A 5-year audit of haemodialysis access

Long Term Outcomes of Arteriovenous Grafts for Hemodialysis in Lower Extremities

Purpose:

The lower extremity has received its fair share of attention as a vascular access site in patients who have exhausted their upper arm vessels. However, experiences with lower extremity arteriovenous grafts (AVGs) have so far been disappointing because of high infection rates and severe limb ischemia. We report our experience with hemodialysis access from the lower extremity.

Materials and Methods:

A retrospective review of 60 lower extremity AVGs created between January 2003 and December 2011 was performed. Age, sex, etiology of end-stage renal disease and complications were tabulated. Primary and secondary patency rates were determined.

Results:

The average age of the study population was 56 years and 38 patients were female. Renal failure was associated with hypertension in 40 (66.7%) patients, diabetes in 28 (46.7%) patients and cardiovascular disease in 9 (15.0%) patients. The follow-up period was 8–108 months. Fifty-four patients had bilateral central vein stenosis. Seven (11.7%) patients had primary failure of their AVG. There was no operation-related death. Primary and secondary patency rates were: 66% and 90% at 1 year, 40% and 90% at 2 years, 27% and 87% at 3 years, and 18% and 87% at 5 years, respectively. There were 105 postoperative complications that developed in 67 patients. Postoperative complications were: thrombosis (30), proximal vein stenosis (56), infection (9), bleeding with hematoma (1), perigraft seroma (3), steal syndrome (2), and pseudoaneurysm (4).

Conclusion:

A lower extremity AVG seems to be a viable option in patients with unusable upper extremity veins.

Arteriovenous grafts in the thigh: an excellent hemodialysis vascular access when arm vasculature is exhausted

The aim of our retrospective analysis with prospective collected data was to evaluate the patency of thigh expanded polytetrafluoroethylene (ePTFE) arteriovenous (AV) grafts, which were placed in chronic hemodialysis patients by the same interventional nephrologist skilled in hemodialysis access vascular surgery. From February 1991 until March 2013, 35 thigh ePTFE grafts were placed in 31 chronic hemodialysis patients. Twenty (57%) were women, mean age 58.7 ± 14.5, dialysis vintage 11.9 ± 7.3 years, mean number of previous vascular accesses 4.4 ± 1.9. Two of the 35 (5.7%) grafts were lost to follow-up, immediate failure occurred in 1/35 (2.8%) grafts, and thrombosis appeared within 30 days in 2/35 (5.7%) grafts. Four of the 31 patients died with functioning grafts, while in 9/31 patients the grafts are still patent. In the remaining 17 AV grafts that thrombosed, no surgical intervention was performed in 8/17, while 18 thrombectomies (two per graft) were performed in 9/17 to maintain graft patency. The immediate success rate was 97.1%. Primary patency was from 0-3251 days, on average 906 ± 898, median 472, cumulative patency (N = 33) was from 0-3251 days, on average 1174 ± 954, median 966. Cumulative patency of the grafts that were patent for more than 30 days (N = 30) was from 153-3251 days, on average 1298 ± 921, median 1207. The ePTFE graft survival after the 1st year was 78%, after the 2nd year 74%, after the 3rd year 66%, after the 4th year 56%, after the 5th year 52%, and after the 9th year 13 %. The longest patency was 3251 days without any intervention. Steal syndrome occurred in two patients after 2522 and 275 days after fistula placement.

The effect of new clinical pathways on the outcome of vascular access surgery

PURPOSE

Prior to 2007, the waiting time for vascular access surgery at our center was approximately 107 days compared to a UK average of 45 days. Two new pathways were developed; the rapid and super-rapid pathways incorporating an access liaison nurse who organized vessel mapping and referred patients for surgery. This audit was to determine whether the pathways were effective in reducing the waiting times and improving vascular accesses outcomes.

METHODS

All 210 patients with established renal failure undergoing 232 vascular access procedures between January 2008 and March 2011 were studied. Detailed patient information including type of procedure and cause of access failure were stored in an Excel spreadsheet and analyzed using SPSS for Windows.

RESULTS

One hundred and twenty patients had a brachiocephalic fistula, 61 a radiocephalic fistula, 39 an access using the basilic vein ± transposition, and 11 a transposition of the long saphenous vein and one a brachio-axillary graft. Overall median waiting time from referral to access surgery was 23 days. Patients were followed up for a median of 248 days after surgery. The overall primary failure rate was 9.1% and 25 of 27 accesses failed because of thrombosis. The overall cumulative survival probability of accesses at one year was 61.4% with a mean survival of 621.2 days (SEM = 34.8).

CONCLUSION

The clinical pathways have improved VA service to patients with a drastic reduction in waiting times, elimination of synthetic access, and maintenance of satisfactory results.

Vascular access for hemodialysis in the elderly

OBJECTIVE

The number of elderly patients needing hemodialysis is constantly increasing year by year. Elderly patients with end-stage renal failure represent a challenge for the surgeons who create vascular accesses. The aim of this study was to analyze the outcome of conduit creation in the elderly in our institution and to compare it with the outcome of a cohort of patients aged <65 years.

METHODS

The study was performed retrospectively on prospectively collected data. The study period was between January 1, 2000, and December 31, 2006. We identified first attempts at conduit creations, including arteriovenous fistulas (AVFs) and grafts, in elderly patients (aged ≥65 years) who were allocated to group A, and in nonelderly patients (<65 years) who were allocated to group B. Subsequent attempts at conduit creations in the same patient were omitted from the data set.

RESULTS

There were 246 first AVFs in group A and 89 in group B. At a mean follow-up of 25.46 months (SD, 18.93 months), the primary patency (PP) rate of all AVFs was 70% in group A and 68% in group B (P = .75). The assisted PP rate was 73% in group A and 77% in group B (P = .4). The secondary patency (SP) rate was 73% in group A and 79% in group B (P = .9). Also, the differences in the 12-month cumulative patency rates (including PP, assisted PP, and SP) in the two groups (65% vs 60%) were not significant. At a mean follow-up of 25 months, death with a functioning conduit occurred at the same rate in both groups (56% and 54%), and mean conduit survival did not differ according to age (516 and 511 days). The incidence of failure to mature was higher in group A (6.1% vs 1.1%, P = .03). Patency rates for different types of conduits were similar between the two groups, although polytetrafluoroethylene grafts had a higher cumulative patency in group A (94% vs 69%; P = .05). The rate of procedures to salvage conduits was 2.5% in group A vs 10.1% in group B. Mean hospital stay for group A and group B was 3.2 days.

CONCLUSIONS

In our experience, the creation of permanent hemodialysis access in the elderly with AVF is not only possible but also proved to have a short hospital stay, high patency rates, and an acceptable rate of further intervention.

Thigh grafts contribute significantly to patients' time on dialysis

BACKGROUND AND OBJECTIVES

Thigh grafts are placed in hemodialysis patients who have exhausted all arm access sites. The goal of this study was to compare the survival, complication rates, and overall contribution of thigh grafts with arm grafts and fistulas in patients with at least one functional thigh graft during their dialysis history.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This longitudinal review of a prospectively acquired clinical database included 85 thigh graft recipients. The rates of survival, thrombosis, infection, and other complications were determined for a total of 268 fistulas, arm grafts, and thigh grafts placed in these patients.

RESULTS

In this patient subset, thigh graft primary failure rate was lower than arm grafts and fistulas (3 versus 13 and 61%, respectively). Excluding primary failures, thigh grafts survived longer than both arm grafts and mature fistulas (53 versus 14 and 32%, at 3 years; 47 versus 3 and 11% at 5 years). Thigh grafts had a lower thrombosis rate than arm grafts (0.543 versus 1.457/patient-year) but similar rates of loss as a result of infection and surgical revision. In patients with previous arm accesses, thigh grafts contributed 51% of total dialysis time compared with 38 and 11% for arm grafts and fistulas.

CONCLUSIONS

Thigh grafts provide long-term, thrombosis- and infection-free dialysis access for patients with exhausted arm access sites. The decision for thigh graft placement should, therefore, be made as soon as there is evidence for unavailability of arm access sites so that catheter use can be minimized.

Thigh grafts: a preferable alternative to catheters when upper extremity access sites are exhausted

Hemodialysis patients with failed upper extremity (arm) access sites comprise 5-10% of the dialysis population. In these patients, arm vessels are either unsuitable for access placement due to trauma or peripheral vascular disease, or have been exhausted following dialysis usage. Synthetic grafts in the lower extremity (thigh) would benefit these patients, but surgeons are often reluctant to place them, due to concerns of infection and vascular complications. As a result, these patients receive tunneled central venous catheters as their permanent dialysis access. Recent studies have shown, however, that survival and complication rates of thigh grafts are similar to arm grafts and fistulas. Moreover, thigh grafts have lower infection and mortality rates than catheters and provide higher blood flows and dialysis adequacy. In this editorial we argue that thigh grafts are the better option in patients who have lost all arm access sites; they should be placed in preference to tunneled central venous catheters.

Randomized clinical trial comparing decellularized bovine ureter with expanded polytetrafluoroethylene for vascular access

BACKGROUND

The SynerGraft model 100 (SG 100) is a decellularized bovine uereter graft developed to improve on prosthetic conduits for vascular access. Its clinical performance was compared with polytetrafluoroethylene (ePTFE) in a prospective, pilot randomized study.

METHODS

Patients requiring haemodialysis with no native vein options were included. Between June 2004 and June 2007, 29 patients received SG 100 and 27 ePTFE grafts. Forty-five patients had undergone previous access surgery. All grafts were between the brachial artery and the axillary vein.

RESULTS

Clinical details were similar between the groups; overall mean(s.d.) follow-up was 469(398) days. After 1 year, there were no significant differences in primary patency (28 per cent for SG 100 versus 48 per cent for ePTFE; P = 0.290), assisted primary patency (52 versus 64 per cent; P = 0.430) or secondary patency (57 versus 68 per cent; P = 0.370). Freedom from infection at 1 year was 96 per cent for SG 100 and 91 per cent for ePTFE (P = 0.410). Fifty-seven further procedures (18 endovascular and 39 surgical) were needed to maintain patency in 50 grafts (23 SG 100 and 27 ePTFE).

CONCLUSION

Both grafts were adequate conduits for haemodialysis and were amenable to repair. Anticipated advantages for SG 100 were not seen in either patency or stability.

Pre-operative vessel mapping and early post-operative surveillance duplex scanning of arteriovenous fistulae

PURPOSE

To increase the proportion of dialysis patients using native arteriovenous fistulae (AVF), improved selection of the most appropriate procedure must be coupled with early access surveillance to determine which access would likely mature and when intervention might lead to access salvage. This study was aimed at auditing pre-operative vessel mapping and post-operative access surveillance against the primary outcome measure of AVF maturation.

METHODS

Between January 2006 and August 2007, 113 AVF created in 101 patients were studied. Data on pre-operative vessel mapping, type of AVF, post-operative surveillance scans were analyzed against the outcome AVF.

RESULTS

Pre-operative mapping and post-operative scanning were carried out in 86% and 91%, respectively. A maturing fistula on post-operative scan highly correlated with a satisfactory outcome (p<0.001). The sensitivity and specificity of the post-operative scan were 100% and 85%, respectively. There were 79 brachiocephalic and 34 radiocephalic fistulae with a primary failure rate of 23% and 47%, respectively, giving an overall failure rate of 30%. Nine fistulae had further intervention (angioplasty or thrombolysis) and five (56%) were salvaged. Seventy-two AVF matured satisfactorily giving a primary cumulative patency of 71% (72/102).

CONCLUSION

This study shows that preoperative vessel mapping provides useful information regarding the choice of AVF. Access surveillance duplex scanning at 6-8 weeks post-operatively is viable and has a high sensitivity and specificity for final outcome of fistula. Identifying AVF with potential problems early means that further intervention or surgery can be planned earlier, which will have a positive impact on patients.

Primary Vascular Access

Primary vascular access is usually achievable by a distal autogenous arterio-venous fistula (AVF). This article describes the approach to vascular access planning, the usual surgical options and the factors affecting patency.