Use of Bovine Mesenteric Vein in Rescue Vascular Access Surgery

We describe a technique for rescue surgery of autologous arterovenous fistula (AVF), using Bovine Mesenteric Vein (BMV), which may be used in patients with autologous AVF malfunction caused by steno-occlusion on the arterial side or by fibrosis of the first portion of the vein. To preserve the autologous AVF, we replaced the diseased portion of the artery, or the first centimeters of the vein, by a segment of BMV, with the aim of saving the patency and functionality of the access. We used this technique in 16 cases. All patients underwent hemodialysis treatment immediately after the procedure. Infection or aneurismal dilatation of the graft in implanted BMV was never observed.

Long-Term Results of Biological Grafts for Haemodialysis Vascular Access

The quest for suitable conduits for dialysis access has continued since the first patients were dialysed. Whilst synthetic grafts made from expanded polytetrafluoroethylene (ePTFE) have been the main definitive option after autologous arteriovenous fistulas they have a number of drawbacks, which has led to the use and development of biological grafts such as autografts, homografts or xenografts. Technology continues to improve and currently biosynthetic options are available which may combine the benefits of a readily available product without the drawbacks of PTFE. The history and evidence of biological options for haemodialysis access are discussed.

Allogenous vein graft as vascular access for hemodialysis--lost battle?

PURPOSE

The purpose of this paper is to assess a long-term outcome of allogenous vein grafts (ALVG) as vascular access for hemodialysis.

MATERIALS AND METHODS

For nearly eight years (between 9/2002 and 9/2011) a total of 78 patients with 112 ALVGs were involved in the study. The register included 46 women and 32 men, mean age 66.1 ± 11.2 years; range 20-88 years. The patient database was retrospectively reviewed and statistical processing was performed.

RESULTS

Almost all ALVGs were treated by PTA or surgically, very often repeatedly. The number of radiologic interventions was 316, the number of surgical procedures 31. Mean follow-up time was 795 days, range 28-3522 days. Thirty-five patients died of unrelated causes, nineteen with functional graft, fourteen patients were lost to follow-up. Forty ALVGs failed for various reasons, mostly because of occlusion. Only one patient underwent successful renal transplantation, no patient converted to peritoneal dialysis. Thirty-seven ALVGs remain correctly functioning. Primary patency rates at 6, 12, and 24 months were 81 ± 5%, 63 ± 5%, and 34 ± 2% respectively. Secondary patency rates at 6, 12, and 24 months were 96 ± 2%, 82 ± 4%, and 65 ± 5% respectively.

CONCLUSIONS

Allogenous vein grafts, in spite of the high number of necessary radiologic and surgical interventions and reinterventions, show acceptable clinical usability and durability, comparable with other types of prosthetic grafts.

Neointimal hyperplasia associated with synthetic hemodialysis grafts

Stenosis is a major cause of failure of hemodialysis vascular grafts and is primarily caused by neointimal hyperplasia (NH) at the anastomoses. The objective of this article is to provide a scientific review of the biology underlying this disorder and a critical review of the state-of-the-art investigational preventive strategies in order to stimulate further research in this exciting area. The histology of the NH shows myofibroblasts (that are probably derived from adventitial fibroblasts), extracellular matrices, pro-inflammatory cells including foreign-body giant cells, a variety of growth factors and cytokines, and neovasculature. The contributing factors of the pathogenesis of NH include surgical trauma, bioincompatibility of the synthetic graft, and the various mechanical stresses that result from luminal hypertension and compliance mismatch between the vessel wall and graft. These mechanical stimuli are focal in nature and may have a significant influence on the preferential localization of the NH. Novel mechanical graft designs and local drug delivery strategies show promise in animal models in preventing graft NH development. Successful prevention of graft stenosis would provide a superior alternative to the native fistula as hemodialysis vascular access.