This case brings up several teaching points, and there aren’t many things more frustrating than the apparently well placed catheter that just does not flow well…

Regarding this case, there does not appear to be any significant central venous stenosis post your initial sheath disruption in figure 1. I suspect this is all fibrin sheath, but it’s hard to be certain just based on these images. There was clearly a recurrent sheath in figure 3.

We usually encounter catheter-associated central venous stenosis in patients with a more prolonged period of time with catheter dependence (greater than 1-2 years), but this can be variable. This is more frequent with left-sided catheters.

Usually any central “narrowing” seen in a patient with relatively short-term catheter dependence is a fibrin sheath. Sometimes, the only way to tell is to see how easily the lesion opens – where a fibrin sheath usually opens easily, while a central venous lesion requires greater pressure to angioplasty open.

Our technique to break open a fibrin sheath involves advancing a balloon (usually an 8x4) to the deep right atrium, then inflating the balloon and dragging it back to the venotomy site while still inflated. This is usually adequate to break open a sheath.

If there is a site of resistance when dragging this balloon back, then that is often a true stenosis (which we then treat with conventional angioplasty). Usually this is going to be a stubborn lesion, which will need to be addressed if the catheter is removed and an AV access is created.

Placement of catheter tips can be challenging. These tips constantly move with patient movements, and even move when blood is flowing through them. We always place them deep in the right atrium - but at times the true anatomy of a 3-D right atrium is challenging to appreciate on a 2-D fluoroscopy image.

The key is to have a variety of tip configurations and sizes available, to attempt to tailor the right catheter for the right patient. Here’s a nice overview:

http://evtoday.com/pdfs/et0615_F3_Ross.pdf

What’s missing in this review is the Centros catheter (now owned by Merit):

https://www.merit.com/peripheral-intervention/access/renal-therapies-accessories/centros-centrosflo-hemodialysis-catheters/

I suspect many instances of catheter dysfunction at the right atrium are due to the tips hitting the vessel walls, and the Centros design seems to minimize this issue. I’ll usually place these at the right atrium as well.

When I have poor Centros flow at the right atrium, I’ll actually place a shorter one at the SVC/ right atrium junction (which is actually a preferred position in the IFU). Paradoxically; for certain patients, a more proximal tip position provides superior long-term blood flow.

When nothing else works, at times I’ve placed a longer split tip or step-tip catheter through the SVC and down to the IVC.

I’ve seen very aggressive sheaths, as you have encountered here. I usually try a larger balloon to disrupt the recurrent sheath (9-10mm), and try a different catheter tip. Usually this works, despite aggressive sheath formation.

There’s no good data on coated catheters, and the cost is significantly higher. I also don’t like any pharmacological treatments here, with poor data and risks of anticoagulation.

Thanks for your excellent comments. In fact, expecting a thick sheath due to a long indwelling catheter for 2 years, I used a 10x40mm balloon each time. Also, I have identical technique. Centros may be an interesting choice. Our publication on Centros was just published in Hemodialysis International.

We expected that the patient will return and had planned a new entry site in case of a quick return. Le tus see what happens with this left IJ catheter. We used Palindromes for all these exchanges, but placed a Cannon (retrograde) catheter for the new placement. Thanks

This is an interesting case. I agree that the catheter is the problem. One issue in looking at the first images, there appears to be a stenosis in the right innominate vein. Dr. Beathard has always said that we under-size central veins too much. I always use, at least, a 10mm angioplasty catheter to perform a fibrin sheath ablation. Sometimes, I have found that a 12mm balloon is needed. I also angioplasty along the course of the sheath as well as pulling the balloon cephalad from a position in the right atrium. This makes sense in reviewing Loay Salman's data that showed that the fibrin sheath is not completely free-floating in the central veins, but that it is actually intermittently tethered to the central veins along its course. I also agree that the fibrin sheath re-formed. I had a patient form a sheath over the weekend. All patients are different. Additionally, antiplatelet agents are not useful. In this patient, I would have considered an IVC placement. I think some of these patients likely have abnormalities or thrombus in the right atrium that cause problems even with proper placement of the catheter. I have used the Centros catheter with variable success. If the catheter dysfunction was due to an abnormality in the right atrium, then this catheter might fix the issue. I have had fibrin sheaths form around the Centros catheters as well. It made a nice outline of the catheter and the curved tips.
Therefore, Dr. Webb's comments are apropros. Still, with no perfect world, it is hard to effect change. One of my partners loved sending me patients with a GFR less than 10 ml/min/1.73 m2 and needing impending dialysis within weeks. Most of these patients had microscopic fistulae that had been created by less than adept surgeons. Imagine trying to control the contrast dose while getting a uremic patient ready for dialysis within a few weeks! Arrgh!
So, lastly, in concerns with Dr. Webb's comments, ASDIN should move forward with SIR, VASA, and the Advisory Council for Vascular Surgery to form a rating and evaluation system for dialysis access surgeons. The problem is, vascular surgeons will send out data showing how many fistulae he or she created. What we need is: how many accesses are created per month?How many function at 30, 60, 90 days? How many need intervention due to delayed maturation (not necessarily an issue with the surgeon)? How many need to be revised? How many are still being used at 12 and 24 months? Similar data should be studied for grafts. Also, similar data should be ascertained about nephrologists: incident dialysis patients with an access; Time period from catheter (if any) to a permanent access. Also, confounding issues should be part of the evaluation: patient compliance, etc.
Dr. Webb's best advice: get rid of the amateurs. With good data, our patients can go to the best surgeons. We need to get rid of the "good ol' boy referral system". My referral system is as such: "where would I send my mother?"

Thanks for posting an interesting case.
Other question that this case brings up is, whether it is worth fighting a tough fibrin sheath in the area not involving the catheter tip (arterial or venous opening).
From the images, I don't see a significant residual fibrin sheath in right atrium. Does this mean that recurrence of fibrin sheath is more likely if you leave any residual fibrin sheath higher up? Has this been reported in any of the studies? If not then Centros or other means of solving this catheter issue may be more relevant than breaking that fibrin sheath higher up.

I would add that - in my experience - catheters that don't provide adequate flow at the time of insertion (ability to aspirate 30mL/5 seconds) never work well for dialysis and lead to the patient's rapid return for (another) catheter. So I never send a patient out w/o having adequate flow . . .

"How do we get rid of the amateurs?" was Dr. Ross's question, not mine, but I agree with him. He actually put together a rating system taking into account all the factors you mention some years ago - I have a copy in my "files" somewhere, but I am sure he would be able to dust it off for consideration.

if a recurrent/persistent fibrin sheath is thought of to be the problem, can starting all over and inserting a new catheter help rather than trying to replace the catheter(and thereby try avoid the catheter getting in to the fibrin sleeve)?
-pardon my ignorance

Hi Anil - (in my opinion)

Q1. What does the figure 1 show- left over sheath vs. brachiocephalic stenosis?
- Anil, Figure 1 shows a sheath, evidenced by the balloon shape. This is a classic appearance. The formation of the sheath starts from the cuff of the catheter and takes several weeks to extend down the entire length of the catheter. The biology, characteristics, who gets FS and who doesn't, why some cuffs have more FS and other have less, etc. has never been articulated. We have done (for academic reasons) contrast CT scans of the BC vein and found extensive synechiae extending from the sheath to the vessel walls. In angioplastying the sheath, we are NEVER getting rid of the origins of the sheath....


Q2. Does anyone have a different technique to ensure that the sheath is completely disrupted?

- Agree with using a large balloon 12 mm usually and running it up and down a securely positioned wire in the IVC. Given that the new catheter is inserted through the same access site, the proximal end of the sheath is still intact in the SQ tunnel and accounts for a 100% recurrence rate.

Q3. In either case, the tip of the catheter was in lower right atrium. Why was there resistance to suction?

- a "catch" was the sheath forming a valve on the catheter port that you were aspirating from. the harder you aspirate, the tighter the valve gets

The patient returned 4 days later as the catheter was again found to be 'positional' in dialysis. Repeat cathetergram (figure 3) showed a well formed sheath again (in 4 days!). This was angioplastied and catheter was replaced, but the 'catch' was again evident. The patient was convinced to get an AVG placed the next week and was sent to dialysis where it was able to be done, with only occasional alarm.

Q4. What else can be done to diagnose the issue?

- The sheath was probably ruptured, but not disrupted entirely and that is why it came back together so quickly (my guess)

Q5. Is the time to reformation of sheath proportional to the dwelling time of catheter?

- Sheath formation in the first instance takes weeks to develop as the reaction starts from the cuff and extends. When the 2nd, 3rds and other instances occur, half the sheath is already there, so the time to extend down the length of the catheter is shorter

Q6. Would use of antiplatelet of anticoagulant help reduce growth of sheath at all?
- Anecdotal and without evidence....as above.


Sumit Kumar, MD
Texas Kidney Institute

Dr Kumar
Thanks for answering the above questions. Do you think that creating a new tunnel (instead of exchanging the catheter through the same tunnel) would help? As this would entirely disrupt the sheath.

Thanks for everyone's excellent comments. The left IJ catheter that I placed did not work for very long either. He underwent an Accuseal graft placement, to be used tomorrow!
Let me take the liberty of commenting on some of the posts. Feeling like an amateur keeps you on your toes and keeps your thinking cap on. With over a thousand catheter procedures, I still have that feeling during every procedure. I feel that my role is to do the best for the patient, not limited to the procedure itself. With all imaging and moving the tip around, I could not get rid of that 'catch'. I did think of a new stick, new site etc. I also thought of a larger balloon. But, I believed no matter what I would have done, catheter would have dysfunctioned- may be with a few days longer patency, with risk of some additional trauma. I do not send people out with dysfunctional catheters but I needed only a small window to make an alternative plan. My concern was lack of an AV accesss in someone with decent life expectancy. I took the opportunity to do a heart to heart talk and convinced him for an AVG.

Other than all the relevant discussion, my take home message is to make every catheter an opportunity for AV access. It is not what you can do, but what you should do. Also, as mentioned by many, there is a need to study the fibrin sheath in a meaningful way.
Thanks all for your valuable comments.

I may have missed some of the thread on this one but this is the type of case I may try parking the tip in the IVC even if the venotomy is the IJ. This is the subject of a paper which I have just submitted to the JVA where I have 13 cases over 5 years and I did one more last week and works well when all other options have failed. I apologize if this was discussed earlier.

Hi, Anil. FWIW, we've all been there. I want to point out that "your job is not done." While there is no compelling long-term lare poulation study to cite, I'd suspect this patient is a set up for a central venous stenosis due to the catheter exposure, fibrin sheath issues, and the quite necessary interventions he's had. Other than watching for edema and flow issues and elevated venous pressures, would you consider a venogram from the graft in the near term to assess the central venous drainage on that side? I don't know of any guidelines on this but would certainly consider it.

Jeff Packer

I have placed Cath tips in IVC as well. Thanks Ramesh.
Agree with Jeff, I am concerned as well. Will follow closely!

I can't sleep - so I roam the net ...
(1) I am glad the patient got an early cannulation graft - we should do more as soon as the patient is stabilized, say after they lose the 20-30 pounds of water that new dialysis patients shed the first month - the graft can be used right away, and the catheter removed in short order. In my experience, early thrombosis of the graft is around 5%.
(2) It is remarkable how patients seen acutely in the hospital truly seem to have no fistula options by bedside ultrasound exam, but in the office weeks later all of a sudden have developed veins - so I caution against jumping to a graft in the first month just to "get something in" - better to get it right.
(3) In the same fashion, patients without a usable vein in the office can be very different in the OR - laying flat, relaxed, and vasodilated by anesthesia, I sometimes change from a planned graft to a fistula - maybe 5%, but often enough that I discuss the chance with patients in pre-op. ALWAYS re-do the ultrasound in the OR.
(4) I used to "just check" on things, but am now more defensive about indications for procedures. Some findings are subtle - one of my patients has no arm swelling, but develops a supraclavicular "cushion" from collaterals when her subclavian starts to stenose again; another blooms visible ipsilateral chest wall veins without any other finding.

Dear all,
Coming back from the CIDA meeting in AUSTIN.
I was very surprised by the results of the survey of our patients in my city in north of France for a presentation: we have 11 % of catheters and only one PTFE graft. The others have fistulas and most of them at the forearm (83% of fistulas).
Like Marc said, it is mandatory to find out the good veins, even small, to create distal fistulas. This is possible with nephrologists thinking in the same way, protecting the veins of both upper limbs as soon as possible.
I do fistulas for children, and we have something like a "no limit politic" for the size of the vein with the use of microscop. This last years, all the fistulas made for children were radio-cephalic.
We must retrieve the catheters quickly.
In some cases, I also create snuffbox fistulas as a first step towards another better forearm fistula, and in dedicated cases, I dilate simultaneously the feeding artery to improve immediately the flow.
And I do not forget the transposition of the brachial vein and the femoral vein.
Regards.
Thierry POURCHEZ