovenous fistula following first percutaneous transluminal angioplasty

BACKGROUND

Percutaneous transluminal angioplasty (PTA) has generally replaced surgical procedures to treat arteriovenous fistula (AVF) dysfunction, but the predictors of post-intervention patency are highly variable. This study aimed to determine predictors of primary patency following PTA of dysfunctional AVF.

MATERIALS AND METHODS

Retrospective analysis of first-time PTA of 307 AVF in 307 patients (171 males, mean age 64.3 ± 12.4 years). Demographic, clinical, anatomical and medication variables were reviewed and subjected to univariate and multivariate Cox regression analysis.

RESULTS

The post-intervention primary patency rates at 6, 12, 24, and 36 months were 76.3%, 58.3%, 43.2%, and 38.2%, respectively. The higher aortic arch calcification (AAC) grade patients were older, had higher incidence of comorbidities and cardiomegaly, and younger AVF age, but their dialysis vintage term was shorter and diastolic blood pressure was lower, and the maximum diameter of balloon angioplasty was mostly ≤ 6 mm, and had lower phosphorus level and less calcium-containing phosphate binder use. In multivariate Cox proportional hazard analysis, the presence of higher AAC grade [hazard ratio (95% confidence interval): (1.46 (1.02-2.09); p = 0.037)] and stenosis at upper arm [1.76 (1.16-2.67); p = 0.008] were associated with shorter post-intervention primary patency.

CONCLUSION

In conclusion, higher AAC grade and anatomic factor related to the location of AVF (upper arm) were the important predictors of AVF dysfunction after PTA. These results could assist in tailoring surveillance programs and performing appropriate interventions for risky AVF.

Paclitaxel-Coated Balloon versus Plain Balloon Angioplasty for Dysfunctional Autogenous Radiocephalic Arteriovenous Fistulas: A Prospective Randomized Controlled Trial

Objective

To report the mid-term results of a single-center randomized controlled trial comparing drug-coated balloon angioplasty (DBA) and plain balloon angioplasty (PBA) for the treatment of dysfunctional radiocephalic arteriovenous fistulas (RCAVFs).

Materials and Methods

In this prospective study, 39 patients (mean age, 62.2 years; 21 males, 18 females) with RCAVFs failing due to juxta-anastomotic stenosis were randomly assigned to undergo either both DBA and PBA (n = 20, DBA group) or PBA alone (n = 19, PBA group) between June 2016 and June 2018. Primary endpoints were technical and clinical success and target lesion primary patency (TLPP); secondary outcomes were target lesion secondary patency (TLSP) and complication rates. Statistical analysis was performed using the Kaplan-Meier product limit estimator.

Results

Demographic data and baseline clinical characteristics were comparable between the groups. Technical and clinical success rates were 100% in both groups. There was no significant difference between the groups in the mean duration of TLPP (DBA group: 26.7 ± 3.6 months; PBA group: 27.0 ± 3.8 months; p = 0.902) and TLSP (DBA group: 37.3 ± 2.6 months; PBA group: 40.4 ± 1.5 months; p = 0.585). No procedural or post-procedural complications were identified.

Conclusion

Paclitaxel-coated balloon use did not significantly improve TLPP or TLSP in the treatment of juxta-anastomotic stenosis of dysfunctional RCAVFs.

Undersized stent graft for treatment of cephalic arch stenosis in arteriovenous hemodialysis access

Cephalic arch stenosis (CAS) is a common cause of AV dialysis access failure and is notoriously difficult to treat with conventional venoplasty. Although stent graft (SG) placement has improved patency rate, they are prone to stent failure caused by edge stenosis. We investigate the effect of SG diameter relative to cephalic vein on patency rate among hemodialysis patients with dysfunctional arteriovenous access caused by CAS. We identified 22 patients with recalcitrant cephalic arch stenosis or post-venoplasty vessel rupture and received SG placement. Patients were divided into two groups based on the stent-to-vessel diameter (S/V) ratio: undersized group, < 1; and apposed group, 1–1.2. Outcomes were assessed through follow-up angiography. S/V ratio was significant smaller in the undersized patient group (p < 0.001). Placement of undersized SG demonstrated higher primary stent (p = 0.001) and access patency rates (p = 0.021) and a reduced number of post-treatment reinterventions per access year (p = 0.021). A decreased number of lateral edge stenosis was noted in undersized SG (p = 0.005). Increased S/V ratio was significantly associated with lateral edge stenosis (OR = 5.19; p = 0.027). Undersized SG is associated with higher primary stent and access patency rate, and decreased number of post-SG interventions, and are suggested in the treatment of cephalic arch stenosis.

Study protocol of a pilot study on sirolimus-coated balloon angioplasty in salvaging clotted arteriovenous graft

Background

In arteriovenous graft (AVG) for haemodialysis, the primary cause of failure is venous stenosis of the graft-vein junction from neointimal hyperplasia (NIH), resulting in thrombosis. While interventions to salvage clotted AVG are known to have high clinical success rates, long-term patency rates have been suboptimal. Drug-coated balloon (DCB) has been used to treat stenosed arteriovenous access in recent years with encouraging results but data on its effect in clotted AVG is unavailable.

Methods

This is an investigator-initiated, single-center, single-arm prospective pilot study to determine the safety and outcome of the sirolimus-coated balloon (SCB) in the salvage of thrombosed AVG. Twenty patients who undergo successful percutaneous thrombectomy will receive treatment with SCB at the graft vein junction. The patients will be followed-up for 6-months. The primary endpoint is the patency rates at 3-month while the secondary endpoints are the patency rates and the number of interventions needed to maintain patency at 6-month.

Discussion

Unremitting efforts have been made to prolong the patency of AV accesses over the years. DCB angioplasty combines mechanical and biological treatment for vascular stenosis. Sirolimus, being a cystostatic anti-proliferative agent, has been successfully used in coronary artery interventions. As the primary pathology of vascular stenosis in the dialysis circuit is neointimal hyperplasia, the use of sirolimus in balloon angioplasty may be effective. With this prospective study, we evaluate the efficacy and safety of SCB in patients with clotted AVG.

Trial registration

ClinicalTrials.gov Identifier: NCT03666208 on 11 September 2018.

Promising results of stent graft placement for cephalic arch stenosis after repeated failure of angioplasty in patients on hemodialysis

Objective

Cephalic arch stenosis (CAS) causes repeated dysfunction and failure of arteriovenous access. Percutaneous transluminal angioplasty is the standard initial treatment for CAS, but its outcome is unsatisfactory. This study aimed to evaluate the outcome of stent graft placement for CAS in patients on hemodialysis.

Methods

A retrospective chart review from a tertiary medical center was performed in patients receiving stent graft placement for CAS between January 2012 and 2016. Patency was analyzed using the Kaplan–Meier method.

Results

Twenty-one patients received stent graft placement for CAS. Technical and clinical success rates were 100%. Primary target lesion patency was 95% (95% confidence interval [CI], 86%–100%), 76% (95% CI, 58%–94%), and 43% (95% CI, 22%–64%) at 3, 6, and 12 months, respectively. No significant difference in patency was observed between the arteriovenous fistula and arteriovenous graft groups. Assisted primary patency was 95% (95% CI, 86%–100%), 71% (95% CI, 52%–91%), and 57% (95% CI, 36%–78%) at 3, 6, and 12 months, respectively. Secondary patency was 100% at 3, 6, and 12 months.

Conclusions

After repeated failed angioplasty for cephalic arch stenosis, patients on hemodialysis who receive stent graft placement have effective and durable outcomes.

Diagnosis and Treatment of Nonmaturing Fistulae for Hemodialysis Access via Transradial Approach: A Case-Control Study

PURPOSE

To compare outcomes of transradial access for endovascular treatment of nonmaturing hemodialysis fistulae compared to brachial arteriography followed by unidirectional or bidirectional fistula access for intervention.

MATERIALS AND METHODS

In this institutional review board-approved, retrospective, case-control study, 56 consecutive patients with nonmaturing arteriovenous fistulae underwent percutaneous intervention between 2015 and 2018. The transradial group (n = 28) underwent radial artery access for diagnostic fistulography and intervention. The control group (n = 28) underwent retrograde brachial artery access for fistulography followed by unidirectional/bidirectional fistula access for intervention. Both groups had similar demographics, fistula characteristics, and stenosis locations.

RESULTS

Fewer punctures were required in the transradial group compared to controls (1.2 vs 2.4, P < .0001), and procedure time was shorter (64.9 vs 91.3 minutes, P = .0016). Anatomic, technical, and clinical success rates trended higher in the transradial group compared to controls (93% vs 86%, 96% vs 89%, and 82% vs 64%, respectively). Nonmaturation resulting in fistula abandonment was lower in the transradial group (3.7% vs 25%, P = .025). Primary unassisted patency at 3, 6, and 12 months was 77.1% ± 8.2%, 73.1% ± 8.7%, and 53.3% ± 10.6% in the transradial group, respectively, and 63.0% ± 9.3%, 55.6% ± 9.6%, and 48.1% ± 9.6% in the control group, respectively (P = .76). Primary assisted patency at 12 months was 92.3% ± 5.3% in the transradial group compared to 61.8% ± 9.6% at 12 months in the control group (P = .021). No major complications occurred. Minor complications were lower in the transradial group than in the control group (14% vs 39%, P = .068).

CONCLUSIONS

Treatment of nonmaturing fistulae via a transradial approach was safe, improved midterm patency, and was associated with lower rates of fistula abandonment.

Outcome of Central Vein Occlusion Recanalization in Hemodialysis Patients and Predictors for Success: A Retrospective Study

Background:

Catheter-directed treatment is the standard approach for the management of chronic central venous occlusion.

Purpose:

The objective of this study is to report the outcome of conventional recanalization of chronic central vein occlusion in hemodialysis patients and to determine the predictors for success.

Material and Methods:

All hemodialysis patients who underwent endovascular recanalization of central vein occlusion from January 2012 to December 2016 were retrospectively evaluated. The procedure was percutaneous transluminal angioplasty. Stenting was performed in case of a significant recoil stenosis. Kaplan-Meier analysis was used to evaluate central vein patency. Univariate analysis and multivariate logistic regression were used to calculate the predictive factors.

Results:

Ninety-seven patients (mean age, 61.2 years; range, 25‒89 years old) with 97 central vein occlusions were enrolled. Technical success was achieved in 49 patients (50.5%). The primary patency rates of central veins at 6 and 12 months were achieved in 17 patients (34.4%) and 8 patients (15.8%), respectively. The assisted primary patency rates at 6 and 12 months were achieved in 38 patients (77.3%) and 30 patients (61%), respectively. Patient age ≥60 years and a tapered-type of lesion were significant predictive factors for successful recanalization.

Conclusion:

Endovascular treatment of the central vein occlusion using a conventional technique is moderately effective and safe. Angioplasty alone and stenting were not significantly different in terms of patency rate. The age of the patients and type of occlusion were significant predictors for successful recanalization.

Nitinol stent-assisted maturation of the dysfunctional cannulation zone in the immature arteriovenous fistula

INTRODUCTION

The native arteriovenous fistula may remain immature despite adequate arterial inflow after formation. This may occur when the puncturable vein segment (cannulation zone) is too small to be reliably punctured, occluded or too deep under the skin for needle access. We performed stenting (stent-assisted maturation) of arteriovenous fistulas with an immature cannulation zone, allowing for a large subcutaneous channel which could then be immediately punctured for dialysis.

METHODS

We performed a retrospective review of 49 patients (mean age was 58.7 ± 16.09 (12-83) years, mean arteriovenous fistula age of 162.6 ± 27.28 days) with end-stage renal failure who underwent balloon dilatation and bare-metal stent implantation (1.6 ± 0.67 (1-3) stents, median diameter and length of 8 (5-14) mm and 80 (40-150) mm, respectively) through their cannulation zone (forced maturation). Radiocephalic (35 arteriovenous fistulas), brachiocephalic (10 arteriovenous fistulas) and autogenous loop arteriovenous fistulas (4 arteriovenous fistulas) were included with 30 patients (61.2%) having an inadequate cannulation zone venous diameter, 9 patients (18.4%) having an absent cannulation zone and 10 patients (20.4%) having a patent cannulation zone deeper than 1 cm which was not reliably puncturable. The study was conducted over 9 years (January 2008-December 2016) with implantation of the SMART^® stent and Absolute Pro^® stent in 61.2% and 38.8%, respectively. Long-term outcomes including primary useable segmental and access circuit patency as well as assisted primary access circuit patency, rate of re-intervention, technical success and complications were analysed.

RESULTS

At 6 months, 12 months and 4 years, respectively, cannulation zone primary patency was 84.4%, 74.4% and 56.1% and access circuit primary patency was 62.2%, 45.3% and 23.2%; however, assisted primary access circuit patency was 95.6%, 91.1% and 83.8%, achieved with an endovascular re-intervention rate of 0.53 procedures/year with only four thrombosed circuits occurring.

DISCUSSION

Forced maturation using nitinol stents allows for long-term haemodialysis access with a low rate of re-intervention.

Outcomes after endovascular mechanical thrombectomy in occluded vascular access used for dialysis purposes

Purpose

Endovascular mechanical thrombectomy using the AngioJet™ system can be considered to reestablish patency in occluded vascular access. The aim of this study was to review our results for endovascular mechanical thrombectomy using the AngioJet™ system in patients with arteriovenous fistulae (AVF) and arteriovenous grafts (AVG).

Methods

Data collected in a database of patients requiring hemodialysis for renal failure were analyzed. Patients who underwent endovascular mechanical thrombectomy procedures with the AngioJet™ system for occlusion of vascular access were included. Clinical and technical success rates and patency rates were calculated. Multivariate analysis was used to identify factors of influence.

Results

A total of 92 AngioJet™ procedures in 60 patients with thrombosed vascular access were reviewed during a mean follow‐up period of 21.5 months in patients with an AVF and 11.9 months in patients with an AVG. Technical and clinical success was achieved in 92.6% of AVF cases and 92.0 and 90.8% of AVG cases with an AVG, respectively. Significantly higher primary and primary‐assisted patency rates were observed in the AVF group. Multivariate regression analysis indicated that left‐sided vascular access and female sex were independent predictors for failure regarding primary patency in AVG patients. Immunosuppressive drugs and older age were negative predictors for secondary patency in AVG patients.

Conclusions

The AngioJet™ system can be deemed an effective technique to reestablish patency in occluded vascular access with minimal use of central venous catheters for dialysis. Good technical and clinical success rates were achieved with acceptable patency rates, especially in AVF patients.

Factors influencing outcomes of rheolytic thrombectomy on thrombosed dialysis access grafts: Door to angiographic bed time and what else?

BACKGROUND

The aim of this study was to investigate the effect of the time interval from clinical presentation of arteriovenous graft thrombosis and the thrombectomy procedure by the AngioJet system in terms of technical and clinical success and to identify factors influencing success.

METHODS

A total of 60 consecutive patients (35 men and 25 women; mean age = 52 ± 7.89 years) who had undergone percutaneous thrombectomy by the AngioJet device from 2016 to 2019 were retrospectively enrolled. Demographics and fistula data, previous treatments, time from clinical onset of thrombosis to intervention, procedural details and complications were recorded. Technical and clinical success and primary and secondary patency rates were calculated. One-way analysis of variance was performed to test any correlation between patient-related and fistula/procedure-related variables and technical/clinical success. Odds ratio and relative risk were also calculated when necessary.

RESULTS

Technical success and clinical success were 95% and 91.7%, respectively. Post-interventional primary and secondary patency rates at 1 year were 72.5% and 84.3%, respectively. Complication rate was 6.7%. One-way analysis of variance showed that clinical success was higher in patients with no previous treatment (p = 0.015). Furthermore, clinical success was significantly associated with door to angiographic bed time (p = 0.002): p-value for the 24-h and the 72-h cut-off was 0.012 and 0.006, respectively.

CONCLUSION

Percutaneous rheolytic thrombectomy is safe and effective for thrombosed arteriovenous grafts, with acceptable primary and secondary patency rates. Higher clinical success was found in patients never treated before and when the procedure was carried out within 24 h from the clinical onset of thrombosis.

Arteriovenous Access Graft Infection: Standards of Reporting and Implications for Comparative Data Analysis

There is presently a lack of organization and standardized reporting schema for arteriovenous graft (AVG) infections. The purpose of this article is to evaluate the various types of treatment modalities for access site infections through an analysis of current publications on AVG. Key proposals are made to support standardization in a data-driven manner to make infection reporting more uniform and thereby facilitate more meaningful comparisons between various dialysis modalities and AVG technologies.

Outcomes of endovascular salvage of clotted arteriovenous access and predictors of patency after thrombectomy

OBJECTIVE

This study aimed to report the outcomes of endovascular salvage of clotted arteriovenous (AV) accesses and to determine potential predictors of poor patency rates after thrombectomy.

METHODS

Records of hemodialysis patients who underwent endovascular salvage of clotted AV access were reviewed retrospectively. Technical and clinical success rates, complication rates, and 3- and 6-month patency rates were determined. Multivariate analysis was performed to determine the predictors of patency after thrombectomy.

RESULTS

A total of 294 patients underwent endovascular salvage of clotted AV access during the study period; 156 patients had arteriovenous fistula, whereas the remaining 138 were arteriovenous grafts (AVGs). The technical and clinical success rates were 96.3% and 93.2%; the major and minor complication rates were 0.7% and 9.9%. Post-thrombectomy primary, assisted primary, and secondary patency rates were 62.9%, 76.2%, and 77.6% at 3 months and 43.9%, 59.5%, and 61.6% at 6 months. The patency rates were significantly better for arteriovenous fistula than for AVG except for 6-month assisted primary and secondary patency. Multivariate Cox regression analysis showed that prior thrombosis within 90 days was significantly associated with loss of primary patency (hazard ratio [HR], 1.90; 95% confidence interval [CI], 1.21-2.98; P < .01), assisted primary patency (HR, 2.42; 95% CI, 1.42-4.13; P < .01), and secondary patency (HR, 2.52; 95% CI, 1.40-4.53; P < .01). Having an AVG was also negatively associated with primary patency.

CONCLUSIONS

Most clotted AV accesses can be salvaged by endovascular technique. Recurrent thrombosis within 90 days is associated with poor short- and long-term patency even after successful endovascular reinterventions.

Pull-through technique combined with percutaneous angioplasty for treating high-grade arteriovenous fistula stenosis

PURPOSE

The aim of this study was to investigate the effectiveness of a new pull-through technique through a brachial artery approach combined with angioplasty for the treatment of arteriovenous fistula.

METHODS

In this retrospective study, a total of 56 arteriovenous fistula patients with high-grade stenosis induced by arteriovenous fistula, which was divided into pull-through technique through a brachial artery approach (pull-through group, n = 28) and solely through a venous approach (control group, n = 28), were analyzed. Both groups underwent percutaneous transluminal angioplasty treatments simultaneously.

RESULTS

The success rate of the pull-through group (89.3%, 25 out of 28) was similar to that of the control group (75.0%, 21 out of 28, p = 0.296). Fistula restenosis occurred with time in both groups but no significant differences in the post-operative fistula patency were found between the pull-through and control groups in follow-ups at 3, 6, and 12 months (71.4% vs 67.9%, 57.1% vs 60.7%, and 20.0% vs 30.0%, respectively, p > 0.05). No significant difference in the post-operative patency rate in patients with diabetes, hypertension, or coronary disease was found between the pull-through and control groups in the follow-ups at 3 and 12 months, respectively. The pull-through group had significantly shorter operation times compared with the control group (45 ± 9 min vs 65 ± 15 min, p < 0.001). No surgical complications were reported in the pull-through group in contrast to three cases (11%, 3 out of 28) with puncture hematoma and acute occlusion in the control group.

CONCLUSION

The pull-through technique combined with percutaneous transluminal angioplasty is an effective, safe and lasting option to treat high-grade arteriovenous fistula stenosis in the upper limb.

Temporal distribution and biological determinants of thrombotic events after interventions for dialysis vascular access

Endovascular therapy is the principal therapy for haemodialysis vascular access dysfunction. Nonetheless, the incidence and determinants of post-intervention thrombotic events are unclear. This prospective cohort study evaluated the incidence and timing of thrombotic events after endovascular therapy and analysed the clinical, angiographic, and biological determinants of thrombosis. Of the 236 patients enrolled, 91 experienced post-intervention thrombotic events within 1 year. The 1-year thrombosis-free patency was 28% for thrombosed accesses, 53% for non-thrombosed grafts, and 78% for non-thrombosed fistulas. Forty-one of the 91 thrombotic events (45%) occurred within 3 months post-intervention. In the univariate analysis, early thrombosis was associated with longer haemodialysis duration (hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.01–1.02), graft access (HR, 7.69; 95% CI, 3.33–20.0), multiple stenoses (HR, 2.69; 95% CI, 1.36–5.37), and high indoxyl sulphate (IS) levels (HR, 1.55; 95% CI, 1.32–1.82). Late thrombosis was associated with diabetes (HR, 1.89; 95% CI, 1.01–3.57), cardiovascular disease (HR, 2.38; 95% CI, 1.27–4.54), and endothelial progenitor cell counts (HR, 0.97; 95% CI, 0.93–0.99). After multivariate adjustment, high IS was the major predisposing factor for early post-intervention thrombosis (HR, 1.41; 95% CI, 1.18–1.69). Our findings suggest that measures to decrease IS could target the most critical period of thrombosis.

Thrombosed native hemodialysis fistulas: Technical and clinical outcomes of endovascular recanalization and factors influencing patency

Purpose:

To evaluate the technical and clinical results of endovascular recanalization of thrombosed native hemodialysis fistula and the factors influencing patency.

Methods:

A retrospective study was conducted with 73 patients who had thrombosed arteriovenous fistulas and were treated with endovascular methods. Patient characteristics, arteriovenous fistula-related characteristics, and endovascular procedures were analyzed. Technical and clinical results and patency rates were evaluated. The factors influencing patency were analyzed using a univariate and multivariate Cox proportional hazards model.

Results:

Technical and clinical success rates were 93% (68/73) and 85% (62/73), respectively. At 3, 6, and 12 months, the primary patency rates were 87.9%, 73.3%, and 64.8%; assisted primary patency rates were 89.2%, 78.6%, and 70.7%; and secondary patency rates were 90.8%, 87.2%, and 83.1%, respectively. Previous intervention and cephalic arch stenosis were risk factors for lower primary and assisted primary patency ( p < 0.05 for all). Cephalic arch stenosis was the only risk factor for lower secondary patency ( p < 0.05). No major complications associated with the procedures were noticed.

Conclusion:

Endovascular treatment was effective for the immediate recanalization of thrombosed arteriovenous fistula. In addition, previous intervention and cephalic arch stenosis were significantly related to lower arteriovenous fistula patency.

Hybrid salvage of thrombosed dialysis access grafts

BACKGROUND

To report our experience and evaluate the results of a hybrid procedure comprising of surgical thrombectomy and adjuvant high pressure balloon angioplasty for management of thrombosed arteriovenous grafts (AVGs) with underlying venous anastomotic stenosis.

METHODS

Between January 2015 and June 2017, 148 patients with first-time thrombosis of AVGs were considered for treatment with surgical thrombectomy followed by high pressure balloon angioplasty of the underlying venous anastomotic lesions. Monitoring and surveillance was subsequently performed using clinical and hemodialysis criteria to detect a failing/failed access. Primary, assisted primary, and secondary patency rates were calculated using Kaplan-Meier analysis.

RESULTS

This hybrid procedure was technically successful in 135 cases (91.2%) and clinically successful in 131 cases (88.5%). The postintervention primary patency rate of the target lesions was 68.2%, 52.4%, and 44.2% at 3, 6, and 12 months, respectively. Endovascular re-interventions increased significantly the postintervention assisted primary patency to 79.1%, 71.9%, and 66.8% (P=0.0004), and the postintervention secondary patency to 86.5%, 82.2%, and 78.6% (P<0.0001) at the same time points, respectively.

CONCLUSIONS

Hybrid salvage of thrombosed AVGs using high pressure balloon angioplasty of the venous anastomotic stenosis following surgical thrombectomy by Fogarty catheter is a highly successful and safe procedure, with acceptable short-term primary patency. The need for repeated interventions demonstrates the necessity of continuous graft monitoring and surveillance to improve both assisted primary, and secondary patency rates.

Clinical Evaluation of the Cook Advance Enforcer 35 Focal-Force PTA Balloon Catheter for Treatment of Hemodialysis Fistula Stenoses: A Feasibility Study

PURPOSE

A prospective, single-center, single-arm feasibility study evaluated procedural and short-term performance of the Advance Enforcer 35 focal-force percutaneous transluminal angioplasty (PTA) balloon catheter in treating stenoses of mature native arteriovenous (AV) hemodialysis access circuits.

MATERIALS AND METHODS

Twenty-eight patients undergoing treatment for stenosis of a mature native AV hemodialysis access circuit were enrolled at a single institution. Angiographic assessments of the study lesion were required at baseline and after the procedure. Adjunctive procedures for significant residual stenosis were permitted, and patients had clinical and imaging follow-up for as long as 6 months.

RESULTS

Treatment with the study balloon was effective in reducing the average percent diameter stenosis of the treated lesion from 66.3% (range, 43.8%-93.3%) before the procedure to 23.7% (range, -6.7% to 51.4%) after the procedure. The average inflation pressure required was 12.3 atm. Only 1 patient required an adjunctive procedure, and all patients could resume normal dialysis following the study procedure. At 3 months, 62.0% of study lesions remained patent, and the 6-month patency rate was 25.1%. Two adverse events associated with the study procedure were reported: access-site hematoma and forearm pain (3.6% each).

CONCLUSIONS

The results demonstrate safety of the study balloon in treating AV access stenosis. Nominal-diameter angioplasty was achieved at relatively low pressure in most study patients without the use of adjunctive procedures, and resumption of normal dialysis was achieved for all patients.

Ultrasound-guided Angioplasty of Arteriovenous Fistulas for Hemodialysis: Benefits and Limitations

BACKGROUND

Ultrasound-guided percutaneous angioplasty of arteriovenous fistulas (AVFs) makes it possible to avoid contrast agents and X-rays, to optimize the puncture site and to locate some stenoses on the fistulography, but is it really useful? Our objective is to report the results of our experience.

METHODS

Between November 2012 and November 2017, all the patients treated according to this method in our center were collected retrospectively. The surgical indications were an insufficient maturation of the AVF, an increase in the venous pressure, an inadequate outflow, difficulties in puncture, a prolonged bleeding time, a flow drop, or an aneurysmal evolution.

RESULTS

During this period, 50 patients had 72 ultrasound-guided angioplasties, 64 on native AVFs (88.9%) and 8 on prosthetic AVFs (11.1%). The technical success rate was 100%. The average preoperative flow of AVFs was 506.8 ± 302.2 vs. 955.9 ± 371.4 mL/min after angioplasty. The mean duration of follow-up was 13.4 ± 12.9 months. The cumulative rates of primary, assisted primary, and secondary patency were 43.5%, 68.8%, 81.5% at 1 year and 31.7%, 63.9%, 76.8% at 2 years, respectively.

CONCLUSIONS

AVF angioplasty under ultrasound guidance only is feasible, effective, and represents an interesting alternative. A controlled study comparing ultrasound guidance with angioplasties performed under conventional angiographic guidance as the reference technique would better clarify the value of this technique.

Mid-term Results of a Novel Dedicated Venous Stent for the Treatment of Chronic Thoracic Central Vein Obstruction of Benign Aetiology

OBJECTIVES

Endovascular treatment is indicated for the treatment of symptomatic thoracic central vein obstruction (TCVO) but is limited by high rates of restenosis and the need for re-intervention. The aim was to assess the safety and mid-term patency of a novel dedicated venous stent for the treatment of TCVO of benign aetiology.

METHODS

This was a prospective single centre observational study of 20 patients (median age 65 years, 50% male) referred for the treatment of symptomatic chronic (>three months duration) TCVO between May 2016 and January 2018. Balloon angioplasty with implantation of a self expanding nitinol stent (Vici, Boston Scientific, Marlborough, MA, USA) was performed in all patients. Clinical records including demographics, aetiologies and types of TCVO, and procedural details were recorded. Patients were followed up clinically at one, six, and 12 months. Primary and assisted primary patency were reported.

RESULTS

All 20 lesions were total occlusions, of which 55% (n = 11) were de novo, 10% (n = 2) peri-stent restenosis, and 35% (n = 7) in-stent re-occlusion. The aetiology of TCVO was predominantly (95%) because of multiple or prolonged central venous line insertion. The procedural success rate was 90% (18/20) with no procedural complications. The median follow up was 13.5 months. Primary patency was 100% at 6 months. One patient required re-intervention for stent in segment restenosis at 7 months. The assisted primary patency rate was 100% at 12 months.

CONCLUSION

Endovascular treatment of benign TCVO with the novel dedicated venous stent was safe and effective in relieving obstructive symptoms with excellent one year patency rates.

Patency rates of dysfunctional central hemodialysis venous catheter: Comparison between catheter exchange alone and catheter exchange with fibrin sheath angioplasty

PURPOSE

The purpose of this study was to compare patency rates and risk of obstruction of catheter exchange (CE) with that of CE with fibrin sheath angioplasty (CE+FSA) in dysfunctional tunneled central hemodialysis venous catheter (CHVC).

MATERIALS AND METHODS

A total of 107 consecutive patients with dysfunctional CHVC were retrospectively included. There were 66 men and 41 women with a mean age of 67.8±12.5 (SD) years (range: 23.0-86.0 years). Seventy-three of 107 patients (68.2%) underwent CE procedure and 34 of 107 (31.8%) underwent CE+FSA. Kaplan-Meier log-rank test and multivariate Cox regression analyses were performed to determine patency rates and risk of obstruction according to type of endovascular procedure.

RESULTS

Patency rates after endovascular procedures at 3, 6, 12, 24 and 36 months follow up were 75%, 75%, 65%, 65% and 65% in CE+FSA group and 70%, 65%, 62%, 30% and 0% in CE group. Mean time until obstruction of CHVC was 778.4 days after CE+FSA and 497 days after CE (P=0.211). Endovascular procedure was unrelated to risk of obstruction in adjusted model (HR=1.34; P=0.515).

CONCLUSIONS

Our findings suggest that both techniques are equivalent in terms of patency and safety results, so other aspects as cost assessment should be considered when choosing between both techniques.

A pilot study on adjunctive use of parametric colour-coded digital subtraction angiography in endovascular interventions of haemodialysis access

Background

Two-dimensional digital subtraction angiography (DSA) is the gold standard for angiographic evaluation of dysfunctional haemodialysis access. We aim to investigate the utility of parametric colour coded DSA in providing hemodynamic analysis during haemodialysis access interventions.

Methods

We retrospectively studied 20 patients who underwent access intervention and applied parametric colour-coding on selected DSA acquisitions before and after percutaneous transluminal angioplasty (PTA). The difference in time to peak (dTTP) contrast enhancement and time attenuation curve (TAC) of pre- and post-stenotic regions of interest (ROIs) were obtained and compared after treatment.

Results

Improvements were seen in mean percent of stenosis after PTA (p < 0.0001) for all cases. Median dTTP improved from 0.52 (IQR 0.26, 0.8) to 0.25 (IQR 0, 0.26) seconds (p = 0.001). Median 50% contrast washout time improved from 0.77 (IQR 0.39, 1.17) to 0.42 (IQR 0.23, 0.59) seconds (p = 0.031). Significant correlation was seen for dTTP vs. percent of stenosis (r = 0.723, p = 0.043) pre-PTA and for change in dTTP vs. percent change in stenosis post-PTA (r = 0.786, p = 0.021) for inflow lesions. Such correlation was however not seen in outflow lesions.

Conclusions

Adjunctive use of parametric colour-coded DSA may provide potentially useful hemodynamic information during vascular access interventions. Larger prospective studies are needed to validate our findings.

Pilot study using intraoperative fluorescence angiography during arteriovenous hemodialysis access surgery

INTRODUCTION:

In this pilot study, we used indocyanine green fluorescence angiography during hemodialysis access surgery. The aim was to evaluate its relevance as a diagnostic tool to visualize changes in hand microperfusion.

PATIENTS AND METHODS:

In this prospective single-center study, 47 adult patients (33 male, 14 female) with renal disease (24 preemptive, 23 endstage) were enrolled. Surgical creation of an arteriovenous fistula was performed (22 forearm, 25 upper arm). Microperfusion of the ipsilateral hand and fingers was evaluated intraoperatively using indocyanine green fluorescence angiography. We compared the cumulated microperfusion parameters ingress (In) and ingress rate (InR) before and after opening of the anastomosis. To compare the dimension of microcirculatory decline, we calculated the ratios of the parameters (RatioIn and RatioInR) after to those before anastomosis opening.

RESULTS:

The cumulated microperfusion parameters In and InR showed a significant decrease after completion of anastomosis and declamping. This effect has been seen in all patients for the hand and for each finger consecutively. During follow-up (mean 4.6, range 3-11 months), 5 patients (10.6%) complained about hemodialysis access-induced distal ischemia. The ratio of intraoperative microperfusion in those five hemodialysis access-induced ischemia patients was significantly lower compared to asymptomatic patients (RatioIn 0.23 vs 0.58, p = 0.001, and RatioInR 0.25 vs 0.62, p = 0.003).

CONCLUSION:

Intraoperative fluorescence angiography could visualize the deterioration of ipsilateral hand microperfusion after surgical creation of an arteriovenous fistula. It seems to be a promising tool to detect patients at risk for hemodialysis access-induced distal ischemia early in the peri- or even intraoperative stage.

Endovascular management in immature arteriovenous fistula for hemodialysis

To evaluate the outcomes and prognostic factors of endovascular management in immature arteriovenous fistula (AVF) for hemodialysis.From April 2007 to September 2017, 54 patients (male:female = 31:23, mean age 65.63 years, range 33-90 years) who underwent endovascular management for the salvage of immature AVF were retrospectively reviewed. Clinical data, procedural details, and results were evaluated. Primary and secondary patency rates and factors influencing the patency were also analyzed.Technical and clinical success rates were 88.9% (48/54) and 85.2% (46/54), respectively. Mean primary and secondary patency was 42.10 (±8.85) and 91.5 (±14.77) months, respectively. Primary and secondary patency rates were 66% and 89% in 1 year, 66% and 78% in 2 years, and 51% and 78% in 3 years. In multivariate analysis, only brachiocephalic AVF and antegrade access procedures showed significantly shorter primary patency (HR 5.196; 95% CI (1.04-25.77); P = .044, HR 8.096; 95% CI (1.36-48.00); P = .021). There was no statistically significant factor associated with secondary patency in the multivariate study.Endovascular management in immature AVF is safe and effective to make the AVF available. Brachiocephalic AVF and antegrade access procedures are the factors influencing the patency in multivariate analysis.

Drug Coated Balloon Angioplasty in Failing AV Fistulas: A Randomized Controlled Trial

BACKGROUND

Restenosis remains a problem in hemodialysis access interventions. Paclitaxel-coated balloons have shown promise in reducing access-related restenosis in small trials. The primary hypotheses for our multicenter trial were superior effectiveness at 180 days and noninferior safety at 30 days of a drug-coated balloon compared with conventional angioplasty for treatment of dysfunctional arteriovenous fistulas.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This randomized trial enrolled 285 patients with dysfunctional arteriovenous fistulas at 23 centers. Grafts, central venous stenoses, thrombosed fistulas, and immature fistulas were excluded. All patients received angioplasty of the lesion responsible for access dysfunction. After successful angioplasty (≤30% residual stenosis), lesions were treated with either a paclitaxel-coated balloon or an uncoated control balloon of similar design to the drug-coated balloon. Access function during follow-up was determined per centers' usual protocols; reintervention was clinically driven. The primary efficacy outcome assessment was done at 6 months, and the safety assessment was done within 30 days of the procedure. Prespecified secondary end points included assessment of postintervention target lesion primary patency and access circuit primary patency at 6 months.

RESULTS

The 180-day end point was not met with target lesion primary patency (71%±4% for the drug-coated balloon and 63%±4% for control; P=0.06), representing a difference of 8%±6% (95% confidence interval, -3% to 20%). Access circuit primary patency did not differ between groups. Interventions to maintain target lesion patency were fewer for the drug-coated balloon at 6 months (0.31 versus 0.44 per patient; P=0.03). The primary safety noninferiority end point was met and did not differ between groups (P=0.002).

CONCLUSIONS

Paclitaxel-coated balloon-assisted angioplasty did not meet the primary effectiveness end point at 180 days compared with conventional angioplasty. Both arms showed equivalent safety (ClinicalTrials.gov number NCT02440022).

Comparison between open and pharmacomechanical repair of acutely thrombosed arteriovenous hemodialysis fistulae within a decade

INTRODUCTION

Different declotting techniques are available for acutely thrombosed arteriovenous hemodialysis fistulae (AVF). The aim of this single-center study was to compare immediate and follow-up results between surgical repair and a modified interventional lyse-and-wait technique characterized by prolonged local reaction times of recombinant tissue-plasminogen activator (rtPA).

MATERIALS AND METHODS

We retrospectively analyzed medical records of 110 consecutively treated patients between the years 2003 and 2013. All patients were on hemodialysis (HD) and suffered from an acutely thrombosed AVF. The treatment standards changed in the course of time, wherefore we compared 2 groups: the open repair (OR) (N = 50) and the endovascular repair (ER) group (N = 60).

FINDINGS

We found no significant differences in success rates (OR 92%/ER 96.7%; P = 0.28), immediate failures (IFs) (OR 8%/ER 10%; P = 0.71), and temporary catheter placements (TCPs) (OR 10%/ER 6.7%; P = 0.52). Furthermore, there were no differences in cumulative primary patency rates (P = 0.42) and secondary patency rates (P = 0.97).The infection rate was significantly increased after OR (8%) compared to ER (0%); P = 0.026. The hospital stay in days was shorter after ER (5.2 ±2.8) vs. OR (9.0 ± 3.5); P < 0.001.

CONCLUSION

The modified lyse-and-wait technique with prolonged local reaction times is a successful alternative to surgical repair for acutely thrombosed AVF. Clear benefits are less infections and significant shorter hospital stays after ER. However, OR remains the preferred treatment for aneurysms and anastomotic stenoses.

Comparing the 12-month patency of low- versus high-pressure dilation in failing arteriovenous fistulae: A prospective multicenter trial (YOROI study)

PURPOSE

This study was performed to investigate the effect of the balloon dilation pressure on the 12-month patency rate in patients with failed arteriovenous fistulas undergoing hemodialysis.

MATERIALS AND METHODS

In this multicenter, prospective, randomized trial, the 4-mm-diameter YOROI balloon was used for dilation of stenotic lesions. The balloons were inflated to a pressure of 8 atm (low-pressure group) or 30 atm to achieve complete expansion (high-pressure group). The 12-month patency rate after balloon angioplasty was analyzed by the Kaplan-Meier method and log-rank test and/or a Cox proportional hazard model. We also investigated the dilation pressure required to achieve complete expansion in the high-pressure group.

RESULTS

In total, 71 patients were enrolled and allocated to either the low-pressure group (n = 34) or the high-pressure group (n = 37). The 12-month patency rates showed no significant difference between the low- and high-pressure groups (47% and 49%, respectively; p = 0.87). In the low-pressure group, the patency rate was not different between patients with complete dilation and residual stenosis (44% and 50%, respectively; p = 0.87). The Cox proportional hazard model revealed that the 12-month patency rate was associated with the stenosis diameter (hazard ratio 0.36; p = 0.001) and the presence of diabetes (hazard ratio 0.33; p = 0.018). Finally, the pressure required to achieve complete dilation was ≤20 atm in 76% of patients and ≤30 atm in 97% of patients. One patient required a dilation pressure of >30 atm.

CONCLUSION

The patency rate does not differ between low-pressure dilation and high-pressure dilation.

Angioplasty to promote arteriovenous fistula maturation and maintenance

The arteriovenous fistula is currently the best permanent access for the hemodialysis patient. Unfortunately, stenosis impairs maturation, long-term survival, and function of the arteriovenous fistula. Angioplasty currently is the best procedure for the treatment of immature and dysfunctional arteriovenous fistulas. In this review, the authors discuss the optimum time to evaluate arteriovenous fistulas for maturity, methods of evaluation for maturity, and the role of angioplasty in salvaging immature arteriovenous fistulas. The review also discusses the effect of stenosis on dysfunction in mature arteriovenous fistulas and the role of angioplasty to treat this complication. Finally, the impact of cutting balloons and drug-eluting balloons in the treatment of resistant and recurrent stenosis, respectively, is also discussed.

Cephalic Arch Stenosis in Autogenous Brachiocephalic Hemodialysis Fistulas: Results of Cutting Balloon Angioplasty

Purpose

Cephalic arch stenosis is a known cause of hemodialysis access failure in patients with brachiocephalic fistulas (BCFs). Outcomes of endovascular treatment are affected by resistance of the stenosis to balloon dilation, a high vein rupture rate and the development of early restenosis. The purpose of this retrospective study was to report outcomes after cutting balloon angioplasty (CBA) of cephalic arch stenosis.

Methods

In our vascular access database we identified 74 dysfunctional BcFs of which 30 (41%) were caused by cephalic arch stenosis. Seventeen fistulas in 17 patients (13 males and four females; median age 62 yrs; range 52–86) were treated with CBA (June 2005 to January 2008). Twenty-five procedures were performed. In 15 procedures, a cutting balloon was used alone and in 10 procedures CBA was followed by standard or high-pressure balloon angioplasty. Restenosis rates were calculated and patency rates were estimated with the Kaplan-Meier method.

Results

Primary patency rates (±SEE) at 3, 6, 12 and 15 months were 94% (±6%), 81% (±10%), 38% (±14%) and 22% (±15%), respectively. Assisted primary patency rates (±SEE) at the same intervals were 100% (±0%), 94% (±6%), 77% (±12%) and 63% (±13%), respectively. The mean interval between radiological interventions was 13 months (SD=8) and the mean number of interventions required per patient-year of dialysis was 0.9.

Conclusion

Treatment of cephalic arch stenosis with CBA did not improve patency compared to published results of conventional PTA, but our results indicate that CBA may lower the frequency of required re-interventions.

Aggressive Approach to Salvage Non-Maturing Arteriovenous Fistulae: A Retrospective Study with follow-up

Purpose

To establish a standardized approach for the maturation of non-maturing arteriovenous fistulae.

Methods

consecutive patients (n=122) with non-maturing fistulae presented to our outpatient vascular access center for percutaneous interventions to assist in maturation. The techniques used included flow rerouting, competing branch vein elimination, staged balloon angioplasty, and limited controlled extravasation.

Results

Successful fistula maturations were achieved in 118/122 patients. Fistulae were divided into two classes according to initial vessel size: class 1 (6.0–8.0 mm diameter, >6 mm deep) and class 2 (2.0–5.0 mm diameter) fistulae were evaluated for differences in technical procedures and clinically successful fistula maturation. Class 1 and class 2 fistulae were evaluated for mean number of procedures to maturation (1.6 and 2.6, respectively), and time to maturation (5 and 7 weeks, respectively). Follow-up for 109 of the initial 118 patients was achieved (mean=24 months, range=0.25–60 months). Class 1 and class 2 fistulae had primary patencies of 17 and 39% at 6 months; and secondary patencies of 72 and 77% at 12 months, 53 and 61% at 24 months, and 42 and 32% at 36 months, respectively. Primary and secondary patencies (Mann-Whitney test, p=0.44 and p=0.38, respectively) of class 1 and class 2 fistulae did not differ significantly, and secondary patencies were comparable to other fistula salvage studies.

Conclusion

Fistula salvage attempts should not be limited by factors such as a diffusely small diameter or an inaccessibly deep position.

Race and Sex Disparities in Outcomes of Dialysis Access Maintenance Interventions

PURPOSE

To determine whether utilization and outcomes of dialysis access maintenance interventions vary by patient race or sex.

MATERIALS AND METHODS

Data for this retrospective cohort study of first-time arteriovenous (AV) access recipients were drawn from a 5% sample of Medicare beneficiaries, containing claims from all clinical settings (2009-2014) in 2,693 patients who received their first AV fistula/graft in 2009. Maintenance interventions-angiography, angioplasty, thrombolysis, stent placement, and venous embolization-were identified by corresponding Current Procedural Terminology codes. Outcomes of primary patency (PP), postinterventional primary patency (PIPP), and postinterventional secondary patency (PISP) were calculated with utilization records. Associations between demographic data and patency times were evaluated by a multivariate survival approach, controlling for baseline differences in patient age, comorbid disease, type of dialysis access, and interventionist specialty.

RESULTS

AV grafts (AVGs) were created with greater frequency in women (32% vs 23% in men; P < .001) and minority patients (39% in black, 32% in Hispanic, and 29% in Asian patients vs 21% in white patients; P < .001). Women were at greater hazards for loss of PP (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.09-2.14) and PIPP (HR, 1.42; 95% CI, 1.01-2.00). Black patients were at greater hazards for loss of PP (HR, 1.37; 95% CI, 1.23-1.54) and PISP (HR, 1.29; 95% CI, 1.01-1.65). AVG creation predisposed patients to patency loss in all models (P < .001).

CONCLUSIONS

Dialysis access patency rates are lower for women and black patients. More frequent primary AVG creation in women and minority patients additionally predisposes these patients to patency loss.

Percutaneous treatment of thrombosed arteriovenous fistulae using the Gelbfish-Endovac aspiration thrombectomy device

Purpose

To study the efficacy and safety of percutaneous treatment of thrombosed hemodialysis arteriovenous fistulae (AVF) using the Gelbfish-Endovac aspiration thrombectomy device (Gelbfish-Endovac).

Methods

From September 2003 to May 2004, twenty-nine percutaneous thrombectomy procedures were performed in 27 patients (median age of 67 years, 14 females) with thrombosed hemodialysis AVF using the Gelbfish-Endovac. Prior interventions, procedure time, anticoagulation, use of additional devices/thrombolytic agents, technical success, clinical success, complication rates, and patency at 30, 60 and 90 days were evaluated.

Results

Sixteen upper arm and 13 forearm AVF were declotted. Seventeen AVF had prior percutaneous interventions. Three AVF had not matured. Median AVF age was 9 months. Heparin was used in 14 procedures. Sixteen arterial lesions and 25 venous lesions were uncovered and treated. Two AVF required the additional use of the Arrow-Trerotola percutaneous thrombectomy device. One AVF underwent side branch ligation. No thrombolytic agents were used. Median procedure time was 70 minutes. Initial technical success was achieved in 24 AVF and clinical success was achieved in 22 AVF. Eleven complications occurred. Ten AVF remained open at 30 days, 10 at 60 days and 8 at 90 days without further interventions. With additional percutaneous interventions, 16 AVF remained open at 30 days, 16 at 60 days and 15 at 90 days.

Conclusion

The Gelbfish-Endovac aspiration thrombectomy device is safe and efficacious for percutaneous de-clotting of AVF.

Vascular Access Outcomes Reported in Maintenance Hemodialysis Trials: A Systematic Review

BACKGROUND

Many randomized controlled trials have been performed with the goal of improving outcomes related to hemodialysis vascular access. If the reported outcomes are relevant and measured consistently to allow comparison of interventions across trials, such trials can inform decision making. This study aimed to assess the scope and consistency of vascular access outcomes reported in contemporary hemodialysis trials.

STUDY DESIGN

Systematic review.

SETTING & POPULATION

Adults requiring maintenance hemodialysis.

SELECTION CRITERIA

All randomized controlled trials and trial protocols reporting vascular access outcomes identified from ClinicalTrials.gov, Embase, MEDLINE, and the Cochrane Kidney and Transplant Specialized Register from January 2011 to June 2016.

INTERVENTIONS

Any hemodialysis-related intervention.

OUTCOMES

The frequency and characteristics of vascular access outcome measures were analyzed and classified.

RESULTS

From 168 relevant trials, 1,426 access-related outcome measures were extracted and classified into 23 different outcomes. The 3 most common outcomes were function (136 [81%] trials), infection (63 [38%]), and maturation (31 [18%]). Function was measured in 489 different ways, but most frequently reported as "mean access blood flow (mL/min)" (37 [27%] trials) and "number of thromboses" (30 [22%]). Infection was assessed in 136 different ways, with "number of access-related infections" being the most common measure. Maturation was assessed in 44 different ways at 15 different time points and most commonly characterized by vein diameter and blood flow. Patient-reported outcomes, including pain (19 [11%]) and quality of life (5 [3%]), were reported infrequently. Only a minority of trials used previously standardized outcome definitions.

LIMITATIONS

Restricted sampling frame for feasibility and focus on contemporary trials.

CONCLUSIONS

The reporting of access outcomes in hemodialysis trials is very heterogeneous, with limited patient-reported outcomes and infrequent use of standardized outcome measures. Efforts to standardize outcome reporting for vascular access are critical to optimizing the comparability, reliability, and value of trial evidence to improve outcomes for patients requiring hemodialysis.

Viabahn stent for hemodialysis shunt: efficacy, long segment recanalization and prognostic factors for reintervention

INTRODUCTION

The study evaluated the Heparin Bioactive Surface (HBS) Viabahn Stent (W.L. Gore & Associates, Flagstaff, Arizona) efficacy in the maintenance or re-establishment of hemodialysis.

MATERIALS AND METHODS

Fifty HBS Viabahn stents deployed in 37 consecutive patients with hemodialysis dysfunction from January 2008 to May 2016 were evaluated in a single-institution retrospective review. Outcomes were stent patency intended as primary circuit patency (PP), assisted primary patency (APP), target lesion primary patency (TLPP) and secondary patency (SP). Moreover, the risk factor analysis for hemodialysis dysfunction that required reintervention was performed. A subgroup analysis was conducted to assess patency of Viabahn stent to treat peripheral venous long segment obstruction (LSO).

RESULTS

Overall Kaplan-Meyer PPs were 60% at 12 months and 42% at 24 months. Overall TLPP estimated rates were 68% and 49% at 12 and 24 months, respectively. The corresponding SP rates were 85% and 78% at the same period. Estimated PP rates at 12 and 24 months for stent placement after peripheral venous long segment recanalization procedure were 53% and 31%, respectively. Corresponding SP rates were 82% and 68%, respectively. The APP rates were 79% at 12 months and 61% at 24 months. Female sex, access age and thrombosis were associated with reduced primary patency.

CONCLUSIONS

Considering the high rates of PP, TLPP, APP and SP, Viabahn stents have been proven effective in maintaining or re-establishing the hemodialysis access. Moreover, stent placement after recanalization of LSO of venous out-flow represented a valid approach to rescue a dysfunctional fistula that would otherwise be abandoned.