Nephrologists are the Ones Surgically Creating Fistulas.

Nephrologists Take Fistulas Into Their Own Hands

Published: May 9, 2014 | Updated: May 11, 2014
By Kristina Fiore, Staff Writer, MedPage Today

Every year, Rick Mishler creates about 250 fistulas in patients' arms, stitching artery to vein so they can have a chance at successful dialysis.

But Mishler is not a surgeon, nor is he a radiologist. He's a nephrologist -- a specialty that traditionally has had little to do with interventional or surgical procedures.

"We're filling in a gap that others aren't doing with the urgency and the expertise these [procedures] demand," Mishler said over the phone from his practice in Arizona. "We can do a fistula with the same effort that it takes most places to do a catheter."

Mishler is one of a handful of nephrologists around the country who are creating their own fistulas and grafts, driven by a need for better national outcomes for dialysis. Fistulas have a high failure rate -- estimates range from 30% to 60% -- and the idea is that greater volume and expertise could lead to better chances these arteriovenous ports will take.

Mishler has been doing them for 10 years for the Arizona Kidney Disease and Hypertension Center, which has one full surgical center and four vascular access centers. He's accumulated data that's being mined for outcomes, and he estimates his failure rate is below 20%, with a post-procedure hospitalization rate between 0.5% and 1%.

In his retrospective analysis of a prospectively collected vascular access database 84% had patent AVFs at an average follow-up of approximately 9 m0nths.

But will more nephrologists follow that path, which is already pushing the boundaries of the relatively nascent field of interventional nephrology -- a movement that allows kidney doctors to specialize largely in endovascular procedures for dialysis patients?

Creating fistulas and grafts is "difficult work," noted Jim Barone, MD, a retired chair of surgery. Who will pick up the slack if a procedure goes wrong? he asks. "It probably won't be the vascular surgeons who they took the work away from."

Fistula Frenzy

Demand for fistulas has been growing, sparked by the National Kidney Foundation's (NFK) "Fistula First" initiative, which started more than 10 years ago, largely prompted by better outcomes in countries where fistula use was more prevalent. It has since become "Fistula First, Catheter Last" to emphasize that clinicians should do all they can to make infection-prone catheters their last option for dialysis patients.

The push seems to have worked, as the proportion of dialysis patients with fistulas doubled, from about 30% to 60% since the time the initiative was launched, according to Joseph Vassalotti, MD, chief medical officer of the NKF.

The society's push led to changes in reimbursement from Medicare, which now penalizes doctors for allowing patients to maintain catheters for more than 90 days. Bundled payments are reduced after that time, but are increased for patients who get fistulas.

The trouble is, fistulas are hard to get working. They take 2 to 4 months to set, and about 30% to 60% fail. Some have described a graft as a decent alternative, since it takes only 2 to 3 weeks to set and has lower infection rates than catheters.

Once fistulas take, however, their long-term efficacy is unparalleled, experts say. So having interventionalists -- be they surgeons, radiologists, or nephrologists -- who are dedicated to doing them might increase the success rate.

Interventional Nephrology

Creating fistulas and grafts is a step beyond current boundaries of interventional nephrology, which allows nephrologists to do interventional procedures like ultrasound-guided kidney biopsy, angiography to maintain fistulas, or placement of peritoneal catheters.

Several academic centers have created programs in interventional nephrology -- the University of Wisconsin, Emory University, and Harvard among them -- and there are a handful of private clinics that train professionals in these basic interventional procedures for renal patients.

The field even has a trade group, the American Society of Diagnostic and Interventional Nephrology (ASDIN), which has developed a certification program and guidelines for interventional procedures in kidney patients.

Mishler has gone one step further than the interventional nephrology programs to create fistulas and grafts himself.

He trained with a German surgeon, Klaus Konner, MD, whom he described as a good friend and a willing teacher. The surgeon required 100 formal cases under supervision before Mishler could practice on his own.

Now he's in the business of training other nephrologists in the art and science of making fistulas and grafts. Four other doctors currently work with Mishler at the kidney practice; most are nephrologists but one is an orthopedic surgeon from China.

That's the only team member with any prior surgical training, but Mishler doesn't consider himself a "vascular access snob" who would refuse to train specialists other than nephrologists.

"Anyone who is committed to getting these patients what they need -- we're happy to have them," he said.

In fact, the society is comprised of specialists from all disciplines, Alexander Yevzlin, MD, of the University of Wisconsin and president of ASDIN, noted, including interventional radiology, surgery, and nephrology, and doesn't have any position on which type of doctor should be creating fistulas and grafts.

"We take the position that everyone doing [fistula creation] should be a dedicated expert," Yevzlin said. "We're trying to define a set of criteria that will shape that expertise."

Certification in Fistula Creation?

The society is currently trying to create a certification program for fistula and graft creation, but it's in its infancy and it's unclear what shape the program will take.

The inclusiveness across specialties has done much to remedy the turf wars that happened early in the development of ASDIN, according to one of its co-founders, Gerald Beathard, MD, of Lifeline Vascular Access in Austin, Texas. Beathard is also widely regarded as the pioneer of interventional nephrology.

"When we first started out, radiologists and surgeons were opposed to nephrologists doing [vascular procedures]. They wrote papers saying it was a mistake, that patients would be injured," Beathard told MedPage Today. "I think that was very valuable to us as nephrologists because it forced us to live up to a high standard. We realized that we had others looking over our shoulder and that we had to adhere to the highest standards."

Since those early days (ASDIN was founded in 2000), studies have shown that nephrologists do as well as interventionalists, if not better -- with lower complication rates, less radiation, and lower costs, Beathard said. It just took about 5 or 6 years for radiologists and surgeons to accept the practice and jump on board.

"Some of our greatest detractors became our greatest supporters," he said.

Still, some vascular surgeons believe anyone creating fistulas and grafts should have significant clinical training -- such as the 5 to 9 years of training surgeons have before practicing on their own.

"During that time, you're not only learning how to do the procedure, but how to get out of trouble," said Juan Carlos Pereda, MD, a vascular surgeon at South Miami Heart Center. "Surgical skill takes a lot of time to develop."

But surgeons aren't surprised nephrologists are encroaching on surgical or interventional space.

"It's part of the changing landscape of medicine in general," Barone said. "Everyone is looking for something else to do to augment their incomes. I suppose it is appealing to those nephrologists who feel they are being squeezed to branch out and do something else."

Appealing to Nephrologists?

Mishler's work has been well-received in the community. Beathard acknowledged his unique "rigorous training," but cautioned that such training may be a barrier to wider uptake in the future -- especially given that nephrologists are ready to finally get to work after 2-year fellowships.

It may also be unlikely to set up training programs for fistula creation with academic centers, and it will more likely happen at private clinics, Beathard said.

NKF chair Vassalotti agreed that while Mishler's work is valuable and that having specialists dedicated to fistula creation would help, it's "probably not realistic in this country."

He also cautioned that there are not yet extensive data on outcomes for nephrologists dedicated to vascular access creation.

"Conceptually, I would support this kind of movement," Vassalotti said, "but we need to see what kind of data they have."

Still, Mishler's work catches the eye of young nephrologists who want to build their skill set. Amanda Valliant, MD, a second-year nephrology fellow at the University of Wisconsin, wants to learn how to create fistulas and grafts to she can treat patients in rural Kansas, where she grew up.

Such places have even less access to doctors experienced in fistula creation, Valliant explained, which can certainly impact outcomes.

"I think it would benefit the population there if they had more reliable access to someone who is not only capable," she said, "but invested in the process."

Pereda agreed that the one situation where he could see nephrologists performing surgery would be in underserved areas: "It beats not having a fistula at all."

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