Secondary Arteriovenous Fistulas: Converting Prosthetic AV Grafts to Autogenous Dialysis Access

Hemodialysis Vascular Access: A Historical Perspective on Access Promotion, Barriers, and Lessons for the Future

This review describes the history of vascular access for hemodialysis (HD) over the past 8 decades. Reliable, repeatable vascular access for outpatient HD began in the 1960s with the Quinton-Scribner shunt. This was followed by the autologous Brecia-Cimino radial-cephalic arteriovenous fistula (AVF), which dominated HD vascular access for the next 20 years. Delayed referral and the requirement of 1.5-3 months for AVF maturation led to the development of and increasing dependence on synthetic arteriovenous grafts (AVGs) and tunneled central venous catheters, both of which have higher thrombosis and infection risks than AVFs. The use of AVGs and tunneled central venous catheters increased progressively to the point that, in 1997, the first evidence-based clinical practice guidelines for HD vascular access recommended that they only be used if a functioning AVF could not be established. Efforts to promote AVF use in the United States during the past 2 decades doubled their prevalence; however, recent practice guidelines acknowledge that not all patients receiving HD are ideally suited for an AVF. Nonetheless, improved referral for AVF placement before dialysis initiation and improved conversion of failing AVGs to AVFs may increase AVF use among patients in whom they are appropriate.

The outcomes of a novel two-stage proximal brachial artery to proximal basilic/brachial vein arteriovenous graft extension for dialysis access

BACKGROUND

We describe a technique to mature a basilic/brachial vein in the mid-arm in preparation for a second stage loop proximal brachial artery to basilic/brachial vein arteriovenous graft (BBAVG). This can occur after a failed basilic/brachial vein transposition or a lack of adequate veins in the distal arm. This allows a mature vein to be used in an end-to-end configuration as an outflow to a BBAVG while preserving proximal vessels for the future.

METHODS

This single-center retrospective study was performed from 2015 to 2021, including 104 AVG patients divided into three groups: (1) Patients who failed a basilic vein transposition and had an enlarged vein suitable for an AVG outflow; (2) Patients who had a small caliber basilic/brachial vein after the transposition, requiring a mid-arm brachial artery to brachial/basilic arteriovenous fistula (AVF) creation with a subsequent AVG extension; (3) and lastly, patients who had no distal arm veins available and required a primary brachial artery to basilic/brachial AVF with AVG extension. A survival analysis was performed looking at time to loss of primary and secondary patency, calculated with Kaplan-Meier estimates and Cox regression models adjusted for covariates.

RESULTS

The median follow-up time was 11 months (IQ = 11-30 months). The survival analysis showed 28% lost primary patency at a median time of 9 months, and 14% lost secondary patency at a median time of 61 months. Overall secondary patency of the vascular access measured at 12 months was 85.6%. Loss of primary (p = 0.008) and secondary patency (p = 0.017), as well as patency during the first 12 months (p = 0.036), were all significantly associated with increased age when adjusting for covariates.

CONCLUSIONS

Our results suggest that the graft extension technique using a mature vein from a previous fistula can result in reliable and durable access. This is important for patients with limited access for hemodialysis, as the axillary vein is preserved for future use if needed.

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.

Forearm loop arteriovenous grafts preserve and may create new upper arm access sites

INTRODUCTION

This study evaluated the mid-term patency of forearm loop arteriovenous grafts and the dilation of previously inadequate upper arm basilic and cephalic veins after failed forearm loop arteriovenous graft.

METHODS

All access procedures from September 2009 to December 2015 were reviewed. Vein mapping measurements were used to determine whether there was "adequate" upper arm cephalic and/or basilic vein, defined as ⩾3 mm by duplex ultrasound, at the time of forearm loop arteriovenous graft creation. Outcomes of forearm loop arteriovenous graft were compared with upper arm arteriovenous fistula, and primary and cumulative patencies were evaluated.

RESULTS

Thirty-eight forearm loop arteriovenous grafts and 278 upper arm arteriovenous fistulas were created. In the forearm loop arteriovenous graft cohort, nine were inserted with adequate upper arm vein, group A, and 29 were inserted with inadequate upper arm vein, group B. Cumulative patency was lower for forearm loop arteriovenous graft compared with upper arm arteriovenous fistula at 6 months, 1 year, and 2 years (67% vs 91%, 61% vs 85%, and 49% vs 80%, respectively, P < .01). Comparison of group A forearm loop arteriovenous graft and upper arm arteriovenous fistula did not show a statistical difference in cumulative patency at 6 months, 1 year, and 2 years (P = .80, .62, and .70, respectively). Of group B with failed forearm loop arteriovenous graft, 36% became candidates for upper arm arteriovenous fistula with dilation of ipsilateral upper arm cephalic or basilic vein to ⩾3 mm.

CONCLUSION

In this study, forearm loop arteriovenous graft with adequate upper arm vein did not show a statistical difference in mid-term patencies compared with upper arm arteriovenous fistula. For those forearm loop arteriovenous grafts with inadequate upper arm vein, approximately one-third of patients became candidates for upper arm arteriovenous fistula demonstrating the benefits forearm loop arteriovenous graft.

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.

Successful Hemodialysis Arteriovenous Fistula Creation in a Patient With Continuous-Flow Left Ventricular Assist Device Support

Heart failure necessitating left ventricular assist device (LVAD) support can lead to kidney failure requiring dialysis. Some of these patients may require long-term hemodialysis (HD). Optimal vascular access for a patient on long-term HD therapy with an LVAD remains a complex issue. The majority of LVADs are of the continuous-flow type, and it has been theorized that native arteriovenous fistula maturation may be impaired in a setting of decreased pulsatile arterial flow. We describe a case of successful creation and use of an arteriovenous fistula in an HD-dependent patient with a continuous-flow LVAD.

American Society of Nephrology Quiz and Questionnaire 2015: ESRD/RRT

The Nephrology Quiz and Questionnaire remains an extremely popular session for attendees of the Annual Kidney Week Meeting of the American Society of Nephrology. During the 2015 meeting, the conference hall was once again overflowing with eager quiz participants. Topics covered by the experts included electrolyte and acid-base disorders, glomerular disease, ESRD and dialysis, and kidney transplantation. Complex cases representing each of these categories together with single best answer questions were prepared and submitted by the panel of experts. Before the meeting, training program directors of nephrology fellowship programs and nephrology fellows in the United States answered the questions through an internet-based questionnaire. During the live session, members of the audience tested their knowledge and judgment on the same series of case-oriented questions in a quiz. The audience compared their answers in real time using a cellphone application containing the answers of the nephrology fellows and training program directors. The results of the online questionnaire were displayed, and then, the quiz answers were discussed. As always, the audience, lecturers, and moderators enjoyed this highly educational session. This article recapitulates the session and reproduces selected content of educational value for the readers of the Clinical Journal of the American Society of Nephrology Enjoy the clinical cases and expert discussions.

Creating Arteriovenous Fistulas using Surgeon-performed Ultrasound

Purpose

An arteriovenous fistulas (AVF) is the preferred vascular access for hemodialysis and is associated with lower mortality, morbidity and cost when compared with grafts and particularly with central venous dialysis catheters. This study reviews a series of new patients where an autogenous access was constructed for each individual utilizing surgeon-performed ultrasound (SP-US).

Methods

Consecutive new patients referred for a permanent vascular access during an 11-year period were retrospectively reviewed. In addition to physical examination, each patient underwent SP-US evaluation for preoperative vessel mapping and post-operative evaluation for access maturation. SP-US was also used in the evaluation of access dysfunction in mature AVFs.

Results

We identified 1874 patients. Ages were 8-94 years (mean 60 years). Of these, 51% were female and 59% were diabetic; 33% had previous failed access operations. Follow-up was 3-127 months (mean 23 months). An autogenous access was constructed for each individual. No grafts were used. Direct AVFs were constructed in 1240 (66%) patients and 634 (34%) individuals required a transposition or translocation procedure. Primary and cumulative patency rates were 60.0% and 93.0% at 12 months and 47.3% and 90.2% at 24 months, respectively. AVF arterial inflow was most commonly supplied by the proximal radial artery (67%).

Conclusions

Creating a functional autogenous vascular access is possible for most patients. No grafts were used in this series of 1874 consecutive new patients. Important elements for success included SP-US evaluation, utilization of the many vascular access options available, establishing radial artery AVF inflow when feasible, and prompt intervention when indicated.

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.

Fistula first breakthrough initiative: targeting catheter last in fistula first

An arteriovenous fistula (AVF) is the optimal vascular access for hemodialysis (HD), because it is associated with prolonged survival, fewer infections, lower hospitalization rates, and reduced costs. The AVF First breakthrough initiative (FFBI) has made dramatic progress, effectively promoting the increase in the national AVF prevalence since the program's inception from 32% in May 2003 to nearly 60% in 2011. Central venous catheter (CVC) use has stabilized and recently decreased slightly for prevalent patients (treated more than 90 days), while CVC usage in the first 90 days remains unacceptably high at nearly 80%. This high prevalence of CVC utilization suggests important specific improvement goals for FFBI. In addition to the current 66% AVF goal, the initiative should include specific CVC usage target(s), based on the KDOQI goal of less than 10% in patients undergoing HD for more than 90 days, and a substantially improved initial target from the current CVC proportion. These specific CVC targets would be disseminated through the ESRD networks to individual dialysis facilities, further emphasizing CVC avoidance in the transition from advanced CKD to chronic kidney failure, while continuing to decrease CVC by prompt conversion of CVC-based hemodialysis patients to permanent vascular access, utilizing an AVF whenever feasible.

Simple and Durable Resolution of Steal Syndrome by Conversion of Brachial Artery Arteriovenous Fistulas to Proximal Radial Artery Inflow

Dialysis associated steal syndrome (DASS) is relatively uncommon but constitutes a serious risk for patients undergoing vascular access operations. We report two patients with DASS where brachial artery vascular access inflow was revised to the proximal radial artery for arteriovenous fistula (AVF) inflow. DASS was resolved in both patients with the permanent resolution of symptoms, in addition to the healing of ulcerations and ischemia. Both AVFs were immediately functional and durable.

Endovascular stents for dialysis access: under what circumstances do the data support their use?

Despite strict K/DOQI clinical practice guidelines regarding the deployment of stents in the hemodialysis vascular circuit, their use has increased exponentially over the last 10 years in both arteriovenous fistulas and grafts. The literature is very scant regarding outcomes, with most studies suffering from design flaws. Some authors have advocated the use of stents for specific clinical scenarios, such as patients with thrombosed arteriovenous grafts or ones with a severe stenosis at the venous anastomosis. Others have advocated a more liberal strategy to deploy stents at a variety of sites if the stenotic lesion remains greater than 30% after angioplasty. Although not approved for the treatment of pseudoaneurysms in the AV grafts, stent use in this setting is emerging to be an important strategy. The use of stents as a treatment for rupture of a vessel while performing a percutaneous angioplasty is well described and performed routinely. It is important to recognize the clinical scenarios when stent placement may present a distinct disadvantage (eg, loss of a potential secondary fistula creation in the same extremity). Finally, well-designed studies need to address all these issues to clarify indications and to provide stronger scientific guidelines for stent use.