Reporting Standards for Percutaneous Interventions in Dialysis Access

Recanalization of thrombosed arteriovenous fistulas for hemodialysis by minimal venotomy

The present work describes the preliminary results of a new method of minimally invasive thrombectomy in the treatment of thrombosed arteriovenous fistula (AVF) with dilated aneurysm. Data from 25 patients who were treated with this minimal venotomy technique were retrospectively reviewed. The minimal venotomy was made on the dilated fistula, and thrombectomy was performed with forceps and Fogarty catheters through the venotomy site. Technical and clinical success was achieved in all 25 patients. There were two major and two minor complications (8% each). The two major complications consisted of bleeding at the venotomy site after early suture removal.

Endovascular Repair of Symptomatic Hemodialysis Access Graft Pseudoaneurysms

Aim

Repeated needle punctures of arteriovenous hemodialysis grafts can lead to the development of pseudoaneurysms. As they enlarge, graft pseudoaneurysms are associated with significant morbidity and require treatment. We present our single-center experience using stent grafts in selected patients to exclude symptomatic hemodialysis graft pseudoaneurysms.

Materials and Methods

Between March 2007 and December 2010, 11 consecutive patients (7 men and 4 women, mean age 57 years) underwent percutaneous endovascular repair of symptomatic hemodialysis access graft pseudoaneurysms. Indications for treatment were rapidly enlarging pseudoaneurysm in 5 patients, high venous pressures, limb edema and pseudoaneurysm in 3, skin breakdown over the pseudoaneurysm site in 2 and acute rupture and bleeding in 1 patient. No patient was lost to follow-up.

Results

Technical success across the 11 patients was 90.9%. The patient who presented with rupture required ligation of the access due to continuous bleeding after stent graft insertion. Balloon angioplasty of a separate hemodynamically significant stenosis at the time of stent graft insertion was performed in 7 of 11 (63.6%) patients. The primary access patency rates were 72.7% (95% CI of 0.390-0.939) at 3 months and 36.4% (95% CI 0.109-0.692) at 6 months. Secondary access patency rates were 72.7% at 6 months (95% CI 0.233-0.832). There were no procedure-related complications. Mean follow-up was 9 months (range 2-29 months).

Conclusions

Endovascular treatment of symptomatic hemodialysis graft pseudoaneurysms is safe and effective with similar patency rates to surgical approaches. Importantly, this approach allows aggressive management of associated access circuit stenoses at the same time and avoids interval tunneled dialysis line insertion.

Endovascular stent placement of juxtaanastomotic stenosis in native arteriovenous fistula after unsuccessful balloon angioplasty

Background

In hemodialysis patients, the most common problem in arteriovenous fistulas, as the best functional vascular access, is the juxtaanastomotic located lesions. Percutaneous transluminal angioplasty is accepted as the treatment method for juxtanastomotic lesions.

Objectives

To assess juxtaanastomotic stent placement after insufficient balloon angioplasty in the treatment of autogenous radiocephalic or brachiocephalic fistula dysfunction.

Patients and Methods

Between July 2003 and June 2010, 20 hemodialysis patients with autogenous radiocephalic or brachiocephalic fistula dysfunction underwent stent placement for the lesion located at the juxtaanastomotic region. Indications for stent placement were insufficient balloon dilatation, early recurring stenosis, chronic organizing thrombus and vessel rupture. The Kaplan-Meier method was used to calculate the stent patency rates. All patients who had fistula dysfunction (thrombosis of hemodialysis access, difficult access cannulation, extremity pain due to thrombosis or decreased arterial access blood flow) were evaluated by color Doppler ultrasound. The stenoses were initially dilated with standard noncompliant balloons (3 to 10-mm in diameter). Dilatation was followed by high pressure (Blue Max, Boston Scientific) or cutting balloons (Boston Scientific), if the standard balloon failed to dilate the stenotic segment.

Results

Twenty-one stents were applied. The anatomical and clinical success rate was 100%. Seventeen additional interventions were done for 11 (55%) patients due to stent thrombosis or stenosis during follow-up. Our 1- and 2-year secondary patency rates were 76.2% and 65.5%, respectively and were comparable to those after balloon angioplasty and surgical shunt revision.

Conclusion

Metallic stent placement is a safe and effective procedure for salvage of native hemodialysis fistula after unsuccessful balloon angioplasty.

Retrospective review of angiography before cannulation of newly created vascular accesses in hemodialysis patients

PURPOSE

To investigate vascular access status before first cannulation and the clinical implications of angiography performed before cannulation.

MATERIALS AND METHODS

A retrospective review of 300 consecutive patients who underwent angiography after vascular access surgery and before cannulation between August 2004 and April 2010 was performed. Angiography was performed 4-6 weeks after the surgery but before the first cannulation.

RESULTS

Angiography revealed 94 (31.3%) cases of severe stenosis (≥ 50% luminal narrowing) that required percutaneous transluminal angioplasty (PTA) or a second operation. No stenosis was observed in 122 (40.7%) cases, and mild stenosis (< 50% luminal narrowing) was observed in 84 (28%) cases. For the 94 cases with severe stenosis, PTA was performed in 66, and a second operation was performed in 16. In the other cases (n = 12), HD was maintained by a permanent catheter, or the patients were transferred to another institution. PTA was an immediate success in all patients who underwent the procedure except two. Of 84 patients with mild stenosis, 70 were followed for 1 year; vascular access dysfunction occurred in 15, and 11 of these underwent successful PTA. Of the 122 patients with normal angiographic findings, 102 were followed for 1 year, and vascular access dysfunction did not occur in any of these patients.

CONCLUSIONS

Early postoperative angiography before the first hemodialysis is helpful for the early detection and treatment of vascular access dysfunction.

Stent grafts for central venous occlusive disease in patients with ipsilateral hemodialysis access

PURPOSE

To assess long-term outcomes of stent grafts in patients with symptomatic central venous stenoses and occlusions ipsilateral to hemodialysis grafts or fistulas.

MATERIALS AND METHODS

The study included 52 of 55 consecutive patients with symptomatic stenoses of the central veins draining upper limb dialysis access grafts or fistulas treated with stent grafts. Indications for stent grafts were poor angioplasty results, rapid recurrence, or total occlusion. Endpoints were lesion patency and access patency following intervention. Mean follow-up was 25 months with a median of 24 months and 1.25 additional procedures per patient year. Patency rates were calculated using Kaplan-Meier analysis.

RESULTS

All stent grafts were successfully deployed. The lesion patency rates at 6, 12, 24, and 36 months after intervention were 60%, 40%, 28%, and 28%. The access patency rates at 6, 12, 24, and 36 months after intervention were 96%, 94%, 85%, and 72%. There was one major complication and no minor complications. In 40 patients (77%), the internal jugular vein confluence was covered by the stent graft. In five patients, the dialysis circuits became occluded, with no clinical sequelae in four; one patient was lost to follow-up. The contralateral brachiocephalic vein was covered in three patients (6%), preventing contralateral access construction in one patient.

CONCLUSIONS

Central vein stent graft placement in patients with hemodialysis access is associated with prolonged access patency. Coverage of major vein confluences, which occurred in 83% of the patients in this series, can compromise future access and should be avoided whenever possible by careful technique.

Objective and subjective assessment of physician labor and resource utilization in maintenance percutaneous transluminal angioplasty of nonthrombosed hemodialysis arteriovenous fistulas versus arteriovenous grafts

PURPOSE

To complement prior studies that have shown that arteriovenous fistula (AVF) thrombectomies require more time and equipment than arteriovenous graft (AVG) thrombectomies by measuring work via established instruments to determine whether there is also a difference in maintenance percutaneous transluminal angioplasty (PTA) of nonthrombosed AVFs versus AVGs.

MATERIALS AND METHODS

PTA procedures performed on a consecutive cohort of 42 patients with AVFs and 27 patients with AVGs were prospectively compared. To quantify resource utilization, procedure time and disposable equipment were measured. Established instruments developed by the American Medical Association for Current Procedural Terminology code valuation were used to measure subjective "physician work," including mental effort and judgment, technical skill, physical effort, and psychological stress. These items were scored by 1 of 12 attending interventional radiology physicians performing the procedure.

RESULTS

Mean PTA procedure time was 74 minutes (range, 18-183 minutes) for AVFs and 71 minutes (range, 28-204 minutes) for AVGs; hemostasis time was 12 minutes for AVFs and 11 minutes for AVGs. There was no significant difference in equipment use between groups. "Physician work" for AVFs scored significantly higher in four categories (P≤ .05).

CONCLUSIONS

Using established subjective instruments, maintenance PTA of AVFs was scored as more cognitively, physically, and psychologically demanding than maintenance PTA of AVGs. However, there was no significant difference in resource utilization between maintenance PTA of AVFs versus AVGs, as has been previously shown with thrombectomy of thrombosed AVFs and AVGs.

Endovascular treatment of hemodialysis arteriovenous fistulas: is immediate post-interventional blood flow a predictor of patency

PURPOSE

The purpose of this study was to investigate if the immediate hemodynamic outcome of an endovascular intervention on a dysfunctional hemodialysis arteriovenous fistula is a prognostic factor for primary patency.

METHODS

This was a prospective observational study including 61 consecutive patients with dysfunctional arteriovenous fistulas referred to our endovascular unit. Patients were treated in accordance with institutional standard protocol including immediate pre- and post-interventional blood flow measurements using an intravascular catheter system. The primary endpoint was primary patency at 12 months in patients with an immediate post-interventional blood flow above or below 600 ml/min. Primary patency was estimated using the Kaplan-Meier method with the standard error of the estimate. Multivariate Cox regression analysis was used to study the effect of blood flow and other potential predictor variables.

RESULTS

Post interventional flow did not significantly influence primary patency (p = 0.76). Primary patency was found to be affected by having a history of previous intervention(s) (p = 0.008, hazard ratio 2.9) or low fistula age (P=.038, hazard ratio 0.97 [one-month increase]). Primary patency in group 1 (previous intervention(s)) was 34% ± 13% at 12 months. In group 2 (no previous intervention), primary patency at 12 months was 62% ± 9%.

CONCLUSIONS

The results of this study do not provide scientific support for using the immediate hemodynamic outcome of an intervention as a prognostic factor for primary patency. Low fistula age and a history of previous intervention in particular were found to reduce primary patency significantly.

Treatment of hemodialysis vascular access rupture irresponsive to prolonged balloon tamponade: retrospective evaluation of the effectiveness of N-butyl cyanoacrylate seal-off technique

OBJECTIVE

The current study retrospectively evaluated whether the percutaneous N-butyl cyanoacrylate (NBCA) seal-off technique is an effective treatment for controlling the angioplasty-related ruptures, which are irresponsive to prolonged balloon tamponade, during interventions for failed or failing hemodialysis vascular accesses.

MATERIALS AND METHODS

We reviewed 1588 interventions performed during a 2-year period for dysfunction and/or failed hemodialysis vascular access sites in 1569 patients. For the angioplasty-related ruptures, which could not be controlled with repeated prolonged balloon tamponade, the rupture sites were sealed off with an injection of a glue mixture (NBCA and lipiodol), via a needle/needle sheath to the rupture site, under a sonographic guidance. Technical success rate, complications and clinical success rate were reported. The post-seal-off primary and secondary functional patency rates were calculated by a survival analysis with the Kaplan-Meier method.

RESULTS

Twenty ruptures irresponsive to prolonged balloon tamponade occurred in 1588 interventions (1.3%). Two technical failures were noted; one was salvaged with a bailout stent-graft insertion and the other was lost after access embolization. Eighteen accesses (90.0%) were salvaged with the seal-off technique; of them, 16 ruptures were completely sealed off, and two lesions were controlled as acute pseudoaneurysms. Acute pseudoaneurysms were corrected with stentgraft insertion in one patient, and access ligation in the other. The most significant complication during the follow-up was delayed pseudoaneurysm, which occurred in 43.8% (7 of 16) of the completely sealed off accesses. Delayed pseudoaneurysms were treated with surgical revision (n = 2), access ligation (n = 2) and observation (n = 3). During the follow-up, despite the presence of pseudoaneurysms (acute = 1, delayed = 7), a high clinical success rate of 94.4% (17 of 18) was achieved, and they were utilized for hemodialysis at the mean of 411.0 days. The post-seal-off primary patency vs. secondary patency at 90, 180 and 360 days were 66.7 ± 11.1% vs. 94.4 ± 5.4%; 33.3 ± 11.1% vs. 83.3 ± 8.8%; and 13.3 ± 8.5% vs. 63.3 ± 12.1%, respectively.

CONCLUSION

Our results suggest that the NBCA seal-off technique is effective for immediate control of a venous rupture irresponsive to prolonged balloon tamponade, during interventions for hemodialysis accesses. Both high technical and clinical success rates can be achieved. However, the treatment is not durable, and about 40% of the completely sealed off accesses are associated with developed delayed pseudoaneurysms in a 2-month of follow-up. Further repair of the vascular tear site, with surgery or stent-graft insertion, is often necessary.

Radial artery approach to salvage nonmaturing radiocephalic arteriovenous fistulas

PURPOSE

To evaluate the usefulness of an approach through the radial artery distal to the arteriovenous anastomosis for salvaging nonmaturing radiocephalic arteriovenous fistulas.

METHODS

Procedures that fulfilled the following criteria were retrospectively reviewed: (1) autogenous radiocephalic fistulas, (2) fistulas less than 3 months old, (3) distal radial artery approach for salvage. From 2005 to 2011, a total of 51 patients fulfilling the above criteria were enrolled. Outcome variables were obtained from angiographic, clinical and hemodialysis records, including the success, complication, and primary and secondary patency rates.

RESULTS

The overall anatomical and clinical success rates for the distal radial artery approach were 96 and 94%, respectively. The average procedure time was 36 ± 19 min. Six patients (12%) experienced minor complications as a result of extravasations. No arterial complication or puncture site complication was noted. The postinterventional 6-month primary patency rate was 51%, and the 6-month secondary patency rate was 90%. When the patients were divided into a stenosed group (20 patients) and an occluded group (31 patients), there were no differences in the success rate, complication rate, or primary and secondary patency rates.

CONCLUSION

An approach through the radial artery distal to the arteriovenous anastomosis is an effective and safe alternative for the salvage of nonmaturing radiocephalic arteriovenous fistulas, even for occluded fistulas.

Evaluation of immature hemodialysis arteriovenous fistulas based on 3-French retrograde micropuncture of brachial artery

OBJECTIVE

The objective of our study was to assess outcomes after evaluation of immature hemodialysis arteriovenous fistulas (AVFs) via 3-French brachial artery access and to identify the incidence of arterial and venous puncture site spasm.

MATERIALS AND METHODS

One hundred twenty-three outpatients (82 men, 41 women; mean age, 58 years; age range, 20-90 years) with immature AVF were identified retrospectively in whom diagnostic fistulography was performed via 3-French retrograde brachial artery puncture. Percutaneous transluminal angioplasty was performed via a separate venous puncture during the same visit in 95 patients. Patient age and sex, fistula age and type, and technical success and complications were recorded. Images were reviewed for lesion location, potentially competing vessels, and arterial and venous puncture-related spasms.

RESULTS

The mean fistula age was 99 days (range, 21-639 days). There were 49 AVFs in the left forearm; 30 in the left upper arm; 26 in the right forearm; and 18 in the right upper arm. Twenty-eight AVFs were transposed. Angioplasty was technically successful in 81 of 95 patients (85%; mean diameter, 7 mm; range, 4-10 mm). Brachial artery puncture caused no major complication. Arterial spasm occurred in 19 patients (15%) and was severe in one patient. There were two hematomas (1.6%). Venous spasm, ranging from mild (four patients) to occlusive (8 patients), occurred in 38 patients (40%) at the site of venipuncture for intervention. Nitroglycerin (mean, 325 mcg; range, 100-600 mcg) was used in 26 procedures (21%). Venous spasm was more common with forearm (50%) than upper arm (24%) fistulas (p = 0.02) and with decreasing vein diameter (p = 0.02).

CONCLUSION

Evaluation of immature AVFs based on 3-French micropuncture of the brachial artery can be safely performed on an outpatient basis. Spasm is more common in forearm AVFs and in smaller veins.

Pictorial essay: Interventional radiology in the management of hemodialysis vascular access - A single-center experience

Chronic kidney disease (CKD) is a worldwide public health problem and is associated with high morbidity and mortality. The majority of patients with CKD stage 5 (CKD-5), who cannot undergo renal transplant, depend on maintenance hemodialysis by surgically created access sites. Native fistulae are preferred over grafts due to their longevity. More than half of these vital portals for dialysis access will fail over time. Screening procedures to select high-risk patients before thrombosis or stenosis appears have resulted in aggressive management. These patients are referred for angiographic evaluation and/or therapy. We present the patterns of dialysis-related interventions done in our institution.

Comparative outcomes of primary autogenous fistulas in elderly, multiethnic Asian hemodialysis patients

BACKGROUND

The number of elderly (≥65 years) end-stage renal disease (ESRD) patients on hemodialysis is rapidly increasing. Vascular access outcomes remain contradictory and understudied across different elderly populations. We hypothesized age might influence primary autogenous fistula use and outcomes in a predominantly diabetic multiethnic Asian ESRD population.

METHODS

Demographic and clinical factors affecting fistula patency and maturation were retrospectively compared among patients with incident ESRD aged <65 and ≥65 years at a single center. Fistula patency was estimated by Kaplan-Meier curves with log-rank test comparison.

RESULTS

We analyzed 280 primary fistulas (59% radiocephalic, 33% brachiocephalic, and 8% brachiobasilic) in this cohort consisting of 31.8% aged ≥65 years, 50% Chinese, 39% Malay, 42% women, and 70% diabetic. One- and 2-year primary and secondary patency in patients aged <65 vs ≥65 years were comparable: 41.3% vs 36.7% and 28.7% vs 24.4% (P = .547) and 57.7% vs 56.8% and 47.1% vs 47.2% (P = .990). On multivariate analysis, only non-Chinese, dialysis initiation with tunneled catheters, and surgical/endovascular interventions affected fistula survival hazard ratios (HR): 0.622 (95% confidence interval [CI], 0.43-1.00), 0.549 (95% CI, 0.297-0.841), and 2.503 (95% CI, 1.695-3.697), respectively. Nonmaturation and intervention rates were also similar at 56.7% vs 61.8% and 34% vs 32.2% at 3 and 6 months and 0.31 vs 0.36 per access year, respectively (P > .05). Females and tunneled catheters were the only risk factors for nonmaturation (HR, 1.568; 95% CI, 1.148-1.608, and HR, 1.623; 95% CI, 1.400-1.881, respectively).

CONCLUSIONS

A primary fistula strategy in incident elderly ESRD is feasible and does not result in inferior outcomes. Age should therefore not be a determinant for primary fistula creation.

Efficacy of a modified pharmacomechanical thrombolysis technique for endovascular treatment of thrombosed prosthetic arteriovenous grafts

Objective

We applied a modified pharmacomechanical thrombolysis (PMT) technique to endovascular treatment of thrombosed arteriovenous (AV) grafts without the use of any mechanical thrombectomy devices. The aim of this study was to evaluate the efficacy of the PMT technique in the treatment of thrombosed AV grafts by analyzing the long-term patency.

Materials and Methods

Eighty-two patients with thrombosed AV grafts were treated with the PMT technique. AV graft surveillance to detect failing/failed access was followed by endovascular treatment.

Results

The technical and clinical success rates were 95% and 95%, respectively. The total number of thrombolysis sessions was 279. A post-intervention primary patency rate was 45% and 22% at 12 and 24 months, respectively. The secondary patency rate was 96% and 91% at 12 and 24 months, respectively. No major complications were noticed.

Conclusion

The modified PMT technique is effective in endovascular treatment of thrombosed AV grafts.

Outcomes of AngioJet® Thrombectomy in Hemodialysis Vascular Access Grafts and Fistulas: Pearl I Registry

Purpose

Results are reported from the PEARL I Registry for procedures where a mid-length AngioJet catheter was used for thrombosed hemodialysis arteriovenous grafts and fistulae.

Methods

The PEARL I Registry was a prospective, multicenter, observational database collecting information on the AngioJet procedures for a variety of thrombotic conditions. Patient demographics, procedural information, outcome data, and safety information were collected through 3 months postprocedure on AngioJet procedures. This paper describes the data collected for subjects presenting with hemodialysis access thrombosis.

Results

A total of 72 (16%) of the 452 subjects enrolled in the PEARL 1 Registry had thrombosed hemodialysis access sites. Procedural success was reported in 66/72 subjects (92%); surgical interventions were required in 6/72 subjects (8%). There was a statistically significant improvement (p<0.0001) in vessel occlusion from baseline to final angiography. Eighty-eight percent of access sites were patent at the end of the procedure and 97% of vessels showed improved occlusion status of ≥1 grades. Among prosthetic grafts, 53% (20/38) remained patent at the 3-month follow-up, 18% (7/38) were restenosed, and 29% (11/38) rethrombosed. Among autologous fistulas, 86% (18/21) remained patent without intervention at the 3-month follow-up; 3 fistulas rethrombosed. Four subjects (5%) died; none of the deaths were considered related to the AngioJet device or procedure.

Conclusions

Outcomes from the PEARL I registry corroborate other studies of AngioJet thrombectomy and the overall literature of endovascular thrombectomy procedures. A high procedural success rates with acceptable near-term patency rates and low rates of adverse events are achieved with AngioJet thrombectomy.

A proposed management algorithm for fistulae between hemodialysis access circuits and adjacent veins

PURPOSE

Fistulae between an arteriovenous hemodialysis graft (AVG) or fistula (AVF) and an adjacent vein are an unusual complication of hemodialysis access. Such fistulae may theoretically cause steal syndrome, extremity edema, or access dysfunction. We sought to use our experience and existing literature to develop a management algorithm for this access complication.

METHODS

Twelve patients with AVG/AVF to adjacent vein fistulae found on fistulography were identified using a quality assurance database. Indications for fistulography, treatment rendered for both the fistulae and access stenosis, and outcome of treatment were determined. AVG/AVF to adjacent vein fistulae, when identified and considered to be significant, were treated with embolization.

RESULTS

Five out of twelve patients had successful embolization of their AVG/AVF to adjacent vein fistulae. Reasons for treatment included partial thrombosis of the access to the level of the fistula (n=1), contribution to bleeding during dialysis (n=1), and concern for competing flow causing thrombosis (n=5). No recurrence was identified. Seven patients did not undergo embolization either because of failure to recognize the fistula (n=3) or determination that treatment was not indicated (n=4). Two untreated fistulae were found occluded at follow-up. Additional access treatment included angioplasty (n=11), covered stent (n=1), and mechanical thrombectomy (n=3).

CONCLUSIONS

The significance of AVG/AVF to adjacent vein fistulae remains unclear; some resolve spontaneously, possibly related to PTA of outflow stenosis. Embolotherapy is an effective treatment for such fistulae when determined to be significant.

Vascular access surveillance: an ongoing controversy

Hemodialysis vascular access surveillance continues to be widely recommended despite ongoing controversy as to its benefit in prolonging access patency compared with clinical monitoring alone. The most common screening tests are access blood flow and dialysis venous pressure measurements. When surveillance test results cross a predetermined threshold, accesses are referred for intervention with correction of stenosis to reduce future thrombosis and prolong access survival. Current surveillance strategies have four components: (1) underlying condition; (2) screening test; (3) intervention; and (4) outcomes. However, limitations exist within each component that may prevent achieving the desired outcomes. This review discusses these limitations and their consequences. To date, randomized controlled trials have not consistently shown that surveillance improves outcomes in grafts, and there is limited evidence that surveillance reduces thrombosis without prolonging the life of native fistulae. In conclusion, current evidence does not support the concept that all accesses should undergo routine surveillance with intervention.

Factors influencing technical success and outcome of percutaneous balloon angioplasty in de novo native hemodialysis arteriovenous fistulas

OBJECTIVE

To determine predictors of technical success, dysfunction recurrence and patency after percutaneous transluminal angioplasty (PTA) of de novo dysfunctional hemodialysis arteriovenous fistulas (AVFs).

METHODS

Retrospective analysis of first time PTA of 167 AVF in 162 patients (100 men, 66±13 years). Anatomical (location, length, grade and number of stenoses) and clinical variables (sex, age, prior AVF, diabetes mellitus and AVF age, side and location) were reviewed.

RESULTS

217 stenoses or segmental occlusions were treated. Technical success rate (84.4%) was higher in radiocephalic AVF compared to brachial artery-median vein AVF (p=0.030) and was negatively correlated with initial stenosis (p=0.049). Dysfunction recurrence was seen in 52.7% and correlated negatively with technical success (p=0.013) and AVF age (p=0.008). Early dysfunction (within 6 months) was negatively correlated with AVF age (p=0.016) and positively with diabetes (p=0.003). Higher AVF age resulted in higher primary (p=0.005) and secondary patency rates (p=0.037-0.005).

CONCLUSIONS

Technical success of PTA in hemodialysis AVF is affected by AVF type and initial stenosis and has significant effect on dysfunction recurrence, but not on AVF longevity. Younger AVF has increased risk for (early) recurrent dysfunction and lower patency rates. Patients with diabetes mellitus have higher risk for early dysfunction.

Standardized definitions for hemodialysis vascular access

Vascular access dysfunction is one of the leading causes of morbidity and mortality among end-stage renal disease patients. Vascular access dysfunction exists in all three types of available accesses: arteriovenous fistulas, arteriovenous grafts, and tunneled catheters. To improve clinical research and outcomes in hemodialysis (HD) access dysfunction, the development of a multidisciplinary network of collaborative investigators with various areas of expertise, and common standards for terminology and classification in all vascular access types, is required. The North American Vascular Access Consortium (NAVAC) is a newly formed multidisciplinary and multicenter network of experts in the area of HD vascular access, who include nephrologists and interventional nephrologists from the United States and Canada with: (1) a primary clinical and research focus in HD vascular access dysfunction, (2) national and internationally recognized experts in vascular access, and (3) a history of productivity measured by peer-reviewed publications and funding among members of this consortium. The consortium's mission is to improve the quality and efficiency in vascular access research, and impact the research in the area of HD vascular access by conducting observational studies and randomized controlled trials. The purpose of the consortium's initial manuscript is to provide working and standard vascular access definitions relating to (1) epidemiology, (2) vascular access function, (3) vascular access patency, and (4) complications in vascular accesses relating to each of the vascular access types.

Outcomes of arteriovenous fistula creation after the Fistula First Initiative

BACKGROUND AND OBJECTIVES

The arteriovenous fistula (AVF) is the preferred hemodialysis access, but AVF-failure rate is high, and complications from AVF placement are rarely reported. There is no clear consensus on predictors of AVF patency. This study determined AVF outcomes and patency predictors at Mayo Clinic Rochester following the Fistula First Initiative.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A retrospective cohort study of AVFs placed at Mayo Clinic from January 2006 through December 2008 was performed. The AVF placement-associated primary and secondary failure rates, complications, interventions, and hospitalizations were examined. Kaplan-Meier survival curves and Cox proportional hazard models were used to determine primary and secondary patency and associated predictors.

RESULTS

During this time frame, 317 AVFs were placed in 293 individual patients. The primary failure rate was 37.1% after excluding patients not initiated on hemodialysis during follow-up (n = 38) or those with indeterminate outcome (37 lost to follow-up; six died; two transplanted). Of usable AVFs, 11.4% later failed. AVF creation incurred complications and hospitalization in 21.2% and 12.3% of patients, respectively. The risk for reduced primary patency was increased by diabetes (HR, 1.54; 95% CI, 1.14 to 2.07); the risk for reduced primary and secondary patency was decreased with larger arteries (HR, 0.83; 95% CI, 0.73 to 0.94; and HR, 0.69; 95% CI, 0.56 to 0.84, respectively).

CONCLUSIONS

Primary failure remains a major issue in the post-Fistula First era. Complications from AVF placement must be considered when planning AVF placement. Our data demonstrate that artery size is the main predictor of AVF patency.

Sharp Needle Recanalization for Salvaging Hemodialysis Accesses with Chronically Occluded Peripheral Outflow

Purpose

To assess the effectiveness of sharp needle recanalization (SNR) for treatment of chronically occluded venous outflow in hemodialysis access.

Methods

A retrospective analysis of patient records from January 2006 to March 2010 was conducted. Forty-four hemodialysis patients (31 fistulas, 13 grafts) were referred for arm swelling (18%), excessive bleeding after dialysis (29%), and thrombosis (53%). All patients had chronic occlusion of the outflow vein which failed conventional recanalization techniques. A new outflow pathway was established by advancing a 21g needle and dilating the subcutaneous tract to bridge the fistula body to a juxtaposed patent vein. If necessary, uncovered or covered stents were utilized to maintain patency of the newly formed subcutaneous tract.

Results

Forty-four patients underwent 45 SNR procedures, with restoration of normal function and complete relief of symptoms in 40 (91%) patients. The average tract length was 15 mm (range, 1 to 32) and the average dilatation diameter was 8 mm. During the initial SNR procedure, bare metal (n=21) or covered (n=5) stents were inserted in 26 patients. The average follow-up was 18.4 months (range, 0.2 to 48 months). No major complications were observed with the procedure. At 12 months, the primary access, primary tract, and secondary access patencies were 10%, 51%, and 92%, respectively. Percutaneous thrombectomy procedures were performed at a rate of 1.16 per access-year and the number of interventions within the tract was 0.94 per access-year.

Conclusions

Sharp needle recanalization is an effective percutaneous treatment for restoring function to hemodialysis accesses with chronically occluded venous outflow pathways.

Evaluation of expanded polytetrafluoroethylene-covered stents for the treatment of venous outflow stenosis in hemodialysis access grafts

PURPOSE

To investigate the use of an expanded polytetrafluoroethylene-coated nitinol stent-graft in patients with failing hemodialysis access circuits and compare grafts with and without a heparin-coated surface.

MATERIALS AND METHODS

A single-institution retrospective review of 16 patients (average age, 55 years; seven men) treated for hemodialysis access circuit stenoses was performed. Patients had a prosthetic arteriovenous (AV) graft (n = 10) or autogenous AV fistula (n = 6), all with clinically relevant access stenoses that were refractory to angioplasty alone; 10 patients also had access circuit thrombosis at the time of treatment. Stents were placed in the basilic (n = 4), brachial (n = 7), cephalic (n = 4), and femoral (n = 1) veins. Study endpoints included primary treatment area patency, primary circuit patency, primary assisted circuit patency, and secondary circuit patency, followed to a maximum of 6 months.

RESULTS

Primary treatment area patency rates at 30 days and 180 days were 75% and 31%, respectively. Secondary patency rates at the same time points were 88% and 68%, respectively. Mean primary treatment area patency was 93 days. Thrombosis was a major cause of failure, occurring in seven of 11 cases of primary treatment area patency loss. Subgroup analysis demonstrated that the heparin-coated configuration (n = 7) showed a 6-month primary patency rate of 57%, compared with 11% for the stent-grafts without heparin bonding (n = 9; P = .06).

CONCLUSIONS

Overall, the majority of deployed stent-grafts lost primary patency within 6 months, with thrombosis a major cause of failure. However, the addition of a heparin-coated surface appeared to improve results in these otherwise treatment-refractory access circuits.

Technical success rates and long-term patency of endovascular treatment for occluded native hemodialysis fistulas: comparison between thrombotic occlusion and nonthrombotic occlusion

PURPOSE

This study evaluated the technical success and long-term patency of endovascular treatment for occluded native hemodialysis fistulas caused by thrombotic occlusion (TO) and nonthrombotic occlusion (NTO).

MATERIALS AND METHODS

This cohort included 96 consecutive occlusions (70 TOs and 26 NTOs) at the forearm. Clinical success and patency rates of endovascular treatment were calculated and compared between the TO and NTO groups.

RESULTS

Overall clinical success rate was 91.6%; and primary, assisted primary, and secondary patency rates at 1, 2, and 3 years were 49.6%, 30.7%, and 28.3%, respectively; 73.8%, 48.3%, and 48.3%, respectively; and 80.7%, 72.3%, and 66.2%, respectively. Clinical success rates of the TO and NTO groups were 91.4% and 92.3%, respectively. The 1-, 2-, and 3-year primary, assisted primary, and secondary patency rates of the TO group were 54.4%, 29.3%, and 25.6%, respectively; 70.7%, 49.4%, and 49.4%, respectively, and 78%, 68.8%, and 64,2%, respectively. Those of the NTO group were 38.9%, 32.4%, and 32.4%, respectively; 81.2%, 47.3%, and 40.6%, respectively; and 87%, 80.3%, and 70.2%, respectively. There were no significant differences between the clinical success and patency rates of the two groups.

CONCLUSION

Occluded native hemodialysis fistulas were restored with high frequency, without significant differences between clinical success and patency in the TO and NTO groups.

Central Vein Stenosis or Occlusion Associated with Cardiac Rhythm Management Device Leads in Hemodialysis Patients with Ipsilateral Arteriovenous Access: A Retrospective Study of Treatment Using Stents or Stent-Grafts

Purpose

Symptomatic central vein stenosis commonly occurs when cardiac rhythm management device (CRMD) leads are placed via the subclavian vein ipsilateral to arteriovenous (AV) hemodialysis (HD) access. The purposes of this study were to determine the outcomes, complications, and patency following stenting of CRMD lead-associated central vein stenosis or occlusion, and to determine the effect of stents on CRMD function.

Methods

Fourteen HD patients with AV access and an ipsilateral CRMD were treated with stents for symptomatic central vein stenosis or occlusion following inadequate response to angioplasty from January 2005 to December 2009. Subsequent access interventions, complications, and outcomes were reviewed retrospectively. Cardiology records were examined to assess CRMD function.

Results

Treatment of stenosis or occlusion with angioplasty and stenting resulted in 100% procedural success and no complications. At 6 and 12 months, respectively, primary patency rates were 45.5% and 9.0%; primary-assisted patency rates were 90.9% and 80.0%; secondary patency rates were 100% and 90.0%. There were 42 repeat interventions performed in 12 patients; five received additional stents. The mean number of subsequent interventions was 3.2 per patient (2.1 per patient-year). All CRMD testing demonstrated normal function with no device or lead failure. Seven of the 14 subjects died resulting in a 35.3% annual mortality rate. No deaths were attributable to dysrhythmia or CRMD failure and no patient required CRMD removal or exchange.

Conclusions

Placement of stents for CRMD lead-associated stenosis or occlusion yields high success and low complication rates with no effect on CRMD function. Patency rates are similar to those reported in other series of central venous stents.

Clinical Outcome of Overlapping Stents in Hemodialysis Access

Purpose

Endovascular stents have recently been shown to extend access patency in thrombosed and stenotic arteriovenous grafts. Given this improved patency, stent placement has outpaced balloon angioplasty in hemodialysis (HD) access interventions. However, concern remains over localized corrosion and increased neointimal hyperplasia of overlapping stents in the access circuit and whether this promotes premature stent failure.

Methods

This is a retrospective analysis of HD patients referred for access dysfunction during a 2-yr period. Using a prospectively collected, vascular access database, we identified 76 patients seen for follow-up angiography due to access dysfunction after stent placement. We compared the outcomes of overlapping vs. non-overlapping stents in measured primary assisted patency and mean percent luminal diameter as a marker of lesion severity.

Results

The two groups did not differ significantly in demographics or comorbid conditions. Only gender had a significant discrepancy between the two groups, with 65.5% vs. 42.9% male (p=0.01) in the overlapping vs. non-overlapping stent groups, respectively. The mean percent luminal stenosis was found to be 83.7 ± 17.3 and 85.5 ± 12.6 (p=0.55) for the overlapping vs. non-overlapping stent groups, respectively. For overlapping and non-overlapping stents, 30-day primary patency was 94% and 89%, respectively, 60-day primary patency was 77% and 63%, respectively, and 90-day primary patency was 68% and 50%, respectively. Using multiple regression analysis, no risk factors were identified to be associated with the severity of luminal stenosis. No identifiable risk factors were found to be associated with improved primary patency. In particular, overlapping vs. non-overlapping stents were not identified as a statistically significant factor influencing primary (assisted) patency (hazards ratio 0.60; 95% cI 0.34 to 1.06; p>0.05).

Conclusions

This study provides evidence that the theoretical concern of metal on metal corrosion and increased neointimal hyperplasia that can be seen with overlapping stents does not play a significant clinical role.

Ultrahigh-Pressure Angioplasty versus the Peripheral Cutting Balloon™ for Treatment of Stenoses in Autogenous Fistulas: Comparison of Immediate Results

Purpose

To compare the immediate results of ultrahigh-pressure (UHP) balloons vs. peripheral cutting balloons (PCB) for the treatment of stenoses associated with autogenous fistulas using intra-access blood flow measurements.

Materials and Methods

This prospective randomized study consisted of 22 hemodialysis (HD) patients with autogenous fistulas who had decreased intra-access blood flow (<500 mL/min). All patients underwent a fistulogram and intraprocedural blood flow measurements. Patients were randomized once into two groups; one group undergoing UHP angioplasty and the second group undergoing PCB angioplasty. Randomization occurred once after the diagnostic fistulogram and each patient in each arm only underwent percutaneous transluminal angioplasty with either UHP or PCB. The study cohort consisted of 12 patients in the UHP group and 10 patients in the PCB group. Data collected included fistula anatomy, degree of stenosis, length of stenosis, balloon specifications and residual stenosis.

Results

The 22 study patients underwent 35 angioplasty procedures; 23 in the UHP group (12 patients) and 12 in the PCB group (10 patients). The technical success rate was 91%. The pre-intervention mean blood flow was 288 mL/min in the UHP group and 391 mL/min in the PCB group. The post-intervention mean blood flow was 613 mL/min in the UHP group and 606 mL/min in the PCB group. The mean increase in blood flow was 325.8 mL/min in the UHP group and 213 mL/min in the PCB group. This represents a relative mean increase in blood flow of 253% in the UHP group and 85% in the PCB group. An unpaired t-test showed there was no significant difference between the groups with respect to pre-flow, post-flow, and mean and relative mean increase in flow. There were two failures; one in the UHP group and one in the PCB group. There was one minor complication (2.8%) but no major complications.

Conclusions

In this small group of HD patients with autogenous fistulas our comparison of UHP to the PCB demonstrated that the immediate results, as determined by measurement of intra-access blood flow, were equivalent. Further long-term follow-up will be required to determine the longevity of these results

Access Flow Reduction and Recurrent Symptomatic Cephalic Arch Stenosis in Brachiocephalic Hemodialysis Arteriovenous Fistulas

Background

Recurrent cephalic arch stenosis (CAS) has been linked to high flow and has a high rate of recurrence following angioplasty. This study investigates the effectiveness of access flow reduction in decreasing rapidly recurrent symptomatic CAS.

Methods

A retrospective study of patient records from February 2005 to April 2009 was conducted. Patients with brachiocephalic fistulas who had undergone two or more instances of cephalic arch angioplasty within 3 months, and thereafter underwent flow reduction via banding of the access inflow (n=33) were included. A before-and-after analysis was conducted: the rates of cephalic arch angioplasty were calculated for each patient before and after the banding procedure, and compared via a paired t-test.

Results

At 3, 6, and 12 months, the cephalic arch primary lesion patency was 91%, 76%, and 57%. The cephalic arch intervention rate was reduced from 3.34 to 0.9 per access-year (t=7.74, p<.001). The average follow-up time was 14.5 months (range, 4.8–32).

Conclusion

Flow reduction of a brachiocephalic arteriovenous hemodialysis fistula may effectively diminish the incidence of symptomatic CAS.

Percutaneous intervention in axillary loop-configured arteriovenous grafts for chronic hemodialysis patients

Objective

The purpose of this study was to evaluate the fistulographic features of malfunctioning axillary loop-configured arteriovenous grafts and the efficacy of percutaneous interventions in failed axillary loop-configured arteriovenous grafts.

Materials and Methods

Ten patients with axillary loop-configured arteriovenous grafts were referred for evaluation of graft patency or upper arm swelling. Fistulography and percutaneous intervention, including thrombolysis, percutaneous transluminal angioplasty and stent placement, were performed. Statistical analysis of the procedure success rate and the primary and secondary patency rates was done.

Results

Four patients had graft related and subclavian venous stenosis, two patients had graft related stenosis and another four patients had subclavian venous stenosis only. Sixteen sessions of interventional procedures were performed in eight patients (average: 2 sessions / patient) until the end of follow-up. An interventional procedure was not done in two patients with central venous stenosis. The overall procedure success rate was 69% (11 of 16 sessions). The post-intervention primary and secondary patency rates were 50% and 63% at three months, 38% and 63% at six months and 25% and 63% at one year, respectively.

Conclusion

Dysfunctional axillary loop-configured arteriovenous grafts almost always had subclavian venous and graft-related stenosis. Interventional treatments are helpful to overcome this and these treatments are expected to play a major role in restoring and maintaining the axillary loop-configured arteriovenous loop grafts.

Patency rates for angioplasty in the treatment of pacemaker-induced central venous stenosis in hemodialysis patients: results of a multi-center study

While hemodialysis access ligation has been used to manage pacemaker (PM) and implantable cardioverter-defibrillator (ICD) lead-induced central venous stenosis (CVS), percutaneous transluminal balloon angioplasty (PTA) has also been employed to manage this complication. The advantages of PTA include minimal invasiveness and preservation of arteriovenous access for hemodialysis therapy. In this multi-center study we report the patency rates for PTA to manage lead-induced CVS. Consecutive PM/ICD chronic hemodialysis patients with an arteriovenous access referred for signs and symptoms of CVS due to lead-induced CVS were included in this analysis. PTA was performed using the standard technique. Technical and clinical success was examined. Technical success was defined as the ability to successfully perform the procedure. Clinical success was defined as the ability to achieve amelioration of the signs and symptoms of CVS. Both primary and secondary patency rates were also analyzed. Twenty-eight consecutive patients underwent PTA procedure. Technical success was 95%. Postprocedure clinical success was achieved in 100% of the cases where the procedure was successful. The primary patency rates were 18% and 9% at 6 and 12 months, respectively. The secondary patency rates were 95%, 86%, and 73% at 6, 12, and 24 months, respectively. On average, 2.1 procedures/year were required to maintain secondary patency. There were no procedure-related complications. This study finds PTA to be a viable option in the management of PM/ICD lead-induced CVS. Additional studies with appropriate design and sample size are required to conclusively establish the role of PTA in the management of this problem.

Endovascular treatment of autogenous radiocephalic fistulas with the "eighth note" deformity for hemodialysis

The purpose of this paper is to describe a unique "eighth note" deformity of the autogenous radiocephalic fistula for hemodialysis and to retrospectively evaluate the efficacy and safety of its endovascular treatment. Over 3 years, a total of 808 patients and 558 autogenous radiocephalic fistulas were treated for vascular access dysfunction or thrombosis. These included 14 fistulas in 14 patients (9 men, 5 women; mean age, 58.2 +/- 2.8 years; range 27-79 years) whose fistulograms before treatment resembled a musical note, the eighth note. Endovascular treatment sought to remodel the deformed vascular access to a classic radiocephalic fistula and increase the number of cannulation sites available for hemodialysis. The technical and clinical success rates were each 92.8% (13/14). Fistula remodeling was successful in 13 patients. The postintervention primary patency was 100% at 90 days, 91.7 +/- 0.8% at 120 days, 78.6 +/- 13.9% at 180 days, 62.9 +/- 17.9% at 360 days, 31.4 +/- 24.0% at 540 days, and 0% at 720 days. The postintervention secondary patency was 100% at 90 days, 100% at 120 days, 100% at 180 days, 85.7 +/- 13.2% at 360 days, and 85.7 +/- 13.2% at 720 days. No major complications were noted. Minor complications were found in 71.4% of patients, all of which resolved spontaneously. In conclusion, endovascular treatment of fistulas with the eighth note deformity can effectively increase the number of available cannulation sites, facilitate fistula maturation, and facilitate thromboaspiration after fistula thrombosis.