Postintervention Primary Patency Research Articles

Percutaneous transluminal angioplasty combined with thrombolysis for acute thrombosis in arterio-venous fistula and graft

To evaluate the efficacy of ultrasound or fluoroscopic-guided percutaneous transluminal angioplasty (PTA) combined with thrombolysis for the treatment of acutely thrombosed arteriovenous fistula (AVF) or grafts (AVG). One hundred and ninety-two hemodialysed patients, in whom the thrombosed arterio-venous AVF or AVG developed less than 72 h and there were no contraindications for thrombolysis and PTA, underwent PTA combined with thrombolysis therapy in Sir Run Run Shaw Hospital of Zhejiang University from October 2014 to October 2017. Under ultrasound and/or fluoroscopic guidance, balloon catheter was introduced to thrombosis sites along a guide wire. Then the balloon was inflated and normal saline mixed with urokinase and heparin was injected for thrombolysis. After blood flow was restored, angioplasty was performed on vascular stenosed sites. A total of 274 endovascular interventional operations were performed for 192 patients. The procedure success rate was 98.2%, clinical success rate was 93.8%and complication rate was 1.46%. The post-intervention primary patency rates for AVF group were 87.4%, 76.7%and 63.9%at 3, 6 and 12 months, respectively; while the post-intervention secondary patency rates were 93.7%, 91.6%and 83.0%, respectively. The post-intervention primary patency rates for AVG group were 60.7%, 51.5%and 43.1%at 3, 6 and 12 months, while the post-intervention secondary patency rates were 82.7%, 77.1%and 70.8%, respectively. PTA combined with thrombolysis is an effective and safe therapeutic option for AVF and AVG thrombosis, which would prolong hemodialysis access and save vascular resources for hemodialyzed patients.

SS31. Comparable Patency of Open and Endovascular Treatment of Venous Anastomotic Lesions in Hemodialysis Grafts

Arteriovenous graft (AVG) failures are typically associated with venous anastomotic stenosis. Most studies comparing outcomes of open vs endovascular thrombectomy have shown equipoise, but the inherent bias of these studies has been the fact that the venous anastomosis was managed with endovascular means even in the open surgical thrombectomy groups. There is little evidence to support balloon venoplasty or stenting as more durable compared with patch venoplasty or proximal bypass extension of the AVG. Consecutive patients with an AVG who underwent the first thrombectomy and a venous anastomosis intervention between January 2014 and July 2018 were included in our study. Patients’ demographics, previous access history, central vein patency, AVG anatomy, type of intervention, and follow-up data were recorded. Kaplan-Meier analysis was used to analyze time from thrombectomy to first reintervention (postintervention primary patency) and time to abandonment (postintervention secondary patency). Cox regression analysis was performed to evaluate predictors of failure. Our study included 105 patients (51 women; 64.2 ± 14.9 years old) with 42 forearm, 51 upper arm, and 12 lower extremity AVGs. There were 37 open revisions (26 patches, 11 proximal jump bypasses) and 68 endovascular interventions at the venous anastomosis (14 stent grafts, 5 cutting balloons); 6 of these were performed entirely percutaneously. Technique selection was based on the physician’s preference. There were no differences between open and endovascular groups in baseline demographics or graft anatomy, material, or age. Grafts undergoing open revision had an average of 1.3 ± 1.9 previous interventions, whereas those undergoing endovascular intervention had 0.46 ± 1.0 (P < .01). Postintervention primary patency for open and endovascular groups was 31.2% and 36.0% at 6 months and 21.0% and 14.0% at 12 months (P = .727). Secondary patency was 63.9% and 51.4% at 6 months for open and endovascular interventions, respectively, and 40.5% and 36.6% at 12 months (P = .677). The open group required an average of 3.0 procedures to maintain secondary patency to 12 months, whereas the endovascular group averaged 1.8 procedures (P = .198). The strongest predictor for primary failure was percutaneous thrombectomy (hazard ratio [HR], 4.18; P < .01), whereas the presence of an existing stent at the venous anastomosis (HR, 3.85; P < .05) and the age of the graft (HR, 0.973; P < .05) were predictive of abandonment. Open vs endovascular intervention was not predictive of failure or abandonment. Open and endovascular interventions at the venous anastomosis of AVGs lead to poor but comparable patency rates at 6 and 12 months.

Management of Port Occlusions in Adults: Different-Site Replacement versus Same-Site Salvage

PurposeTo compare the safety and effectiveness of different-site port placement versus same-site port salvage in adult patients with occluded ports. Materials and MethodsNinety-five occluded subcutaneous infusion ports (ports) in 95 patients presenting between July 1, 2002, and June 30, 2017, were retrospectively reviewed: 48 (51%) different-site placements (replacements; same-day indwelling port removal and different-site new port placement) and 47 (49%) same-site salvages (salvages; 35 fibrin sheath strippings, 12 over-the-wire exchanges). Demographic information, indication for initial placement and replacement or salvage, procedural details, post-intervention primary catheter patency, and post-intervention port sequelae were recorded. Post-intervention primary catheter patency, and malfunction and infection rates were compared with Kaplan-Meier estimation and the log-rank test, and Fisher exact test, respectively. The association of patient risk factors and port patency was assessed with Cox regression. ResultsMedian primary catheter patency after replacement was 254 days (interquartile range [IQR], 297) and after salvage was 391 days (IQR, 906) (P = .25). Within the salvage group, median primary catheter patency after stripping was 391 days (IQR, 658) and after exchange was 666 days (IQR, 1412) (P = .08). There was no statistical difference in malfunction (P = .12) and infection (P = .74) rates between the replaced and salvaged groups or in malfunction (P = .09) and infection (P = .1) rates between the exchanged and stripped subgroups. None of the patient or catheter characteristics assessed were significantly associated with primary catheter patency. ConclusionsThere was no statistical difference between patency, malfunctions, or infections after replacement and salvage, or after stripping and exchange, so technique selection should be based on the patient’s estimated lifetime venous access requirements, cost, and physician preference.

Abstract No. 477 Endovascular arteriovenous dialysis fistula intervention: outcomes and factors contributing to fistula failure

To determine post-intervention patency rates and contributing factors for fistula failure in pre-dialysis patients with arteriovenous (AV) dialysis fistulas. Institutional review board approval was obtained for this single-institution retrospective study. All pre-dialysis patients who underwent upper extremity AV fistula creation for anticipated dialysis between October 1995 and January 2015 and who required subsequent endovascular therapy to maintain patency were reviewed. A total of 210 patients were identified. The medical record was queried for patient demographics, procedural details and outcomes. Multiple AV fistula configurations were reviewed: 138 brachiocephalic, 39 radiocephalic, 30 brachiobasilic, 2 ulnocephalic and 1 radiobasilic. Median post-intervention primary patency was 2.7 years, median post-intervention primary-assisted patency was 3.2 years, and median post-intervention secondary patency was 3.6 years. There were 293 initial stenosis treated. This included 5 stenosis in the inflow artery, 50 at the anastomosis, 71 in the juxta-anastomotic segment, 71 in the cannulation zone of the outflow vein, 16 in the noncannulation zone, 10 at the swing point of basilic vein transpositions, 57 in the cephalic arch, and 13 in the central veins. Stenoses in the non-cannulation zone of the outflow vein had the highest rate of target lesion revascularization (TLR) (76.7%), whereas central venous stenosis had the lowest rate of TLR (7.7%). The radiocephalic fistula configuration had better post-intervention primary patency (hazard ratio [HR] 0.58; 95% confidence interval [CI] 0.35-0.96; p=0.034). Conversely, brachiocephalic fistulas had higher risk for loss of post-intervention primary patency (HR 1.90; 95% CI 1.13-3.20; p=0.015). Among predialysis patients who undergo initial endovascular therapy to maintain patency of the AV fistula, the radiocephalic configuration was found to have the best post-intervention primary patency compared to other configurations. While the majority of hemodynamically significant lesions occurred at the anastomosis, lesions in the non-cannulation zone of the outflow vein had the highest rates of TLR.

Use of Drug-Coated Balloons in Dysfunctional Arteriovenous Dialysis Access Treatment: The Effect of Consecutive Treatments on Lesion Patency

PurposeA retrospective longitudinal analysis was performed to evaluate the outcome of consecutive treatments with drug-coated balloons (DCBs) in dysfunctional arteriovenous (AV) dialysis access (fistulae and grafts). Materials and MethodsFrom January 2015 to December 2017, 339 DCBs were used in 257 procedures in 165 patients with dysfunctional accesses. Of these, 38 patients had ≥ 2 procedures and were included in the analysis. A total of 112 procedures were performed with 133 devices (22 patients treated twice, 4 treated 3 times, 7 treated 4 times, 2 treated 5 times, and 3 treated 6 times). Mean balloon diameter was 8.13 mm (min-max range, 3–12 mm) and length was 63.16 mm (min-max range, 40–150 mm). Primary outcome measures were safety and effectiveness based on the noninferiority hypothesis that the second treatment would be as effective as the first regarding postintervention primary patency (PIPP). Secondary outcome measures included independent factors that may influence outcomes. ResultsMean lesion follow-up was 617 d (range, 175–1,100 d). Median PIPP durations were 216.5 d for the first intervention and 280 d for the second (P = .37; hazard ratio, 1.271; 95% confidence interval, 0.75–2.16). There was a significant difference in PIPP in favor of the second intervention when patients with only 2 interventions (22 of 38; 57.9%) were included (first intervention, 269 d; second intervention, 520 d; P = .03; hazard ratio, 2.354; 95% confidence interval, 1.087–5.098). ConclusionsThere was no significant difference in PIPP between the first and second DCB procedures. Results suggest consistency in PIPP with the use of DCBs regardless of aging AV access.

Hybrid salvage of thrombosed dialysis access grafts.

To report our experience and evaluate the results of a hybrid procedure comprising of surgical thrombectomy and adjuvant high pressure balloon angioplasty for management of thrombosed arteriovenous grafts (AVGs) with underlying venous anastomotic stenosis. Between January 2015 and June 2017, 148 patients with first-time thrombosis of AVGs were considered for treatment with surgical thrombectomy followed by high pressure balloon angioplasty of the underlying venous anastomotic lesions. Monitoring and surveillance was subsequently performed using clinical and hemodialysis criteria to detect a failing/failed access. Primary, assisted primary, and secondary patency rates were calculated using Kaplan-Meier analysis. This hybrid procedure was technically successful in 135 cases (91.2%) and clinically successful in 131 cases (88.5%). The postintervention primary patency rate of the target lesions was 68.2%, 52.4%, and 44.2% at 3, 6, and 12 months, respectively. Endovascular re-interventions increased significantly the postintervention assisted primary patency to 79.1%, 71.9%, and 66.8% (P=0.0004), and the postintervention secondary patency to 86.5%, 82.2%, and 78.6% (P<0.0001) at the same time points, respectively. Hybrid salvage of thrombosed AVGs using high pressure balloon angioplasty of the venous anastomotic stenosis following surgical thrombectomy by Fogarty catheter is a highly successful and safe procedure, with acceptable short-term primary patency. The need for repeated interventions demonstrates the necessity of continuous graft monitoring and surveillance to improve both assisted primary, and secondary patency rates.

Transfemoral Venous Access Facilitates Upper Extremity Dialysis Interventions: Procedural Success and Clinical Outcomes.

To report technical success and clinical outcomes of transfemoral venous access for upper extremity dialysis interventions. A total of 15 patients underwent a transfemoral venous approach for fistulography (n = 4; 27%) or thrombectomy (n = 11; 73%) over a 14-month period. Access characteristics, sheath size, thrombectomy method, angioplasty site, fluoroscopy time, radiation dose, technical and clinical success, complications, and post-intervention primary and secondary patency rates were recorded. Access type included arteriovenous fistulas (n = 10; 67%) and grafts (n = 5; 33%). The most common configuration was brachio-brachial (n = 6; 38%). Mean age of access was 37months. Mean prior interventions were 4. Right CFV access was used in all patients using 6-8-French (most common: 7-French [n = 10; 67%]) sheaths. Most thrombectomies (n = 11; 73%) required both pharmacologic and mechanical maceration (n = 9; 82%). All accesses required angioplasty to treat underlying stenosis at the outflow vein (n = 12; 80%) or arteriovenous anastomosis (n = 9; 90%). Mean fluoroscopy time was 26.43min. Air kerma and dose area product were 178.06 ± 225.77mGy and 57,768.83 ± 87,553.29μGym2, respectively. Procedural and clinical success rates were 93% and 80%, respectively. Technical failure was due to persistent stenosis in one patient. Clinical failure was due to unsuccessful dialysis immediately following intervention in three patients. Mean post-intervention primary patency and secondary patency durations were 2.8 and 4.8months, respectively. Primary patency rates at 1 and 3 months were 50% and 35%, respectively. Secondary patency rates at 1 and 3 months were 58% and 30%, respectively. A transfemoral venous approach for intervention of upper extremity dialysis accesses may be a valuable adjunct to traditional approaches.

Recent developments in endovascular interventions to sustain vascular access patency in haemodialysis patients.

There is amassed evidence regarding the use of endovascular procedures for the treatment of vascular access stenosis and thrombosis. A review was conducted based on available randomized trials, cohort studies and retrospective analyses published after 2000 on endovascular treatment of dysfunctional and thrombosed vascular access, with an aim to illustrate the available device and procedural options. The use of paclitaxel-coated balloons, cutting balloons and covered stents is described in the field of vascular access stenosis. The broad spectrum of available devices and endovascular declotting procedures ranging from thrombolysis to thrombectomy is also discussed. Overall, in this review we demonstrate the increasing role of endovascular procedures in vascular access treatment and the improved patency outcomes provided by the implementation of novel endovascular devices. Moreover, the improvement of post-intervention primary patency rates after endovascular declotting procedures and the shift to more thrombectomy-dependent procedures over time is also highlighted. In conclusion, endovascular treatment of dialysis access stenosis and thrombosis has an established role, owing to the implementation of sophisticated devices, allowing, when needed, the simultaneous treatment of thrombosis and the underlying stenosis.

A prospective randomized study of stent graft placement after balloon angioplasty versus balloon angioplasty alone for the treatment of hemodialysis patients with prosthetic graft outflow stenosis

BackgroundHemodialysis graft outflow stenosis is a significant complication occurring in hemodialysis patients with prosthetic grafts for vascular access. Balloon angioplasty remains the first-line endovascular treatment of this complication, although covered stent graft implantation after balloon angioplasty also appears to be an effective and promising treatment. The aim of this study was to evaluate the efficacy and durability of stent graft placement after balloon angioplasty in comparison to balloon angioplasty alone for the treatment of graft outflow stenosis in hemodialysis patients. MethodsWe conducted a prospective randomized study of 98 patients with clinically significant dialysis graft outflow stenosis treated in the vascular surgery section of a tertiary medical center. The patients were randomized into two groups; 49 patients were treated with stent graft placement after balloon angioplasty, and 49 patients were treated with balloon angioplasty alone. All patients underwent angiography of the graft site at 3 and 6 months after intervention, and restenosis rates were compared between the two groups. In addition, the duration of postintervention primary patency in the two groups was recorded and analyzed. ResultsThe postintervention restenosis rate of the stent graft placement group was superior to that seen in the balloon angioplasty alone group (9% vs 69% at 3 months [P < .0001] and 29% vs 72% at 6 months [P < .0001]). The mean postintervention primary patency duration was 380.22 ± 28.54 days for the stent graft placement group and 151.08 ± 16.79 days for the balloon angioplasty alone group (P < .0001). ConclusionsThe use of stent grafts in hemodialysis patients with graft outflow stenosis yielded superior results compared with the results seen in hemodialysis patients treated with balloon angioplasty alone. Patients treated with stent grafts after balloon angioplasty had a lower restenosis rate and a longer duration of postintervention primary patency. The placement of a stent graft after balloon angioplasty appears to be an optimal therapeutic approach for the treatment of hemodialysis patients with graft outflow stenosis.

Endovascular bypass for salvage of vascular access in hemodialysis catheter-consigned patients.

This study was performed to retrospectively assess the efficacy of percutaneous creation of an intervascular bypass with or without stent graft deployment (endovascular bypass) for salvage of abandoned vascular access sites in hemodialysis catheter-consigned patients. Salvage of abandoned vascular access sites was attempted in 16 patients with hemodialysis catheters. These vascular access sites were salvaged using endovascular bypass techniques to redirect the access flow to a nonarterialized vein as a new outflow conduit or cannulation segment. The postintervention primary, assisted primary, and secondary patency rates of the access site and bypass were calculated using the Kaplan-Meier method. The procedural and clinical success rates were both 100%. The postintervention primary patency rate of the bypass and access site at 360 days was 75.7 ± 12.5% and 56.8 ± 14.9%, respectively. The mean follow-up period was 461.9 days (range: 121-900 days). No major complications were observed. One bare bypass tunnel rupture and one pseudoaneurysm were noted during the procedure. Salvage of abandoned vascular access sites for hemodialysis catheter-consigned patients can be technically feasible and clinically successful using endovascular bypass techniques in selected patients when surgical revision is not considered or is not possible.

Clinical effectiveness of open thrombectomy for thrombosed autogenous arteriovenous fistulas and grafts

ObjectiveArteriovenous (AV) fistulas are the preferred hemodialysis access for patients with end-stage renal disease, although multiple interventions are typically needed to maintain patency. When AV fistulas thrombose, however, there is debate as to whether open thrombectomy should be attempted, particularly for salvage of upper arm fistulas. This study was designed to evaluate outcomes after open thrombectomy of upper arm and forearm AV fistulas compared with AV grafts. MethodsWe identified all patients who underwent an open thrombectomy procedure for a thrombosed AV fistula or graft at a single academic medical center between January 2006 and March 2017. The specific type of AV fistula or graft was evaluated, as were the patients' demographics, comorbidities, medications, adjunctive procedures during thrombectomy, and secondary interventions. The primary outcome measures, postintervention primary patency and postintervention secondary patency, were analyzed using Kaplan-Meier curves and Cox regression models for risk adjustment. ResultsDuring the study period, 209 open thrombectomy procedures were performed in 139 patients; 73 (35%) were undertaken in AV fistulas and 136 (65%) in grafts. Patients with upper arm fistulas (n = 52; 54% brachiocephalic, 46% brachiobasilic) and forearm fistulas (n = 16) were more likely to be male but less likely to have cerebrovascular disease or ischemic heart disease and to be receiving anticoagulation therapy compared with graft patients. After thrombectomy, the majority of patients underwent dialysis successfully (70% upper arm fistulas, 56% forearm fistulas, 63% grafts; P > .05), and 1-year survival rates were similar in all three cohorts. Postintervention primary patency at 1 year was significantly higher for AV fistulas vs grafts (33% for upper arm fistulas and 25% for forearm fistulas vs 9% for grafts; P < .05), which was confirmed in multivariate analysis, where upper arm AV fistulas had a 46% lower risk of recurrent thrombosis or secondary intervention (hazard ratio, 0.56; 95% confidence interval, 0.35-0.85; P < .05). Postintervention secondary patency at 1 year was similar between AV fistulas and grafts (44% for upper arm fistulas vs 43% for forearm fistulas vs 31% for grafts; P = .16), but in multivariate analysis, upper arm fistulas were significantly less likely to fail (hazard ratio, 0.63; 95% confidence interval, 0.40-1.00; P = .05). ConclusionsOur data suggest that AV fistula thrombectomy is successful in up to 70% of cases, with significantly improved risk-adjusted 1-year primary and secondary patency rates for upper arm fistulas compared with grafts. Whereas the risk of access failure is high after thrombectomy, efforts to salvage upper arm AV fistulas are effective in most patients and should be undertaken when feasible.

Clinical Trial End Points for Hemodialysis Vascular Access: Background, Rationale, and Definitions.

Hemodialysis vascular access is the “lifeline” for patients on hemodialysis. Unfortunately, because of its poor patency and significant complication rate, it is also the “Achilles heel” of hemodialysis. For example, the current unassisted arteriovenous fistula (AVF) maturation rate is only

Race and Sex Disparities in Outcomes of Dialysis Access Maintenance Interventions

PurposeTo determine whether utilization and outcomes of dialysis access maintenance interventions vary by patient race or sex. Materials and MethodsData for this retrospective cohort study of first-time arteriovenous (AV) access recipients were drawn from a 5% sample of Medicare beneficiaries, containing claims from all clinical settings (2009–2014) in 2,693 patients who received their first AV fistula/graft in 2009. Maintenance interventions—angiography, angioplasty, thrombolysis, stent placement, and venous embolization—were identified by corresponding Current Procedural Terminology codes. Outcomes of primary patency (PP), postinterventional primary patency (PIPP), and postinterventional secondary patency (PISP) were calculated with utilization records. Associations between demographic data and patency times were evaluated by a multivariate survival approach, controlling for baseline differences in patient age, comorbid disease, type of dialysis access, and interventionist specialty. ResultsAV grafts (AVGs) were created with greater frequency in women (32% vs 23% in men; P < .001) and minority patients (39% in black, 32% in Hispanic, and 29% in Asian patients vs 21% in white patients; P < .001). Women were at greater hazards for loss of PP (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.09–2.14) and PIPP (HR, 1.42; 95% CI, 1.01–2.00). Black patients were at greater hazards for loss of PP (HR, 1.37; 95% CI, 1.23–1.54) and PISP (HR, 1.29; 95% CI, 1.01–1.65). AVG creation predisposed patients to patency loss in all models (P < .001). ConclusionsDialysis access patency rates are lower for women and black patients. More frequent primary AVG creation in women and minority patients additionally predisposes these patients to patency loss.

Timely thrombectomy can improve patency of hemodialysis arteriovenous fistulas

ObjectiveThe urgency with which salvage of thrombosed vascular accesses for dialysis should be attempted remains unknown. We examined the effect of a timely thrombectomy approach on vascular access outcomes for dialysis. MethodsA before-and-after study was conducted with patients on hemodialysis who had undergone endovascular thrombectomy. A timely thrombectomy initiative (ie, salvage within 24 hours of thrombosis diagnosis) was started in July 2015 at our institution. Data about thrombectomy procedures, performed within 1 year before and after the initiative was introduced, were abstracted from an electronic database. Immediate outcomes and patency outcomes were compared between the preinitiative (control) and postinitiative (intervention) groups. ResultsDuring the study period, 329 patients were enrolled, including 165 cases before and 164 cases after the initiative. The intervention group had more thrombectomy procedures performed within 24 hours (93% vs 55%; P < .01) and within 48 hours (97% vs 79%; P < .01) than the control group. No between-group differences in procedural success or clinical success rates were found. At 3 months, the intervention group had a higher postintervention primary patency rate than the control group, although this did not reach statistical significance (58% vs 48%; P = .06). After stratification into native or graft accesses, the patency benefit was observed in the native access group (68% vs 50%; P = .03) but not in the graft access group (50% vs 46%; P = .65). After adjusting for potential confounders, timely thrombectomy remained an independent predictor of postintervention primary patency (hazard ratio, 0.449; 95% confidence interval, 0.224-0.900; P = .02) for native dialysis accesses. ConclusionsOur results suggest that a timely thrombectomy approach, in which salvage is attempted within 24 hours of thrombosis diagnosis, improves postintervention primary patency of native but not graft accesses for dialysis.

Abstract No. 141 - Management of central venous stenosis in hemodialysis patients: comparison of outcomes with the Hemodialysis Reliable Outflow (HeRO) graft versus stenting

To evaluate outcomes of HeRO graft placement and compare its efficacy to central venous stenting in hemodialysis patients with recalcitrant central venous stenosis. We performed a retrospective review of hemodialysis patients who underwent HeRO graft placement or stenting for central venous stenosis between January 2010 and September 2016. The fraction of patients requiring no further intervention, the post-intervention primary lesion patency and number of interventions per patient year for both groups were analyzed. We identified 29 patients with a total of 30 HeRO graft placement procedures. Two patients with no follow-up information after graft placement were excluded from this study. One patient whose HeRO graft was removed due to infection had a repeat HeRO graft placement. We also identified 14 patients who underwent stenting for their central venous stenosis. At the time of this interim analysis, in the HeRO group, 16/28 (57%) were still patent with no further intervention after the graft placement, with a mean follow-up time of 582 days (± 532). In the stent group, 4/14 (28%) were still patent with no further intervention after stenting, with a mean follow up of 579 days (± 371). Among patients requiring an intervention, mean post-intervention primary lesion patency for the HeRO graft (N = 12) was 479 days versus 332 days for the stent group (N = 10). The average number of interventions per patient year for the HeRo and stent groups were 1.4 and 2.3, respectively. Student’s t-test for post-intervention primary lesion patency and number interventions per year for the two groups showed no statistically significant differences (p-values: 0.115 and 0.401, respectively). For the stent group, mean number of intervention per year for covered stent (N = 4) was 0.43 versus 2.12 for non-covered stent (N = 10). Our preliminary analysis of this ongoing study shows no statistically different outcome in patients treated with the HeRO graft versus stenting for central venous stenosis. HeRO is a viable option for hemodialysis patients with recalcitrant central stenosis who are non-surgical candidates for AV fistula.

Application of interventional ultrasound in hybrid procedure to treat thrombosis of arteriovenous graft

Objective To preliminarily investigate the methods, safety and short to medium-term effectiveness of the interventional ultrasound applying in the hybrid procedure to treat the thrombosis of arteriovenous graft(AVG). Methods Twenty patients with the thrombosis of AVG, who received the hybrid procedure defined as Fogarty catheter thrombectomy and percutaneous transluminal angioplasty(PTA) guided by the ultrasonography, were retrospectively investigated. The display effects of the ultrasonography were observed. The technical and clinical success rates were evaluated. All the cases were followed up every 3 months for at least 1 year to evaluate the post-interventional assisted primary patency and the post-interventional secondary patency. Results All the processes were clearly displayed and well guided by the interventional ultrasound during the procedure. The technical and the clinical success rates were both 100%. No major complications were recorded. The post-intervention assisted primary patency rate was 100%, 92.9%, 85.7%, 71.4% at 3, 6, 9, 12 months, respectively. The post-intervention secondary patency was 100%, 100%, 89.5%, 89.5% at the correspondent months. Conclusions This pilot research shows the hybrid procedure guided by the interventional ultrasound to treat the thrombosis of AVG has high success rate and satisfied patency in short to medium-term. The interventional ultrasound is an effective, safe and convenient guiding method to the hybrid procedure, and has the value for clinical application. Key words: Ultrasonography, interventional; Arteriovenous graft; Thrombosis; Hybrid procedure

Ultrasound-guided angioplasty for treatment of peripheral stenosis of arteriovenous fistula - a single-center experience.

In patients with end-stage renal disease, arteriovenous fistulas (AVFs) are the access of choice for hemodialysis but are often complicated by stenosis. We present single-center experience of 78 ultrasound-guided angioplasty procedures for treating peripheral stenoses of AVFs. Between January 2013 and November 2015, 78 angioplasties were performed under ultrasound guidance in 53 patients with end-stage renal disease who were referred from dialysis centers with low flow rate, difficult cannulation, increased cannulation site bleeding, immature or thrombosed AVF. Angioplasties were carried out in the presence of a structural lesion in the AVF resulting in at least 50% reduction in vein diameter with a blood flow of &lt;250 mL/min or a peak systolic velocity &gt;300 cm/s. Clinical success, anatomical success and post-intervention primary and secondary patency rates at 6, 12, 18 and 24 months were studied. In 49/53 patients (92.4%), 74 angioplasty procedures were successfully performed, whereas 4/53 patients (7.6%) had primary failure. A total of 35/49 patients (71.4%) underwent single angioplasty procedure whereas 14/49 patients (28.6%) underwent multiple angioplasty procedures. Post-intervention primary patency rates at 6, 12, 18 and 24 months were 78.6%, 60.2%, 53.8% and 48.9%, respectively. Post-intervention secondary patency rates at 6, 12, 18 and 24 months were 100%, 100%, 95.4% and 89%, respectively. Clinical success and anatomical success was 94.8% and 89.7%, respectively. Ultrasound-guided angioplasty is an effective method with good long-term outcomes in selected dialysis patients with peripheral stenosis of AVF.

Postintervention Patency: A Comparison of Stenting versus Patch Angioplasty for Dysfunctional Hemodialysis Access Sites

Arteriovenous access dysfunction is commonly caused by venous outflow stenosis, leading to thrombosis of the conduit. Given that there are limited lifetime hemodialysis access sites, the preservation of existing sites through novel means is of high priority. This study compares the efficacy of balloon angioplasty and stent placement to surgical patch angioplasty for upper arm (brachium) thrombosed or dysfunctional hemodialysis access sites in a group of patients at a single institution. Using the operating room log and electronic medical record system, we retrospectively examined the outcomes of 52 consecutive patients (3 were lost to follow-up), who had either stent placement (34 patients) or patch angioplasty (15 patients) for hemodialysis access salvage to calculate postintervention patency. Initial postinterventional patency (PIP1) for patch angioplasty compared with stentplacement was not statistically significant at any time during a mean 6-month follow-up (60% vs. 67.65% at 1month, 33.33% vs. 41.18% at 3months, and 13.33% vs. 17.65% at 6months, respectively; P=0.75). Patency after secondary reintervention (PIP2) was longer for patients who had stent placement as the initial intervention (n=15) than patientswho had patch angioplasty (n=5; 100% vs. 80% at 1month, 66.68% vs. 80% at 3months, and 46.67% vs. 40% at 6months, respectively), but again there was no statistically significant difference between the 2 groups (P=0.84). At last, the initial PIP1 of arteriovenous fistula (AVF) and arteriovenous graft (AVG) salvaged before occlusion was significantly different from that of occluded access sites (40% vs. 10% at 6months, P=0.024). Our data suggest that AVF had a longer postinterventional primary patency than AVG though the difference did not reach statistical significance. Stents extended PIP1 for the thrombosed or failing arteriovenous access longer than patch angioplasty, but the difference was not statistically significant. Patency is longer if intervention is made before graft thrombosis. Our data also indicate better prolongation of patency with a second reintervention (PIP2) if the first intervention was a stent placement. Patch angioplasty appears to be a less attractive alternative for correction of venous outflow stenosis given the more invasive and occasionally technically difficult procedure.

Randomized Trial Comparing the Primary Patency following Cutting Versus High-Pressure Balloon Angioplasty for Treatment of de Novo Venous Stenoses in Hemodialysis Arteriovenous Fistulae

PurposeA single-center randomized clinical trial was performed to compare postinterventional primary patency rates achieved by cutting balloon angioplasty and high-pressure balloon angioplasty in the treatment of de novo stenoses within autogenous arteriovenous (AV) fistulae for hemodialysis. Materials and MethodsForty-eight patients undergoing their first angioplasty were prospectively randomized to undergo angioplasty with a cutting balloon or high-pressure balloon 4–8 mm in diameter because cutting balloons larger than 8 mm are not available. Nine patients were excluded after angiography, with seven requiring balloons larger than 8 mm. In the remaining 39 patients, there were 42 stenoses in the following regions: juxtaanastomotic (38%), perianstomotic (38%), midcephalic (9%), and cephalic arch (14%). Patients in the cutting balloon group were younger (mean age difference, 9 y; P = .04), but other demographic variables were comparable (range, P = .08–.89). The mean follow-up period was 8.5 mo (range, 24 d to 32 mo). Kaplan–Meier analysis was used to compare duration of patency. Mann–Whitney rank-sum t test and χ2/Fisher exact tests were used to compare continuous and categoric variables, respectively. ResultsTechnical success was achieved in all 39 patients. At 3, 6, and 12 months, the postinterventional primary patency rates for the cutting balloon group were 61.1% (95% confidence interval [CI], 35.75%–82.70%), 27.7% (95% CI, 9.69%–53.48%), and 11.1% (95% CI, 1.38%–34.71%), respectively, compared with 70.0% (95% CI, 45.72%–88.11%), 42.1% (95% CI, 20.25%–66.50%), and 26.3% (95% CI, 9.15%–51.20%), respectively, for the high-pressure balloon group (P < .3 at each interval). ConclusionsCompared with high-pressure balloon angioplasty, cutting balloon angioplasty does not improve postinterventional primary patency of de novo stenotic lesions in autogenous arteriovenous fistulae.

Postintervention Patency Rates and Predictors of Patency after Percutaneous Interventions on Intragraft Stenoses within Failing Prosthetic Arteriovenous Grafts

PurposeTo determine postintervention patency rates after endovascular interventions on intragraft stenosis within failing prosthetic arteriovenous (AV) grafts, as well as predictors of patency. Materials and MethodsRetrospective review of percutaneous interventions on prosthetic AV grafts presenting with first-time intragraft stenoses over a 7-year period revealed 183 patients (81 male; mean age, 59.7 y). “Intragraft” was defined as 2 cm or more from the arterial or venous anastomosis. Procedural imaging was retrospectively reviewed. Patency rates were estimated by Kaplan–Meier test. Predictors of patency were calculated by Cox proportional-hazards model. ResultsTwo-hundred twenty-nine intragraft stenoses were identified in 183 grafts. Intragraft stenoses were treated at a median of 20.7 months (interquartile range, 12.0–33.9 mo) after graft creation. Graft thrombosis was present in 62%. The anatomic success rate of angioplasty was 85%. Fifteen percent required stent or stent-graft deployment because of inadequate response to angioplasty. A concurrent nonintragraft stenosis within the access circuit was identified in 76% of grafts. At 3, 6, and 12 months, postintervention primary patency rates were 56%, 40%, and 23%, respectively. Secondary patency rates were 84%, 77%, and 67%, respectively. The lesion-specific patency rates were 89, 75%, and 63%, respectively. Graft thrombosis (hazard ratio [HR], 1.43; P = .048) and concurrent nonintragraft lesion (HR, 1.51; P = .047) were independent negative predictors of primary patency. Graft thrombosis (HR, 1.81; P = .029) was a negative predictor of lesion patency, and stent or stent-graft deployment (HR, 0.42; P = .045) was a positive predictor of lesion patency. ConclusionsEndovascular interventions on intragraft stenoses resulted in primary, secondary, and lesion-specific patency rates of 40%, 77%, and 75%, respectively, at 6 months. Stent or stent-graft deployment may prolong lesion patency.