Ultrasound Improves Fistula Patency

By Peter Laird, MD

Fistula First, the initiative to improve placement of arteriovenous fistulas for dialysis access reached 57.1% in October of 2010, yet this still falls short of nations such as Japan with over 90% of patients utilizing fistulas for dialysis access.  A recent randomized study on the use of preoperative vascular ultrasound may improve the success rate of fistula placement:

Routine Preoperative Vascular Ultrasound Improves Patency and Use of Arteriovenous Fistulas for Hemodialysis: A Randomized Trial

Results: AVFs were made in 208 of 218 randomized patients. Clinical and ultrasound groups were similar in terms of patient characteristics, allocation to individual surgeons, and proportion of forearm AVFs. The ultrasound group had a significantly lower rate of immediate failure (4% versus 11%, P = 0.028) and, among failed AVFs, less thrombosis (38% versus 67%, P = 0.029). Primary AVF survival at 1 year was not statistically different (ultrasound = 65%, clinical = 56%,P = 0.081). Assisted primary AVF survival at 1 year was significantly better for the ultrasound group (80% versus 65%, P = 0.012). The number of patients requiring preoperative ultrasound to prevent one AVF failure was 12.

Conclusions: Routine preoperative vascular ultrasound in addition to clinical assessment improves AVF outcomes in terms of patency and use for dialysis. National Research Register, United Kingdom, trial number N0046131432.

Previous studies also show that the number of fistulas placed in training by vascular surgeons corresponds to better rates of success as well.  For those that perfom less than 25 fistula procedures in training, they have poor rates of patency.

Enhanced Training in Vascular Access Creation Predicts Arteriovenous Fistula Placement and Patency in Hemodialysis Patients: Results From the Dialysis Outcomes and Practice Patterns Study. 

Significant predictors of fistula versus graft placement in hemodialysis patients included number of fistulae placed during training (adjusted odds ratio [AOR] = 2.2 for fistula placement, per 2 times greater number of fistulae placed during training, P < 0.0001) and degree of emphasis on vascular access creation during training (AOR = 2.4 for fistula placement, for much-to-extreme emphasis vs. no emphasis, P = 0.0008). Risk of primary fistula failure was 34% lower (relative risk = 0.66, P = 0.002) when placed by surgeons who created >/=25 (vs. <25) fistulae during training.

CONCLUSIONS: Surgical training is key to both fistula placement and survival, yet US surgical programs seem to place less emphasis on fistula creation than those in other countries. Enhancing surgical training in fistula creation would help meet targets of the Fistula First Initiative.

Microscopic surgical techniques more widely used in pediatric cases is also a promising adjunct to increased cases in training and vascular ultrasound.  Perhaps the best indicator of success with fistula placement is the size and condition of the veins in the arm.  All patients with CKD who may be at risk of developing the need for renal replacement therapy need to preserve these veins by avoiding blood draws and BP checks.  Using the distal veins in the hands is the preferred site for blood draws.  Exercises to improve circulation in the arms is highly recommend as well.  A concerted effort to improve dialysis access is a proven method of reducing dialysis related complications.  Use of the vascular ultrasound is a step in the right direction.

Comments

[roberta mikles]

As I read the above, I was reminded that maybe once,twice in six years, did any staff actually listen to the fistula sounds with a stethoscope. Can't recall the nephrologist at the unit either, but he might have once, twice When we started dialysis, I thought this was somewhat standard practice, especially if there were difficulties. I do remember going to the access center once and the interventional nephrologist doing an ultrasound, to recall, think that is what was done. He then decided it was not necessary to do an invasive procedure.
Roberta Mikles
www.qualitysafepatientcare.com

[Peter Laird, MD]

Roberta, just one more instance where the professionalism in dialysis units falls short.

[Brian Riddle - Lynchburg, VA]

It amazes me on how many people I have talked to who do not even own a stethescope let alone listen to/feel their fistula. When I ask them, they say that they were never trained/told to do so. When they ask their center for a stethescope, many are told they must purchase their own.
Should this be something that goes home with a patient after fistula surgery or something their clinic follows up with? or both? I remember I was given a stress ball, a stethescope and a packet on how to care for my fistula.

[Peter Laird, MD]

Interesting on the stethoscope idea. The purpose of the stethoscope in this instance is assessing the bruit, the noise made by the fistula from the turbulent arterial flow in the vein. In many people, you can simply feel the bruit if it is vigorous enough.

I personally don't like folks placing a stethoscope on my fistula for infection control issues. Just call me a germaphobe, but the simple fact is that stethoscopes as well as doctors cell phones and pagers are some of the filthiest items in the hospital setting. Few clinicians cleanse their stethoscopes in between patients nor do nurses. Access flow measurements done in-center correspond poorly to predicting stenosis of fistulas until fairly late as well. Home dialysis does not do this measurement with the NxStage. In this setting, arterial and venous pressure changes may indicate access problems which should be discussed with your medical team if you encounter them. That is what I watch for with each dialysis session.

So for me, simply feeling for my bruit and avoiding anything that could injure my fistula is my daily habit. Stethoscopes have their place, but only if they clean them well between every patient.

[MooseMom]

I specifically asked if I should do anything special to get my fistula to mature or to take care of it post surgery. Both my neph and my vascular surgeon told me, and I quote, to "just ignore it." I was never given an exercise ball nor any kind of nifty neato information packet. My neph's nurse listens to my fistula with her stethoscope whenever I have my appts, but since I have not yet used the fistula, I am not concerned about infection (although I had never thought of this before).

Certainly no one has ever suggested that I buy my own stethoscope, but all I have to do is look at my fistula to see it pulsating like crazy.

[roberta mikles]

This is yet, another aspect of patient education that is greatly lacking. I once suggested that providers give to patients a manual of 'everything and anything' related to their dialysis. It would be something that could be used ongoing by the patient, at their leisure, used for reference, etc. The patient's are given a packet at the first treatment with papers to sign etc. Remembering, patients are on overload the beginning of their dialysis journey and often do not take time to read the detailed language on the papers they have signed. A manual would be something they could always refer to.... for educational purposes. The pamphlet/book that we received was greatly lacking a lot of information that would have been beneficial. I have always wondered why the Networks did not so such.

As far as disinfecting stethoscopes, this is why there needs to be adequate supervision in the units to ensure staff are implementing correct practices. Blood pressure cuffs and tv screens are often not disinfected which staff do not realize places patients in harm's way. I just can't imagine staff being aware of correct practices but not implementing same. This, in my opinion, is a deliberate action of the part of staff that places the patient in harm's way.... if staff are aware of correct practices, do not implement such, then is this considered intentional? I ask all of you? Of course, there needs to be training of staff that instills the importance of carrying forth correct practices. I am actually reminded of a specific incident. We reported a staff for not implementing correct practices e..g. gloves in pockets, not washing hands, etc. This staff we were told was then put through extra infection control training. However, after six years, there are still complaints about this staff. So, my point is that either this staff does not care that the actions are placing patients in harm's way,my opinion, or this staff has not been fully educated. Either way, the fact remains that these simple practices are not being implemented.

MooseMom, did they feel your fistula was already matured enough? Hmm.
Although I know patients who have never been given a ball or even instructed.

As far as infection --- our staff used alcohol only... which does not last long... knowing that dialysis patients are susceptible, more than others, we asked if the staff could use alcohol and then betadine. However, we had to tell the staff, and my father often reminded staff to let the betadine dry for three minutes as some staff were applying the betadine and then wiping it off. Patients must be educated and staff must be accepting of such and work with patients to ensure safe care. However, most, in my opinion, are not trained in this aspect of care. Besides, patients should NOT have to tell staff how to do their job e.g. correct practices.
Roberta Mikles BA RN Patient Safety Advocate
www.qualitysafepatientcare.com

[MooseMom]

Roberta, I asked my neph and my surgeon both pre-and post operatively if I needed to exercise my fistula once it was placed and the wound had healed. My mother had spent 5 years on dialysis, so I knew enough to ask. I was specifically told to "ignore it", perhaps because they assumed I had time for it to fully mature before I might actually need it (which has indeed been the case).

I have never received any pre-dialysis information from any source other than the internet. I've read just about every neph blog going and have researched modalities, etc. I suspect that many pre-dialysis patients don't have internet access or the educational background it takes to wade through the vast amounts of information on dialysis and related issues. It's easy to say "be your own best advocate", but I for one was never given a place to start. Perversely, I think my neph has given me excellent pre-dialysis care, but education has most assuredly NOT been part of that process.

I plan to do dialysis at home because it seems to be safer...fewer people around carrying cooties.

[Roberta Mikles]

If you can do home dialysis --- DO IT. There are many advantages to doing home dialysis e.g. overall feeling better, taking less medications, and having more control over your own care. Many patients can not do home dialysis for a variety of reasons. It is my opinion, that home is better for the above reasons, but I also believe, having reviewed facility inspection reports www.qualitysafepatientcare.com (California 2009 and 2010) that it is safer, often at home. You are right about education pre dialysis. When my father was to start dialysis we were given information about modalities, e.g. PD, but he was not a candidate for that. I don't remember anything about other modalities. When we did decide to do home we took it upon ourself to find a home unit and meet with them, however, due to the development of pseudoaneurysms and having to be cannulated daily in two different places versus buttonhole, we could not do home, unfortunately. Also, you are right that there is still a huge population of patients who do not have internet access, therefore, ongoing patient education is even more important... However, as I have been stating for years.. (1) staff must be fully educated and understand the rationale for all practices, (2) unit level supervision must be such that if staff are not implementing correct practices there are consequences, but there must be unit-level appropriate supervision and (3) staff and physician have bought into the thought process that it is ok for patients to question what staff are doing as well to ask questions. And, most important, if a patient is educated and observes an incorrect practice that staff are accepting of such without any level of reprisal.
Roberta Mikles RN
Patient Safety Advocate