Fistula Questions

[aintnorock]

I just had a fistula put in my arm and I'm very confused about a couple things.  I've asked my doctors and nurses, but have yet to get a definitive answer.

I know that a fistula is a connection between a vein and an artery.  Are there any picutres, diagrams, or such on the web that I can see how they're connected?  The few pictures I've looked at are not definitive.

When they put needles in, are they actually going into the artery?  What prevents you from bleeding out?  Doesn't the artery ever get worn out from all those needle sticks?

Can anyone explain why a fistula, using a small bore needle, can process blood quicker than through a 1/4 inch catheter?  It just doesn't make sense to me from a fluid dynamics point of view.

Thanks,

Carl

[monrein]

A fistula, by connecting an artery into a vein effectively turns that vein into an artery...arterial blood which is oxygenated (bright red) is being pumped directly from the heart so the flow is much faster than venous blood which is a more passive flow and the vein would eventually collapse from the needles, just like a junkie's veins do over time.

The needles are going into a vein (veins are closer to the surface although in the upper arm they are sometimes deeper than we'd like) but the vein has been turned into an artery by diverting arterial blood into it.

Yes, the vein can get worn out from putting the needle in the same spot over and over and aneurysms can develop.  That's why it's so vital to do a very consistent laddering technique OR develop buttonholes and use blunts.

The reason you can process more blood with a fistula and needles is that the blood coming out of a catheter and going back in, is very close together so you end up with some degree of  re-circulation, essentially cleaning the same blood over and over.  The arterial needle should take blood from below the venous return so it should always be fresh blood (that is different from the blood being returned to the body) that is being pulled out and going into the machine.

http://www.nature.com/ncpneph/journal/v2/n9/fig_tab/ncpneph0239_F1.html


There is a lot of info on the net but here is one diagram.  I hope this helps to answer some of your questions. 

[Rerun]

http://www.davita.com/dialysis/treatment/a/1301

They connect the artery blood which is more forceful to a vein so that the rush of blood into the vein will expand or dialate the vein so it is large enough for the needles to slip in easily and the volume of blood will be there for dialysis.  The vein will heal enough each time that it may be stuck many times.  There is also a "Button Hole" method where the needle is inserted in the same hole and you use it again and again.  I don't use the Button hole method although I would like to.

The catheter "they say" is more susceptible to infection and it is a hassle taking a shower with one.  Although a pain in the ARM... if you have a good one... a fistula is the best way to go.

[paul.karen]

Good answers ladies.

Is there any proof that a fistula is better then a Cath?

I have read people feel better(not all) and have much less food / water restrictions when using a cath.

Also is it a good idea if your gonna get a Cath to also get a fistula in case the Cath gets infected or breaks down for whatever reason.

[Zach]

Is there any proof that a fistula is better then a Cath?

Yes there are studies that show fistulas are better. Catheters come with higher infection rates.

I have read people ... have much less food / water restrictions when using a cath.

Not true at all.

[monrein]

Good answers ladies.

Is there any proof that a fistula is better then a Cath?

I have read people feel better(not all) and have much less food / water restrictions when using a cath.

Also is it a good idea if your gonna get a Cath to also get a fistula in case the Cath gets infected or breaks down for whatever reason.

Fistula is absolutely the way to go (I assume you're not talking about a peritoneal catheter here Paul) and is considered the gold standard for hemo access, for the reasons Zach stated.  Some people might feel better with their cath because there is no associated needle pain or uncertainty about getting a good site but the cath goes directly into the heart (there are some that don't but those are even more temporary) and that can cause tremendous trouble if things go wrong.

Less fluid restrictions only come into play if a person is still passing a fair bit of urine but that eventually dries up so in the beginning, a patient might think (incorrectly) that they could have more fluids with the cath but the same would have been true with a fistula at first.

I believe, and so do all the medical people I have ever spoken with, that the fistula is always preferable to a catheter. 

[petey]

My Marvin has had it all -- 14 perm caths, 4 grafts, 2 AV fistulas, and 2 Tenckhoff caths (for PD) -- along with a temp cath in the groin.  Marvin says he feels that he gets a much, much "cleaner run" with his fistula.

[paul.karen]

Monrein i actually did mean a peritoneal cath.
I am still getting use to all the terminology. Sorry :-(

would this make a difference in your opinion?
And does everyones urine output stop completely after starting dialysis?

[2_DallasCowboys]

No  going on dialysis does not mean
you automatically stop peeing

My husband can still urinate, and has been
on D for almost 3 yrs

Some folks, tho do lose the ability to urinate

I guess it depends on the individual

Anne

[Wallyz]

Hi Carl!  Carl(aintnorock) is  a friend of mine from another site.

[monrein]

Going on D does not mean that everyone automatically stops peeing.  However, output will decrease over time and I have never met a D patient who pees as much as with functioning kidneys or even as much as when first starting D.  I'm not sure they don't exist but I've never met one who does.  I still urinate too but certainly not as much as when I first started.  Last time I did D for 5 years and my output decreased even more gradually but decrease it did.  The time it takes to lose output does definitely depend on the individual.

Paul, you don't have to be sorry for confusing the terminology but it is important to sort out the differences in order to understand the choices and decide what is right for you.

Some people prefer peritoneal dialysis, some prefer hemodialysis.  Some do peritoneal and have to switch over because of infections or other reasons but that does not mean that one type of dialysis is in all cases better than the other.  I have never tried peritoneal because I don't want a catheter in my belly or anywhere but that's my personal preference.  Others prefer the peritoneal (which requires a peritoneal cath, there is no other way to do it) because they're freaked out by needles.  To be perfectly honest, I was 26 when I first started D and felt that a peritoneal catheter would be a bother in my sex life.  Purely personal and sex lives are still entirely possible with peritoneal catheters.  I didn't want one and I still don't because hemo works well for me.  Other people are totally repulsed by the idea and sight of a fistula, I'm not at all, and want peritoneal for that reason alone.  That's valid also.  Unfortunately none of the options are perfect.  Both types of D have advantages and disadvantages and sometimes the choices get even narrower if there are persistent infections with peritoneal or terrible vascular problems with hemo.

If you choose peritoneal you will have a catheter and you must be very careful with your sterile techniques to avoid peritonitis.  Some people do this successfully for years and would have it no other way.  There are usually less dietary restrictions with peritoneal because the process is more continuous than three hemo sessions per week.  However, with more frequent hemo, like short daily or nocturnal 6 nights a week then restrictions are also less severe.

If you choose hemodialysis, then a fistula is the way to go if at all possible.  It is the safest way to avoid infections (as opposed to hemo catheters that go into a vein and some right into the heart) get enont oneugh blood flow for adequate clearances of toxins.  The catheters discussed for hemodialysis are generally considered temporary measures although we have one member here who would (and has) disagree(d) vigourously with this.  He had a hemo catheter for eight years and swears they are fantastic but all the medical people I've talked to and everything I've read are not on board with that thinking.

Hope this helps rather than creates more confusion.

[Wallyz]

As to the dynamics of pump speed,the issue is the size of the catheter, and the length of the tube inside the aorta.   The length and smaller size restrict the blood flow.  The needle is smaller than the external cannula, but larger than the internal part.

[paul.karen]

Monrein thank you.
That for sure helped not confused me.

As did wallyz's Photo.  

Do most all Fistulas end up bulging up like i have seen in some videos on youtube?

[Wallyz]

It depends on your veins reation to the pressure. Mine is smallish, but some are big and ugly.  You don't know until it matures.

[monrein]

I would also add that how the fistula is needled has much to do with the development of bumpy bulges.  I did a very very consistent ladder technique on my first (forearm) fistula and the vein got to be about the size of my little finger and about 6 inches long.  However, it was very even, no bulges at all.  Now, it's clotted off and is just a totally flat, long scar.  It's important not to just go for the easiest spots because aneurysms will then develop in those spots.  My current fistula is in my upper arm and I do buttonholes so it's different but still no bulges. This is why I strongly advocate that we try to do our own sticking because then we have more control and the consistency is built in. I can feel two little hard bumps under the skin where the buttonholes are and those are the tunnels that I go into each and every time with a blunt needle. 
It's not a perfect world so sometimes we just have to make do and the fistula can become awful but in general, if we have the info we need right from the beginning we can avoid some troubles.

[paul.karen]

Ok one more lesson please.
Blunt needle as in not sharp?
Wouldn't a sharp go into the buttonhole easier?
or do you use blunts as to not penetrate outside the buttonhole?

And if i go with the PD do you think i should get a fistula just as well incase of infection.
To avoid a hemo cath.  Im catching on

[monrein]

Yes, the blunt is not sharp, (very pointed but not slicing, cutting sharp) the idea being that you wiggle through the tunnel, sort of like a pierced earring hole, then punch into the vein itself.  Because you're going into the same spot, there's less trauma to the vein and you're not cutting through flesh like you are with a sharp.  Sometimes you have to use a sharp but I never have since establishing my buttonholes.  The sharps over and over will puncture a slightly different spot each time causing eventual weakness to the area and possibly bulges.

I'm not sure how to answer the should you get a fiatula as well as peritoneal cath question.  Some recommend it, others take a more wait and see attitude.  Hopefully other PD people will weigh in on this for you Paul.  Like Peleroja, or rookiegirl or Ken Shelmerdine.  I personally THINK I'd do both but I've never actually had to make that particular decision.

[Wallyz]

The thing about PD is that everybody on PD wil have to go on Hemo for a while.  Do you want surgery now, and avoid a neck catheter, or wait until you have  a severe peretoneal infection and are under dialyzed to have surgery on your neck and arm?

[paul.karen]

Yeah i say now is the time.

thx for the help and answers guys

[Wattle]

Hi paul,

I am on PD and do not have a fistula. I initially chose PD for many reasons, none of which was to avoid a fistula as such. I was told PD maintains your residual kidney function a little longer than Haemo, and the fluid and diet restrictions are a lot easier.

It was an easy choice for me. My Dad had been on dialysis when I was young and I had seen it all. He had a lot of access problems and I am trying to avoid the mistakes made with him. I was 37 when I started dialysis and knew it was going to be a long sew-saw ride the rest of my life.

If I have a fistula now, it may well clot over before I use it, and then there is one access point down the drain. While PD is working for me I will save my veins until I need them. I am hoping to make it to a transplant before I need a fistula. That way when the transplant fails (as I know it will eventually) I have a clear slate for access. I do keep asking my Neph if I should get one now. His answer is lets get you transplanted first.  After almost 4 years of PD I know I am skating on thin ice. I have never (touch wood) had any infections.

Ask your Neph all the questions you can think of and make the decision that YOU think is right for YOU.   

[jessup]

I have found this thread most informative too
Hope you don't mind if I jump on and ask another question

My Dad's fistula is in his wrist
He is worried about the visual lumps developing in his forearm - he has seen quite a few other patients who have "unsightly" (his words - bloody big lumpy veins that look big and weird)
I have assured him about the ladder technique and how it will make his fistula strong
So on Friday he asked the nurse to stick him in his upper arm (about 4-5 cm above his elbow)
My sister was with him and she said that they used a smaller gauge needle
Well I looked at his arm today (Saturday) and it is bruised to buggary

I don't get it - isn't needling him 15-20 cm away from normal needling area make a difference 
Will moving the needling are that far from the fistula stop the lumpy visual veins (that's what Dad thinks)
It is so much easier to "see" the vein to needle in his lower area (from the elbow down to his wrist - 6 -10 cm) than above his elbow
Because of massive weight loss Dad has a lot of flabby skin above his elbow
Anyway hope you mob can help me

[monrein]

I'm surprised that they can needle him that far away from the fistula but only because my vein went too deep that far up when the fistula was at the wrist.  However, don't confuse the bruising with the unsightly lumps.
The bruising is often fairly bad at the beginning because the vein isn't tough yet so it infiltrates easily and can look quite angry.  This should settle down in time.  The thing about the laddering is IMO not to jump about all over the place on the arm but to systematically move the sites up the vein from lowest to highest point and once you've reached the highest accessible spot begin again at the bottom and start laddering up again.  The entire vein will bulge of course but hopefully he can avoid the big bumpy bulges which tend to happen when the easiest spots are stuck repeatedly.  The bruising is just the arm saying "Hey, what the hell d'ya think you're doing to me?  I'm an arm, flesh and blood not a bloody pincushion". 

[paddbear0000]

Ok, now I have a question. Or rather, two. Where do they needle if you have a graft--int graft itself or in the vein it's attached to? And does the graft allow your vein to get bigger?

[kitkatz]

They needle the graft itself. The body will accept the graft material and treat it like a normal vein, except if it gets big, go see the doctor immediately! Aneurysms are no laughing matter on a graft.

[breezysummerday]

This link might help answer a lot of questions.

http://kidney.niddk.nih.gov/kudiseases/pubs/choosingtreatment/index.htm