Angioplasty Of Arteriovenous Fistula Research Articles

Dialysis-associated steal syndrome as a rare complication of arteriovenous fistula angioplasty

Abstract The angioplasty of arteriovenous fistulas (AVF) has become indispensable in preserving haemodialysis access. Though well-known complications, such as pseudoaneurysm formation and rupture, can occur, the incidence of severe dialysis-associated steal syndrome (DASS) following AVF angioplasty is low. We describe a patient with limited dialysis options who developed significant DASS following angioplasty of his AVF. After excluding flow-limiting causes of DASS, the patient underwent a successful Revision Using Distal Inflow procedure, redirecting blood flow to his distal arm. Subsequently, all ischaemic symptoms resolved. While effective surgical options are available for the management of DASS, preventive measures such as proper angioplasty balloon sizing remain key.

Drug-coated balloons versus conventional percutaneous transluminal angioplasty for treatment-naïve dysfunctional arteriovenous fistulas.: A 10-year single center retrospective study.

To compare the primary patency and restenosis rates in treatment naieve dialysis arteriovenous fistulas (AVFs) after drug-coated balloons (DCB) versus plain balloon angioplasty (PTA). This retrospective study included 157 patients who underwent AVF angioplasty for treatment-native AVF stenosis between January 2012 to 2022. The fistulas were Brachiocephalic (75%), Brachiobasilic (17%), and radiocephalic (8%). The index intervention was with either DCB or percutaneous transluminal angioplasty (PTA) with subsequent follow up. Patients with central venous stenosis, thrombosed fistula, fistula stents, AV graft or surgical intervention after the index procedure were excluded. Arteriovenous fistula angioplasty was done in 28 patients using DCB and in 129 patients using PTA. A total of 108 patients presented with a single stenosis, 42 with 2 stenoses, and 7 with 3 stenoses. The location of these stenoses was in the venous outflow (57%), the juxta anastomotic segment (31%), and cephalic arch (12%). The median time to re-intervention for the PTA was 216 days compared to 304 days for the DCB (p=0.079). Primary patency at 6 months was 60.4% for PTA and 75% for DCB (p=0.141) CONCLUSION: Although DCB angioplasty of treatmentnaïve dysfunctional AVF tends to improve the time to intervention and 6-month primary patency compared to PTA, this difference did not reach statistical significance.

Endovascular tools for vascular access stenosis: Flow-chart proposal.

Stenosis represents the most relevant arteriovenous fistula (AVF) pathology and can affects the entire conduit forming the fistula, from afferent artery to central venous vessels. Correction of vascular access stenosis significantly affects the survival and quality of life for end stage renal disease patients (ESRD) dependent on hemodialysis. Guidelines consider the procedure of percutaneous transluminal angioplasty (PTA) relevant for the primary treatment of these lesions with excellent results in restoring AVF immediately at the end of the procedure. From first AVF angioplasty in 1981 to now, wide scientific innovation has led to development of new devices, composed by different materials and technologies, specific for the site and the type of stenosis to be treated, able to manage resistant stenotic lesion and to reduce stenosis recurrences. International guidelines do not clearly specify all treatment possibilities in the individual case. In this review the authors want to provide specific information on most used devices for stenosis treatment based on literature evidence, showing when and where to use the various tools available with flow-chart treatment proposal.

Analysis of risk factors for late arteriovenous fistula failure and patency rates after angioplasty in hemodialysis patients: a retrospective cohort study.

The incidence of chronic kidney disease (CKD) and end-stage kidney disease (ESKD) is increasing worldwide. Hemodialysis (HD) is the mainstay of renal replacement therapy for patients with ESKD. Risk factors associated with late arteriovenous fistula (AVF) failure in HD patients are poorly investigated. Therefore, the aim of this study was to identify factors associated with late AVF failure in HD patients. Patients with end-stage renal disease (ESRD) who underwent forearm or upper arm AVF angioplasty at Second Affiliated Hospital of Chongqing Medical University between September 2009 and August 2018 were included. Patients were followed up for 36 months. Baseline characteristics were collected using electronic medical records (EMRs). Variables associated with late AVF failure were identified using Cox proportional hazards models. There were 137 patients (64% male, 36% female) included in this study, with 50 (36.5%) experiencing AVF failure. Univariable log-rank analysis showed that age, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), intact parathyroid hormone (iPTH), albumin (ALB), and AVF patency rate were significantly different between patients who did and did not experience AVF failure. Cox regression analysis showed that CRP [P=0.002, hazard ratio (HR) =2.719, 95% confidence interval (CI) for HR: 1.432-5.164], ESR (P=0.030, HR =2.431, 95% CI: 1.088-5.434), iPTH (P=0.013, HR =0.325, 95% CI: 0.133-0.793), and ALB (P=0.040, HR =0.539, 95% CI: 0.299-0.972) were independently associated with AVF failure. Kaplan-Meier survival analysis showed that the cumulative patency rates of AVF at 6, 12, 18, 24, 30, and 36 months were 84%, 74%, 69%, 64%, 64%, and 64%, respectively. CRP, ESR, iPTH, and ALB were associated with AVF failure and should be used as reference in clinical practice.

Lumen diameter is associated with the patency after percutaneous angioplasty of arteriovenous fistulas.

To assess the value of lumen diameter after percutaneous angioplasty (PTA) to predict functional dialysis use (FDU) of arteriovenous fistulas (AVF). We performed a retrospective study of all patients who underwent first PTA because of AVF stenosis between March 2019 and March 2021. The outcome was FDU of AVF at 6 months follow up. Independent factors of FDU were identified using multivariate regression analyses. Receiver operating characteristic (ROC) curve was performed to investigate the predictive ability of lumen diameter for FDU. A total 68 patients were included into this study and the AVF of 53 cases (77.9%) were good for FDU after 6 months. The AVF age was younger in failure group than that in success group (16.1 ± 9.1 months vs 28.3 ± 20.0 months, p = 0.026). Compared with failure group, the post-PTA minimum luminal diameter (MLD) was bigger in success group (4.5 [4.0-4.5 mm] vs 5.5 mm [4.5-5.5 mm], p < 0.001). Meanwhile, the gain of lumen diameter in success group was also bigger than that in failure group (2.5 mm [2.0-3.0 mm] in failure group vs 3.0 mm [2.75-3.5 mm] in success group, p = 0.012). The residual stenosis was higher in failure group than that in success group (30% [10%-40%] vs 10% [0%-20%], p = 0.003). Logistic regression showed that AVF age and post-PTA MLD were independent predictors of FDU. ROC analysis showed that the gain of lumen diameter, post-PTA MLD and improvement of stenosis were comparable to predict FDU. For post-PTA MLD, the area under ROC curve was 0.804 (95% CI, 0.681-0.927, p < 0.001). The best cutoff is 4.75 mm, with the sensitivity and specificity was 71.7% and 80.0%, respectively. AVF age and post-PTA MLD were independently predictors for FDU of AVF after PTA. To get the best performance, a minimum vein diameter of 4.75 mm should be obtained after angioplasty.

Drug-coated balloons and dialysis vascular access: is there light at the end of the tunnel . . .

This commentary uses the negative results of the PAVE (Paclitaxel-coated Balloons and Angioplasty of Arteriovenous Fistulas) study to (i) discuss the role of drug-coated balloons in the armamentarium of therapies for dialysis vascular access stenosis and (ii) suggest a more patient centered, individualized, and precision medicine-based approach for the future care of patients with dialysis vascular access dysfunction.

A case of peritoneal dialysis-associated peritonitis caused by Rhodococcus kroppenstedtii

BackgroundRhodococcus kroppenstedtii is an aerobic, gram-positive bacterium firstly identified in the environment, which has not been reported in human-related infection. Herein, we reported the first case of peritoneal dialysis (PD)-associated peritonitis caused by R. kroppenstedtii which was identified by whole genome sequencing.Case presentationA 69-year-old man was admitted to hospital with abdominal pain and fever. Over the last 2 years, he had been undergoing continuous ambulatory peritoneal dialysis (CAPD) due to end-stage renal disease. Clinical symptom and sign in combination with laboratory examinations supported the clinical diagnosis of PD-associated peritonitis. Thus, ceftizoxime and teicoplanin were empirically used after PD effluent was collected for bacterial culture. A gram-positive bacterium was found from the PD effluent culture, which could not be identified by either Vitek 2 Compact ANC card or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The strain was finally confirmed to be R. kroppenstedtii by whole genome sequencing (WGS) through the average nucleotide identity (ANI) analysis. With a continuous treatment with teicoplanin and imipenem for 15 days and intraperitoneal catheter removed, the infection symptom was improved evidenced by a normal body temperature, also with white blood cell count (WBC), procalcitonin (PCT) and C-reactive protein (CRP) dropped to normal levels. Peritoneal dialysis effluent culture showed a negative result. Then, hemodialysis and arteriovenous fistula angioplasty were performed, but the patient developed a progressive blood pressure loss, accompanied by multiple organ disorder, and died on Feb 25, 2020.ConclusionsTo the best of our knowledge, this is the first time to report a peritoneal dialysis-associated peritonitis caused by R. kroppenstedtii which was identified by average nucleotide identity analysis based on WGS.

A multicenter randomized controlled trial indicates that paclitaxel-coated balloons provide no benefit for arteriovenous fistulas

The role of paclitaxel-coated balloons has been established in the coronary and peripheral arterial circulations with recent interest in the use of paclitaxel-coated balloons to improve patency rates following angioplasty of arteriovenous fistulas. To assess the efficacy of paclitaxel-coated angioplasty balloons to prolong the survival time of target lesion primary patency in arteriovenous fistulas, we designed an investigator-led multi-center randomized controlled trial with follow up time variable for a minimum of one year. Patients with an arteriovenous fistula who were undergoing an angioplasty for a clinical indication were included but patients with one or more lesions outside the treatment segment were excluded. Following successful treatment with a high-pressure balloon, 212 patients were randomized. In the intervention arm, the second component was insertion of a paclitaxel-coated balloon. In the control arm, an identical procedure was followed, but using a standard balloon. The primary endpoint was time to loss of clinically driven target lesion primary patency. Primary analysis showed no significant evidence for a difference in time to end of target lesion primary patency between groups: hazard ratio 1.18 with a 95% confidence interval of 0.78 to 1.79. There were no significant differences for any secondary outcomes, including patency outcomes and adverse events. Thus, our study demonstrated no evidence that paclitaxel-coated balloons provide benefit, following standard care high-pressure balloon angioplasty, in the treatment of arteriovenous fistulas. Hence, in view of the benefit suggested by other trials, the role of paclitaxel-coated angioplasty balloons remains uncertain.

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

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. Multicenter, prospective, randomized, open-label, blinded end point, controlled trial. A total of 161 hemodialysis patients with fistula dysfunction from 10 centers in China. Participants were randomized 1:1 to treatment with initial dilation followed by DCB angioplasty or conventional high-pressure balloon (HPB) angioplasty. 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. 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. Small sample size; short follow-up period; procedural differences between the 2 groups such as unequal inflation times and balloon lengths. 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. Funded by ZhuHai Cardionovum Medical Device Co., Ltd. Registered at ClinicalTrials.gov with study number NCT02962141.

Clinical experience with distal transradial access for endovascular treatment of various noncoronary interventions in a multicenter study.

BackgroundTransradial access is a well-known alternative to conventional transfemoral access for interventional procedures. Recently, transradial access through the “snuffbox”, which lies in the radial dorsal aspect of the hand, has been introduced as a new technique with positional versatility. In this study, we aimed to evaluate the clinical feasibility and safety of distal transradial access for interventional procedures in a retrospective, multicenter study.Material & methodsDistal transradial access was attempted in 46 patients (36 men and 10 women; mean age, 64 years) who underwent 47 consecutive procedures from January 2018 to December 2019. Procedures included chemoembolization (19/47, 40.4%), bronchial artery embolization (7/47, 14.9%), renal intervention (3/47, 6.4%), arteriovenous fistula angioplasty (7/47, 14.9%), subclavian artery stenting (5/47, 10.6%), other embolization (5/47, 10.6%), and uterine artery embolization (1/47, 2.1%). We recorded the success rate of the procedures, complications, and postprocedural hemostasis time during the follow-up period.ResultsThe technical success of distal transradial access without major complications was 97.9% (46/47). Of the 46 patients, one patient (2.2%) had a minor complication, which was a thrombotic segmental occlusion of the distal radial artery. Of the enrolled patients, only one patient did not complete the transradial access procedure via the snuffbox because the left proximal subclavian artery was occluded and a crossover to conventional transfemoral access was performed. The mean postprocedural hemostasis time was 131.7 minutes (range, 120–360 minutes).ConclusionDistal transradial access can be a valid option for the endovascular treatment of various noncoronary interventions with technical feasibility and safety.

A Novel Model of Balloon Angioplasty Injury in Rat Arteriovenous Fistula

Background: There are very few animal models of balloon angioplasty injury in arteriovenous fistula (AVF), hindering insight into the pathophysiologic processes following angioplasty in AVF. The objective of the study was to develop and characterize a rat model of AVF angioplasty injury. Methods: Balloon angioplasty in 12- to 16-week-old Sprague-Dawley rats was performed at the arteriovenous anastomosis 14 days post-AVF creation with a 2F Fogarty balloon catheter. Morphometry and protein expression of endothelial nitric oxide synthase (eNOS), monocyte-chemoattractant protein-1 (MCP-1), alpha-smooth muscle actin (α-SMA), CD68 (macrophage marker), and collagen expression in AVFs with and without angioplasty were assessed. Results: In AVFs with angioplasty versus without angioplasty: (1) angioplasty increased AVF-vein and artery intimal hyperplasia, (2) angioplasty decreased eNOS protein expression in AVF-vein and artery at 21 days post-AVF creation and remained decreased in the AVF-vein angioplasty group at 35 days, (3) angioplasty increased AVF-vein and artery α-SMA expression within the intimal region at 35 days, (4) angioplasty increased the expression of AVF-vein MCP-1 at 21 days and CD68 at 21 and 35 days, and (5) angioplasty increased AVF-vein and artery collagen expression at 35 days. Conclusion: Our findings describe a reproducible rat model to better understand the pathophysiologic mechanisms that ensue following AVF angioplasty.

KDOQI 2019 Vascular Access Guidelines: What Is New?

The new Kidney Disease Outcomes Quality Initiative Vascular Access Guidelines now focus on a more comprehensive overall patient strategy. The patient's vascular access needs are part of a dialysis access strategy, which itself is part of an End Stage Kidney Disease Life-Plan strategy that stems from a unique patient's individualized needs. The End Stage Kidney Disease Life-Plan is an individualized and comprehensive map for dialysis modalities and dialysis access for the lifetime of the patient. New targets are introduced that align with this patient-centered approach. The Guidelines made significant changes to the use of surveillance techniques to detect stenosis and found insufficient evidence to make a recommendation for routine arteriovenous fistula surveillance by measuring access blood flow, pressure monitoring, or imaging for stenosis that was in addition to routine clinical monitoring. Routine surveillance is not recommended in arteriovenous grafts. Similarly, pre-emptive angioplasty of arteriovenous fistulas or arteriovenous grafts with stenosis, not associated with clinical indicators, is not recommended. The Guidelines represent a rigorous review of the evidence; however, the available evidence to guide vascular access practice remains limited. There is a significant need and opportunity for new and ongoing high-quality research to inform best practice.

The effect of angioplasty of single arteriovenous fistula-associated stenosis on arteriovenous fistula blood flow rate.

Percutaneous balloon angioplasty of arteriovenous fistula-associated stenosis is performed for a variety of indications. Successful percutaneous transluminal angioplasty (PTA) is expected to increase in arteriovenous fistula blood flow rate (Qa). A validated approach to predicting changes in Qa based upon stenosis characteristics is not available. Three baseline parameters were determined in a group of patients with a single arteriovenous fistula-associated stenosis undergoing PTA. These were percent estimated stenosis, stenosis minimum luminal diameter, and baseline Qa. The relationship between these parameters and changes in Qa following PTA was analyzed using Spearman's rank correlation and linear regression. 113 patients (total group) were studied. Of these,106 had peripheral stenosis (total peripheral subgroup) and 7 had central stenosis. For the total group and total peripheral subgroup, a highly significant inverse correlation was seen between changes in Qa and baseline Qa. A weaker correlation was seen between changes in Qa and minimum luminal diameter, but no correlation was seen with percent estimated stenosis. A minimum luminal diameter ⩽2.0 mm was predictive of ⩾300-mL/min increases in Qa, whereas a minimum luminal diameter >4.5 mm was associated with <300-mL/min increases in Qa. PTA of Central vein stenosis was not associated with significant changes in Qa. Baseline Qa is the best predictor for change in Qa following PTA. Stenosis minimum luminal diameter cutoffs of ⩽2.0 and >4.5 mm are useful in predicting the magnitude of changes in Qa. Percent estimated stenosis is not predictive of change in Qa. PTA of central veins does not seem to change Qa.

Rupture, Breakdown, and Pulmonary Artery Embolism of a Balloon Catheter Tip during Percutaneous Transluminal Angioplasty of Arteriovenous Fistula

Percutaneous transluminal angioplasty is a well-known treatment for arteriovenous fistula stenosis. Balloon rupture during endovascular procedures is a rare but possible complication. The bursting balloon itself does not cause a serious problem, but it can occasionally cause entrapment, especially in case of breakdown of the balloon catheter tip. Here, we present four cases of balloon rupture during angioplasty in the hemodialysis circuit. In three cases, the ruptured balloon catheter was removed by cutdown of access conduit, while in one case, tip of ruptured balloon catheter was migrated into the pulmonary artery and was removed surgically. The operator must attempt to reduce the risk of balloon rupture by gradually expanding the balloons under bursting pressure. If the balloon bursts, it should not be removed excessively and attempt should be made to remove it using endovascular techniques. Surgical removal is considered after careful evaluation of the condition of the balloon and vessel.

Outcomes After Percutaneous Angioplasty of Arteriovenous Fistulas and Grafts in African American Patients

PurposeArteriovenous fistulas and grafts, necessary for hemodialysis, may develop stenoses due to neointimal hyperplasia, which often require percutaneous transluminal angioplasty. Patient and lesion characteristics were evaluated prior to angioplasty and were correlated with 1- and 6-month outcomes. Materials and MethodsThis was an observational study of African American hemodialysis patients who presented for angioplasty of a dysfunctional fistula or graft. Clinical outcomes were ascertained from dialysis facilities 1 month and 6 months after angioplasty. One-month clinical success was defined as dialyzer blood flows of 450 mL/min without complications or interval shunt thrombosis, interventions, or loss of access, which was rarely achieved at 6 months. Logistic regression models were used to evaluate associations of clinical variables with outcomes. ResultsThere were 150 stenoses treated during 99 procedures performed on 82 patients. The clinical success rate at one month was 67% with no complications as a result of the percutaneous transluminal angioplasty. Success at 1 month was positively associated with use of aspirin (P = .005) and with referral for high venous pressures (P = .004). Six-month data were available for 81 procedures, with 45.7% requiring repeat angioplasty and 12.3% suffering major complications (thrombectomy, revision surgery, or access abandonment). Major complications were seen predominantly in patients who were not receiving aspirin. ConclusionsAspirin use and high venous pressure were associated with 1-month clinical success and fewer major complications at 6 months. Future work should investigate biologic mechanisms of action of aspirin and long-term effects of use to maintain vascular access.

Comparison of the efficacy of using paclitaxel-eluting balloon and plain balloon angioplasty for arteriovenous fistula in hemodialysis patients

Introduction: Arteriovanous (AV) access failure is one of the main problems in patients with end stage renal disease (ESRD), who receive hemodialysis. Balloon angioplasty is a favorable method for managing vascular access failure. The purpose of this study was to compare the six-month efficacy of paclitaxel-eluting balloon and plain balloon angioplasty in failed AV access cases among hemodialysis patients.&#x0D; Methods: In this quasi-experimental study (http://en.irct.ir/trial/35333), 50 hemodialysis patients with failure of AV access (stenosis &gt; 50%), who were candidates for angioplasty, were included. They were divided to receive either paclitaxel-eluting balloon (25 patients) or plain balloon (25 patients) angioplasty. Patients were followed up for six months with color Doppler ultrasonography and clinical examination for the hemodynamic success rate of angioplasty.&#x0D; Results: After six months, 19 patients (76%) in paclitaxel-eluting balloon angioplasty group achieved hemodynamic success, which was significantly higher than plain balloon angioplasty group (13 patients, 52%) (P = 0.012). Age, gender, diabetes mellitus, hypertension, and location of AVF (snuff box, forearm, and antecubital fossa) did not associate with hemodynamic success rate in any group.&#x0D; Conclusion: The use of angioplasty with paclitaxel-eluting balloon was superior to plain balloon angioplasty for failed AV access cases in hemodialysis patients. It is recommended to use paclitaxeleluting balloon angioplasty in patients with failure of AV access and requirement for balloon angioplasty.&#x0D;

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

Ultrasound-guided percutaneous angioplasty of arteriovenous fistulas (AVFs) makes it possible to avoid contrast agents and X-rays, to optimize the puncture site and to locate some stenoses on the fistulography, but is it really useful? Our objective is to report the results of our experience. Between November 2012 and November 2017, all the patients treated according to this method in our center were collected retrospectively. The surgical indications were an insufficient maturation of the AVF, an increase in the venous pressure, an inadequate outflow, difficulties in puncture, a prolonged bleeding time, a flow drop, or an aneurysmal evolution. During this period, 50 patients had 72 ultrasound-guided angioplasties, 64 on native AVFs (88.9%) and 8 on prosthetic AVFs (11.1%). The technical success rate was 100%. The average preoperative flow of AVFs was 506.8± 302.2 vs. 955.9±371.4mL/min after angioplasty. The mean duration of follow-up was 13.4±12.9months. The cumulative rates of primary, assisted primary, and secondary patency were 43.5%, 68.8%, 81.5% at 1 year and 31.7%, 63.9%, 76.8% at 2 years, respectively. AVF angioplasty under ultrasound guidance only is feasible, effective, and represents an interesting alternative. A controlled study comparing ultrasound guidance with angioplasties performed under conventional angiographic guidance as the reference technique would better clarify the value of this technique.

Percutaneous transluminal angioplasty in Japan: five-center investigation.

Percutaneous transluminal angioplasty (PTA) is the first-line treatment for vascular access stenosis. To our knowledge, multicenter clinical research of PTA has not been reported in Japan. We examined the efficacy and safety of PTA for arteriovenous fistula (AVF) and arteriovenous graft (AVG) in five centers of Japan. Three hundred cases of angioplasty for AVF and 300 for AVG were examined in three centers each. A hundred consecutive patients from each center who underwent PTA for AVG or AVF prior to March 2014 and met the inclusion criteria were searched retrospectively. Primary patency rates were estimated using the Kaplan-Meier method. The mean age was 69.3 ± 11.2 years in the AVF group and 70.2 ± 11.9 years in the AVG group. The anatomical success rates were 51.7% (155 of 300) in the AVF group and 72.0% (216 of 300) in the AVG group. The clinical success rates were 99.7% (299 of 300) in the AVF group and 100% (300 of 300) in the AVG group. A total of 25 complications (4.17%) were encountered in both groups including one major complication (0.17%). The primary patency was 99.0% at 1 month, 87.9% at 3 months and 51.7% at 6 months in the AVF group, and 96.0% at 1 month, 64.8% at 3 months and 20.4% at 6 months in the AVG group. The clinical success rate of PTA in five centers was relatively high and a major complication rate was only 0.17%. However, anatomical success rates were low comparing with the previous studies and the primary patency rates were inferior to the past data.

Intravascular Ultrasound-Guided Angioplasty of Hemodialysis Loop Graft in a Patient with Contrast Allergy

A surveillance duplex scan detected a stenosis within a left groin hemodialysis loop graft in a 57-year-old woman who was allergic to both iohexol and gadolinium contrast agents. This precluded the use of standard angioplasty treatment techniques. Intravascular ultrasound (IVUS) uses a catheter mounted with a miniaturized ultrasound probe to produce detailed cross-sectional vessel images. Clinically, it has been used in the assessment of coronary artery disease but has also supplemented standard angiography techniques in the assessment of peripheral vascular and hemodialysis access lesions. IVUS was utilized as the solitary imaging modality to identify the graft stenosis and guide the placement of a 6 mm diameter angioplasty balloon. Two areas of stenosis were successfully dilated and subsequent IVUS re-examination showed abolition of the stenosis. Twelve-month follow-up surveillance scan showed that the graft remained functional with good flow rates. In the setting of contrast allergy, IVUS may provide a valid and safe tool in the localization and treatment of peripheral vessel stenosis, including arteriovenous fistula angioplasty. To our knowledge this is the first reported use of IVUS for hemodialysis graft salvage adopting a completely 'contrast-free' technique. More studies are required to establish the true role of IVUS in the management of hemodialysis access angioplasty, but this successful case contributes valuable information to the literature on its clinical application.

The impact of peripheral arterial disease on outcome after percutaneous transluminal angioplasty for arteriovenous fistula: a 1-year retrospective analysis

The impact of peripheral arterial disease on outcome after percutaneous transluminal angioplasty for arteriovenous fistula: a 1-year retrospective analysis