Reporting Standards for Percutaneous Interventions in Dialysis Access

Safety and Performance of a Cell-Impermeable Endoprosthesis for Hemodialysis Vascular Access Outflow Stenosis: A Brazilian Multicenter Retrospective Study

PURPOSE

To evaluate the safety and performance of Wrapsody™, a cell-impermeable endoprosthesis (CIE), for treating hemodialysis vascular access outflow stenosis.

MATERIALS AND METHODS

Investigators retrospectively analyzed 113 hemodialysis patients treated with a CIE (11/2021-12/2022) across four centers in Brazil. De novo or restenotic lesions were treated. The primary efficacy outcome measure was target lesion primary patency (TLPP) at 1, 3, 6, and 12 months; the primary safety outcome measure was the absence of serious local or systemic adverse events within the first 30 days post-procedure. Secondary outcome measures included technical and procedural success, access circuit primary patency (ACPP), and secondary patency at 1, 3, 6, and 12 months post-procedure.

RESULTS

Thirty-nine patients (34.5%) had thrombosed access at the initial presentation, and 38 patients (33.6%) presented with recurrent stenosis. TLPP rates at 1, 3, 6, and 12 months were 100%, 96.4%, 86.4%, and 69.7%, respectively. ACPP rates were 100% at 1 month, 89.2% at 3 months, 70.9% at 6 months, and 56.0% at 12 months. The target lesion secondary patency rates at 1, 3, 6, and 12 months were 100%, 97.3%, 93.6%, and 91.7%, respectively. In the adjusted multivariate Cox regression analysis, male sex and endoprosthesis with diameters of 10, 12, 14, and 16 mm were associated with improved primary patency rates. No localized or systemic serious adverse event was observed through the first 30 days post-procedure.

CONCLUSION

The CIE evaluated in this study is safe and effective for treating peripheral and central outflow stenoses in hemodialysis vascular access.

LEVEL OF EVIDENCE

Level 2b, cohort study.

Comparison between the 0- and 30-s balloon dilation time in percutaneous transluminal angioplasty for restenosed arteriovenous fistula among hemodialysis patients: a multicenter, prospective, randomized trial (CARP study)

BACKGROUND

This study aims to compare patency rates of the 0- and 30-s (sec) balloon dilation time in hemodialysis (HD) patients with restenosis after percutaneous transluminal angioplasty (PTA).

METHODS

The patients who underwent PTA within 6 months for failed arteriovenous fistula at the forearm were randomly assigned the 0-s or 30-s dilation time group. Effect of dilation time on the 3- and 6-month patency rates after PTA was examined.

RESULTS

Fifty patients were enrolled in this study. The 3-month patency rate in the 30-s dilation group was better than that in the 0-s dilation group (P = 0.0050), while the 6-month patency rates did not show a significant difference between the two groups (P = 0.28). Cox's proportional hazard model revealed that 30-s of inflation time (hazard ratio 0.027; P = 0.0072), diameter of the proximal (hazard ratio 0.32; P = 0.031), and dilation pressure (hazard ratio 0.63; P = 0.014) were associated with better 3-month patency. Dilation pressure between previous and present PTA did not differ in the 0-s (P = 0.15) and 30-s dilation groups (P = 0.16). The 6-month patency rate of the present PTA in the 30-s dilation group was higher than that of the previous PTA (P = 0.015). The visual analog scale did not differ between the two groups (P = 0.51).

CONCLUSION

The presenting data suggest that 30-s dilation potentially results in a better 3-month patency rate than 0-s dilation in HD patients with restenosis after PTA.

Percutaneous Management of Dialysis Access Steal Syndrome: Interventions and Outcomes from a Single Institution's 20-Year Experience

PURPOSE

To determine safety and effectiveness of percutaneous interventions performed by interventional radiologists at a single institution over 2 decades in patients with dialysis access steal syndrome (DASS).

MATERIALS AND METHODS

A retrospective review of fistulograms from 2001 to 2021 (N = 11,658) was performed. In total, 286 fistulograms in 212 patients with surgically created dialysis accesses met inclusion criterion of fistulography for suspected DASS. Chart review collected data regarding patient demographics, comorbidities, access characteristics, fistulography findings, intervention(s) performed, and outcomes. Procedures with and without DASS intervention were compared. Odds ratios (ORs), adjusted for age, sex, comorbidities, access characteristics, and multiple within-patient events, were calculated using logistic regression to determine associations between steal intervention status and outcome variables: (a) major adverse events, (b) access preservation, and (c) follow-up surgery. A percutaneously treatable cause of DASS was present in 128 cases (45%). Treatment of DASS lesions was performed in 118 cases. Fifteen embolizations were also performed in patients without DASS lesions.

RESULTS

Technical success of DASS interventions, defined by the Society of Interventional Radiology (SIR) reporting standards, was 94%; 54% of interventions resulted in DASS symptom improvement at a median follow-up of 15 days. Patients with steal intervention had 60% lower odds of follow-up surgery (OR, 0.4; P = .007). There was no difference in major adverse events (P = .98) or access preservation (P = .13) between groups.

CONCLUSIONS

In this retrospective cohort study, approximately half of DASS fistulograms revealed a percutaneously treatable cause of steal. Over half of DASS interventions resulted in symptomatic relief. Percutaneous intervention was associated with lower odds of follow-up surgery without compromising access preservation.

Study protocol for a Prospective, Randomized controlled trial of stEnt graft and Drug-coated bAlloon Treatment for cephalic arch stenOsis in dysfunctional arteRio-venous fistulas (PREDATOR)

BACKGROUND

Treatment of cephalic arch stenosis (CAS) is associated with high risk of failure and complications. Although stent-graft (SG) placement has improved patency rates, stent edge restenosis has been raised as a potential limiting factor for SG usage in CAS. This study aims to evaluate the safety and efficacy of combining stent graft placement with paclitaxel-coated balloon (PCB) angioplasty versus PCB alone in the treatment of CAS.

METHODS

This is an investigator-initiated, prospective, international, multicenter, open-label, randomized control clinical trial that plans to recruit 80 patients, who require fistuloplasty from dysfunctional arteriovenous fistula (AVF) from CAS. Eligible participants are randomly assigned to receive treatment with SG and PCB or PCB alone in a 1:1 ratio post-angioplasty (n = 40 in each arm). Randomization is stratified by de novo or recurrent lesion, and the participants are followed up for 1 year. The primary endpoints of the study are target lesion primary patency (TLPP) and access circuit primary patency (ACPP) rates at 6-months. The secondary endpoints are TLPP and ACPP at 3- and 12-month; target lesion and access circuit assisted primary and secondary patency rates at 3, 6, and 12-months and the total number of interventions; complication rate; and cost-effectiveness.

DISCUSSION

This study will evaluate the clinical efficacy and safety of combination SG and PCB implantation compared to PCB alone in the treatment of CAS for hemodialysis patients.

Use of a Paclitaxel Drug-Eluting Stent for the Treatment of Hemodialysis Access Outflow Stenosis

PURPOSE

To evaluate the outcomes and durability of drug-eluting stents (DESs) for the treatment of hemodialysis access outflow stenosis.

MATERIAL AND METHODS

A single-center retrospective analysis was conducted of all patients with hemodialysis vascular access outflow stenosis treated with a paclitaxel-coated DES (Eluvia; Boston Scientific, Marlborough, Massachusetts) between January 2020 and July 2022. A total of 34 DESs were implanted to treat outflow stenosis in 32 patients. Primary target lesion patency after stent deployment was the main outcome. Comparison between the time interval free from target lesion reintervention (TLR) after previous plain balloon angioplasty (PBA) and that after stent deployment for the same target lesion was considered a secondary outcome.

RESULTS

The primary patency at 6, 12, and 18 months was 63.1%, 47.6%, and 41.7%, respectively. The secondary patency rate was 100% at 18 months. The median time interval free from TLR increased from 4.1 to 11.9 months (P < .001). No adverse events were observed during the median follow-up period of 387 days.

CONCLUSIONS

The patency rates after use of DES for hemodialysis access outflow stenosis were comparable with results for drug-coated balloons and stent grafts, addressing recoil and minimizing the risk of jailing by a covered stent.

Cephalic arch stenosis: an analysis of outcome by type of first intervention

BACKGROUND

Cephalic arch stenoses (CAS) occur in near 70% of elbow arteriovenous fistulas. Percutaneous transluminal angioplasty (PTA) remains first-line treatment despite documented stent-grafts (SG) efficacy. The study aim is to report long-term outcomes based on initial treatment of CAS.

METHODS

Retrospective review of 12-year data in single tertiary centre. Outcomes included technical success, rupture rate, primary patency (PP), dialysis performance; categorical variables assessed via χ2 or Fisher's; nonparametric tests used for skewed data. Kaplan-Meier analysis used for PP and cumulative patency. Cox proportional hazard regression model to assess explanatory variables in PP.

RESULTS

One hundred one brachio- and radiocephalic fistulas with CAS were included. SG as first intervention had higher success than PTA (85% vs 61%, p = 0.003). Rupture occurred in 9/85 (10.6%) PTA vs 0% in SG (p = 0.046). In a subgroup with poor urea reduction rate (URR), both PTA and SG improved dialysis performance post-intervention (p = 0.002). SG demonstrated better PP than PTA (79,73,60% patency at 3, 6, 9 months; versus 71,51,47%; p = 0.195) and cumulative patency (73,61,61% at 1, 2, 3 years; versus 60,34,26%; p < 0.001). Of the variables analyzed, technical success of PTA was the only discriminating factor (coeff.-1.01; RR 35%, p = 0.035). Accesses that underwent secondary stenting performed better than primarily stented CAS (p = 0.01).

CONCLUSIONS

SG superiority is confirmed in CAS, particularly when angioplasty is unsuccessful. While PTA has short-lived benefits, it can improve dialysis performance. Other than higher success rate, primary CAS stenting did not have advantages compared to post-PTA stenting in our study. Other factors related to inflow, outflow, conduit characteristics are presumed to be involved in access longevity.

A Prospective Multicenter Randomized Controlled Trial for Comparing Drug-Coated and Conventional Balloon Angioplasty in Venous Anastomotic Stenosis of Hemodialysis Arteriovenous Grafts

PURPOSE

To evaluate the efficacy and safety of drug-coated balloon angioplasty compared to conventional balloon angioplasty in the treatment of dysfunctional arteriovenous grafts.

MATERIALS AND METHODS

This prospective, multicenter, randomized clinical trial enrolled 190 patients with venous anastomotic stenosis in arteriovenous grafts at five participating hospitals. During pre-dilation, 4 patients dropped out due to ruptures requiring further treatment (n = 2) and residual stenosis of > 30% (n = 2). On successful pre-dilation with a 7 mm conventional balloon, patients were randomized to undergo either a 7 mm drug-coated balloon (n = 94) or conventional balloon angioplasty (n = 92). The primary out-come measure was target lesion primary patency at 3 and 6 months. The secondary out-come measures included target lesion primary patency at 12 months and access circuit primary patency at 6 and 12 months, clinical and technical success rates, and 12-month mortality differences between the groups.

RESULTS

The target lesion primary patency and access circuit patency rates at 3 and 6 months were significantly higher in drug-coated balloon angioplasty group as compared to conventional balloon angioplasty group. The technical and clinical success rates were 100% for both the groups. As a procedure-related complication, anastomotic site rupture occurred during pre-dilation in 4 cases. The number of deaths during the 12-month follow-up was one for each group. The number of early thrombotic events (at < 3 months) was significantly higher in the drug-coated balloon group (p = 0.002).

CONCLUSION

Drug-coated balloon angioplasty was more effective and safer for the treatment of dysfunctional arteriovenous grafts compared to conventional balloon angioplasty.

Systematic review and meta-analysis: Efficacy and safety of balloon angioplasty in salvaging non-matured arteriovenous fistulas

This study aimed to evaluate the clinical and technical success rates achieved after performing balloon-assisted maturation (BAM) for non-matured arteriovenous fistula (AVF). For this, a systematic review and meta-analysis were conducted by searching PubMed and Scopus databases. Studies regarding AVFs not suitable for use based on clinical examination or ultrasound criteria and BAM use for correcting the underlying stenotic lesion were eligible for inclusion in the meta-analysis. Accordingly, 13 studies with 1427 patients with non-matured AVF who underwent BAM were included. The pooled random effect for the clinical success rate was 90% (95% CI, 86%-93%), and that for the technical success rate was 97% (95% CI, 94%-99%). Complications after BAM were reported in 1.7%-41% of the patients. Complications included venous ruptures, wall hematomas, and puncture site hematomas. Early-BAM group had better clinical success rates. BAM is an effective intervention for salvaging non-matured AVF. The procedure is safe and feasible, and high clinical and technical success rates can be achieved. The complications were also manageable without serious sequelae.

Dialysis Access Maintenance: Plain Balloon Angioplasty

Plain balloon angioplasty remains the first-line treatment for dialysis access stenosis. This chapter reviews the outcomes of plain balloon angioplasty from cohort studies and comparative studies. Angioplasty outcomes are more favourable in arteriovenous fistulae (AVF) compared to arteriovenous grafts (AVG) with primary patency at 6 months ranging from 42-63% compared to 27-61%, respectively, and improved for forearm fistulae compared with upper arm fistulae. Higher pressures are required to treat stenoses in AVFs compared to AVGs. Outcomes are worse in more severe stenoses, increased patient age, previous interventions and fistulae that develop early stenoses. Major complication rates following angioplasty in dialysis access are between 3 and 5%. Repeat treatments and the use of adjuncts such as drug-coated balloons and stents can prolong the patency of dialysis access. Level of Evidence No level of evidence (Review paper).

Trans-radial percutaneous intervention for thrombosed hemodialysis access: A single-center experience

BACKGROUND

Traditionally, percutaneous transluminal angioplasty (PTA) is a first-line approach for stenosed dialysis accesses and has been performed through the non-thrombosed vein segment. For thrombosed accesses, thrombectomy (whether open or percutaneous) is a standard approach. The primary objective of our study is to determine the clinical and technical outcomes of the trans-radial approach of PTA among thrombosed dialysis accesses, in terms of safety and feasibility, technical and clinical aspects and factors influencing them, as well as assisted primary patency, secondary patency at 6 and 12 months.

METHODS

This is a single-center retrospective study that included 150 patients over 3 years. About 123 patients underwent successful percutaneous balloon angioplasty through the radial access.

RESULTS

We report an overall technical and clinical success rate of 82%, assisted primary patency rate of about 90.25% at 3 months, 82.93% at 6 months, 73.18% at 1 year, and secondary patency rate of 94% at 1 year. Twenty-seven patients were referred for surgical revisions/creation of a new fistula for reasons like inability to pass wire (6 patients), unfavorable anatomical variations like aneurysms at the proximal segments (5 patients), inability to cross the fistula (5 patients), and persistent fistula dysfunction with no flow after initial balloon dilatation (11 patients). Three patients had hematoma at the radial access site (2.5%) while two patients had the AV fistula segment rupture and were successfully treated conservatively.

CONCLUSION

We conclude that PTA through the trans-radial approach to completely thrombosed hemodialysis accesses is a good alternative to transvenous access and has a very good assisted primary patency and secondary patency at 1 year without major complications.

Prospective, Multicenter, Observational Study to Evaluate a Cell-Impermeable Endoprosthesis for Treatment of Stenosis or Occlusion within the Dialysis Outflow Circuit of an Arteriovenous (AV) Fistula or AV Graft (The WRAP Registry)

PURPOSE

Dysfunctional vascular access due to stenosis/occlusion within the arteriovenous fistula or graft (AVF/AVG) negatively affects the clinical management of patients undergoing hemodialysis. Results from the feasibility study of the WRAPSODY™ Cell-Impermeable Endoprosthesis demonstrated that the device can achieve high patency rates and maintain integrity of the dialysis outflow circuit. This study was designed to assess real-world evidence of safety and efficacy outcomes following device placement.

MATERIALS AND METHODS

This is a prospective, multicenter, non-investigational, post-market observational study of 500 patients at up to 50 centers worldwide with a mature AVF/AVG dialysis access (≥ 1 hemodialysis session) who experience stenosis/occlusion of the outflow circuit prior to placement of WRAPSODY. Patients will be divided into the following two cohorts: peripheral or central thoracic. Primary outcome measures include target lesion primary patency (TLPP) at 6 months and procedure and/or device-related events through 30 days post-procedure. Secondary outcome measures include TLPP, safety events, and the number of interventions needed to maintain patency through the 24 month study period. Exploratory endpoints include time to access abandonment, resumption of successful dialysis, functional patency, and pending available imaging data, any incidence of stent fractures, migration, or edge stenosis. Study enrollment began in June 2022, the last patient visit is expected in 2026.

DISCUSSION

It is expected that this study will provide real-world evidence regarding the performance of the WRAPSODY device in a diverse population of patients, which may encourage its use in the continuum of hemodialysis access management.

TRIAL REGISTRATION

NCT05062291.

Manual compression technique improves the success rate in the treatment of thrombosed aneurysmal arteriovenous fistula: A single-center experience

OBJECTIVE

Endovascular intervention for thrombosed aneurysmal arteriovenous fistula (AVF) is still a challenge. Manual compression technique (MCT)-assisted angioplasty may be helpful, but there is no evidence or data to support it.

METHODS

From January 2018 to May 2021, patients with thrombosed aneurysmal AVFs were retrospectively enrolled. The patients were separated into the MCT group or the traditional group according to the procedure received. Technical failure, clinical failure, 90-day patency, and safety were analyzed.

RESULTS

A total of 159 cases (64 ± 12 years old, 60% male) were enrolled, of which 87 cases received MCT and 72 underwent traditional angioplasty. No technical failure was observed in the MCT group, while five technical failures were observed in the traditional group (0% vs. 7%, p = 0.02). There were no differences in the clinical failure rate (3% vs. 7%, p = 0.30), 90-day patency rate, or procedure time between the MCT group and the traditional group. There was no symptomatic pulmonary embolism or other complication in the two groups.

CONCLUSION

MCT is a low-cost, less invasive, and safe procedure for thrombosed aneurysmal AVF, and it achieves a higher technical success rate than traditional angioplasty.

Long-term mortality and patency after drug-coated balloon angioplasty in the hemodialysis circuit: A systematic review and meta-analysis of randomized controlled trials

PURPOSE

To compare all-cause mortality and primary patency with drug-coated balloon angioplasty (DCBA) compared with plain balloon angioplasty (PBA) in people with hemodialysis-related stenosis.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane Library databases were searched from November 1966 to February 2021 to identify randomized controlled trials (RCTs) that assessed the use of DCBA versus PBA for stenosis in hemodialysis circuits. Data extracted from the articles were integrated to determine all-cause mortality, target lesion primary patency (TLPP), circuit access primary patency (CAPP), 30-day adverse events, and technical success for the two approaches. We performed meta-analysis on these results using a fixed-effects model to evaluate odds ratios (ORs) and 95% confidence intervals (CIs) where I2 < 50% in a test for heterogeneity, or a random-effect model if otherwise. Sensitivity and subgroup analyses were also performed.

RESULTS

Sixteen RCTs of 1672 individuals were included in our meta-analysis, of which 839 individuals received DCBA and 833 received PBA. The pooled outcome showed no statistical difference between DCBA and PBA in all-cause mortality at 6 months (OR = 1.29, 95% CI = 0.72-2.32, p = 0.39, I2 = 4%), 12 months (OR = 1.02, 95% CI = 0.68-1.53, p = 0.91, I2 = 0%), and 24 months (OR = 1.50, 95% CI = 0.87-2.57, p = 0.15, I2 = 0%), 30-day adverse events (OR = 1.09, 95% CI = 0.30-3.98, p = 0.90, I2 = 66%), and technical success (OR = 0.18, 95% CI = 0.02-1.92, p = 0.16, I2 = 65%). The DCBA had significantly better outcomes versus PBA in TLPP at 6 months (OR = 2.37, 95% CI = 1.84-3.04, p < 0.001, I2 = 44%) and 12 months (OR = 1.77, 95% CI = 1.22-2.56, p = 0.002, I2 = 56%), and CAPP at 6 months (OR = 2.07, 95% CI = 1.21-3.54, p = 0.008, I2 = 67%) and 12 months (OR = 1.66, 95% CI = 1.29-2.15, p < 0.001, I2 = 0%).

CONCLUSION

In hemodialysis circuit stenosis, DCBA appears to have similar safety but greater efficacy than PBA.

Bare-Metal Stent in Dysfunctional Hemodialysis Access: An Assessment of Circuit Patency according to Access Type and Stent Location

Purpose

To evaluate the circuit patency after nitinol bare-metal stent (BMS) placement according to the type of access and location of the stent in dysfunctional hemodialysis access.

Materials and Methods

Between January 2017 and December 2019, 159 patients (mean age, 64.1 ± 13.2 years) underwent nitinol BMS placement for dysfunctional access. The location of stents was as follows: 18 brachiocephalic vein, 51 cephalic arch, 40 upper arm vein, 10 juxta-anastomotic vein, 7 arteriovenous (AV) anastomosis, and 33 graft-vein (GV) anastomosis. Circuit patency was evaluated by the Kaplan-Meier method, and cox regression model.

Results

A total of 159 stents were successfully deployed in 103 AV fistula (AVF) and 56 AV graft (AVG). AVG showed lower primary and secondary patency at 12-months compared with AVF (primary patency; 25.0% vs. 44.7%; p = 0.005, secondary patency; 76.8% vs. 92.2%; p = 0.014). Cox regression model demonstrated poorer primary patency at 12 months after stenting in the cephalic arch and GV anastomosis compared with the other sites.

Conclusion

AVF showed better primary and secondary circuit patency at 12 months following the placement of BMS compared with AVG. Stents in the cephalic arch and GV anastomosis were associated with poorer primary patency at 12 months compared to those in other locations.

Study protocol for Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID)

Background

A functioning vascular access (VA) is crucial to providing adequate hemodialysis (HD) and considered a critically important outcome by patients and healthcare professionals. A validated, patient-important outcome measure for VA function that can be easily measured in research and practice to harvest reliable and relevant evidence for informing patient-centered HD care is lacking. Vascular Access outcome measure for function: a vaLidation study In hemoDialysis (VALID) aims to assess the accuracy and feasibility of measuring a core outcome for VA function established by the international Standardized Outcomes in Nephrology (SONG) initiative.

Methods

VALID is a prospective, multi-center, multinational validation study that will assess the accuracy and feasibility of measuring VA function, defined as the need for interventions to enable and maintain the use of a VA for HD.

The primary objective is to determine whether VA function can be measured accurately by clinical staff as part of routine clinical practice (Assessor 1) compared to the reference standard of documented VA procedures collected by a VA expert (Assessor 2) during a 6-month follow-up period. Secondary outcomes include feasibility and acceptability of measuring VA function and the time to, rate of, and type of VA interventions.

An estimated 612 participants will be recruited from approximately 10 dialysis units of different size, type (home-, in-center and satellite), governance (private versus public), and location (rural versus urban) across Australia, Canada, Europe, and Malaysia.

Validity will be measured by the sensitivity and specificity of the data acquisition process. The sensitivity corresponds to the proportion of correctly identified interventions by Assessor 1, among the interventions identified by Assessor 2 (reference standard). The feasibility of measuring VA function will be assessed by the average data collection time, data completeness, feasibility questionnaires and semi-structured interviews on key feasibility aspects with the assessors.

Discussion

Accuracy, acceptability, and feasibility of measuring VA function as part of routine clinical practice are required to facilitate global implementation of this core outcome across all HD trials. Global use of a standardized, patient-centered outcome measure for VA function in HD research will enhance the consistency and relevance of trial evidence to guide patient-centered care.

Trial registration

Clinicaltrials.gov: NCT03969225. Registered on 31st May 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02987-1.

Clinical outcomes of endovascular therapy with vascular stents for central venous obstruction in hemodialysis patients

BACKGROUND

Symptomatic central venous obstruction (CVO) is sometimes observed in patients undergoing hemodialysis. Angioplasty is generally performed for salvage purposes, and stent implantation is performed as a last resort to prevent permanent venous occlusion. However, published reports about the clinical outcomes of stenting for CVO have been limited by the small number of included patients and the relatively old generation of analyzed stents. This study aimed to clarify the safety and efficacy of endovascular therapy (EVT) using stents for symptomatic CVO in contemporary practice.

METHODS

This retrospective review was performed between May 2012 and August 2021. We retrospectively analyzed consecutive 31 lesions (31 patients, 64 ± 10.7 years old) treated with a vascular stent for elastic recoil after balloon angioplasty or recurrent stenosis <3 months after angioplasty. The primary outcome was primary patency, defined as freedom from target lesion revascularization. The secondary outcome was assisted primary patency, defined as freedom from permanent occlusion of the target stents.

RESULTS

In all cases, stents were successfully deployed on the target lesions. No EVT-related complications were observed. Self-expandable and balloon-expandable stents were used in 26 and 5 lesions, respectively. The median follow-up period was 18 months (interquartile range, 7-40). Kaplan-Meier analysis revealed that the primary patency rates were 66.1 % at 6 months, 61.7 % at 12 months, and 38.4 % at 24 months after EVT. The assisted primary patency rate was 70.3 % 24 months after EVT. In the multivariate analysis, younger age was the only independent predictor of target lesion revascularization (hazard ratio: 0.92, 95 % CI: 0.85-0.99, p = 0.04).

CONCLUSIONS

Stent implantation for CVO that is resistant to standard angioplasty seems safe and effective.

Cleaner XT Rotational Thrombectomy: An Efficacious Endovascular Technique for Salvage of Thrombosed Arteriovenous Access and a 12 Month Outcome Analysis

Purpose:

This study aims to describe an efficacious method using Cleaner XT rotational thrombectomy with catheter-directed thrombolysis and drug-eluting balloon angioplasty for the salvage of thrombosed arteriovenous fistulae and grafts.

Materials and Methods:

Retrospective analysis of all patients with thrombosed hemodialysis accesses who underwent endovascular salvage using the Cleaner XT rotational thrombectomy system at a single institution between June 2019 and September 2020 was performed. Patency was presented as Kaplan-Meier survival curves, and regression analysis was performed to examine predictors of postintervention primary patency and assisted primary patency based on Cox proportional-hazards model.

Results:

Thirty-four patients with thrombosed accesses underwent Cleaner XT rotational thrombectomy between June 2019 and September 2020. Technical and clinical success were both 100%. Mean procedure time was 62 ± 20 minutes. Mean postintervention primary patency time was 152 ± 51 days; 30, 90, 180, and 365 day postintervention primary patency rates were 89%, 80%, 68%, and 56%, respectively. Mean postintervention-assisted primary patency time was 157 ± 59 days; 30, 90, 180, and 365 day postintervention-assisted primary patency rates were 91%, 82%, 71%, and 59%, and 180 and 365 day secondary patency rates were 97.2% and 94.4%, respectively.

Conclusion:

The Cleaner XT rotational thrombectomy device demonstrates excellent clinical and technical success rates, with good patency results at all time points up to 12 months postintervention.

Hemodialysis Arteriovenous Fistula Dysfunction: Retrospective Comparison of Post-thrombotic Percutaneous Endovascular Interventions with Pre-emptive Angioplasty

OBJECTIVES

We aimed to compare the clinical outcomes of pre-emptive angioplasty versus post-thrombotic percutaneous endovascular restoration of dysfunctional arteriovenous fistula (AVF).

METHODS

This retrospective study reviewed data from 80 patients who underwent 114 endovascular interventions for a malfunctioning AVF from July 2016 to August 2019. Stenotic AVFs were treated with pre-emptive angioplasty. Thrombosed AVFs were treated with percutaneous pharmacomechanical fibrinolysis with urokinase used only during the operation or continuously infused. The differences in patency rates were evaluated using Kaplan-Meier method. In addition, univariate and multivariate regression Cox models were used to determine influential factors on the post-intervention primary patency.

RESULTS

Post-thrombotic interventions and pre-emptive angioplasty yielded statistically similar rates in clinical success (100% vs 100%), anatomic success (94% vs 89%; p = .52), complication (4% vs 11%; p = .29), as well as postintervention primary, assisted primary and secondary patency (p = .80; .57; .57). The use of pre-emptive angioplasty was associated with reduced total cost (¥25108 vs ¥30833, p< .001). The patients who used urokinase only during the operation prolonged both the primary and assisted primary patency (p = .02; .002), while those with continuous infusion of urokinase had worst patency rates and high costs (¥39275 vs ¥25108 vs ¥27140, p< .001). Compared with the other locations, dysfunction in the anastomotic or juxta-anastomotic segment (HR = .41, p = .001) was associated with prolonged postintervention primary patency.

CONCLUSIONS

No clinical outcome differences was found between the post-thrombotic percutaneous endovascular interventions and pre-emptive angioplasty. However, pre-emptive angioplasty decreased access expenditure.

Endovascular Versus Surgical Arteriovenous Fistulas: A Systematic Review and Meta-analysis

Rationale & Objective

To facilitate the process of dialysis for patients with kidney failure, an arteriovenous fistula (AVF) is created using either a surgical or percutaneous approach. We sought to compare the efficacy and procedural outcomes in creating an AVF percutaneously using Ellipsys (Avenu Medical) or WavelinQ (Becton Dickinson Medical) with surgery in all patients with kidney failure requiring a permanent AVF for dialysis.

Study Design

Systematic review and meta-analysis.

Setting & Study Populations

All patients requiring a permanent AVF for dialysis.

Selection Criteria for Studies

We included studies that compared either the Ellipsys device or WavelinQ directly with surgery to create an AVF for long-term dialysis.

Data Extraction

Two reviewers independently reviewed the studies and extracted the data. Conflicts were resolved with a discussion and approval from the senior author.

Analytical Approach

Fixed-effects or random-effects models were used to pool the fixed sizes and 95% CIs based on the level of heterogeneity.

Results

There was no statistically significant difference observed between surgical AVF and endovascular AVF when comparing the primary outcomes of procedural success (OR = 1.44; 95% CI, 0.35, 5.88; P = 0.61; I2 = 0%), complications (OR = 0.28; 95% CI, 0.06, 1.46; P = 0.13; I2 = 69%), and the secondary outcomes of interest that included follow-up time (mean difference [MD] = -17.71; 95% CI, -189.53, 154.12; P = 0.84; I2 = 94%), failure rate (OR = 1.03; 95% CI, 0.21, 5.13; P = 0.97; I2 = 85%), and time to 2-needle cannulation (MD = -5.40; 95% CI, -38.88, 28.08; P = 0.75; I2 = 0%). However, a statistically significant difference was seen among the 2 groups for procedural time (MD = -54.25; 95% CI, -59.78, -48.71; P < 0.001; I2 = 98%), number of interventions needed to maintain patency (OR = 1.73; 95% CI, 1.22, 2.45; P < 0.01; I2 = 94%), and primary patency rate (OR = 0.34; 95% CI, 0.23,0.52; P < 0.001; I2 = 0%).

Limitations

The total number of studies included in this review was limited, with 3 of the 4 included studies being retrospective and only 1 being prospective. There was a lack of heterogeneity and randomization.

Conclusions

Percutaneous fistula creation using Ellipsys or WavelinQ is a unique and safe alternative with outcomes comparable to surgery. Future studies are needed, including observational studies in current clinical practice, to evaluate the efficacy and outcomes of endovascular AVF creation in clinical populations.

Paclitaxel coated balloon versus conventional balloon angioplasty in dysfunctional dialysis arteriovenous fistula: a systematic review and meta-analysis of randomized controlled trials

Purpose

To compare the efficacy and safety between paclitaxel coated balloon (PCB) angioplasty and conventional balloon (CB) angioplasty in the treatment of dysfunctional arteriovenous fistula (AVF).

Methods

We searched four major electronic databases (PubMed, EMBASE, Web of Science and the Cochrane Library) for randomized controlled trials (RCTs) published from inception through November 28, 2021. Outcomes of interest included target lesion primary patency (TLPP), technical success and all-cause mortality. The STATA package version 15.1 was utilized to undertake meta-analyses.

Results

Fourteen RCTs totaling 1535 patients were analyzed. The available data showed that there were no significant differences of TLPP rates at 3, 6, 9 and 12 months between the PCB group and the CB group (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.93–1.07, p = 1.000, I² = 33.5%, Cochrane Q test p = 0.185, fixed-effect model; RR 1.17, 95% CI 0.99–1.39, p = 0.065, I² = 75.4%, Cochrane Q test p = 0.000, random-effect model; RR 0.81, 95% CI 0.35–1.89, p = 0.625, I² = 62.8%, Cochrane Q test p = 0.045, random-effect model; RR 1.19, 95% CI 0.97–1.47, p = 0.096, I² = 40.5%, Cochrane Q test p = 0.071, random-effect model). In addition, two groups had similar technical success rates (RR 1.00, 95% CI 0.97–1.03, p = 1.000, I² = 0.0%, Cochrane Q test p = 0.596, fixed-effect model) and all-cause mortality rates (RR 1.00, 95% CI 0.54–1.84, p = 1.000, I² = 0.0%, Cochrane Q test p = 0.599, fixed-effect model).

Conclusions

PCB angioplasty did not appear to convey any obvious advantage over CB angioplasty in the treatment of dysfunctional AVF. However, further multi-center, large-scale and well-designed RCTs are needed to prove outcomes.

Ultrasound-guided nitinol stent implantation in treatment of early recurrent stenosis of arteriovenous fistula

To investigate the feasibility, methods and efficacy of ultrasound-guided nitinol stent implantation for the treatment of early recurrent stenosis of arteriovenous fistula (AVF). Thirty patients with early recurrent stenosis after percutaneous transluminal angioplasty (PTA) who received ultrasound-guided nitinol stent implantation in Sir Run Run Shaw Hospital of Zhejiang University from April 2018 to July 2020 were followed up. The imaging features of the procedure and the interventional devices were observed under ultrasonography. The technical success rate and the clinical success rate as well as the incidence of complication were assessed. The post-interventional primary patency rates of access circuit, primary patency rates of target lesion and secondary patency rates were estimated. Ultrasonography was able to demonstrate the operation process and the interventional devices clearly. The technical and clinical success rates were both 100.0%. Eight patients had in-stent restenosis, which were treated by PTA. The post-interventional primary patency rates of the access circuit after 3, 6, 9 and were 91.3%, 86.2%, 86.2% and 64.2%, respectively; the post-interventional primary patency rates of target lesion were 100.0%, 100.0%, 86.4% and 69.3%, respectively; the post-interventional secondary patency rates were 100.0%, 100.0%, 100.0% and 94.4%, respectively. Compared with previous PTA in these cases, stent implantation had a higher post-interventional primary patency rates of target lesion and a lower cost-effectiveness (both <0.05). No other complications such as vascular rupture, pseudohemangioma, stent infection, stent displacement and stent exposure were observed during the follow-up. Ultrasonography can accurately guide the nitinol stent implantation in AVF, and the technique is feasible in treatment for the early recurrent stenosis after PTA with good short- and medium-term efficacy.

SIroliMus coated angioPlasty versus plain balloon angioplasty in the tREatment of dialySis acceSs dysfunctION (IMPRESSION): study protocol for a randomized controlled trial

Background

Percutaneous transluminal angioplasty is the current standard treatment for arteriovenous fistula (AVF) stenosis. The mid- and long-term patency with plain balloon angioplasty (PBA) is however far from satisfactory. While paclitaxel-coated balloon angioplasty has been shown to be superior to PBA, concern over its safety profile has recently arisen after a reported possible increased mortality risk with a meta-analysis of large lower limb studies. An angioplasty balloon with a new type of drug coating, the sirolimus-coated balloon (SCB), has been proven to improve patency in the coronary arteries. However, its effect on AV access has yet to be studied.

Methods/design

This is an investigator-initiated, prospective, multicenter, double-blinded, randomized controlled clinical trial to assess the effectiveness of SCB compared to PBA in improving the patency of AVF after angioplasty. A total of 170 patients with mature AVF that requires PTA due to AVF dysfunction will be randomly assigned to treatment with a SCB or PBA at a 1:1 ratio, stratified by location of AVF and followed up for up to 1 year. The inclusion criteria include [1] adult patient aged 21 to 85 years who requires balloon angioplasty for dysfunctional arteriovenous fistula [2]; matured AVF, defined as being in use for at least 1 month prior to the angioplasty; and [3] successful angioplasty of the underlying stenosis with PBA, defined as less than 30% residual stenosis on digital subtraction angiography (DSA) and restoration of thrill in the AVF on clinical examination. The exclusion criteria include thrombosed or partially thrombosed access circuit at the time of treatment, presence of symptomatic or angiographically significant central vein stenosis that requires treatment with more than 30% residual stenosis post angioplasty, and existing stent placement within the AVF circuit. The primary endpoint of the study is access circuit primary patency at 6 months. The secondary endpoints are target lesion primary patency; access circuit-assisted primary patency; access circuit secondary patency at 3, 6, and 12 months; target lesion restenosis rate at 6 months; total number of interventions; complication rate; and cost-effectiveness. The trial is supported by Concept Medical.

Discussion

This study will evaluate the clinical efficacy and safety of SCB compared to PBA in the treatment of AVF stenosis in hemodialysis patients.

Trial registration

ClinicalTrials.govNCT04409912. Registered on 1 June 2020

Safety and efficacy of arteriovenous fistula angioplasties performed by nephrologists: report from a Brazilian interventional nephrology center

Introduction:

Arteriovenous fistulas (AVF) are the first choice vascular access for hemodialysis. However, they present a high incidence of venous stenosis leading to thrombosis. Although training in interventional nephrology may improve accessibility for treatment of venous stenosis, there is limited data on the safety and efficacy of this approach performed by trained nephrologists in low-income and developing countries.

Methods:

This study presents the retrospective results of AVF angioplasties performed by trained nephrologists in a Brazilian outpatient interventional nephrology center. The primary outcome was technical success rate (completion of the procedure with angioplasty of all stenoses) and secondary outcomes were complication rates and overall AVF patency.

Findings:

Two hundred fifty-six angioplasties were performed in 160 AVF. The technical success rate was 88.77% and the main cause of technical failure was venous occlusion (10%). The incidence of complications was 13.67%, with only one patient needing hospitalization and four accesses lost due to the presence of hematomas and/or thrombosis. Grade 1 hematomas were the most frequent complication (8.2%). The overall patency found was 88.2 and 80.9% at 180 and 360 days after the procedure, respectively.

Conclusion:

Our findings suggest that AVF angioplasty performed by trained nephrologists has acceptable success rates and patency, with a low incidence of major complications as well as a low need for hospitalization.

Initial Clinical Experience with a Symmetric Tip Tunneled Hemodialysis Catheter Without Side Holes

The purpose of this article is to assess the performance and safety of a novel, symmetric, side-hole-free tunneled cuffed catheter hypothesized to sustain adequate flow without the need for side holes. Between November 2016 and January 2019, Pristine hemodialysis catheters were placed de novo in 45 end-stage renal disease patients (27 males and 18 females) at a single investigational site. Forty-one catheters were placed in the right and four in the left internal jugular vein. There were no incidents of insertion failure. Patients had dialysis three times per week and were followed at four investigational sites. Nominal catheter flows, incidence of poor flow, and catheter-related infections were recorded at each dialysis session and analyzed. The average follow-up time was 161.69 days for a total of 7116 catheter days. Nine patients died from reasons unrelated to the catheter and one patient switched to fistula. Four patients had poor flows necessitating catheter replacement. Four patients had catheter-related bloodstream infections which resolved with antibiotics. These equate to 0.56 events per 1000 catheter days. Catheter survival was 100%, 97.6%, and 89.7% at 30, 90, and 180 days, respectively. The initial clinical assessment of the symmetric Pristine hemodialysis catheter featuring a Y-tip devoid of side holes revealed good catheter performance and survival and a low complication rate.

Comparison of Management for Central Venous Stenosis With or Without Previous Catheter Placement

Objective: To compare central venous stenosis/occlusion with or without previous jugular catheter placement history.

Methods: Data of patients with central vein stenosis/occlusion receiving endovascular intervention in our hospital from January 2015 to December 2018 were collected and analyzed.

Results: Twenty-nine patients with previous jugular catheter placement history (CVC group) and 33 patients (excluded two with technical failure) without such history (non-CVC group) are included in this study. Previous jugular catheter placement history raised the risk of postintervention recurrence 1.02 times (CVC group vs. non-CVC group, HR = 2.02 95%CI: 0.91–4.48). The primary patency rate at 6, 12, 18, and 24 months was 76.9, 54.2, 45.5, and 25.0% separately in the CVC group and 80.6, 70.0, 67.9, and 44.4% separately in the non-CVC group. The assisted primary patency rate at 6, 12, 18, and 24 months was 92.3, 91.7, 86.4, and 68.8% separately in the CVC group and 93.5, 90.0, 82.1, and 61.1% separately in the non-CVC group. Patients in the CVC group received a higher frequency of reintervention (0.7 times/year/patient vs. 0.3 times/year/patient). There was no significant difference in the assisted primary patency rate between the two groups. Different primary interventions (angioplasty alone, bare metal stent, stent graft) did not affect primary patency and assisted primary patency, but percutaneous transluminal stenting (PTS) with a bare metal stent had a significant lower primary patency rate between 3 and 24 months compared with PTS with a stent graft (p = 0.011).

Conclusion: Central venous stenosis/occlusion with a previous jugular catheter placement history develops symptoms earlier and had a worse prognosis after endovascular intervention. More efforts are needed to carry out end-stage kidney disease life plan to reduce the harm of evitable catheter placement.

Comparison of 2 effect-site concentrations of remifentanil with midazolam during percutaneous transluminal balloon angioplasty under monitored anesthesia care: A randomized controlled study

BACKGROUND

Until now, target-controlled infusion of remifentanil with midazolam in percutaneous transluminal balloon angioplasty for dysfunctional hemodialysis fistulas has not been described. Here, we investigate 2 effect-site concentrations of remifentanil with intermittent bolus midazolam for percutaneous transluminal balloon angioplasty under monitored anesthesia care.

METHODS

A prospective, randomized controlled trial including patients who received a percutaneous transluminal balloon angioplasty between March 2019 and March 2021 was conducted. Group 1 and Group 2 were, respectively, administered an initial effect-site concentration of remifentanil of 1.0 and 2.0 ng/mL by a target-controlled infusion pump with Minto model. In both groups, maintenance of the effect-site concentration of remifentanil was adjusted upward and downward by 0.5 ng/mL with intermittent bolus midazolam to keep the Observer's Assessment of Alertness/Sedation scale between 2 and 4, mean arterial pressure and heart rate at baseline levels ± 30%, and patient comfort (remaining moveless). The primary outcome was to determine the appropriate effect-site concentration of remifentanil for the procedure in terms of patient comfort (remaining moveless), hemodynamic conditions, and adverse events. Secondary endpoints included the total dosage of anesthetics and total times of target-controlled infusion pump adjustments.

RESULTS

A total of 40 patients in Group 1 and 40 patients in Group 2 were eligible for analysis. Most parameters were insignificantly different between 2 groups, except Group 1 having higher peripheral oxygen saturation, while local anesthetic injection compared with Group 2. In addition, Group 1 patients had less apnea with desaturation (peripheral oxygen saturation < 90%; 0 vs 6, P = .034), less remifentanil consumption (189.65 ± 69.7 vs 243.8 ± 76.1 μg, P = .001), but more intraoperative movements affecting the procedure (14 vs 4; P = .016), total times of target-controlled infusion pump adjustment [2 (1-4) vs 1 (1-2), P < .001] compared with Group 2.

CONCLUSION

In percutaneous transluminal balloon angioplasty for dysfunctional hemodialysis fistulas, target-controlled infusion with remifentanil Minto model target 2.0 ng/mL with 3 to 4 mg midazolam use provided appropriate hemodynamic conditions, sufficient sedation and analgesia, and acceptable apnea with desaturation.

Sharp Needle Recanalization Technique for Peripheral Hemodialysis Arteriovenous Fistula Occlusion

PURPOSE

To determine the efficacy of a percutaneous sharp needle recanalization technique for the treatment of peripheral hemodialysis arteriovenous fistula (AVF) occlusion.

MATERIALS AND METHODS

This study included 13 patients (14 procedures) between May 2010 and February 2020 with non-thrombotic AVF occlusion wherein guidewire passage through the occluded segment had failed. We successfully passed the guidewire through the occluded segment using a sharp needle recanalization technique with Chiba or Colapinto needles, under ultrasound or fluoroscopic guidance. The type of AVF, site and length of occlusion, technical success, complications, and long-term patency were analyzed.

RESULTS

Technical success was achieved in 12 (85.7%) out of 14 procedures. The procedure failed in two patients due to the poor angle of approach in the axillary area and diffuse severe stenosis in the draining cephalic vein. In eight procedures, sharp needle recanalization was performed under ultrasound guidance, while the other six procedures were performed under fluoroscopic guidance. Chiba and Colapinto needles were used in five and nine procedures, respectively. The mean length of occlusion was 2.7 cm (range 1.8-4.2 cm). There was one case of mild complication, that is, mild contrast extravasation, which was treated by stent deployment. The post-intervention primary patency rates at 6 months, 1 year, and 2 years were 81.8%, 36.4%, and 18.2%, respectively.

CONCLUSION

The results of this limited series suggest that the sharp needle recanalization technique is a simple and effective method for the treatment of peripheral non-thrombotic AVF occlusion.

Long-Term Outcomes of the Flixene Vascular Graft Used for Haemodialysis

Introduction

The Flixene™ vascular graft (Maquet-Atrium Medical, Hudson, NH) has emerged as a new generation synthetic graft, which allows for early needling for haemodialysis. Most studies have shown satisfactory early results. The aim of this study is to report on long-term outcomes of the Flixene graft over eight years in a cohort of patients.

Methods

From February 2011 to September 2019, 61 patients had 64 arteriovenous graft fistulas (AVGs) by using the Flixene grafts. The median patient age was 67 years; the male to female ratio was 30:31. Diabetes was the reason for the majority of kidney failures (57%). The configuration of the grafts used was mostly upper arm straight AVG. The primary patency rate, secondary patency rate, and surgical complications were assessed.

Results

In a median follow-up of three years (interquartile range (IQR): 2 - 6), 36 of the AVGs required a fistulogram. Venous side stenosis was the most common cause of high venous pressure or AVG occlusion in 97%. The one-year primary patency rate was 30%. The secondary patency rate was 94.8%, 83.7%, and 77.7% at one, three, and five years, respectively. The longest functional AVG was observed for up to seven years.

Conclusions

This study has shown satisfactory long-term results of the Flixene graft used for hemodialysis. The Flixene graft could be needled within 72 hours without increased complications, which allows the creation of an AVG under an emergency setting to avoid the placement of a central venous catheter (CVC). This strategy should be advocated in future clinical practice.

Clot accumulation at the tip of hemodialysis catheters in a large animal model

Background:

The issue of side holes in the tips of the tunneled cuffed central venous catheters is complex and has been subject to longstanding debate. This study sought to compare the clotting potential of the side-hole-free Pristine hemodialysis catheter with that of a symmetric catheter with side holes.

Methods:

Both jugular veins of five goats were catheterized with the two different catheters. The catheters were left in place for 4 weeks and were flushed and locked with heparin thrice weekly. The aspirated intraluminal clot length was assessed visually prior to each flushing. In addition, the size and weight of the clot were recorded upon catheter extraction at the end of the 4-week follow-up

Results:

The mean intraluminal clot length observed during the entire study follow-up measured up to a mean of 0.66 cm in the GlidePath (95% CI, 0.14–1.18) and 0.19 cm in the Pristine hemodialysis catheter (95% CI, −0.33 to 0.71), the difference being statistically significant (p = 0.026). On average, 0.01 g and 0.07 g of intraluminal clot were retrieved from the Pristine and GlidePath catheters, respectively (p = 0.052).

Conclusion:

The Pristine hemodialysis catheter was largely superior to a standard side hole catheter in impeding clot formation, and, contrary to the side hole catheter, allowed for complete aspiration of the intraluminal clot.

Effect of short-term low molecular weight heparin on patency following successful salvage of arteriovenous access with recurrent thrombosis

AIM

This study aims to investigate the effect of low molecular weight heparin (LMWH) in maintaining the patency of arteriovenous (AV) access with recurrent thrombosis.

METHODS

Following successful thrombectomy, 66 patients with recurrent thrombosis were included in the study. The primary, assisted primary and secondary patency rates of patients who received LMWH (n = 24) were compared with those who did not receive anticoagulant (n = 42) using Kaplan-Meier analysis. Cox-regression analysis was performed to investigate potential predictors of patency rates.

RESULTS

The mean dose of enoxaparin used was 40 ± 13.1 mg or 0.74 ± 0.2 mg/kg daily for a median duration of 14 (IQR 7,28) days. The mean trough anti-Xa concentrations measured after two doses of LMWH was 0.17 ± 0.13 IU/mL. Kaplan-Meier analyses for mean primary, assisted primary and secondary patency rates of LMWH vs no anticoagulation groups were 149 (95% CI: 91 - 207) vs 87 (95% CI: 42-132) days (P < .006), 230 (95% CI: 142-320) vs 107 (95% CI: 62-150) days (P = .01) and 438 (299-579) vs 294 (95% CI: 197-392) days (P = .08) respectively. LMWH remained a significant protective predictor of primary (HR: 0.49; 95% CI: 0.25-0.86; P = .02) and assisted primary patency rates (HR: 0.51; 95% CI: 0.27-0.98; P = .04) after adjusting for patient age, access age, type of AV access, presence of peripheral vascular disease and haemoglobin levels.

CONCLUSION

LMWH may improve short and mid-term patency rates for AV accesses with recurrent thrombosis.

Salvage of a Radiocephalic Arteriovenous Hemodialysis Fistula by Percutaneous Angioplasty to Increase Retrograde Flow from the Palmar Arch in Patients with an Occluded Radial Artery

This brief report presents 12 patients who underwent percutaneous transluminal angioplasty (PTA) to increase the retrograde blood flow from the palmar arch. All the patients had radiocephalic arteriovenous fistulas with occluded feeding arteries. The technical success rate was 100%. Three patients (25.0%) underwent surgical repair for restenosis, 2 patients (16.6%) underwent surgical repair for other reasons, 5 patients (41.8%) underwent repeated PTAs for restenosis, and 2 patients (16.6%) had no further treatment. The target lesion primary patency rates at 6, 12, 36, and 60 months were 90.9%, 54.5%, 36.4%, and 18.2%, respectively.

Early (6 months) results of a pilot prospective study to investigate the efficacy and safety of sirolimus coated balloon angioplasty for dysfunctional arterio-venous fistulas: MAgicTouch Intervention Leap for Dialysis Access (MATILDA) Trial

Background

The aim of this pilot study was to evaluate the safety and efficacy of the MagicTouch™ sirolimus-coated balloon (SCB) catheter (Concept Medical Inc., Tampa, FL, US) on improving the patency of failing arterio-venous fistulas (AVF) with de novo and recurrent stenoses. MATILDA reports early outcomes at 3- and 6 months post intervention.

Methods

Single-centre, single-arm prospective pilot study of 33 (18 males; mean age 64.7±11.6 years) end-stage renal failure Asian patients with a dysfunctional AVF, who underwent SCB angioplasty between May 2019-January 2020. All procedures were performed under local anaesthetic without sedation and as day surgery. All patients were prescribed dual antiplatelet therapy for 3 months and followed up with Duplex ultrasound at 3 and 6 months.

Results

47 stenotic target lesions treated and 24/33 (72.7%) patients were for restenosis. Main indications for intervention was low/dropping access flow (21/33; 63.6%) and most common target lesion was in the juxta-anastomosis (19/47; 40.4%). There was 100% technical and procedural success. There were no peri-procedural complications related to the SCB. The target lesion primary patency rates at 3 and 6 months were 46/47 (97.9%) and 29/35 (82.9%) respectively. Circuit access patency rates at 3 and 6 months were 31/33 (93.9%) and 17/25 (68%) respectively. There was one (2.9%) death at 6 months and 4/33 (12.1%) overall to date, all from patients’ underlying co-morbidities.

Conclusions

SCB angioplasty for dysfunctional AVF circuits is a safe and efficacious modality in Asian haemodialysis patients at six months comparable if not better than the paclitaxel data reported to date in the literature.

Use of the Viabahn covered stent for the treatment of venous rupture during interventions of dysfunctional or thrombosed hemodialysis vascular access

BACKGROUND

Angioplasty-related vessel rupture is a common complication of interventions. The effect of covered stents to treat venous rupture has been evaluated in smaller series, but should be further evaluated.

OBJECTIVE

To report the immediate outcomes and patency rates of a covered stent to rescue angioplasty-related venous rupture of hemodialysis vascular access.

METHODS

From January 2013 to December 2018, 113 procedures complicated with vessel ruptures were retrospectively analyzed from a prospectively collected database of 8146 hemodialysis access interventions. The strategies to salvage vessel ruptures were based on the discretion of the treating physicians. Follow-up outcomes were obtained via review of the angiographic images, procedural notes, and medical and dialysis records within 12 months after the index procedures.

RESULTS

A total of 52 vessel ruptures (21 fistulas, 31 grafts) salvaged by using Viabahn covered stents were enrolled. Vessel ruptures developed in 28 (53.8%) thrombectomy procedures. Device success was achieved in all procedures (100%) and clinical success was achieved in 50 (96.2%). The primary patency of the stent area was 66.0% at 6 months and 50.0% at 12 months. The primary patency of the entire access circuit was 27.4% at 6 months and 16.0% at 12 months. The most common cause of access circuit primary patency loss was thrombotic occlusion for graft accesses and restenosis at stent area for native accesses. Eleven vascular accesses were abandoned within 12 months after vessel ruptures, and the secondary patency rate of the entire access circuit was 78.0% at 12 months.

CONCLUSIONS

Treatment of angioplasty-induced vessel rupture of hemodialysis vascular accesses by using Viabahn covered stents has good immediate outcomes and patency results at the stent area. Nonetheless, the patency rate of entire access circuit was still below the threshold recommended by guidelines.

Percutaneous intervention for salvage of non-maturing arteriovenous fistulas: Which is the better approach, arterial or venous?

Objectives

To evaluate the efficacy and long-term patency of endovascular treatment for non-maturing native arteriovenous fistulas according to the approach route (arterial vs. venous).

Methods

Eighty-five patients underwent percutaneous transluminal angioplasty for non-maturing fistulas (63 radiocephalic and 22 brachiocephalic) between 2010 and 2019. Outcome variables such as procedural success, complications, and primary and secondary patency rates were analyzed from the patients’ demographic, angiographic, clinical, and hemodialysis records according to the approach route (venous access group, n = 53 and arterial access group, n = 32). The Kaplan-Meier method was used to analyze the patency rates.

Results

The mean duration from fistula creation to fistulography was 78.4±51.4 days (range, 1–180 days). The anatomical and clinical success rates were 98.8% and 83.5%, respectively. Lesions were most commonly located at the juxta-anastomosis (55.3%). Accessory cephalic veins were observed in 16 patients. The primary patency rates were 83.9%, 71.9%, and 66.3% and the secondary patency rates were 98.6%, 95.9%, and 94.2% at 3 months, 6 months, and 1 year, respectively. The degree of hypertension (P = 0.023), minimal preoperative vein size (P = 0.041), and increment in postoperative vein diameter were higher in the venous access group than in the arterial access group (P<0.01). The frequency of using cutting balloons (P = 0.026) and complication rate were higher in the arterial access group than in the venous access group (arterial access: 1 major, 8 minor; venous access: 4 minor; P = 0.015).

Conclusions

Aggressive evaluation and endovascular therapy can salvage most non-maturing fistulas. Transradial and distal radial approaches can be effective even for challenging lesions.

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.