The arteriovenous fistula may be the gold standard for dialysis access, but it may not always be the best option for some patients – particularly those who have already had multiple failed accesses.
NN&I interviewed Stephen E. Hohmann, MD, a board certified vascular surgeon with Dallas-based Texas Vascular Associates. His group handles a variety of access surgeries, including carotid endarterectomies, placing vascular stents, thoracic dissections, aortic aneurysms, and other access surgeries. The group is affiliated with Baylor Heart and Vascular in Dallas, TX
His seven-member practice has collectively placed over 100 of the HeRO (Hemodialysis Reliable Outflow) graft in the last six years. We asked Hohmann, who has placed 80 heRO grafts himself, about the access dilemma in dialysis care and about the role of the HeRO in his surgical toolbox.
NN&I: What do you think are the main problems in selecting and delivering a good access?
Stephen Hohmann, MD: It can be difficult to find the right surgeon interested in doing dialysis access surgery. Sometimes they aren’t trained well, and they don’t have a lot of enthusiasm for doing dialysis access. Implanting a catheter in the central venous system is particularly challenging for some surgeons, and that’s what I think got our attention when we heard about the HeRO graft. The HeRO works well in the central venous system when nothing else does. Stents have about a 20% success rate. They just aren’t really effective.
NN&I: Some 80% of dialysis patients start on a temporary catheter. In many cases these are emergent patients, but do you have any thoughts on how to change this scenario?
Hohmann: For me, I think access planning is most important – you need to think ahead of time and plan for the long term when selecting that initial access. Communication between the nephrologist and the surgeon is vital; we can’t have everyone working in silos. If we have a difficult case, its helpful for me to know how much time we have. Can we place a graft instead of a catheter? As a surgeon, I think it is important to be in the clinic, be involved in the vein mapping, and emphasize patient involvement. Educate patients on why we want to do what we want to do.
NN&I:With proper care and feeding, can a dialysis access last 3, 4 years, maybe a lifetime, without replacing? What do you think are the keys to making that occur?
Hohmann: It’s not unreasonable if you have close monitoring of the access and the patient is involved in its care – maintaining an access is a journey, not a destination. You need to be vigilant; know what your venous pressures are. You need good surveillance techniques. Someone needs to pay attention. The goal is not to have a clotted access.
From a surgical perspective, I am committed to placing as many fistulas as possible. But you also want the right candidates. I talk to patients about the choices and what might be the best option. It’s going to be different for the older diabetic patient vs. the 20-year-old patient with lupus.
NN&I: Are there good and not-so-good surgical techniques for placing an access? Do techniques vary by surgeon?
Hohmann:Our surgical practice really tries to look at things a bit differently. Getting the dialogue started is important. That, in fact, is how we found out about the HeRO graft – a patient came in who had a blockage and we were discussing surgical options, and he said, “I want one of these HeRO grafts.” So we did the research, thought he was a good candidate for it, and placed one.
When we place a graft, we try to make it bulletproof. We spend a lot of time talking with the dialysis center staff. We recognize that the staff nurse or patient care technician may not be the best cannulator in the clinic.
One of the things that came out of our communication efforts with staff and patients is that we send a patient home with an information sheet that includes what we did – an angioplasty, placed a graft, etc. If it is an access, we let the patient know when it can be used, when their follow-up visits are, how to take care of the access, our contact information, etc.
NN&I: So who is the best candidate for the HeRO graft?
Hohmann: There are some interesting things about the HeRO graft. It is a graft, but it solves a very unique problem: central venous stenosis. It has a 40 cm outflow component that you can cut to any length you want. So it is like a stent. So if a patient is 7 foot tall or 5 foot tall, you can still use it for either patient. You can also take it out if there is a problem and put a new one in as needed—unlike stents, which are permanent.
And, you can access the HeRO graft in the same day it is placed.
NN&I: Why do they fail?
Hohmann:It may have migrated in some way, could be an infection, or the graft could be very old.
NN&I:Is the HeRO graft a “last resort” option only, or would you still place it if a graft had a good chance of survival?
Hohmann: About a third of our patientsare in fact in that category, but the benefits of the HeRO graft are the lower risk of infection. It makes the patient happier, the staff happier, and the surgeons as well.
NN&I: Tell us about your success rates with these grafts.
Hohmann:In the beginning, we saw some failures with patients who were heavily occluded everywhere, where there was little chance of any access survival. Then we had patients with undiagnosed hypoquagabiity, or who were extremely hypotensive.
NN&I: Cryolife, the manufacturers of the HeRO graft, says placement of these grafts has resulted in 69% fewer infections than typical temporary catheters. How does this graft reduce the infection risk?
Hohmann:The selling point for the HeRO is not to compare it to a fistula; you can compare its success as a access to a graft. What patients like about it is none of it is exposed – it’s all under the skin. That helps reduce the infection risk.
NN&I: Final thoughts: as a surgeon, what are the key decision points for determining the right access for any dialysis patient? How do you best match up an access type with a patient’s vascular roadmap?
Hohmann: I think the goals at the end of the day is to use as few catheters as possible. It’s important to do the venogram ahead of time so you can see what the central venous system looks like. Then pick the best access for the patient the first time out.In many ways, the HeRO graft can start the conversation: “Why are these patients catheter dependent?” I think the more we ask that question, the fewer we will have.