I just returned from the ANNA meeting and a hot topic was vacular access. Cannulation remains an art not a science. Anyone using the buttonhole technique for AV fistula or graft? Needle bevel down for PTFE cannulation? Flip vs no flip and if a flip when (after into the graft before the needle advancement or after the needle is fully advanced?) Lots of questions with few science based answers. Any comments?

Just curious, when is a bevel down needle insertion appropriate?

Well some units are using bevel down because they feel it will not "core the graft", but no studies had been done to look at bevel down- we need a good study done in amimals with needle cannulations of bevel up, bevel down, no flip, if flip when. Get a sample of PTFE and cannulate it with the needle bevel up and down- see what you think. The best cannuation techinique will create the least amount of damage to the PTFE and promote long term salavge of the cannulation surfaces. Medisystems has a video on cannulation that describes bevel down- to get a copy call 1-800-887-MEDI. (tape 1 is on cannulation and 2 is no fistula issues)References to the unit using bevel down are at the end of the video. Tapes are free and helpful for staff education.


[Note: This message has been edited by Deborah Brouwer]

I am going to show my newness to the HD process. But hey I tell my pts. there are no stupid questions. So here goes. I keep hearing about the buttonhole technique. What exactly is this. In my mind I picture a buttonhole with the thread gong back and forth.

That's a great question!!! A ture buttonhole technique means you cannulate the access in the exact same needle entry area each cannultion. Dr.Twardowski from DCI Columbia MO has used this techinque on fistula pts and this same techinque is used in Europe. At the ANNA meeting a unit stated they are using the technique for PTFE as well. To creat a buttonehole you must cannulate the needle into the same skin and sub Q tissue each time. Most fistula pts have several art/ven needle buttonholes and rotate the use each treatment between the buttonholes. But the needle must be cannulated into the same area. It forms like a peirced ear hole, but the tissue is not cored out from the area- it does close and a scab is formed between use. The technique is currently being used on a vascular access device in clinical trials- a under the skin valve that is cannulated with a fistula needle. The skin tolerates the buttonhole well. See the VascA info on this web site or the LifeSite web site for more info.

When is flipping a needle indicated (or not indicated) ?

From the verbal information I have received, manufacturers of needles and graft materials, as well as our Vascular Surgeons, do NOT reccommend bevel down insertion of or the flipping of needles under any circumstances; it may actually shorten the life of the graft or AVF. Basic phlebotomy advocates the use of sharps, bevel up, when accessing vessels; this prevents jagged, gaping puncture wounds. What is the rationale for this practice?

As for the button hole technique, sounds interesting...any complications with post bleeding d/t scar tissue?

Intresting tecn. My next question in the buttonhole method is there a problem with using lidocaine for ant. use. This seems to cause more scar tissue formation.

The buttonhole will not need lido- the area gets numb from the repeat cannulations and is painless.

The needle flip with cannulation should be done only after the needle bevel is fully into the PTFE (pop and blood flashback) and then flip- the reason is to prevent a backwall infiltration- this can be used for training new staff that tend to get the needle into the graft and not level out the needle -but push the needle into the backwall of the graft. And can be used on a deep graft that is hard to palpate to help prevent a backwall infiltration. This should not be used in AV fistula cannulation- needles with backeyes should be used. The flip in a fistula was for poor bloodflow when the needle without a backeye was sucked up against tne vessel wall. Arterial and venous needles with backeyes should be used to prevent the need for flipping (even if in error the wrong neelde is used from a set). The flip once the needle is advanced should not be needed. The flip itself should not cause any damage to the PTFE as long as the full needle bevel is into the PTFE and the flip is done before the needle is advanced. The flip will not be needed once staff master cannulation and get the feel for the correct angle and needle advancement. No studies had been done to show damage to the assess by any of the cannulation techniques- at this point it is all option based. Good refernces is the WL Gore staff cannulation booklet that has pictures of the proper flip technique. Impra PTFE can be sliced and create a zipper effect where the PTFE can tear- thus the Impra info states not to flip- if the neeldle is flipped with the bevel still in the PTFE it could tear and zipper open a large slice. Get a sample of both Gore and Impra PTFE and try the cannulation techniques for yourself.

For more info on the buttonhole technique- go to the web site for AAKP at www.aakp.org under the listing for educational info- see brochures- then under the vascualr access area is a listing for the Buttonhole. This is a re-print of Dr. Twardowski's article on the technique. This is a good site for Patient Ed info as well. his contact information is also on the article if you want to get more info.

Cool, thanks for all of the info!

I have just read all the information you have given on cannulation. My job is to teach new staff dialysis and I find cannulation is one of the hardest parts as a lot of it is feel and experience. I am interested in the videos you mentioned from Medisystems and the WL Gore staff cannulation booklet. I am in the UK, how would I go about getting hold of these or do you know of similar here.

For Medisystems videos call Denver office in the US at 1-800-369-6334 ask for Maria Paradise and she will mail out the videos to you. Will forward the Gore info as soon as I get it.

I have seen pictures of explanted grafts that had their back walls torn up from flipping needles. The first time I saw that was the last time I flipped a needle.

There are needles with rotating hubs available for those of you that absolutely feel the need to re-orient the bevel.

Personally I have found using good cannulation technique, a needle with a back eye, and the appropriate gauge needle for the desired blood flow has made flipping needles unnecessary.