Q&A: Small Aortic Root Webinar Follow-Up

When CTSNet brought together a panel of experts to discuss the often divisive subject of small aortic root replacement methods, webinar participants had a lot of questions. So many, in fact, that several had to go unanswered because of time constraints. 

Fortunately for us, panelist Dr. Bo Yang, a cardiothoracic surgeon at University of Michigan, generously took the time to thoughtfully respond to the remaining inquiries, including suggestions of helpful references and resources to explore further. 

Read on to see what he has to say.

Question: Doesn’t the Y-enlargement only enlarge the aorta? Isn’t the true nature of Y-enlargement defined by the tilting of the valve?

Answer: The Y-incision enlargement anatomic aortic annulus and there is no tilting of the valve, as shown in the postoperative CTA in our presentation. Please also review the figures in publications regarding this technique, including the most recent publications: “Early Outcomes of Y-incision Enlargement”, and “A novel simple technique to enlarge the aortic annulus by two valve sizes”. 

Question: How do you define whether the LVOT size or the annulus size is the issue at hand?

Answer: LVOT gradient is detected by preoperative TTE or intraoperative TEE to determine if there is LVOT stenosis, such as HOCM or a subaortic web. Intraoperatively, it is also examined to determine if there is a subaortic web. The diameter of a normal aortic annulus is 18-25 mm. If a patient has HOCM or subaortic web, myectomy or resection of subaortic web is performed alongside Y-incision aortic annular enlargement.

Question: What do you think about sutureless aortic valve (Parceval) procedures to avoid PPM?

Answer: It is a good idea to measure the inner diameter of sutureless valve. If the sutureless valve has an inner diameter matching the diameter of the patient’s native aortic annulus, then the patient may not have PPM. However, without annular enlargement, I doubt that will be the case. 

Question: What are your thoughts on the usage of Inspiris Resilia aortic prosthesis, which promises controlled and predictable expansion for valve-in-valve prosthesis? Does this help with maintaining the dynamism of the LVOT, unlike others which blunt annular dynamics? Is it an option in a small annulus vs the stentless ones?

Answer: It is hard to know how much expansion the Inspiris Resilia valve has, or how much increase of the valve’s inner diameter could be achieved with expansion. I do not think it makes much difference in the small annulus. A stentless valve does not make a difference in small annulus either. This study and recent publication in The Journal of Thoracic and Cardiovascular Surgery (JTCVS) showed that a same-size stentless valve may have mildly better hemodynamics, but long-term survival was the same as patients treated with a same-size stented valve. The aortic annulus must be enlarged to put a much larger valve no matter what type of valve is used. 

Question: Are there additional advantages in doing a root replacement over doing a Y-enlargement?

Answer: The indications to do a total root replacement for a small annulus include: 

1. The patient has a root aneurysm.

2. In redo AVR, the aortic root is destroyed from removing the previous prosthetic valve, such as a previous inclusion freestyle root. A homemade composite valve graft using Valsalva graft and stented valve upsized two to three valve sizes is used in this case. 

Question: When doing an MVR plus AVR, how much annular enlargement can be done by the Nicks, Nunez, and Manougian techniques?

Answer: With the prosthetic valve in mitral position, the mitral annulus cannot be cut through, so the Manougian cannot be performed. You could perform modified Nicks (original Nicks cuts through the MV too, see this publication), and Nunez to enlarge the aortic annulus by one to two valve sizes. However, the Y-incision enlargement can definitely be performed to upsize the aortic annulus by three to four valve sizes. We have done multiple cases of Y-incision enlargement with an MVR or MV repair. 

Question: I am a little worried about root dilation in aortic valves with block calcifications and especially in noncoronary cusps. What are your tips?

Answer: I am not sure aortic root dilation is associated with block calcification of the aortic valve. With Y-incision annular enlargement, the aortic root is enlarged significantly. However, there have been questions regarding the dilation of the enlarged root. Since the Dacron patch has been used for the reconstruction of heart or aorta, and it does not dilate significantly, we do not expect patients will develop a root aneurysm after Y-incision annular enlargement. However, long-term follow-up with CTA are needed to confirm this expectation. 

Question: Which is the better procedure for approaching a marginally enlarged aorta—aortoplasty or Dacron graft?

Answer: Native aortic tissue is always better than prosthetic material. In older patients and those with marginally enlarged aorta, I would recommend not to replace it. In younger people, those with family history of aortic disease and especially aortic dissection, and patients with poor tissue quality, I would recommend replacing the aorta. 

Watch the full webinar, “Small Aortic Root—Annular Enlargement vs. Total Replacement,” here. You can also read a summary of the webinar here.

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