A comparison between the HeRO graft and conventional arteriovenous grafts in hemodialysis patients.

Venous stenosis and occlusion are a major cause of vascular access dysfunction and failure. The HeRO Graft bypasses occlusion and traverses stenosis with outflow directly into the central venous circulation. A randomized, multicenter study was conducted to evaluate the efficacy and safety of the HeRO Graft relative to conventional AV grafts. The design was to enroll 143 patients in a 2:1 randomization ratio between HeRO and conventional AV control groups. Data on 72 subjects (52 HeRO Graft and 20 AV graft controls) were obtained. The HeRO Graft and control cohorts were comparable in baseline characteristics. Adequacy of dialysis, bacteremia rates, and adverse events were consistent between groups. Twelve month Kaplan-Meier estimates for primary and secondary patency rates were 34.8% and 67.6% in the HeRO Graft cohort, and 30.6% and 58.4% in the control cohort. There was no statistical difference in terms of patency between groups. The rates of intervention were 2.2/year for HeRO Graft and 1.6/year for the control (p = 0.100). Median days to loss of secondary patency was 238 for HeRO Graft versus 102 for the control (p = 0.032). The HeRO Graft appears to provide similar patency, adequacy of dialysis, and bacteremia rates to those of conventional AV grafts.

Initial experience and outcome of a new hemodialysis access device for catheter-dependent patients.

OBJECTIVE: The effects of a new long-term subcutaneous vascular access device were studied in access-challenged patients who were poor candidates for fistulas or grafts due to venous obstruction. Bacteremia rates, patency, and function of the Hemodialysis Reliable Outflow (HeRO) Vascular Access Device (Hemosphere Inc, Minneapolis, Minn) were evaluated. METHODS: The HeRO device consists of a 6-mm expanded polytetrafluoroethylene graft attached to a 5-mm nitinol-reinforced silicone outflow component designed to bypass venous stenoses and enter the internal jugular vein directly, providing continuous arterial blood flow into the right atrium. The HeRO device was studied in a multicenter clinical trial to test the hypothesis that access-challenged patients would experience a statistically significant reduction in bacteremia rates compared with a tunneled dialysis catheter (TDC) literature control of 2.3/1000 days. HeRO-related bacteremia rates, adequacy of dialysis, patency, and adverse events were analyzed. RESULTS: The HeRO device was implanted in 36 access-challenged patients who were followed for a mean 8.6 months (9931 HeRO days). The HeRO-related bacteremia rate was 0.70/1000 days. All HeRO-related bacteremias occurred during the bridging period when a TDC was still implanted before HeRO graft incorporation. HeRO adequacy of dialysis (mean Kt/V) was 1.7. HeRO primary patency was 38.9%, and secondary patency was 72.2%. CONCLUSIONS: In access-challenged patients, a statistically significant reduction in HeRO-related bacteremia was noted compared with TDC literature. The device had similar function and patency compared with conventional arteriovenous graft literature.

Retrograde migration of an abdominal aortic aneurysm endograft leading to postoperative renal failure.

The phenomenon of antegrade (distal) endograft migration is an extensively documented complication after endovascular abdominal aortic aneurysm repair. This case report describes the finding of postoperative abdominal aortic aneurysm endograft retrograde (proximal) migration occluding bilateral renal arteries and leading to dialysis-dependent renal failure.

Multicenter evaluation of the bovine mesenteric vein bioprostheses for hemodialysis access in patients with an earlier failed prosthetic graft.

BACKGROUND: The number of patients requiring hemodialysis increases each year, with a large cohort of patients still requiring prosthetic grafts for hemodialysis. All available prosthetic vascular access grafts have predictable failure rates, leading to a large group of patients with multiple failed access grafts. This report evaluates use of mesenteric vein bioprosthesis (MVB) as a conduit for patients who have failed at least one earlier synthetic vascular access graft. STUDY DESIGN: Two-hundred seventy-six access grafts were implanted in patients who had at least one earlier failed synthetic graft. Of these grafts, 183 were MVB and 93 were synthetic. Graft histories were obtained from 128 of the 183 patients who received the MVB, representing a nonrandomized historic data set of previously failed grafts as an internal control group (INT). Patency was determined by Kaplan-Meier analysis, and the Cox proportional hazards model was used for multivariate analysis of factors predictive of effect. RESULTS: Primary patency at 12 months was 35.6% MVB versus 28.4% synthetic grafts. At 24 months, secondary patency was 60.3% MVB, 42.9% synthetic, and 18.0% INT (p < 0.0001, log- rank). Complication rates, including dilation, seroma, infection, and thrombosis, were all notably lower for the MVB compared with synthetic grafts by Cox regression (p < 0.001). Intervention rate per patient year was lower in the MVB group (0.97 versus 1.37) compared with synthetic grafts (p = 0.003). CONCLUSIONS: MVB provided superior secondary graft patency compared with both historic graft data or newly implanted nonrandomized synthetic implants. A considerable reduction in thrombosis, infection, and interventions was observed with the MVB graft. These results suggest that MVB offers a safe alternative to patients who have a history of failing synthetic access grafts and may represent an option for extending vascular access to this patient population.

Alternative graft materials for hemodialysis access.

Since the initial description of the arteriovenous (AV) fistula, autogenous access has been the procedure of choice for chronic hemodialysis. Recently established National Kidney Foundation Dialysis Outcome and Quality Initiative guidelines have validated the superiority of arteriovenous fistulas over AV grafts but have also addressed the fact that a significant percentage of the growing dialysis population does not have veins suitable for primary AV fistulas. Recent advances in forearm, upper arm, and femoral venous transpositions have facilitated the performance of increased numbers of autogenous access procedures. Nevertheless, substantial numbers of patients on chronic hemodialysis require prosthetic AV grafts. Since early reports describing hemodialysis access using expanded polytetrafluoroethylene, surgical results with prosthetic graft materials have remained suboptimal. Modifications in polytetrafluoroethylene grafts and the recent development of alternative graft materials for hemodialysis access have yielded encouraging early results in efforts to improve patency of AV grafts. We will review currently available graft materials and recent developments in an ongoing effort to improve the results with prosthetic and biologic hemodialysis access conduits.