Brachiocephalic Arteriovenous Fistula Research Articles

Autologous arteriovenous fistula is associated with superior outcomes in elderly hemodialysis patients

BackgroundThe number of elderly patients with end-stage renal disease is increasing rapidly. The higher prevalence of comorbidities and shorter life expectancy in these patients make it difficult to decide on the type of vascular access (VA). We explored the optimal choice for VA in elderly hemodialysis patients.MethodsWe included elderly patients (> 65 years) visiting our VA clinic and divided them into three groups as follows: radiocephalic arteriovenous fistula (AVF), brachiocephalic AVF, and prosthetic arteriovenous graft (AVG). The primary outcomes were VA abandonment and all-cause mortality. The secondary outcome was maturation failure (MF).ResultsOf 529 patients, 61.2% were men. The mean age was 73.6 ± 6.0 years. The VA types were as follows: 49.9% radiocephalic AVF, 31.8% brachiocephalic AVF, and 18.3% AVG. Patients with an AVG tended to be older, female, and have a lower body mass index. More than half of patients (n = 302, 57.1%) started dialysis with central catheters, but the proportion of predialysis central catheter placement was not different among the VA types. Radiocephalic AVF was significantly superior to AVG in terms of VA abandonment (P = 0.005) and all-cause mortality (P < 0.001) in spite of a higher probability of MF. Brachiocephalic AVF was associated with a shorter time to the first needling and fewer interventions before maturation than radiocephalic AVF.ConclusionsAutologous AVF was suggested as the preferred VA choice in terms of long-term outcomes in elderly patients.

Endovascular management in immature arteriovenous fistula for hemodialysis

To evaluate the outcomes and prognostic factors of endovascular management in immature arteriovenous fistula (AVF) for hemodialysis.From April 2007 to September 2017, 54 patients (male:female = 31:23, mean age 65.63 years, range 33–90 years) who underwent endovascular management for the salvage of immature AVF were retrospectively reviewed. Clinical data, procedural details, and results were evaluated. Primary and secondary patency rates and factors influencing the patency were also analyzed.Technical and clinical success rates were 88.9% (48/54) and 85.2% (46/54), respectively. Mean primary and secondary patency was 42.10 (±8.85) and 91.5 (±14.77) months, respectively. Primary and secondary patency rates were 66% and 89% in 1 year, 66% and 78% in 2 years, and 51% and 78% in 3 years. In multivariate analysis, only brachiocephalic AVF and antegrade access procedures showed significantly shorter primary patency (HR 5.196; 95% CI (1.04–25.77); P = .044, HR 8.096; 95% CI (1.36–48.00); P = .021). There was no statistically significant factor associated with secondary patency in the multivariate study.Endovascular management in immature AVF is safe and effective to make the AVF available. Brachiocephalic AVF and antegrade access procedures are the factors influencing the patency in multivariate analysis.

Cost-Effectiveness of Repeated Interventions on Failing Arteriovenous Fistulas: When Is It Time to Start Over?

Arteriovenous fistulas (AVFs) used for hemodialysis commonly undergo multiple percutaneous and open interventions to maintain function patency, but it is unclear whether this strategy is cost-effective. The aim of this study was to evaluate the cost-effectiveness of performing repeated interventions vs starting a new AVF. We reviewed all patients with mature radiocephalic, brachiocephalic, and brachiobasilic AVFs at a single academic institution between 2000 and 2016 and assessed open and percutaneous interventions to maintain functional patency after the fistula was created. These data were used to parameterize a Markov simulation model to determine the cost-effectiveness for performing an open or percutaneous intervention vs creating an AVF at a new anatomic location. This model compared strategies of creating a new AVF after the first to fourth reintervention within a 1-year time window, with the reference being creation of a new AVF on the fourth reintervention. We used this model to calculate incremental cost-effectiveness ratios (ICERs) using 2016 costs from Medicare’s payer-perspective per quality-adjusted life-year (QALY) gained. A total of 720 mature AVFs were created during the 15-year period, and 283 (39%) underwent at least one intervention to maintain functional patency, with the median (interquartile range) time to first reintervention of 12.6 (10-17) months. For the strategies of creating a new AVF after the first vs the fourth reintervention, costs ranged from $672 to $846 for open procedures and $172 to $846 for percutaneous procedures (Table). The ICERs for open interventions on failing AVFs were $154,273/QALY after the first reintervention and $59,917/QALY after the second reintervention, but creating a new AVF after the third open reintervention was dominated by other strategy and not cost-effective. The ICERs for percutaneous interventions on failing AVFs ranged from $574,494/QALY after the first reintervention to $203,946/QALY after the third reintervention (Table). Whereas the effectiveness of performing percutaneous interventions on failing AVFs diminishes after each reintervention, they are nevertheless less costly than creating a new AVF. In comparison, our data show that creating a new AVF is cost-effective after the second open reintervention procedure.TableCalculation of incremental cost-effectiveness ratios (ICERs) using Medicare costs per quality-adjusted life-year (QALY) gainedStrategyCostQALYsICEROpen reintervention New AVF on the fourth reintervention$6720.5149 New AVF on the third reintervention$6920.5153Dominated New AVF on the second reintervention$7280.5159$59,917 New AVF on the first reintervention$8460.5167$154,273Percutaneous reintervention New AVF on the fourth reintervention$1720.5149 New AVF on the third reintervention$2480.5153$203,946 New AVF on the second reintervention$4040.5159$260,333 New AVF on the first reintervention$8460.5167$574,494AVF, Arteriovenous fistula. Open table in a new tab

Autologous Arteriovenous Loop Fistula in the Forearm With Transposition of a Matured Forearm Cephalic Vein

A 61 year old dialysis patient presented with thrombosed brachiocephalic arteriovenous fistula in the left arm after multiple revisions. On clinical examination it was noted that the patent brachiocephalic anastomosis (arrowhead) was still draining into a considerable length of dilated cephalic vein in the forearm (presenting bruit). Under local anaesthesia a sufficient length of the cephalic vein was dissected free and mobilised (Panel A) to loop back (Panel B, dotted line) for an end to end anastomosis to the basilic vein in the cubital fossa (Panel B, arrow). The presented technique avoids any artificial conduit and spares the brachial site for future interventions.

Treatment Strategies for Cephalic Arch Stenosis in Patients with Brachiocephalic Arteriovenous Fistula

Cephalic arch is one of the sites most susceptible to stenosis in brachiocephalic arteriovenous fistula (BCAVF). We performed a retrospective study to identify the incidence of cephalic arch stenosis (CAS) in BCAVF, to compare the patency of percutaneous transluminal balloon angioplasty (PTA) with that of cephalic vein transposition (CVT), and to establish the optimal treatment strategy for CAS. Between January 2011 and June 2016, 462 patients underwent BCAVF creation. CAS was defined as >50% stenosis at the confluence of the cephalic and axillary veins on ultrasonography. Treatment was planned for clinically significant CAS, which was defined as >25% reduction in flow volume compared to previous examination, elevation of venous pressure, delayed puncture site hemostasis, and/or acute thrombotic occlusion. Seventy-seven (16.7%) patients had CAS and 42 of them (54.5%) were treated for clinically significant CAS. PTA was performed in 36 patients (85.7%), and CVT was done in 6 patients (14.3%) as the initial treatment. Nine patients underwent CVT after PTA, resulting in a total of 15 patients treated with CVT. Investigation of the patency of the 36 cases of PTA and 15 cases of CVT revealed that primary-assisted patency rates at 6 and 12months were 68.2% and 57.3% for PTA and 100.0% and 87.5% for CVT, respectively (P=0.038). Secondary patency rates at 6 and 12months were 72.0% and 56.9% for PTA and 100% and 100% for CVT, respectively (P=0.010). The median intervention rate was 2.5 interventions per access-year in the 36 cases treated with PTA and 1.5 interventions per access-year in the 15 cases treated with CVT. CAS is a common cause of BCAVF dysfunction, and careful surveillance is warranted. CVT should be considered for treatment of CAS to achieve better long-term patency with fewer reinterventions.

Percutaneous Salvage of a Thrombosed Immature Arteriovenous Fistula using a Long Segment Stent Graft across the Juxta-Anastomotic and Outflow Vein

The role for stent grafting in the juxta-anastomotic segment for nonmaturing arteriovenous (AV) fistulas is not well understood. We report a case in which a long segment stent-graft of nearly the entire venous limb of a brachiocephalic AV fistula was stented to salvage an access that would likely otherwise have been abandoned. The patient went on to mature his fistula 3 months later and access it for hemodialysis through percutaneous puncture of the stent graft.

Wewnątrznaczyniowe zamknięcie pękniętego tętniaka przeszczepu z odwróconej żyły odpiszczelowej w poddanej zabiegowi naprawczemu przetoce tętniczo-żylnej — kwestie techniczne

A 49-year-old diabetic woman who had end stage renal disease associated with membranous glomerulonephritis, was undergoing dialysis through a left brachiocephalic arteriovenous fistula. After sometime, fistula became infected and stopped functioning. It was closed and arterial segment was resected and repaired with reverse saphenous vein graft. After 6 months interval, she presented with painful, expansile swelling with intermittent bleeding. Arteriogram showed ruptured aneurysm of reverse saphenous vein graft with a proximal venous stenosis. It was successfully closed with 6 × 60 mm Fluency Plus self-expanding vascular stent graft (Bard, Tempe, AZ) with resolution of her symptoms.

Effect of first cannulation time and dialysis machine blood flows on survival of arteriovenous fistulas.

To study the effect of cannulation time on arteriovenous fistula (AVF) survival. Methods. Analysis of two prospective databases of access operations and dialysis sessions from 12 January 2002 through 4 January 2015 with follow-up until 4 January 2016. First cannulation time (FCT), defined from operation to first cannulation, was categorized as <2 weeks, 2-4 weeks, 4-8 weeks, 8-16 weeks and ≥16 weeks. Early cannulation was defined as FCT within 4 weeks. AVF survival was defined as the date until the AVF was abandoned. Maximum machine blood flow rate (BFR) for the first 29 dialysis sessions on AVF was analysed. Altogether, 1167 AVF with functional dialysis use were analysed: 667 (57%) radial cephalic AVF, 383 (33%) brachiocephalic AVF and 117 (10%) brachiobasilic AVF. The 631 (54%) AVF created in on-dialysis patients were analysed separately from 536 (46%) AVF created in pre-dialysis patients. AVF survival was similar between cannulation categories for both pre-dialysis patients (P = 0.19) and on-dialysis patients (P = 0.83). Early cannulation was associated with similar AVF survival in both pre-dialysis patients (P = 0.82) and on-dialysis patients (P = 0.17). Six consecutive successful cannulations from the start were associated with improved AVF survival (P = 0.0002). A below-median BFR at the start of dialysis was associated with better AVF survival (P < 0.0001). A below-median increase in BFR in the first 2 months was associated with worse AVF survival (P = 0.007). The type of AVF, diabetes, pre-dialysis state at operation and six successful cannulations from the start were independent predictors for AVF survival. FCT is not associated with AVF survival. Failures to achieve six successful cannulations from the start of dialysis and higher machine BFR in the first week of dialysis are associated with decreased AVF survival.

Outcomes of intervention for cephalic arch stenosis in brachiocephalic arteriovenous fistulas

BackgroundDevelopment of recalcitrant stenotic lesions of the cephalic arch is a significant cause of dysfunction of brachiocephalic access arteriovenous fistulas (AVFs). Endovascular and surgical therapy can be used to treat cephalic arch stenosis. The aim of this study was to evaluate the outcomes of endovascular and surgical interventions for cephalic arch stenosis. MethodsA retrospective review of all patients during a 16-year period with a compromised but not occluded brachiocephalic AVF due to cephalic arch stenosis was undertaken. Patency, reintervention, infection, and functional dialysis rates were examined. ResultsFrom January 2000 to December 2015, 219 patients (67% female; mean age, 58 ± 20 years) with a failing brachiocephalic AVF underwent intervention at the cephalic arch. These interventions included angioplasty, primary stent placement, transposition, and bypass. The average time to intervention for cephalic arch stenosis was 1.7 years after primary access placement. The average number of percutaneous interventions before the decision to intervene surgically on the cephalic arch was three (range, two to six). Technical success was superior in the surgical groups (70% and 80% compared with 96% and 100% for balloon angioplasty, stenting, transposition, and bypass, respectively; P = .02). Major adverse cardiovascular events were overall low but significantly higher in the surgical groups (1%, 1%, 0.3%, and 0.3% for transposition, bypass, balloon angioplasty, and stenting, respectively; P = .02). Both surgical options carried significantly superior patency rates at 2 years for transposition, bypass, balloon angioplasty, and stenting, respectively (63%, 59%, 90%, and 92%; P = .04). There was a lower rate of interventions per person-year of follow-up in the surgical groups compared with the endovascular groups (1.9, 1.4, 3.5, and 3.1 for transposition, bypass, balloon angioplasty, and stenting, respectively; P = .04). Functional dialysis durations were significantly superior in the surgical groups compared with the endovascular group (P = .03). ConclusionsCephalic arch stenosis is a significant cause of brachiocephalic AVF malfunction. Surgical options offer superior long-term patency and functional results and should be considered earlier in the treatment of this disease.

Results of Stent Graft Placement to Treat Cephalic Arch Stenosis in Hemodialysis Patients with Dysfunctional Brachiocephalic Arteriovenous Fistulas

PurposeTo determine effectiveness of the VIABAHN (W.L. Gore & Associates, Flagstaff, Arizona) stent graft to treat cephalic arch stenosis in patients with dysfunctional brachiocephalic arteriovenous fistulas after inadequate venoplasty response. Materials and MethodsBetween 2012 and 2015, patients with failed venoplasty of symptomatic cephalic arch stenosis received a VIABAHN stent graft. Follow-up venography was performed at approximately 3, 6, and 12 months. Data were retrospectively analyzed with patency estimated using Kaplan-Meier and log-rank methodology. There were 39 patients included. ResultsTechnical and clinical success was 100%. Primary target lesion patency was 85% (95% confidence interval [CI], 69%–93%), 67% (95% CI, 50%–80%), and 42% (95% CI, 25%–57%) at 3, 6, and 12 months. There was no significant difference in patency with regard to sex or age (P = .8 and P = .6, respectively). Primary assisted patency was 95% (95% CI, 82%–99%) at 3, 6, and 12 months. Access circuit primary patency was 85% (95% CI, 69%–93%), 67% (95% CI, 50%–80%), and 42% (95% CI, 25%–57%) at 3, 6, and 12 months. There was no significant difference in patency between patients with the stent graft as the first treatment episode in the cephalic arch and those that had previous intervention at this site (P = .98). There were 48 repeat venoplasty procedures performed in the cephalic arch to maintain patency, including 7 repeat VIABAHN insertions. No complications were encountered. ConclusionsThe VIABAHN stent graft is a safe, effective, and durable device for treating cephalic arch stenosis when venoplasty fails.

The Effect of Arterial Curvature on Blood Flow in Arterio-Venous Fistulae: Realistic Geometries and Pulsatile Flow

Arterio-Venous Fistulae (AVF) are regarded as the “gold standard” method of vascular access for patients with End-Stage Renal Disease (ESRD) who require haemodialysis. However, up to 60% of AVF do not mature, and hence fail, as a result of Intimal Hyperplasia (IH). Unphysiological flow and oxygen transport patterns, associated with the unnatural and often complex geometries of AVF, are believed to be implicated in the development of IH. Previous studies have investigated the effect of arterial curvature on blood flow in AVF using idealized planar AVF configurations and non-pulsatile inflow conditions. The present study takes an important step forwards by extending this work to more realistic non-planar brachiocephalic AVF configurations with pulsatile inflow conditions. Results show that forming an AVF by connecting a vein onto the outer curvature of an arterial bend does not, necessarily, suppress unsteady flow in the artery. This finding is converse to results from a previous more idealized study. However, results also show that forming an AVF by connecting a vein onto the inner curvature of an arterial bend can suppress exposure to regions of low wall shear stress and hypoxia in the artery. This finding is in agreement with results from a previous more idealized study. Finally, results show that forming an AVF by connecting a vein onto the inner curvature of an arterial bend can significantly reduce exposure to high WSS in the vein. The results are important, as they demonstrate that in realistic scenarios arterial curvature can be leveraged to reduce exposure to excessively low/high levels of WSS and regions of hypoxia in AVF. This may in turn reduce rates of IH and hence AVF failure.

A Single-Institution Study of Permanent Vascular Access Outcomes in Patients undergoing Hemodialysis

BackgroundVascular access (VA) is essential for successful hemodialysis (HD) but its provision poses significant challenges to renal services. This study aimed to report the long-term outcomes for different types of first permanent VA, and identify factors that affected outcomes in a cohort of patients undergoing HD at a single renal unit. MethodsData recorded before April 1, 2013, were collected on factors related to patient characteristics and VA management. Univariate analysis of VA survival was undertaken using the Kaplan-Meier method with log-rank testing used to test for differences between subgroups. Secondary outcomes included VA complication and intervention rates. ResultsOf those first permanent VA attempts (n = 103), 26.2% were radiocephalic arteriovenous fistulae (RCAVF), 54.4% were brachiocephalic arteriovenous fistulae (BCAVF), 10.7% were transposed basilic arteriovenous fistulae (TBAVF), and the remaining 8.7% were polytetrafluoroethylene forearm loop arteriovenous grafts (AVG). Overall cumulative secondary VA survival rates at 6, 12, and 24 months were 90.9%, 82.8%, and 73.4%, respectively. Complication rates for RCAVF, BCAVF, TBAVF, and AVG were 0.5, 1.2, 4.5, and 2.6 per patient year on HD, respectively. Intervention rates for RCAVF, BCAVF, TBAVF, and AVG were 0.4, 0.8, 2.9, and 2.1 per patient year on HD, respectively. A primary renal diagnosis of diabetes (P = 0.022), use of temporary central venous catheter (P = 0.003) or rope-ladder needling (P = 0.013), and the use of TBAVF or AVG (P < 0.001) were predictive of significantly poorer VA survival. ConclusionsRCAVF and BCAVF were associated with significantly superior outcomes compared with TBAVF and AVG in terms of complication and intervention rates, and long-term survival.

The Significance of Inflow Artery and Tourniquet Derived Cephalic Vein Diameters on Predicting Successful Use and Patency of Arteriovenous Fistulas for Haemodialysis

To investigate the significance of inflow artery and cephalic vein diameters on predicting patency of radiocephalic and brachiocephalic arteriovenous fistulas (AVFs). Single centre study with retrospective analysis of prospectively collected data between November 2010 and July 2015. A detailed history and physical examination was undertaken, including age, gender, history and duration of haemodialysis, cause of chronic kidney disease, and the presence of comorbidities/risk factors. Pre-operative arterial and venous upper extremity mapping was performed and inner vessel diameter was recorded, using a tourniquet for the veins. Outcome measures included AVF use (functionality), primary, primary assisted, secondary, and functional secondary patency. One hundred and thirty five AVFs (57 and 78 radiocephalic and brachiocephalic AVFs, respectively) were constructed and followed up for 5 years. A cephalic vein diameter <4.3mm (lower three quartiles) was the single independent predictor of inferior secondary and also functional secondary patency of radiocephalic AVFs (p=.02, HR 11.2, 95% CI 1.44-90.9). A brachial artery diameter ≤4.1mm (lowest quartile) was an independent predictor of AVF functionality (57% vs. 83% for larger arteries, p=.017), and inferior primary, primary assisted, secondary, and functional secondary patency of brachiocephalic AVFs (primary assisted patency 21.9% vs. 55.9% at 3 years, p=.001/log-rank test, HR 3.1, p=.002/Cox regression). The presence of lower extremity PAD or use of dual antithrombotics was also independently associated with an inferior secondary patency. The number of risk factors (brachial artery diameter ≤4.1mm, PAD, and use of dual antithrombotics) demonstrated risk stratification capabilities for functional secondary patency. Among patients undergoing radiocephalic AVFs, a tourniquet derived cephalic vein diameter <4.3mm was the single independent predictor of inferior secondary and functional secondary patency. Among patients undergoing brachiocephalic AVFs, all patency rates were inferior in the presence of a brachial artery diameter ≤4.1mm and secondary patency was inferior in the presence of multiple risk factors.

Upper-arm hemodialysis access in Sweden.

To provide the contemporary use of upper-arm access for hemodialysis in Sweden using data from a unique national registry for hemodialysis access. Data were retrieved from a nation-wide registry for dialysis access in Sweden, Dialysis Access Database (DiAD) on the use and function of specific access types with a focus on upper-arm accesses. The data demonstrate an increased use of upper-arm access, likely dependent on a changing patient population, with brachiocephalic arteriovenous fistula (AVF) as the most common access type. Women received more upper-arm accesses than men. Given the recent establishment of the registry, patency and access function can at this point give preliminary data. Indications of a better function for brachiobasilic AVFs in staged procedures were observed as well as for upper-arm arteriovenous grafts (AVGs) in women. Registry data support an increased use of upper-arm accesses, especially in women. The study also demonstrates the potential of a dedicated national access registry to improve access care.

Brachiocephalic Arteriovenous Fistula for Hemodialysis through the Median Antecubital Vein.

In patients unsuitable for radiocephalic fistula creation, the next option is brachiocephalic fistula. In such patients, we exploited the venous interconnections in the cubital fossa for median cubital vein-Brachiocephalic arteriovenous fistula (AVF) creation. In this article, we describe our experience in the creation of such technical variant of the brachiocephalic fistula AVF, its success and associated complications. A retrospective review of such AVF created between September 2014 and August 2015 was done. The data collected included demographics, co-morbidities, basic disease, operative details, patency, complications, and mortality. A total of 68 vascular access surgeries were done which included 26 (38.2%) brachiocephalic AVF using the median antecubital vein. The mean cephalic vein diameter and mean flow rate were 7.18 mm and 1415 ml/min, respectively 2 months after fistula creation. The primary and secondary failure rates were 3.87% and 7.69% respectively. Complications included aneurysm (7.69%), edema (19.23%), hematoma (11.53%), and wound infection (3.8%). Using reverse flow in the median antecubital vein is a safe and simple way to perform brachiocephalic AVF before brachiobasilic AVF and grafts.

Discriminative role of brachial artery Doppler parameters in correlation with hemodialysis arteriovenous fistula.

PurposeThe aim of this study was to evaluate the flow volume and resistive index parameters of the brachial artery in the functioning and dysfunctioning radiocephalic and brachiocephalic hemodialysis arteriovenous fistula (AVF).Methods82 patients were distributed into three groups according to their hemodialysis function - as normal function, decreased pump flow and increased venous pressure. Flow volumes and resistive indexes (RI) of the brachial artery of radiocephalic and brachiocephalic AVFs were measured by Doppler ultrasound. Flow parameters of the groups were compared.ResultsA statistically significant difference was found between the normal and decreased pump flow groups in terms of flow volume and resistive index values. 770 ml/min flow volume of the brachial artery has a 94% sensitivity and 84% specificity and 0.52 value of RI has an 89% sensitivity and 88% specificity in the the differentiation of normal and decreased pump flow groups.ConclusionDoppler parameters of the brachial artery such as flow volume and RI can provide valuable information about AVF function.

Arteriovenous fistula patency in the 3 years following vonapanitase and placebo treatment

ObjectiveThis study explored the long-term outcomes of arteriovenous fistulas treated with vonapanitase (recombinant human elastase) at the time of surgical creation. MethodsThis was a randomized, double-blind, placebo-controlled trial of 151 patients undergoing radiocephalic or brachiocephalic arteriovenous fistula creation who were randomized equally to placebo, vonapanitase 10 μg, or vonapanitase 30 μg. The results after 1 year of follow-up were previously reported. The current analysis occurred when the last patient treated was observed for 3 years. For the current analysis, the primary end point was primary patency; the secondary end points included secondary patency, use of the fistula for hemodialysis, and rate of procedures to restore or to maintain patency. ResultsThere was no significant difference in the risk of primary patency loss with vonapanitase 10 μg or 30 μg vs placebo. When seven initial patency loss events related to cephalic arch and central vein balloon angioplasty were excluded, the risk of patency loss was reduced with vonapanitase overall (hazard ratio [HR], 0.63; P = .049) and 30 μg (HR, 0.51; P = .03). In patients with radiocephalic fistulas (n = 67), the risks of primary and secondary patency loss were reduced with 30 μg (HR, 0.37 [P = .02] and 0.24 [P = .046], respectively). The rate of procedures to restore or to maintain fistula patency was reduced with 30 μg vs placebo (0.23 vs 0.72 procedure days/patient/year; P = .03) and also reduced in patients with radiocephalic fistulas with 30 μg vs placebo (0.17 vs 0.85 procedure days/patient/year; P = .048). ConclusionsIn this study, vonapanitase did not significantly improve primary patency in the primary analysis but did significantly improve primary patency in an analysis that excluded patency loss due to cephalic arch and central vein balloon angioplasty. In patients with radiocephalic fistulas, 30 μg significantly improved primary and secondary patency. Vonapanitase 30 μg decreased the rate of procedures to restore or to maintain patency in the analysis that included all patients and in the subset with radiocephalic fistulas.

Outcomes of Arteriovenous Fistula for Hemodialysis in Pediatric and Adolescent Patients.

Purpose:This retrospective review aimed to report the outcomes of arteriovenous fistula (AVF) and to evaluate the suitability of AVF as a permanent vascular access in pediatric populations.Materials and Methods:Data were collected for all patients aged 0 to 19 years who underwent AVF creation for hemodialysis between January 2000 and June 2014.Results:Fifty-two AVFs were created in 47 patients. Mean age was 15.7±3.2 years and mean body weight was 46.7±15.4 kg. Of the 52 AVFs, 43 were radiocephalic AVFs, 7 were brachiocephalic AVFs and 2 were basilic vein transpositions. With a mean follow-up of 49.7±39.2 months, primary patency was 60.5%, 51.4%, and 47.7% at 1, 3, and 5 years, respectively and secondary patency was 82.7%, 79.2% and 79.2% at 1, 3, and 5 years, respectively. Age, body weight, AVF type, the presence of a central venous catheter, use of anticoagulation therapy, and history of vascular access failure were not significantly associated with patency rates. There were 9 cases (17.3%) of primary failure; low body weight was an independent predictor. Excluding cases of primary failure, the mean duration of maturation was 10.0±3.7 weeks. During follow-up, 20 patients (42.6%) underwent kidney transplantation, with a median interval to transplantation of 36 months.Conclusion:AVF creation in children and adolescents is associated with acceptable long-term durability, primary failure rate and maturation time. Considering the waiting time and limited kidney graft survival, placement of AVFs should be considered primarily even in patients expected to receive transplantation.

Vas Q – An Innovative External Support Device Improves Functionality of Arteriovenous Fistulas: Pilot Study Results

Introduction: Patients in need of dialysis treatment depend on vascular access. Arteriovenous fistula (AVF), is the gold standard for access, however, while superior to other access methods, it is associated with high early failure rates which necessitates frequent interventions intended to maintain AVF functionality. Large series have shown that although native AVFs have a low rate of complications and improved longevity of use when functional, they suffer from relatively poor early patency rates with more than half being unsuitable for dialysis use by one year. The precise reasons for these early failures remain to be fully elucidated, although it is clear that inability to increase inflow often results from perianastomotic stenosis and venous neointimal hyperplasia. Turbulent flow has been identified as a driver for neointimal hyperplasia and as a cause of stenosis. VasQ, is a new external support device, implanted over the arteriovenous fistula. Targeting the juxta-anastomotic area, the VasQ adjusts anastomosis geometry, regulates flow patterns, and supports the venous wall thereby facilitating fistula maturation and longevity. We present results of a Pilot prospective study, enrolling 20 patients with a follow up period of 6 months. Study objectives included assessment of the implantation procedure and fistula maturation and patency rates. Methods: The trial was conducted as a prospective, single-arm study design so as to determine device safety and initial efficacy. The study was conducted at St. George's Vascular Institute, St. George's University Hospitals Foundation Trust, London, UK. 20 patients were enrolled. Patients were eligible if they were referred for creation of a new brachiocephalic fistula with non-stenotic vein and artery diameter ≥3 mm, and free of significant co-morbidities which can prevent study completion. The VasQ device was threaded proximally on the vein prior to anastomosis suturing and subsequently lowered distally onto the anastomosis after completion. Patients were followed for 6 months post-procedure, with Doppler ultrasound examinations performed at 1, 3, and 6 months. Fistula was considered matured if Doppler measurements showed venous outflow ≥500 ml/min and vein diameter ≥5 mm. Results: Between June 2014 and January 2015, two surgeons implanted VasQ in 20 patients. Device implantation easily integrated with the routine fistula procedure. All patients were free from any device related complications. One patient died following a myocardial infarction. At 1, and 3 months fistula maturation rate were 75% and 79%, Primary patency rates at 1, 3 and 6 months were 95%, 79% and 79%. mean outflow rates at 1, 3 and 6 months were 1130 ml/min and 1426 ml/min, and 1304 ml/min. mean vein diameters were 6.6 mm, 8.4 mm and 10 mm at 1,3 and 6 months respectively. Conclusion: The VasQ used in autogenous brachiocephalic AVFs is associated with higher short- and medium-term maturation and patency rates for externally supported AVFs than previously reported. Larger, longer-term prospective studies are required in order to confirm these promising results. VasQ may obviate some of the problems implicated in early AVF failure providing a fixed outflow diameter and shielding the anastomosis from adhesions and inflammatory reaction. Disclosure of Interest: None Declared.

Outcomes of Intervention for Cephalic Arch Stenosis in Brachiocephalic Arteriovenous Fistulas

Outcomes of Intervention for Cephalic Arch Stenosis in Brachiocephalic Arteriovenous Fistulas