This is a fascinating post – and thank-you for the question. It has revived old memories and stimulated forward thought - all in one post.
I suppose I should preface by saying that research into and advances in arterio-venous fistula alternatives isn’t my area – far from it – as I guess I would class myself as a fistula user, rather than a fistula creator.
But, back in the 70’s, and 80’s, the use of bovine (cow-derived) graft vessels for AVF use was a really ‘hot-to-trot’ topic.
Indeed – and this is fair dinkum (OZ for ‘utterly true’) – I have exactly that - a bovine graft, about 1 foot long, nicely curved, fuzzy at its edges - sitting in 1L of saline in a sterile plastic pack, on my bookshelf, in my office, behind my office desk … if this site took photos, I’d addend it … salvaged from a research project here in the 80’s! True! I have! I was given it as a present - odd presents I get, eh? - back in the mid 80’s when I was a young and, then, inquiring nephrologist.
I have often wondered if it could still be used … don’t worry, any Geelong patients who may read this, I won’t trial it on you! But, seriously, it was a technology ‘going places’… back then!
What’s happened since?
Well, primarily, we have developed (potentially) better stem cell biology such that with the combination of stem cell advances and angiology (the science of growing new blood vessels … or, ‘angiogenesis’) the growth of human stem cell-derived vascular beds, probably shows greater promise.
There is stuff happening here!
Good stuff.
Stuff that has at least the potential to take a patient’s cells – endothelial cells (the cells that line the internal walls of blood vessels) and attach and grow them - living cells - on an inert substrate (a backing structure) to form an artificial blood vessel … not one of a cow (bovine) but of a (1) human and (2) more importantly, the very human requiring the new blood vessel : you!
Just as we can bone marrow, or renal, or pancreas, or heart, or lung transplant … medical science is close to specific ‘cell’ transplanting to grow ‘bits’ to measure, including vessels.
OK … step back a moment. Close?
Close is always a matter of degree. What is ‘close’ to a researcher needs to be ‘now’ for the recipient of the research … and ‘close’ is never ‘now’.
So don’t go off thinking this is next year … far from it. But, coming? – in your time or the next? – yes.
As for using brother/sister donor vessels? That’s not so easy as it seems.
Blood vessels actually bear the brunt of any immunological attack and the laws of transplantation and rejection would still hold … yes … even for something seemingly as small and ‘insignificant’ as a section of vein. So using donor vessels for arterio-venous fistulae just ‘ain’t the answer’ … sorry … but, as they say, them’s the breaks!
The greatest home lies in angiogenesis and autologous (from the same person) vessel engineering through stem cell or other tissue growth methods where the patient’s own cells are used to make the vessel that forms the fistula.
Back to your bovine proposition … cow vessels seemed to die a slow, silent death. Why? Well, they never worked well, stem cell research and research into the ‘promoters’ of angiogenesis took off … and suddenly awesome, fuzzy cow vessels, like the one on the shelf in my office , looked unappealing. As I take it down and gaze at it as I type to you, I am also and again made to ponder … ‘why’.