Predictors of primary patency after percutaneous balloon angioplasty for stenosis of Brescia-Cimino hemodialysis arteriovenous fistula

Influence of balloon type and lesion location on outcomes following fistuloplasty

BACKGROUND

There is limited evidence supporting the optimal use of fistuloplasty to maintain vascular access at various lesion sites, despite its critical role in facilitating renal replacement therapy and the overall high failure rates of arteriovenous fistulas (AVFs). This study aims to identify covariates affecting primary and secondary patency following fistuloplasty of native upper limb vascular access AVFs.

METHODS

This retrospective study included all patients who underwent fistuloplasty at a tertiary vascular centre over 4 years. Baseline characteristics were recorded, and factors associated with primary and secondary patency rates were analysed.

RESULTS

A total of 206 patients (88 male, 118 female) with a mean age of 68 (±14) years underwent fistuloplasty during the study period. The prevalence of diabetes, ischaemic heart disease and antiplatelet usage were 33%, 21% and 70%, respectively. The median number of fistuloplasties per access during the follow-up period was 2 [1-3]. Fistulas were classified as radiocephalic (65), brachiocephalic (102) and brachiobasilic transposition (39). Recurrent stenosis (RS) was identified in 60 patients who had previous fistuloplasty before the study period, while 146 patients had de novo stenoses (DNS). Stenosis location significantly differed between RS and DNS (p = .03), with DNS primarily being anastomotic and RS predominantly in central and mixed locations. Younger fistulas were more likely to have anastomotic stenoses compared to those older than 1 year (p = .001). While no significant differences in primary patency (PP) were observed, secondary patency (SP) varied by stenosis location: Central 32 [13-42] months, Fistula vein 20 [12.5-35.5] months, Mixed 25 [13.5-37.5] months and Anastomotic 19 [7-29.5] months (p = .012).

CONCLUSION

Stenosis location in AVFs is associated with the age and type of the fistula. Younger fistulas often fail due to anastomotic stenoses, which have lower secondary patency compared to stenoses at other sites. Preliminary data suggest that central stenoses, primarily occurring in older fistulas, exhibit better secondary patency following fistuloplasty than stenoses at other locations.

Artificial neural networks analysis predicts long-term fistula function in hemodialysis patients following percutaneous transluminal angioplasty

Kidney failure is particularly common in the United States, where it affects over 700,000 individuals. It is typically treated through repeated sessions of hemodialysis to filter and clean the blood. Hemodialysis requires vascular access, in about 70% of cases through an arteriovenous fistula (AVF) surgically created by connecting an artery and vein. AVF take 6 weeks or more to mature. Mature fistulae often require intervention, most often percutaneous transluminal angioplasty (PTA), also known as fistulaplasty, to maintain the patency of the fistula. PTA is also the first-line intervention to restore blood flow and prolong the use of an AVF, and many patients undergo the procedure multiple times. Although PTA is important for AVF maturation and maintenance, research into predictive models of AVF function following PTA has been limited. Therefore, in this paper we hypothesize that based on patient-specific information collected during PTA, a predictive model can be created to help improve treatment planning. We test a set of rich, multimodal data from 28 patients that includes medical history, AVF blood flow, and interventional angiographic imaging (specifically excluding any post-PTA measurements) and build deep hybrid neural networks. A hybrid model combining a 3D convolutional neural network with a multi-layer perceptron to classify AVF was established. We found using this model that we were able to identify the association between different factors and evaluate whether the PTA procedure can maintain primary patency for more than 3 months. The testing accuracy achieved was 0.75 with a weighted F1-score of 0.75, and AUROC of 0.75. These results indicate that evaluating multimodal clinical data using artificial neural networks can predict the outcome of PTA. These initial findings suggest that the hybrid model combining clinical data, imaging and hemodynamic analysis can be useful to treatment planning for hemodialysis. Further study based on a large cohort is needed to refine the accuracy and model efficiency.

The Role of Drug-Coated Balloon in Haemodialysis Arteriovenous Fistula Stenosis Management

Arteriovenous fistula (AVF) stenosis is a common problem leading to dialysis access dysfunction. The conventional balloon (CB) is the most commonly used device during angioplasty but suffers from poor durability of results due to neointimal hyperplasia-mediated recurrence. The drug-coated balloon (DCB) is an adjunct to balloon angioplasty that reduces neointimal hyperplasia, thereby improving post-angioplasty patency. Despite the heterogeneity of DCB clinical trials to date, the evidence suggests that DCBs of different brands are not necessarily equal, and that patient selection, adequate lesion preparation and proper DCB procedural technique are important to realize the benefit of DCB angioplasty.

Angioplasty of Dysfunctional Dialysis Fistula or Graft with Resveratrol-Excipient and Paclitaxel-Coated Balloon Improves Primary Patency Rates Compared to Plain Angioplasty Alone

In this prospective randomized single-blinded study (reg. ISRCTN11414306), 76 patients with a dysfunctional dialysis fistula or graft due to a single de novo or recurrent stenosis in the access circuit were randomized to receive either conventional PTA (POBA) as a standard of care (n = 38) or PTA + adjunctive PTA with a drug-coated (paclitaxel-resveratrol matrix) SeQuent^® Please OTW balloon (n = 38, DCB). Patients were scheduled for follow-up PTA at 3, 6, 9, and 12 months. The time of clinically driven target-lesion reintervention rate (primary patency rate) after the index procedure was analyzed using the log-rank test. The primary patency rates at 12 months after the index procedure were 17% (DCB) vs. 11% (POBA). At 3 months, they were 87% vs. 74%, at 6 months they were 53% vs. 26%, and at 9 months they were 22% vs. 11%. The hazard ratio for DCB was 0.55 (95%CI 0.32 to 0.95). The median time needed for target-lesion reintervention was longer in the DCB group (181 days) than in the conventional PTA group (98 days, p = 0.019). We conclude that PTA with the paclitaxel-resveratrol drug-coated SeQuent^® Please OTW balloon in patients with de novo or recurrent stenosis in dialysis arteriovenous fistulas or grafts prolongs the time needed for target lesion reintervention and improves primary patency rates in the first year after the index procedure.

Below Knee Angioplasty Using Drug-Eluting Balloons in Patients with Critical Limb Ischemia with Six Months Follow-Up: Single-Center Experience at Tertiary Care Hospital

Aims and Objective The aim of this study was to evaluate 6 monthly safety and primary patency rates of drug-eluting balloons (DEB) angioplasty in below-the-knee (BTK) arteries in critical limb ischemia (CLI) patients.

Methods A prospective observational study was conducted over 2 years in a tertiary care center. A total of 25 patients with CLI were enrolled in this study. Inclusion criteria were patients presenting with CLI (Rutherford class 4 or greater), equal to or more than 50% luminal stenosis or occlusion of at least one tibial artery, and agreement to 6-month evaluation. Exclusion criteria were life expectancy less than 1 year, allergy to paclitaxel, and contraindication to antiplatelet treatment.

Follow-up was performed by clinical and Doppler assessment. The primary endpoint was a 6-month primary patency rate, and secondary endpoints were changes in the Rutherford class and incidence of major amputation. Restenosis rate is defined as a reduction in the luminal diameter by 50% or greater by duplex ultrasound.

Results Six-month primary patency was achieved in 19 (76%) patients. Both Rutherford category improvement and reduction in the percentage of stenosis after angioplasty were statistically significant (p-value <0.0001). At 6 months, better patency rates were seen among diabetics (88.8%) than smokers (69.2%). Limb salvage was observed in 24 (96%) patients with one major amputation (above the ankle).

Conclusion DEBs have shown safe and promising clinical outcomes with successful performance in infrapopliteal arteries in the short-term follow-up. DEB had a substantial 6-month primary patency rate. DEB angioplasty is a safe and effective treatment option for CLI patients with BTK vascular disease.

VOLume flow assistance for optimizing outcomes of dysfunctional autologous arteriovenous fistula Angioplasty: the VOLA Pilot Study

OBJECTIVES

To investigate the feasibility of VF-assisted angioplasty (VFA) in dysfunctional AVF using sequential intraprocedural duplex ultrasound (DUS), to utilize intraprocedural VF as a quantifiable, functional endpoint in endovascular treatment.

METHODS

This prospective study included 20 consecutive patients (23 lesions; 16 men; mean age 67 ± 16 years) with dysfunctional AVF undergoing fluoroscopically guided balloon angioplasty between June 2019 and May 2020. Primary endpoints were quantification of outcome using sequential DUS VF analysis following each dilation, 6-month target lesion re-intervention (TLR)-free rate, standard technical success, procedural success (achievement of a postprocedural VF value equal (or 10% less) or superior to the baseline steady-state access), and correlation between procedural success and TLR-free rate. Secondary endpoints included 6-month lesion late lumen loss (LLL), correlation between balloon diameter used and intraprocedural VF values, and correlation between VF and LLL at 6 months follow-up.

RESULTS

Mean VF increase was 168.5% ± 102.5% (range: 24.24-493.33%). Procedural success was 80% (16/20 cases). VFA improved procedural success by 20% (4/20 cases) compared to standard assessment (< 30% residual stenosis and palpable thrill). TLR-free rate was 78.3% and 67.3% at 6 and 12 months. Significantly less TLR was noted in cases of procedural success (82.4% vs. 66.7% 6 months; p = 0.041). Unweighted linear regression showed a significant positive relationship between diameter of balloon and VF (146.9 ± 42.3 mL/min VF gain per mm of balloon diameter; p = 0.001, R2 = 0.23) and a significant negative relationship between LLL and VF decline at follow-up (102.0 ± 34.6 mL/min loss per mm of LLL; p = 0.01, R2 = 0.35). Optimal VF cutoff value and percentile increase to predict access failure were 720 mL/min (sensitivity 58.3%, specificity 71.4%) and 153% (sensitivity 66.7%, specificity 85.7%), respectively.

CONCLUSION

Intraprocedural VF assessment could be used to optimize AVF angioplasty.

KEY POINTS

• A newly proposed functional endpoint of angioplasty in dysfunctional dialysis fistula was evaluated and angioplasty outcome was quantified using volume flow (VF) assessment with sequential intraprocedural DUS. • Intraprocedural VF assessment improved immediate procedural success; increased balloon diameter was correlated with VF gain and late lumen loss with VF decline. • Intraprocedural VF values ≥ to baseline steady-state values were correlated with less re-interventions.

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.

Efficacy and Safety of Paclitaxel-Coated Balloon Angioplasty for Dysfunctional Arteriovenous Fistulas: A Multicenter Randomized Controlled Trial

RATIONALE & OBJECTIVE

Previous studies have illustrated the potential superiority of drug-coated balloons (DCBs) in maintaining patency after initial angioplasty for arteriovenous fistula (AVF) dysfunction due to stenosis. Our trial evaluated the efficacy and safety of DCBs for preventing fistula restenosis in Chinese hemodialysis patients.

STUDY DESIGN

Multicenter, prospective, randomized, open-label, blinded end point, controlled trial.

SETTINGS & PARTICIPANTS

A total of 161 hemodialysis patients with fistula dysfunction from 10 centers in China.

INTERVENTION

Participants were randomized 1:1 to treatment with initial dilation followed by DCB angioplasty or conventional high-pressure balloon (HPB) angioplasty.

OUTCOMES

The primary end point was target lesion primary patency defined as the target lesion intervention-free survival in conjunction with an ultrasonography-measured peak systolic velocity ratio (PSVR) ≤2.0 at 6 months. The secondary end points included 1) device, technical, clinical, and procedural success; 2) major adverse events; 3) degree of target lesion stenosis at 6 months; and 4) clinically driven target lesion and target shunt revascularization within 12 months.

RESULTS

The percentage with target lesion primary patency as defined by a PSVR ≤2.0 was higher in the DCB group than in the control group (65% vs 37%, respectively; rate difference, 28% [95% CI, 13%-43%]; P <0.001) at 6 months. The target lesion and target shunt intervention-free survival of the DCB group were not superior to those of the control group at 6 months (P = 0.3 and P = 0.2, respectively) but were superior at 12 months (target lesion intervention-free survival: 73% for DCB vs 58% for control [P = 0.04]; target shunt intervention-free survival: 73% for DCB vs 57% for control [P = 0.04]). The average degree of target lesion stenoses at 6 months was not significantly different between the 2 groups (44% ± 16% for DCB vs 49% ± 18% for control; P = 0.09). There were no significant differences in major adverse events or in device, technical, clinical, or procedural success rates between the groups.

LIMITATIONS

Small sample size; short follow-up period; procedural differences between the 2 groups such as unequal inflation times and balloon lengths.

CONCLUSIONS

Compared to conventional HPB angioplasty, DCB treatment achieved superior primary patency defined using PSVR measured at 6 months and superior intervention-free survival of both the target lesion and the target shunt at 12 months without evidence of greater adverse events.

FUNDING

Funded by ZhuHai Cardionovum Medical Device Co., Ltd.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT02962141.

Predictors associated with early and late restenosis of arteriovenous fistulas and grafts after percutaneous transluminal angiography

BACKGROUND

The objective of this study was to assess postintervention patency and analyze the predictive factors associated with early and late restenosis after intervention in hemodialysis arteriovenous fistulas (AVF) and arteriovenous grafts (AVG).

METHODS

This study retrospectively analyzed 284 hemodialysis patients who underwent percutaneous transluminal angioplasty (PTA) due to AVF and AVG stenosis. A total of 350 PTA procedures were performed. Clinical, anatomical, biochemical, and technical variables were analyzed. Using univariate and multivariate analyses, we assessed the postintervention patency of PTA by follow-up, and identified the predictive factors taking into account competing risks.

RESULTS

Postintervention patency rates at 3, 6, 12, and 24 months were 86.5%, 66.4%, 42.6%, and 29.8%, respectively, with a median patency duration of 11±0.71 months. Kaplan-Meier analysis showed that the patency rate of the AVF group (n=271) was dramatically higher than the AVG group (n=79) at 3, 6, and 12 months after PTA, respectively (88.9% vs. 78.5%, 69.0% vs. 57.4%, 48.8% vs. 20.0%, P<0.01). Cox survival analysis revealed that the factors associated with postintervention patency of AVF included age of fistulas, serum albumin (ALB) levels, location of stenoses, lesion length longer than 2 cm, multiple stenoses, and maximal pressure of dilatation lower than 16 atm. In addition, factors related to postintervention patency of AVG included the presence of diabetes and hypertension, and serum ALB.

CONCLUSIONS

This study demonstrated that the risk factors associated with postintervention patency of AVF included age of fistulas, lower levels of serum ALB, location of stenoses, lesion length longer than 2 cm, multiple stenoses, and maximal pressure of dilatation lower than 16 atm. In addition, risk factors related to postintervention patency of AVG included the presence of diabetes and lower levels of serum ALB, while the presence of hypertension was found to be a protective factor for reducing patency loss of AVG. Among all these factors, serum ALB and multiple stenoses tended to predict early restenosis, while pressure of dilatation tended to predict late restenosis.