A Spirited Debate: Annular Root Enlargement vs. Total Root Replacement

On the topic of aortic root replacement, surgeons tend to be divided, using their own skills and preferences to guide their decision in each case. CTSNet brought together some of the biggest names in aortic surgery to discuss their takes on two popular—and sometimes divisive—methods to treat aortic valve disease.

The article below is a summary of a recent webinar, edited for length and clarity. Co-moderators Barbara Hamilton and Vinod Thourani welcomed experts Bo Yang, Michael Reardon, Joseph Bavaria, and Ismail El-Hamamsy to discuss the topic in-depth. Read on for a rundown of important points, quotable moments, and major takeaways from the webinar.

Why Do Patients Need Larger Valves?

To kick off the discussion, Dr. Michael Reardon, cardiac surgeon at Methodist DeBaket Heart & Vascular Center, presented on the benefits of using larger prosthetic valves to prevent patient-prosthetic mismatch. As a proponent of the current United States guidelines that promote using TAVR in younger patients, Dr. Reardon said his choice considers the “physiological risk of the procedure, the anatomic risk of TAVR, and the patient’s wishes.”

Throughout his presentation, Dr. Reardon emphasized the importance of using larger valves to avoid patient-prosthetic mismatch, saying that “any degree of patient-prosthetic mismatch significantly decreases your long-term survival, and increases your readmission rate… It kills you.”

Dr. Reardon’s bottom line? “Your surgical valve should strive to have an inner opening that matches the area derived annular diameter on the CTA to be competitive with TAVR. Because if you really want the patient to have what they need physiologically, you need to base that on their own annular area.”

Aortic Annular Enlargement for AVR in Patients with Normal Aortic Annulus

Dr. Bo Yang, cardiac surgeon at University of Michigan, continued to argue for team aortic root enlargement with his presentation on aortic annular enlargement for AVR in patients with a normal aortic annulus. He presented data to support using larger valves, emphasizing that the true diameter of a prosthetic valve is five to seven millimeters smaller than its labelled diameter.

The trick to using larger valves in patients with normal aortic annulus diameters, Dr. Yang pointed out, is the Y-incision. “The Y-incision annular aortic enlargement is actually very simple and very safe… It’s very easy to upsize three to four valve sizes and, best of all, to prepare the patient for future valve-in-valve TAVR,” he said.

Aortic Root Replacement to Avoid Patient-Prosthesis Mismatch (PPM)

Although Dr. Ismail El-Hamamsy, professor of cardiovascular surgery and director of aortic surgery at Mount Sinai Hospital and Icahn School of Medicine, presented a contrasting argument, he made sure to emphasize that his approach is complementary to those already presented, not opposing them. Dr. El-Hamamsy went on to preface his presentation with a call to stop saying that a patient has a “small aortic annulus.”

“If you look at the normal range of aortic annual dimensions in adult males in the US, it ranges from eighteen to twenty-seven millimeters, and in women it ranges from sixteen to twenty-six millimeters. So, in other words, when a patient has an aortic annulus measuring twenty millimeters, this is not a small aortic annulus.”

Based on this new approach, Dr. El-Hamamsy concluded that prosthetic valves have not been adapted to fit patients with varying annulus sizes, which has resulted in a PPM prevalence of forty to forty-five percent.

Instead of enlargement, Dr. El-Hamamsy prefers to use the Ross procedure in patients under sixty-five years old, and a stentless root replacement in those over sixty-five. He also emphasized the importance of pre-operative imaging to predict PPM.

The Debate Continues…

When the presentations concluded, the question and answer portion of the webinar was underway. Dr. Vinod Thourani, cardiac surgeon at Piedmont Heart Institute and one of the event moderators, began by making the important point that the procedures outlined in the presentations “convert a simple case into a really complex case. I think we have to do a lot of educating to get past this burden.”

Dr. Thourani then raised the question of standardizing the procedure for either of the techniques described, which continued to be a theme for the remainder of the conversation.

In support of avoiding patient-prosthetic mismatch, Dr. Joe Bavaria, cardiac surgeon at the Hospital of the University of Pennsylvania, chimed in. “They should almost always be up one size in a standard AVR procedure… I think we’re getting better at the procedure itself, but that is not what we’re talking about tonight.”

To Dr. Bavaria’s point, the panelists began to dig into the nuances of annular root enlargement versus root replacement, discussing the pros and cons of their varying techniques.

When asked if the Y-incision method is still applicable when the valve is calcified, Dr. Yang made sure to point out that the procedure only fails to be appropriate in extreme instances of calcification. Before long, Dr. Bavaria began to defend his stance on any procedure involving prosthetic valve enlargement.

“I always just do a root [replacement]. I mean, it’s so simple. A root is a beautiful operation. It’s elegant, it’s symmetric, it’s not destructive, you don’t have to put a big patch in—it’s a beautiful, beautiful operation,” Dr. Bavaria explained.

After firmly agreeing with Dr. El-Hamamsy, however, Dr. Bavaria went on to tweak his argument to say that his decision was not based on avoiding PPM, but finding the best procedure to fit both the patient and the surgeon’s skill level. Dr. El-Hamamsy added that, while total root replacement can mean a riskier operation, imaging can help determine the best course of action for the patient. Dr. Thourani seconded that opinion, saying that he also recommends pre-operative scanning.

The Root Replacement: Is It Teachable?

While a total root replacement using the Ross procedure may be the best course of action for surgeons who have this skill, Dr. Reardon made sure to bring up that it is a complicated procedure, and not very commonly taught.

“One thing I like about the annuloplasty is that it is very teachable. I mean, my fellows and residents do all of these—they do the roots too—but it’s something I can teach, and something I think most of our community of surgeons can learn. They’re just not going to learn the Ross.”

Dr. El-Hamamsy countered this observation by agreeing that the Ross is a difficult procedure, but “you can’t replicate biology with a prosthetic valve, no matter what you do.” This prompted Dr. Barbara Hamilton, cardiac surgery resident at University of Michigan and also one of the event moderators, to bring up a viewer’s question—With the small number of ADRs done at hospitals, should we encourage root enlargement or root replacement?

Dr. Bavaria was quick to reply, saying that “a root should be something that’s taught to every cardiac surgeon… I think it’s becoming more democratized.” To this, Dr. Thourani added that root enlargement has a higher rate of operative mortality early on, but the rate is similar to root replacement after five years.

While root replacements are complicated, as Dr. Reardon once again brought up, Dr. El-Hamamsy made sure to emphasize that he believes “roots are very teachable, and in centers that are doing this regularly, all our residents should be leaving knowing exactly how to do a root procedure.”

On the other hand, he added that he believes, in some cases, “it is safer to do a root enlargement than a root procedure. I hate to see patients die from a root replacement to avoid PPM.”

Dr. Reardon rounded out the conversation with a poignant joke, saying “I wouldn’t do my own Ross if I could, I’d go to somebody like Ismael who does them every day.”

This emphasis on experience of the surgeon and needs of the patient is what each surgeon believed to be the bottom line.

Final Takeaways

The webinar ended with each panelist giving a main point for residents and surgeons curious about treatment options for aortic root issues to takeaway and into their practice.

As a fan of aortic root replacement, Dr. Bavaria said that if you don’t feel comfortable doing that procedure, make sure the valve you use for enlargement is large enough to accommodate the existing annulus, and there should be minimal problems.

Dr. Reardon emphasized that hemodynamics are very important, and PPM is a problem in the field of aortic surgery. There are lots of ways to fix this problem, and which one you choose depends on many different factors involving both the patient and your comfort level.

Dr. El-Hamamsy agreed, saying “PPM is bad, but PPM is predictable, so we have to try to avoid it at all costs. If that means we have to refer to someone who can do a root or an enlargement because we don’t feel safe doing it, we have to be honest with the patient and propose that.”

He added, “For the young people on this webinar, and the trainees who are listening in, what is really important to come out with is that just doing AVRs in your training and thinking you can do aortic surgery, that’s not good enough anymore. You need to have aortic root replacement and aortic root enlargement in your toolbox.”

Finally, Dr. Thourani gave two pieces of advice: “Scan everybody. The more knowledge you get, the better off you’ll be. And I agree with Ismael—somebody on your team needs to be an aortic valve specialist.”

At the conclusion of the webinar, both sides made a strong case. Who do you think had the better argument?

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