Equivalent secondary patency rates of upper extremity Vectra Vascular Access Grafts and transposed brachial-basilic fistulas with aggressive access surveillance and endovascular treatment

Outcomes of prosthetic upper arm arteriovenous graft vs brachiobasilic fistula for hemodialysis access

OBJECTIVE

Primary arteriovenous access such as radiocephalic and brachiocephalic fistulas are initial choices for creating vascular access in dialysis patients. When neither of these choices is an option, upper arm arteriovenous graft or brachiobasilic transposition is recommended. Although primary fistula is better than prosthetic graft for suitable patients, there is little data to guide the best treatment strategy in the absence of suitable vein for primary access creation. This study identifies factors that influence patency rates and compares outcomes of patients treated with brachiobasilic fistula vs upper arm graft in patients who have failed forearm access or are not candidates for primary access.

METHODS

A prospectively maintained database of patients with dialysis-dependent renal failure from 2010 to 2022 was analyzed. Primary, primary assisted, and secondary patency rates were calculated. Incidence rates of complications and reinterventions were compared.

RESULTS

There were 148 patients with brachiobasilic fistulas and 157 patients with upper arm grafts. The graft group was older (70.1 ± 14.7 vs 62.5 ± 14.6 years; P = .003) and had a higher incidence of pacemakers (11.9% vs 4.1%; P = .005). Brachiobasilic fistulas had higher 6-month (77.0% vs 64.3%; P = .02) and 1-year (68.2% vs 55.4%; P = .03) primary-assisted patency. Secondary patency rates were better for upper arm grafts at 1-year (82.2% vs 72.3%; P = .05). Access complications of non-maturation and aneurysm were higher in basilic vein transposition (21.6% vs 1.3%; P < .0001; 15.5% vs 6.4%; P = .017). Grafts had higher rates of occlusion (58.0% vs 25.7%; P < .0001). In terms of interventions, upper arm grafts had higher rates of thrombectomy (50.3% vs 18.9%; P < .0001), but there was no difference seen in angioplasty, stent, surgical revision, or steal procedures. Basilic vein transpositions had longer time to cannulation (104.6 ± 81.1 vs 32.5 ± 22.4 days; P < .0001), longer total catheter days (251.1 ± 181.7 vs 72.9 ± 56.3 days; P < .0001), and higher number of procedures to aid maturity (0.7 ± 0.7 vs 0.1 ± 0.3; P < .0001).

CONCLUSIONS

In this retrospective analysis, when forearm access or primary arteriovenous access is not an option, basilic vein transposition and upper arm grafts have fairly equivalent primary patency. Primary assisted patency is slightly better in basilic vein fistulas, but secondary patency is better in upper arm grafts at 1 year. Basilic fistulas also had longer time to cannulation, longer total catheter days, and more procedures to aid maturity.

Influence of the hard segments content on the properties of electrospun aliphatic poly(carbonate-urethane-urea)s

The study investigated the impact of hard segments (HS) content on the morphology and thermomechanical properties of electrospun aliphatic poly(carbonate-urea-urethane)s (PCUUs). The obtained nonwovens exhibited surface porosity ranging from 50% to 57%, and fiber diameters between 0.59 and 0.71 μm. Notably, the PCUUs nonwovens with the highest HS content (18%) displayed superior mechanical properties compared to those with lower HS contents. This study highlights the ability to customize the properties of polymeric nonwovens based on their chemical compositions, offering tailored solutions for specific application needs.

One-staged brachial-basilic vein transposition versus arm straight arteriovenous graft for hemodialysis

OBJECTIVES

After forearm and arm cephalic veins are no longer available as options, the choices of arm vascular access between one-staged brachial-basilic vein transposition (BBAVF) and arm straight arteriovenous graft (AS-AVG) for hemodialysis are controversial. This study aims to compare outcomes between groups.

METHODS

All one-staged BBAVF and AS-AVG from August 2014 to December 2019 were reviewed. In cases of suitable basilic vein of 3 mm or more present from cubital crease to axilla, one-staged BBAVF was preferred. AS-AVG was performed for patients who need timely functioning access or have no suitable basilic vein.

RESULTS

Twenty-eight one-staged BBAVF and 74 AS-AVG were included. Baseline characteristics were not significantly different, except AS-AVG had less previous ipsilateral access (9% vs 39%; p < .001). Postoperative complications were not different. With six loss follow-ups (3 in BBAVF and 3 in AS-AVG), 24 (96%) and 64 (90%) matured after one-staged BBAVF and AS-AVG, respectively (p = .676). BBAVF took about 30 days (95% CI: 10, 51) longer time to first successful cannulation. Primary patency was significantly better for one-staged BBAVF (hazard ratio (HR) of 3.0 (95%CI: 1.2, 7.7)), whereas secondary patency was not different. The total access failure (i.e. failure to mature combined with any thrombosis or intervention to maintain patency) significantly favored BBAVF (HR 2.7 (95%CI: 1.1, 6.6)).

CONCLUSIONS

Provided a suitable arm basilic vein is available, one-staged BBAVF is preferred over AS-AVG when forearm AVF, forearm AVG, and arm cephalic veins are out. However, it requires a longer time to start cannulating than AS-AVG.

Comparison between transposed arteriovenous fistulas and arteriovenous graft for the hemodialysis patients: A meta-analysis and systematic review

It is challenging for a surgeon to determine the appropriate vascular access for hemodialysis patients whose cephalic vein is usually inaccessible. The purpose of the study is to compare the complications and patency rates between transposed arteriovenous fistulas (tAVF) and arteriovenous graft (AVG) for the hemodialysis patients. Studies were recruited from PubMed, Cochrane library, EMBASE, the web of science databases, and reviewing reference lists of related studies from the inception dates to September 2, 2021. Statistical analyses were conducted using the statistical tool Review Manager version5.3 (Cochrane Collaboration, London, UK). I2 > 50% was defined as a high degree of heterogeneity, and then a random-effects model was used. Otherwise, the fixed-effects model was used. Odds ratio with its 95% confidence interval (95% CI) was used. Thirty-three trials (26 retrospective studies, four randomized controlled trials, two prospective trials, and one controlled-comparative study) with 6430 enrolled participants were identified in our analysis. The results showed that tAVF was accompanied with lower thrombosis rate (103/1184 (8.69%) vs 257/1367 (18.80%); I2 = 45%; 95% CI, 0.34 (0.26, 0.45)) and infection rate (43/2031 (2.12%) vs 180/2147 (8.38%); I2 = 0%; 95% CI, 0.20 (0.14, 0.30)) than arteriovenous graft. The significantly better primary patency rates, secondary patency rates, and primary assisted patency rates during follow-up were found in tAVF. However, the failure rate and the prevalence of hematoma were significantly lower in AVG group. No evidence showed the rate of overall mortality, steal syndrome, and aneurysm reduced in tAVF. Our results showed that tAVF is a promising vascular access technique for hemodialysis patients whose cephalic vein is inaccessible. Our data showed that tAVF has less thrombosis, infection risk, and better patency rates when compared with AVG. However, more attentions need to be paid to transposed arteriovenous fistulas maturation and hematoma.

Electrospun Poly(carbonate-urea-urethane)s Nonwovens with Shape-Memory Properties as a Potential Biomaterial

Poly(carbonate-urea-urethane) (PCUU)-based scaffolds exhibit various desirable properties for tissue engineering applications. This study thus aimed to investigate the suitability of PCUU as polymers for the manufacturing of nonwoven mats by electrospinning, able to closely mimic the fibrous structure of the extracellular matrix. PCUU nonwovens of fiber diameters ranging from 0.28 ± 0.07 to 0.82 ± 0.12 μm were obtained with an average surface porosity of around 50-60%. Depending on the collector type and solution concentration, a broad range of tensile strengths (in the range of 0.3-9.6 MPa), elongation at break (90-290%), and Young's modulus (5.7-26.7 MPa) at room temperature of the nonwovens could be obtained. Furthermore, samples collected on the plate collector showed a shape-memory effect with a shape-recovery ratio (Rr) of around 99% and a shape-fixity ratio (Rf) of around 96%. Biological evaluation validated the inertness, stability, and lack of cytotoxicity of PCUU nonwovens obtained on the plate collector. The ability of mesenchymal stem cells (MSCs) and endothelial cells (HUVECs) to attach, elongate, and grow on the surface of the nonwovens suggests that the manufactured nonwovens are suitable scaffolds for tissue engineering applications.

Smoking is associated with a higher complication and failure rate in arteriovenous grafts for haemodialysis: A multi-centre experience

INTRODUCTION

Arteriovenous grafts (AVG) for haemodialysis (HD) access are recommended as a second line modality due to higher morbidity and mortality rates than arteriovenous fistulae (AVF). Smoking is already established as a risk factor in lower extremity bypass graft failure used for peripheral vascular disease, but its effect on AVGs remains unclear. We aimed to investigate the relationship of smoking on AVG outcomes.

METHODS

A 3 year (01/08/2015-01/08/2018) multi-centre retrospective study was carried out on patients receiving an AVG for HD. Data included patient demographics, medical history, operation, type of graft, postoperative course and primary and secondary patency rates. Statistical analyses performed were Kaplan-Meier curves and Cox's proportional hazard regression.

RESULTS

Fifty-five AVGs were performed (1052 AVF performed) in this period. The most common complication was thrombosis (38.9%). Primary patency at 6, 12 and 24 months were 55%, 45% and 44% respectively. Secondary patency at 6, 12 and 24 months were 63%, 56% and 54% respectively. Smoking was found to be a poor prognostic factor for primary (HR 3.734 (1.818-7.668 95% CI) p < 0.001) and secondary patency (HR 6.238 (2.729-14.257) p < 0.001). Smoking was also significantly associated with graft thrombosis (HR 5.741 (2.380-13.848 95% CI) p < 0.001).

DISCUSSION

Primary patency rates are lower than previous reports whilst secondary patency is equivalent. Smoking results in a greater risk of thrombosis and poorer primary and secondary patency. This is recognised in vascular surgical grafts, but has not been previously described in AVGs for HD access. Smoking is a modifiable risk factor and as AVGs are typically used for end-stage vascular access patients. Pre-operative strategies to promote smoking cessation, including patient education and prehabilitation should be employed to improve outcomes.

Assessment of Electrospun Pellethane-Based Scaffolds for Vascular Tissue Engineering

We examined the physicochemical properties and the biocompatibility and hemocompatibility of electrospun 3D matrices produced using polyurethane Pellethane 2363-80A (Pel-80A) blends Pel-80A with gelatin or/and bivalirudin. Two layers of vascular grafts of 1.8 mm in diameter were manufactured and studied for hemocompatibility ex vivo and functioning in the infrarenal position of Wistar rat abdominal aorta in vivo (n = 18). Expanded polytetrafluoroethylene (ePTFE) vascular grafts of similar diameter were implanted as a control (n = 18). Scaffolds produced from Pel-80A with Gel showed high stiffness with a long proportional limit and limited influence of wetting on mechanical characteristics. The electrospun matrices with gelatin have moderate capacity to support cell adhesion and proliferation (~30–47%), whereas vascular grafts with bivalirudin in the inner layer have good hemocompatibility ex vivo. The introduction of bivalirudin into grafts inhibited platelet adhesion and does not lead to a change hemolysis and D-dimers concentration. Study in vivo indicates the advantages of Pel-80A grafts over ePTFE in terms of graft occlusion, calcification level, and blood velocity after 6 months of implantation. The thickness of neointima in Pel-80A–based grafts stabilizes after three months (41.84 ± 20.21 µm) and does not increase until six months, demonstrating potential for long-term functioning without stenosis and as a suitable candidate for subsequent preclinical studies in large animals.

Comparison Between Transposed Brachiobasilic Fistula and Arteriovenous Graft for Upper Limb Arteriovenous Access in Patients on Hemodialysis

BACKGROUND

Creating and maintaining a functioning arteriovenous access is essential for long-term hemodialysis patients. Transposed brachiobasilic fistula (BBF) or arteriovenous graft (AVG) becomes an option when radiocephalic or brachiocephalic fistula cannot be created or fails. This study compared the patency and complications between BBFs and AVGs among patients on hemodialysis.

METHODS

A retrospective study was performed in Shuang Ho Hospital, Taiwan, from November 2015 to May 2020. All the operations were done by a single surgeon. Primary outcomes were primary patency, primary-assisted patency, and secondary patency of the BBF and AVG groups. Secondary outcomes were incidence of complications and reinterventions.

RESULTS

Of the 144 consecutive patients, 20 and 124 patients underwent BBF and AVG creation, respectively. Median follow-up time was 19.2 months. Primary patency at 1 and 2 years were 67% and 19% in the BBF group and 44% and 16% in the AVG group (P = 0.126). Primary-assisted patency at 1 and 2 years were 82% and 54% in the BBF group and 54% and 30% in the AVG group (P = 0.012). Secondary patency at 1 and 2 years were 100% and 82% in the BBF group and 81% and 67% in the AVG group (P = 0.078). The incidence of complication was significantly higher in the AVG than in the BBF group (1.7 per patient-year vs 0.93, P < 0.001).

CONCLUSION

Compared with the AVG group, BBF group showed better primary-assisted patency, less complication and intervention rates. Therefore, BBF is a reliable option for patients with exhausted cephalic veins if basilic vein is available for reconstruction.

Comparing Outcomes of Upper Extremity Brachiobasilic Arteriovenous Fistulas and Arteriovenous Grafts: A Systematic Review and Meta-Analysis

OBJECTIVE

It is unclear what the optimal upper extremity hemodialysis access is for patients without a suitable cephalic vein for arteriovenous fistulas (AVFs). The objective of this systematic review and meta-analysis was to compare the outcomes for upper extremity transposed brachiobasilic AVFs (BBAVFs) and prosthetic arteriovenous grafts (AVGs).

METHODS

A systematic review was performed to identify all English publications and abstracts comparing the patency outcomes of upper extremity BBAVFs and AVGs (January 1st, 1994 to April 1st, 2020). The outcomes assessed were 1-year and 2-year primary and secondary patency rates. Pooled odds ratios (OR) were calculated using the random-effects model, and I² statistic was used to assess between-study variability.

RESULTS

Twenty-three studies examining 2799 patients were identified and included in the study. The 1-year primary patency rates (OR = 1.68, 95% CI 1.24-2.28, p = 0.001, I² = 69.40%) and 2-year primary patency rates (OR = 2.33, 95% CI 1.59-3.43, p < 0.001, I² = 68.26%) were significantly better for BBAVFs than AVGs. Compared to AVGs, the 1-year secondary patency rates (OR = 1.45, 95% CI 1.05-1.98, p = 0.022, I² = 56.64%) and 2-year secondary patency rates (OR = 1.93, 95% CI 1.39-2.68, p < 0.001, I² = 57.61%) were also significantly higher for BBAVFs.

CONCLUSION

The outcomes for upper extremity BBAVFs appear to be consistently superior to prosthetic hemodialysis access. This analysis supports the preferential placement of BBAVFs over AVGs in patients with a suitable upper extremity basilic vein.

Traditional versus Early-access Grafts for Hemodialysis Access: A Single-institution Comparative Study

In those patients requiring urgent hemodialysis, the use of early-access grafts may reduce the need for temporary hemodialysis catheters and their resultant complications such as infection and central venous stenosis. We review a consecutive group of patients undergoing placement of a traditional polytetrafluoroethylene (PTFE) graft as compared with a cohort of patients who underwent insertion of a trilaminate PTFE vascular graft (TPVG). During the period from January 2008 to December 2009, 65 sequential patients received a traditional PTFE graft with 78 subsequent patients having a TPVG inserted. Factors examined included use of temporary hemodialysis catheters during the period of graft maturation, incidence of infection, and primary and secondary graft patency. For all patients, incidence was reported as observed during the first year after graft insertion. With the use of the TPVG, need for temporary hemodialysis catheters was reduced from 91 to 32 per cent, and 1-year overall graft patency was improved from 36 to 77 per cent ( P < 0.01). We report that the use of a trilaminate PTFE graft allowed early access, reduced the need for temporary hemodialysis catheters, decreased overall graft complication rates, and significantly improved 1-year patency.

Brachio-basilic upper arm transposition fistulas vs. prosthetic brachio-axillary vascular access grafts-Which one is preferred for hemodialysis?

INTRODUCTION

There is still controversy on the use of brachio-basilic upper arm transposition fistula (BBAVF) and prosthetic brachio-axillary vascular access grafts (BAPTFE) in patients with no suitable cephalic veins for creating an autogenous brachio-cephalic fistula.

METHODS

In a randomized controlled clinical trial, 60 hemodialysis patients who were not a suitable candidate for BCAVF were randomly assigned into two groups: BBAVF and BAPTFE. The patients were clinically followed up to 1 year and the patency rate and access-related complications were compared between the two groups.

FINDINGS

Access failure rate in the BBAVF and BAPTFE groups was 30.0% and 36.6%, respectively. The primary patency time was 232.73 ± 113.36 and 261.53 ± 147.37 days, respectively (P = 0.40). Thrombosis formation and infection were the two main causes for access failure, yet indicating no significant difference between the two groups (P > 0.05).

DISCUSSION

BBAVF and BAPTFE have comparable clinical outcomes in short-term follow-up. Therefore, BAPTFE can be used as an alternative vascular access for hemodialysis in patients who are not a suitable candidate for BBAVF.

Electrospun polyurethane-based vascular grafts: physicochemical properties and functioning in vivo

General physicochemical properties of the vascular grafts (VGs) produced from the solutions of Tecoflex (Tec) with gelatin (GL) and bivalirudin (BV) by electrospinning are studied. The electrospun VGs of Tec-GL-BV and expanded polytetrafluoroethylene (e-PTFE) implanted in the abdominal aorta of 36 Wistar rats have been observed over different time intervals up to 24 weeks. A comparison shows that 94.5% of the Tec-GL-BV VGs and only 66.6% of e-PTFE VGs (р = 0.0438) are free of occlusions after a 6 month implantation. At the intermediate observation points, Tec-GL-BV VGs demonstrate severe neovascularization of the VG neoadventitial layer as compared with e-PTFE grafts. A histological examination demonstrates a small thickness of the neointima layer and a low level of calcification in Tec-GL-BV VGs as compared with the control grafts. Thus, polyurethane-based protein-enriched VGs have certain advantages over e-PTFE VGs, suggesting their utility in clinical studies.

Immediate-access grafts provide comparable patency to standard grafts, with fewer reinterventions and catheter-related complications

BACKGROUND

No independent comparisons, with midterm follow-up, of standard arteriovenous grafts (SAVGs) and immediate-access arteriovenous grafts (IAAVGs) exist. The goal of this study was to compare "real-world" performance of SAVGs and IAAVGs.

METHODS

Consecutive patients who underwent placement of a hemodialysis graft between November 2014 and April 2016 were retrospectively identified from the electronic medical record and Vascular Quality Initiative database at two tertiary centers. Only primary graft placements were included for analysis. Patients were divided into two groups based on the type of graft implanted. Patients' comorbidities, graft configuration, operative characteristics, and follow-up were collected and analyzed with respect to primary and secondary patency. Additional outcomes included graft-related complications, time to first cannulation, time to tunneled catheter removal, catheter-related complications, and overall survival. Patency was determined from the time of the index procedure; χ², Kaplan-Meier, and Cox regression analyses were used, with the P value set as significant at < .05.

RESULTS

There were 210 grafts identified, 148 SAVGs and 62 IAAVGs. At baseline, the patients' characteristics were similar between groups, except for a greater prevalence of preoperative central venous occlusions in the IAAVG group (16.3% vs 6.8%; P < .04). Of the IAAVG group, 50 were Acuseal (W. L. Gore & Associates, Flagstaff, Ariz) and 12 were Flixene (Atrium Medical Corporation, Hudson, NH). Primary patency was similar at both 1 year (SAVG, 39.4%; IAAVG, 56.7%; P = .4) and 18 months (SAVG, 29.0%; IAAVG, 43.7%; P = .4). Secondary patency was similar at 1 year (SAVG, 50.7%; IAAVG, 52.1%; P = .73) and 18 months (SAVG, 42.3%; IAAVG, 46.3%; P = .73). Overall survival was 48% at 24 months. IAAVG patients required fewer overall additional procedures to maintain patency (mean number of procedures, 0.99 for SAVGs vs 0.61 for IAAVGs; P = .025). There was no difference in occurrence of steal syndrome (SAVG, 6.8%; IAAVG, 8.1%; P = .74) or graft infection (SAVG, 19.0%; IAAVG, 12.0%; P = .276). Seventy-five percent of all grafts were successfully cannulated, with shorter median time to first cannulation in the IAAVG group (6 days; interquartile range [IQR], 1-19 days) compared with the SAVG group (31 days; IQR, 26-47 days; P < .01). Of all pre-existing catheters, 65.75% were removed, with a shorter median time until catheter removal in the IAAVG cohort at 34 days (IQR, 22-50 days) vs 49 days (IQR, 39-67 days) in the SAVG group (P < .01). Catheter-related complications occurred less frequently in the IAAVG group (16.4% vs 2.9%; P < .045).

CONCLUSIONS

IAAVGs allow earlier cannulation and tunneled catheter removal, thereby significantly decreasing catheter-related complications. Patency and infection rates were similar between SAVGs and IAAVGs, but fewer secondary procedures were performed in IAAVGs.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Current Experience and Midterm Follow-up of Immediate-Access Arteriovenous Grafts

BACKGROUND

No independent reviews, with midterm follow-up, of current experience with immediate-access arteriovenous grafts (IAAVGs) exist. The goal of this project was to assess the real-world performance of 2 different IAAVGs over a 2-year period at a large tertiary referral center.

METHODS

Between January 2014 and April 2016, all consecutive patients who underwent placement of Acuseal (Gore) or Flixine (Maquet) IAAVGs were identified for retrospective analysis from the electronic medical record and Vascular Quality Initiative database. Primary, primary-assisted and secondary patency rates, time to first cannulation, time to tunneled catheter removal, and overall survival were recorded.

RESULTS

Forty-three patients were identified to have undergone placement of IAAVG, 31 Acuseal (72%), and 12 Flixine (28%). Of the Acuseal cohort, 7 were implanted with outflow through a HeRO catheter system (Merit Medical). Mean follow-up time was 8.4 months. Overall survival was 57.4% at 18 months. Overall primary, primary assisted, and secondary patency at 18 months were 33.36%, 34.31%, and 51.03%, respectively. Eighty three percent of grafts were successfully cannulated, and 78% of preexisting catheters were removed. Mean time to successful graft cannulation and catheter removal were 14.85 and 32.26 days, respectively.

CONCLUSIONS

Real-world experience with novel arteriovenous access grafts is consistent with results from industry-sponsored studies. Early cannulation of immediate-access grafts can be successfully performed in a wide variety of patients. However, prolonged catheter dwell times persist despite increased rates of successful early-graft cannulation. Further study of methods for promoting catheter removal in this patient population is warranted.

Transposed Brachial-Basilic Arteriovenous Fistula for Vascular Access in Japan

As more than 320,000 patients are currently receiving hemodialysis treatment in Japan, the creation and maintenance of hemodialysis access is a major concern. The national guidelines recommend autogenous arteriovenous hemodialysis, and the brachial-basilic arteriovenous fistula has been the focus of attention, because the need for secondary, tertiary, or even more vascular access is growing. Although favorable results have been reported in terms of patency and access-related complication, this fistula involves various unsolved or controversial issues, with limitations including complex procedures, which might contribute to the lower prevalence at this point in Japan. This review addresses those issues and discusses the role of fistula in Japan.

Early cannulation grafts for haemodialysis: An updated systematic review

Purpose:

Early cannulation grafts are specifically designed for dialysis, whereas standard expanded polytetrafluoroethylene grafts were not. There is developing collective experience and literature available to allow the assessment of outcomes of these early cannulation grafts. The aim of this review was to review the evidence for both short- and long-term outcomes of early cannulation grafts.

Methods:

Using standardized searches of electronic databases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses, the primary outcomes for this study were primary and secondary patency rates for early cannulation grafts for dialysis at 12 months and beyond. Secondary outcomes were timing of first cannulation, rates of access thrombosis, steal syndrome, pseudo-aneurysm and infection.

Results:

A total of 19 studies were identified and included. These were divided into different graft types. Flixene™, Avflo™, Acuseal™ and Vectra™ grafts all showed that early cannulation within 72 h is possible. Twelve-month pooled primary and secondary patency rates were 43.3% (95% confidence interval: 31.6–55.4) and 73.4% (95% confidence interval: 63–82.7) for the Flixene graft, 58.2% (95% confidence interval: 48–68.1) and 79.2% (95% confidence interval: 68–88.7) for the Avflo graft, 43.6% (95% confidence interval: 30.7–56.9) and 70.5% (95% confidence interval: 49.7–87.8) for the Acuseal graft and 63.7% (95% confidence interval: 53.4–73.4) and 85.8% (95% confidence interval: 82.9–88.4) for the Vectra graft. Data for outcome beyond 12 months were limited to the more recent studies.

Conclusion:

This review confirms that early cannulation is not detrimental on the early outcome of early cannulation graft patencies. It has also shown that both Vectra and Avflo grafts have adequate long-term patencies. The data do not allow specific graft recommendations, as comparative trials would be required.

The forearm basilic vein looped transposition fistula as a tertiary option for upper limb vascular access

Introduction:

The forearm basilic vein can serve as an option for haemodialysis access but may not be possible in cases where the wrist arteries are unsuitable. In this setting, the forearm basilic vein can be used in a looped transposition with a brachial artery anastomosis.

Aims:

The aims of this study were to assess the outcome of forearm basilic vein looped transposition as an option for vascular access.

Material and methods:

Data from January 2007 to December 2010 were prospectively collected and analysed. Outcome measures were operative success, complications, maturation and primary and secondary patency following 5 years of follow-up.

Results:

From a total of 583 patients receiving autologous vascular access for haemodialysis, 24 (4.1%) underwent a forearm basilic vein looped transposition. The median age was 60 years (range, 27–80 years), with a slight male predominance (13 male:11 female). Mean follow-up was 34 months (1–60 months). Two patients died and other three were transplanted with subsequent fistula closure. All procedures were successful (100%); however, maturation failure occurred in one case (4.2%). No serious perioperative complications were observed. In two cases, we observed late false aneurysm formation requiring intervention. Primary patency at 1, 2, 3 and 5 years was the following: 77%, 62%, 21% and 10%, whereas secondary patency was the following: 81%, 71%, 61% and 32%, respectively.

Conclusion:

Autologous forearm basilic vein looped transposition is an effective surgical procedure for the creation of access for haemodialysis. This may be a useful option in patients with compromised peripheral arterial diameter or flow and should be considered in patients with a suitable forearm basilic vein.

Angioplasty and stenting for the proximal anastomotic stenosis of a brachio-axillary bypass graft using a helical interwoven nitinol stent: A case report

RATIONALE

Thrombosis due to anastomotic site stenosis is the most common complication in patients with brachio-axillary arteriovenous graft (AVG). Intravascular stent placement may play a special role in the salvage of dialysis grafts that have been previously performed percutaneous angioplasty or surgical procedure on the graft. Herein, we applied a novel stent named Supera which has a high degree of flexibility and resistance to external compression for treating a patient with recurrent venous anastomotic stenosis of brachio-axillary AVG.

PATIENTS CONCERNS AND DIAGNOSES

We report a case of the patient with end-stage renal disease who presented with brachio-axillary AVG malfunction.

INTERVENTIONS

The patient underwent repeated percutaneous angioplasty with thrombectomy for total graft occlusion, and we placed the Supera stent to salvage the graft.

OUTCOMES

Postprocedural Doppler ultrasonography did not show any restenosis on the 1- and 3-month follow-up periods, and average flow volume in the stent was >1000 mL/min. And he has been on dialysis for 6 months without any problems after stent placement.

LESSONS

The Supera stent is a useful treatment option of interventional procedure for recurrent venous anastomotic stenosis of brachio-axillary AVG in the clinical practice.

Outcomes of relocation of basilic vein in brachiobasilic fistulas in chronic renal failure

BACKGROUND

In patients without or with injured cephalic vein, using the basilic vein for creating arteriovenous fistula (AVF) is the best way for hemodialysis. In order to create AVF, the basilic vein should be superficialized and lateralized. This study sought to examine outcome of relocation of basilic vein in brachiobasilic fistulas in patients with chronic renal failure (CRF).

METHODS

We evaluated the outcome of creation of brachiobasilic fistula with transposition of basilic vein in 27 patients (14 males and 13 females with mean age of 60.03 ± 8.04 years) with CRF. The success rate and complications were recorded during the follow-up period. The fistula was regarded efficient if cannulation was feasible conveniently and a minimum flow rate of 250 ml/min for 4 h at least for 3 consecutive hemodialysis sessions through both lines was documented 30 days postoperatively.

RESULTS

The mean time gap between previous AVF creation or try and the relocation of basilic vein was 3.55 months. Thirty days postoperatively, 85.2% of the created AVFs were efficiently working. There were postoperative complications in 40.7% of patients including venous hypertension (14.8%), bleeding (7.4%), hematoma (7.4%) and distal paresthesia (11.1%).

CONCLUSIONS

Brachiobasilic AVF fistula provides a suitable option for vascular access in cases with failed previous AVF. Relocation of basilic vein for brachiobasilic AVF is technically feasible, safe and with excellent patency in short-term and complication rates are acceptable.

Comprehensive Comparison of the Performance of Autogenous Brachial-Basilic Transposition Arteriovenous Fistula and Prosthetic Forearm Loop Arteriovenous Graft in a Multiethnic Asian Hemodialysis Population

Aim. For patients who have exhausted cephalic vein arteriovenous fistula (AVF) options, controversy exists on whether brachial-basilic AVF with transposition (BBTAVF) or a forearm arteriovenous graft (AVG) should be the next vascular access of choice. This study compared the outcomes of these two modalities. Methods. A retrospective study of 122 Asian multiethnic patients who underwent either a BBTAVF (81) or an AVG (41). Maturation time and intervention rates were analyzed. Functional primary, secondary, and overall patency rates were evaluated. Results. The maturation time for BBTAVFs was significantly longer than AVGs. There was also a longer deliberation time before surgeons abandon a failing BBTAVF compared to an AVG. Both functional primary and secondary patency rates were significantly higher in the BBTAVF group at 1-year follow-up: 73.2% versus 34.1% (p < 0.001) and 71.8% versus 54.3% (p = 0.022), respectively. AVGs also required more interventions to maintain patency. When maturation rates were considered, the overall patency of AVGs was initially superior in the first 25 weeks after creation and then became inferior afterwards. Conclusion. BBTAVFs had superior primary and functional patency and required less salvage interventions. The forearm AVG might have a role in patients who require early vascular access due to complications from central venous catheters or with limited life expectancy.

Arteriovenous Access Failure, Stenosis, and Thrombosis

Vascular access–related complications can lead to patient morbidity and reduced patient quality of life. Some of the common arteriovenous access complications include failure to mature, stenosis formation, and thrombosis.

Clinical Outcomes of Cryopreserved Arterial Allograft Used as a Vascular Conduit for Hemodialysis

This single center cohort study aimed to test the hypothesis that use of a cryopreserved arterial allograft could avoid the maturation or healing process of a new vascular access and to evaluate the patency of this technique compared with that of vascular access using a prosthetic graft. Between April 2012 and March 2013, 20 patients underwent an upper arm vascular access using a cryopreserved arterial allograft for failed or failing vascular accesses and 53 using a prosthetic graft were included in this study. The mean duration of catheter dependence, calculated as the time interval from upper arm access placement to removal of the tunneled central catheter after successful cannulation of the access, was significantly longer for accesses using a prosthetic graft than a cryopreserved arterial allograft (34.4 ± 11.39 days vs. 4.9 ± 8.5 days, P < 0.001). In the allograft group, use of vascular access started within 7 days in 16 patients (80%), as soon as from the day of surgery in 10 patients. Primary (unassisted; P = 0.314) and cumulative (assisted; P = 0.673) access survivals were similar in the two groups. There were no postoperative complications related to the use of a cryopreserved iliac arterial allograft except for one patient who experienced wound hematoma. In conclusion, upper arm vascular access using a cryopreserved arterial allograft may permit immediate hemodialysis without the maturation or healing process, resulting in access survival comparable to that of an access using a prosthetic graft.

Surgical and Endovascular Revision of Brachio-Basilic Vein Fistula

Purpose

The brachio-basilic vein fistula (BBVF) is currently the third vascular access option for patients on hemodialysis, following radio-cephalic and brachio-cephalic arterio-venous fistulas. Like all types of hemodialysis vascular access, a variety of procedures may have to be performed in order to maintain long-term use of the BBVF. The aim of the present study was to perform a literature review of endovascular or surgical revisions of BBVFs.

Methods

On Pubmed search, 676 records were obtained and reviewed for relevance with the aim of the search.

Results

A variety of endovascular and surgical revision techniques has been described to manage BBVF poor maturation, dysfunction manifested as failing BBVF (most often the result of a stenosis at the transposed/swing segment), thrombosis, aneurysm formation and hemodialysis access-induced hand ischemia (steal syndrome). The role of revision is crucial in BBVF maintenance, taking into account that around 70% of these fistulas will require some intervention by 18 months and as a result of revision, secondary patency is preserved in the vast majority, according to the results of one study. Endovascular revision is the treatment of choice for most cases of BBVF dysfunction or thrombosis, with redo surgery reserved for failures of endovascular techniques or other specific indications.

Conclusions

BBVF revision, more often in the form of endovascular surgery, plays a crucial role in BBVF maintenance and its continued use for hemodialysis, necessary for reducing graft and catheter use and the associated morbidity.

Basilic Vein Transposition Used as a Tertiary Vascular Access for Hemodialysis: 15 Years of Experience

INTRODUCTION

The quality of the life in patients requiring long term hemodialysis is directly proportional to the long-term patency of their vascular access. Basilic vein transposition for vascular access (BAVA) represents a suitable option for creating a tertiary native vascular access for hemodialysis on the upper extremities for patients requiring long term hemodialysis. The purpose of the study is to compare BAVAs with arteriovenous grafts (AVG).

METHOD

Data collection was based on selecting all of the patients with BAVA created in the time period in between January 1996 and August 2011. A questionnaire was created and sent to the selected hemodialysis centers. The resulting set of data was statistically analyzed and evaluated.

RESULTS

In the time period between 1 January 1996 and August 2011, arteriovenous access for hemodialysis was created in 6754 patients (7203 procedures in total). Out of these patients, 175 BAVAs were created. Our patient database of those undergoing the BAVA procedure consisted of 98 females (56%) and 77 males (44%) with an average age of 64.5 years. The prevalence of diabetes mellitus was 60% (105 patients). Primary patency after 12 months was 68.8%, 24 months 59.7%, 36 months 53.8, 48 months 53.8%, and 60 months 50%. Primary assisted patency after 12 months was 89.9%, 24 months 84.6%, 36 months 77.8%, 48 months 77.9%, 60 months 70.8%. Secondary patency after 12 months was 89.4%, 24 months 86.9%, 36 months 81%, 48 months 78.9%, 60 months 75.7%. Twenty-nine BAVAs (16.5%) were obliterated.

CONCLUSION

Patients benefit from this type of procedure due to the longer patency of a native arteriovenous access, as well as a lower incidence of infectious complications.

Early Cannulation Grafts for Haemodialysis: A Systematic Review

Purpose

Arteriovenous grafts have advantages compared with central venous catheters for dialysis access and guidelines suggest their use as second choice after arteriovenous fistulas. Standard practice with expanded polytetrafluoroethylene (ePTFE) grafts has been to avoid cannulation for 2 weeks following placement, but new generation grafts have been marketed for their early cannulation properties allowing use as an alternative to central venous catheters for prompt access. The aim of this review is to search the current literature for evidence of early cannulation of new generation grafts and to assess their patency and complication rates.

Methods

Electronic databases were searched for studies assessing the use of early cannulation grafts for dialysis in accordance with PRISMA. The primary outcomes for this study were primary patency rate, primary-assisted patency rate and secondary patency rate. Secondary outcomes were timing of first cannulation, rates of access thrombosis, steal syndrome, pseudo-aneurysm and infection.

Results

Following strict inclusion/exclusion criteria by two reviewers, 15 studies were included in our review and divided into the different types of graft. Flixene, Avflo, Rapidax and Acuseal grafts showed that early cannulation within 72 h was possible; there was no evidence of the use of Vectra within 2 weeks of placement. All grafts showed similar patency and complication rates as previously published data on standard ePTFE grafts.

Conclusion

Our review showed that early cannulation is possible without detriment, but data did not allow specific graft recommendations. Therefore, we feel that a multicentre, randomised controlled trial is necessary to compare early cannulation grafts.

Long-Term Results of PTFE Grafts

Vascular surgeons are essential in “lifeline” creation for hemodialysis patients and should be the central player in any multidisciplinary access service together with nephrologists, dialysis staff and interventional radiology. In this position, access surgeons are involved in complicated clinical decision making regarding primary and secondary access selection, which throughout the last decade has been largely aided, and influenced, by national and international guidelines as well as other initiatives. These recommendations, unanimously and appropriately, advocate the placement of native fistulas over synthetic grafts (the majority grafts from expanded polytetrafluoroethylene, ePTFE, herein referred to as PTFE) based on the superiority of fistulas with respect to complications such as infections and thrombosis. Nevertheless, the use of PTFE grafts for hemodialysis access is an accepted and firmly established alternative to native fistulas where data today reveal unwanted consequences to overinterpretation of established guidelines such as increased catheter use. This information highlights a need for an adjustment of access selection strategies based on patient-centered algorithms. Here, available results on PTFE graft performance in hemodialysis access is recapitulated, with respect to both conventional grafts and technical modifications, and conclude with a modified approach to primary access selection.

Randomized controlled trial comparing primary and staged basilic vein transposition

Objective

It is unclear if brachio-basilic vein fistula should be performed as a primary or staged procedure, particularly for smaller basilic veins. Our aim was to report on a randomized controlled trial comparing these two techniques.

Methods

Sixteen patients with a basilic vein ≥2.5 mm were randomized into primary transposed brachio-basilic vein (TBBV) fistula (n = 9) and staged TBBV fistula (n = 7). Patients with basilic veins enlarged by previous arteriovenous fistulas were excluded. Baseline characteristics of the two study groups, including vein size, were comparable (median basilic vein diameter 3.5 mm, range 2.8–4.1 mm). The staged group had a brachio-basilic vein fistula performed first followed by the transposition procedure performed at least 6 weeks later to allow the basilic vein to enlarge. TBBV fistula maturation at 10 weeks, primary, assisted-primary, and secondary patency were the primary outcome measures. Early failures were included in the calculation of patency rates.

Results

Transposed brachio-basilic vein fistula maturation rate after primary procedures (3/9, 33%) was lower compared to maturation rate after staged procedures (7/7, 100%, P = 0.011, Fisher’s exact test), which led to premature termination of the trial. Time to hemodialysis [median (interquartile range)] of primary and staged procedures was 54 (51.5–113.5) days and 97 (93–126) days, respectively (P = 0.16). One-year primary and assisted-primary patency rates of primary and staged procedures were equivalent (44 vs 57%, P = 0.76 and 44 vs 71%, P = 0.29, respectively); however, there was a trend toward a better 1-year secondary patency after staged procedures (86 vs 44% for primary procedures, P = 0.09).

Conclusions

Among candidates for TBBV fistula with a small basilic vein, staged transposition achieves higher maturation rates compared to primary procedures, a difference reflected in long-term secondary patency.

Trial registration

www.ClinicalTrials.gov, identifier NCT01274117.

Review of Transposed Basilic Vein Access for Hemodialysis

Background

There is ongoing debate about the use of transposed basilic vein (TBV) fistula and the choice between it and prosthetic arteriovenous graft (AVG). This paper reviews the available literature relating to TBV fistula in terms of surgical technique, patency rates, complications, access survival and compares it with prosthetic AVG for hemodialysis (HD).

Methods

Review of English language publications on TBV during the last two decades.

Findings

The rate of fistula maturation was higher in the two-stage group, although the mean diameter of the basilic vein was smaller. Dialysis via central venous catheters at time of surgery was most prevalent in patients undergoing staged procedures—14% in one-stage TBV and 43% in two-stage TBV. Several authors report 1-year cumulative patency rate of 47% to 96% and 59% to 90% for TBV and AVG, respectively. TBV provides a more cost-effective option and should be considered the next choice when primary autogenous fistulae are not possible, whereas AVGs are easier to create, can be punctured earlier and have a greater reintervention rate if the access fails.

Conclusions

This analysis shows that TBV has several advantages over AVG and provides a valuable access for HD but raises the need for a comparative trial between TBV and the newer generation AVGs. There is no clear superiority of the one-stage over the two-stage procedure.

Patency Rates Among Heparin-Bonded and Conventional Polytetrafluoroethylene Grafts for Upper Extremity Hemodialysis Access

Background: Although arteriovenous fistulae are the gold standard for vascular access, many patients do not have veins that are suitable for arteriovenous fistulae. These patients require arteriovenous grafts (AVGs). There have been no long-term trials designed to analyze the complication and patency rates of heparin-bonded versus conventional upper extremity AVGs. We aimed to compare patency and complication rates of upper extremity conventional versus heparin-bonded AVGs.

Methods: A retrospective chart review from 2008 through 2012 was conducted. Institutional review board approval was obtained. Patients with an upper extremity conventional or heparin-bonded AVG were included. Exclusion criteria included use of therapeutic anticoagulation and forearm loop grafts. Complication rates, reinterventions, and primary and secondary patency rates were compared using logistic regression analysis.

Results: The cohort consisted of 93 patients. Conventional and heparin-bonded grafts were compared and there was no statistically significant difference between the median time to use (29 vs 32 days; P =.440) or primary patency (P =.673). The duration of time elapsed until intervention was a median of 69 days (mean ±standard error =94.7 ± 10.4 days). Demographic characteristics of patients did not differ between the graft types (61% women; P =0.342). No statistically significant differences were seen between comorbidities in the 2 groups and body mass index did not differ (P =.986).

Conclusions: There is no improved primary patency, secondary patency, or difference in complication rates between patients who received conventional versus heparin-bonded AVGs.

Outcomes of percutaneous interventions in transposed hemodialysis fistulas compared with nontransposed fistulas and grafts

PURPOSE

To compare postpercutaneous intervention outcomes of autogenous venous-transposition arteriovenous fistulas (AVFs) versus those of autogenous nontransposed AVFs (nAVFs) and prosthetic arteriovenous grafts (AVGs).

MATERIALS AND METHODS

A total of 591 hemodialysis accesses (195 transposed AVFs [tAVFs], 205 nAVFs, 191 AVGs) in 522 patients (278 male; mean age, 57 y; range, 15–91 y) underwent percutaneous transluminal angioplasty (PTA) and/or mechanical thrombectomy (ie, declotting). Access characteristics, surgical history, percutaneous interventions, postinterventional primary and secondary access patency, and follow-up data were collected. Cox proportional-hazards regression analyses, Fisher exact tests, and χ2 tests were performed.

RESULTS

Mean follow-up period was 32 months. Mean access ages at initial percutaneous intervention were 260 days (tAVF), 206 days (nAVF), and 176 days (AVG; P < .01). One-year postinterventional primary patency (PIPP) rates were 25% (tAVF), 24% (nAVF), and 14% (AVG). One-year postinterventional secondary patency (PISP) rates were 77% (tAVF), 61% (nAVF), and 63% (AVG). Median PIPP durations were 138 days (tAVF), 121 days (nAVF), and 79 days (AVG; P = .0001). Median PISP durations were 1,076 days (tAVF), 783 days (nAVF), and 750 days (AVG; P = .019). Total interventions needed to maintain PISP were 2.4 (tAVF), 1.3 (nAVF), and 3.2 (AVG) per patient-year (P < .001), which included 1.9, 1.2, and 1.4 PTAs (P < .01) and 0.45, 0.15, and 1.8 declotting procedures, respectively (P < .001).

CONCLUSIONS

Based on the number of percutaneous interventions needed to maintain PISP, these results confirm the current Dialysis Outcomes Quality Initiative access preference of nAVFs before tAVFs before AVGs. tAVFs offered superior postinterventional outcomes than AVGs. With additional interventions, tAVFs could even outperform nAVFs in terms of PISP.

Does Vascular Elasticity Affect Arteriovenous Fistula Maturation?

The vasculopathy of ESRD affects both arteries and veins. The arteries develop arteriosclerosis, which is largely a disease of the media characterized by increased collagen content, calcification, and both hypertrophy and hyperplasia of vascular smooth muscle cells. Veins may exhibit increased width of the intimal and medial layers, and may develop neointimal hyperplasia and calcification. Successful fistula maturation depends upon dilatation and remodeling of the artery and vein, but the stiff and thickened vessels of ESRD patients may respond poorly to signals that promote these adaptations. There is intense interest in accurately predicting fistula maturation outcome and preventing maturation failure. However, definitive criteria for preoperative testing of vessel elasticity have not yet been established. Tests that are adopted for widespread clinical use will need to be easy to apply - a standard that many of these tests may not meet. Finally, effective treatments are needed that prevent or reduce the stiffness of vessels. In conclusion, although there are many promising developments in this emerging field, effective methods of predicting fistula maturation outcome and preventing maturation failure remain to be established.

Arterio venous fistula experience at a tertiary care hospital in Pakistan

OBJECTIVE

To evaluate the two year patency rate of functioning arteriovenous fistula.

METHODOLOGY

This prospective case series study was conducted at Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from 1(st) January 2009 to 31(st) December, 2010. Patients were chosen for CBRC arteriovenous fistula at wrist and patients undergoing other types of vascular access or secondary fistula formation were excluded.

RESULTS

One hundred and eighty two patients underwent arteriovenous fistula formation. The mean ± SD age was 63 ± 13 years and there were 102 (56%) males and 80 (44%) females. 12.6% fistulae failed within first month without dialysis. The primary patency rate was 66.5% at three months and 57.7% at six months. Failing arteriovenous fistula was managed by new arteriovenous fistula in our series. 28.6% patients had redo arteriovenous fistula. This study demonstrated a poor outcome for fistulas in diabetic patients. Fifteen out of 23 (65.2%) who failed primarily were diabetics and out of these diabetics 13 (86.7%) failed in first three months. Infection and burst fistulae were found in nine (4.9%), pseudo aneurysm in 3.2%, fever 4.9%, peri-operative failure 0.55% and burst fistulae 3.2%.

CONCLUSIONS

One-third of radiocephalic fistulas fail within two years. The outcome is worse for women and diabetic patients. This information may be useful in assessing and counseling patients with end-stage renal failure. Arteriovenous fistula is the better and ideal choice for haemodialysis. A Radiocephalic fistula in forearm seems to have better results as comparison to cubital fossa arteriovenous fistula. End to side anastomosis results are better than side to side anastomosis.

A Novel Electrospun Nano-fabric Graft Allows Early Cannulation Access and Reduces Exposure to Central Venous Catheters

Purpose

The use of tunneled central venous catheters (CVC) as vascular access for hemodialysis treatment is increasing worldwide. We present a novel polycarbonate urethane nano-fabric graft, produced by electrospinning technology, which has self-sealing features that avoid seroma formation and allow puncturing within 48 hours. The aim of this study was to assess its advantages in a setting where late referral is common.

Methods

A retrospective single center study assessed 24 implanted grafts in 24 patients with maximal follow-up of 18 months; patency rates, time to first cannulation and post-operative complications were assessed.

Results

Successful access was achieved in all 24 patients within 48 hours. In 50% of the patients cannulation was performed within 24 hours without increasing the complication rate. Twelve month primary and secondary patencies were 50% and 70.8%, respectively. Excluding early failures (within 30 days) because of surgical problems, 12 month primary and secondary patencies were 75% and 81.2% respectively. Complication and infection rates were 10.94 and 0.49/1000 dialysis procedures, respectively. No pseudoaneurysms or seromas were documented at 18 months.

Conclusions

Early cannulation was successful in all patients with good 12-month primary and secondary patency rates, compared to data reported by others on polytetrafluoroethylene (PTFE) grafts. The infection rate was substantially lower than in tunneled CVCs. Therefore, the AVflo graft may improve the clinical status of dialysis patients by decreasing the exposure to CVCs.

Primary patency time of basilic vein transposition versus prosthetic brachioaxillary access grafts in hemodialysis patients

PURPOSE

The aim of this study was to compare the primary patency time of basilic vein transposition and prosthetic brachioaxillary access grafts in hemodialysis patients.

METHODS

In this randomized clinical trial, 60 hemodialysis patients who met the inclusion/exclusion criteria were recruited and randomly assigned to two intervention groups; Basilic vein transpositions (BVT) or Arteriovenous access grafts (AVG). Clinical follow-up for patency of the created accesses in at least one year, was performed at two weeks, one, two, three months and then every three months after surgery. Finally, patency rates and access-related complications were compared in the two groups studied.

RESULTS

Thirty BVTs and thirty AVG were performed in each group studied. The groups were well matched for age, sex and comorbidity. After at least one year of follow-up, the access failure rate in the BVT and AVG groups was 23.3% and 30%, respectively. In addition, the mean primary patency time in the BVT and AVG groups was 244.13 ± 103.65 and 264.97 ± 149.28, respectively and there was no statistically significant difference between the two groups studied (P=.533). The common cause of access failure were thrombosis and infection but there were no statistically significant differences between the two groups (P>.05).

CONCLUSION

Our results show that AVG offer similar patency and complication rates to BVT. Thus, authors consider them as the preferred hemodialysis access when there are no suitable forearm veins to create arteriovenous fistulas.

[Vascular grafts as access for hemodialysis]

Prosthetic arteriovenous grafts have an inferior patency rate and greater morbidity than those with autogenous vessels and are therefore considered as secondary or tertiary vascular access for hemodialysis in patients with fatigued or unsuitable superficial arm veins. Prior access planning in accordance of patient characteristics, careful operative procedure and appropriate revision of complications can ensure long-term functioning of a vascular access using a large variety of possible prosthetic conduits. Arteriovenous grafts remain essential in vascular access surgery and their role may be increasing with higher comorbidities of patients and should be preferred to tunnelled cuffed catheters. This article reviews the indications, alternative configurations and characteristics of arteriovenous grafts.

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.

Long-term complication and patency rates of Vectra and IMPRA Carboflo Vascular Access Grafts with aggressive monitoring, surveillance and endovascular management

The purpose of this study is to compare infection, pseudoaneurysm formation and patency rates during long-term follow-up of polyurethane and polytetrafluoroethylene (PTFE) vascular access grafts maintained with contemporary endovascular methods. During a 34-month period, 239 polyurethane and 125 carbon-impregnated PTFE vascular access grafts were placed in 324 consecutive patients. Thirty-six patients (9.9%) developed a pseudoaneurysm (anastomotic, n = 6 or at the needle-stick site, n = 30). An additional 19 patients (5.2%) required graft excision for infection. Three-year graft infection and pseudoaneurysm formation (at needle-stick site) rates were similar in polyurethane and PTFE grafts (11% versus 8%, P = 0.61, and 17% versus 23%, P = 0.72, respectively). Three-year secondary patency was better in polyurethane than PTFE grafts (69% versus 57%, respectively, P = 0.012). Straight upper arm polyurethane grafts had the best secondary patency ( P = 0.001). Contemporary long-term secondary patency of vascular access grafts is satisfactory. Further follow-up is necessary to compare late infection and pseudoaneurysm formation rates.

Comparison among Transposed Brachiobasilic, Brachiobrachial Arteriovenous Fistulas and Flixene™ Vascular Graft

Objective

To compare the outcomes of 3 upper arm access types: transposed brachiobasilic arteriovenous fistula (BBAVF), autogenous brachial vein–brachial artery access (ABBA), and a new type of ePTFE graft (Flixene™ graft) (AVG), in a consecutive series of patients treated in a tertiary centre.

Methods

A prospective, computerized access database was analysed retrospectively to identify all patients undergoing BBAVF, ABBA, or AVG between January 1, 2008, and December 31, 2009.

Results

A total of 108 patients were identified; of whom 45 had BBAVF, 15 ABBA, and 48 ePTFE brachioaxillary AVG. Early failure was similar in all 3 groups. The 18–month functional patency rates for the ABBAs, BBAVFs, and grafts were 27%, 51%, and 55%, respectively. The median time to first use for AVGs was significantly shorter (p<0.0001). Complications were not more frequent in AVGs than ABBAs and BBAVFs (p=0.127). The total number of access interventions was similar between the AVG and ABBA groups (p=0.58), but it was significantly higher in the AVG group compared with the BBAVF group (p<0.0001).

Conclusions

This study supports the current recommendations of the NKF Kidney Disease Outcomes Quality Initiative for using BBAVFs as third choice after radiocephalic and brachiocephalic arteriovenous fistulas. We also showed good results with a new type of prosthetic graft (Flixene™ graft) that allows cannulation within days of implantation. We now favour the use of this graft instead of basilic vein transposition in elderly patients with short life expectancy and urgent need of renal access.