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Ann Thorac Surg 1995;60:1185-1186
© 1995 The Society of Thoracic Surgeons
DR LAWRENCE I. BONCHEK (Lancaster, PA): This fascinating presentation introduces yet another of Professor Carpentier's innovations in surgery of the mitral valve. I apologize if some of my questions are dealt with in the manuscript, but I was unable to obtain a copy in advance.
Since I observed Professor Carpentier demonstrating his techniques in Paris in 1981, we have had a favorable experience with the classic Carpentier-Edwards ring in almost 250 patients in Milwaukee and Lancaster. Yet, some years ago we were persuaded by reports in the literature to assess a flexible ring, and we inserted a Puig-Massana ring in 12 patients because it had some appealing design features.
We then reviewed our results in a group of patients we had operated on up to that time, and the reoperation rate in 142 patients was 3% with the Carpentier-Edwards ring, but with the Puig-Massana ring it was 25%. The average postoperative interval for reoperation was 2.1 years. Because of this experience we abandoned the use of totally flexible rings. I believe that the classic Carpentier-Edwards ring provides predictable and stable results in the hands of most surgeons because it corrects annular distortion in the manner that Professor Carpentier has always emphasized, including a reduction in the anteroposterior diameter of the annulus.
Our cardiologists are currently reviewing all of our postoperative echocardiograms, and they have not seen postoperative systolic anterior motion or left ventricular outflow obstruction in any of our patients. We attribute this to aggressive use of the sliding plasty technique with reduction in height of the posterior leaflet, supplemented by insertion of artificial chords of Gore-Tex to the posterior leaflet if there is a localized imperfection in the line of closure that could displace the anterior leaflet. These Gore-Tex chords can be inserted even after the ring is in place.
This favorable experience with avoiding systolic anterior motion is yet another reason why we have not thought it necessary or wise to use any of the currently available flexible rings. We always bend the classic ring before insertion to give it a saddle shape, which is now part of the Physio-Ring design.
The other consideration advanced by advocates of flexible rings is the theoretic advantage of optimizing left ventricular performance by preserving systolic motion of the mitral annulus, and it is this reason more than any other that presumably prompted the development of the Physio-Ring. In our clinical experience, which we reported in 1984 in the Journal of Thoracic Surgery, and in that of many other centers, mitral repair with a rigid ring results in preservation of global left ventricular systolic performance. The elegant work done in Craig Miller's laboratory further demonstrated in dogs that a rigid ring preserves regional as well as global left ventricular performance.
Because the vast majority of patients undergoing repair in the United States have degenerative disease with excess leaflet tissue, it is not clear to me that systolic contraction of the annulus after repair is necessarily advantageous, nor can experimental preparations fully mimic the natural condition. So although I am intrigued by the Physio-Ring, I remain a loyalist to the original.
I am generally guided by this philosophy: ``Be not the first by whom the new is tried, nor yet the last to lay the old aside.''
I would like to ask Professor Carpentier several questions. First, what percentage of mitral repairs are you now doing with the Physio-Ring versus the classic ring, and how do you decide which to use? Second, are you planning any randomized studies to demonstrate that flexibility of the ring affects the incidence of systolic anterior motion or the occurrence of left ventricular dysfunction? In regard to left ventricular dysfunction, what is your current method of myocardial protection? We find that retrograde cardioplegia and a topical cooling jacket are ideal for mitral repair because there is no need for frequent reinfusion of cardioplegia, which interrupts the repair.
DR JOSEPH C. CLEVELAND (Missoula, MT): I think you will all realize from hearing the two papers and the other discussants that there are many ways to approach this problem. I was impressed in looking at the abstracts, and again in hearing the papers, that there was an absolute paucity of ischemic mitral regurgitation represented here. There were only 8 cases in Dr Cosgrove's series, and I could find no cases in Dr Carpentier's series.
My colleagues and I looked at our series collected over the last 5 years at St. Patrick Hospital in Missoula by Dr Jim Oury and myself. We have 103 cases. The leading cause was ischemic regurgitation (45 cases) followed by degenerative disease (40 cases), a smattering of rheumatic disease, and others. We used the flexible Duran ring in all of these repairs.
In these 103 cases, we had five deaths, all with ischemic disease, all with bad ventricles (ejection fraction <0.30), all elderly (mean age, 71 years), and several with elevated creatinine levels. Of the survivors, there were no failures, no dehiscence, no late need for prostheses, and no leaks greater than 1+. All patients were operated with transesophageal echocardiography. One patient had minor systolic anterior motion, which resolved in 2 days. In follow-up, 90 patients are in New York Heart Association class I, and 8 are in class II.
We believe that the Duran ring performance with its total flexibility is very important. It is easy to implant; it requires four more sutures than what Dr Cosgrove does. It preserves diastolic anatomy and function. Systolic anterior motion is extremely rare, dehiscence is extremely rare, and, particularly in ischemic mitral regurgitation, the full ring provides complete support for the intertrigonal region as well as posterior annular support.
DR ALBERT STARR (Portland, OR): I would just like to say a few words about the classic ring versus the Physio-Ring. For many years I have been using the classic ring, and I believe that fixing the annulus in its systolic position is an important element in the stability of the repair, just as Professor Carpentier has said.
I have had the opportunity to use the Physio-Ring over the past 6 months, and it has some real advantages over the classic ring while still preserving the systolic shape of the mitral annulus. As Professor Carpentier showed, the coaptibility of the ring is superior to that of the completely rigid classic ring, so that the possibility of dehiscence would be greatly reduced. This may be important in this country, where so many mitral annuloplasties are done for ischemic mitral regurgitation, where we do not have the intense scarring of the annulus that we have in degenerative or rheumatic disease, and where dehiscence could be a real problem in that particular class of patients. So I believe that the principle has not been abandoned, but that the coaptibility may be a very big factor in using this device, especially in ischemic heart disease.
DR MEREDITH L. SCOTT (Orlando, FL): In the past year I have participated in doing 26 Physio-Rings at the Florida Heat Institute and over the past 10 years approximately 480 Carpentier rings. My experience has been very similar to Dr Carpentier's experience with the Physio-Ring, and I look forward to using it further.
DR CARPENTIER: I thank the discussants for their stimulating questions. Doctor Bonchek, nobody here knows better than you what long-term stability of a mitral valve repair means and the value of the remodeling annuloplasty concept to achieve this. I would like to reassure you. Adding flexibility to the remodeling annuloplasty ring made sense to me to explore potential advantages, but we have not compromised the remodeling effect of the ring, which remains indeed the requisite basis of annuloplasty.
To your first question, we have used the Physio-Ring in all the cases except in two situations: (1) patients in a foreign country, because of an inherent difficulty of accurate follow up; and (2) patients with an exceptionally high anterior leaflet, in whom a classic ring was preferred. This is actually the only contraindication I see today for the Physio-Ring, and it represents 7% to 10% of the cases. In this situation, the classic ring is preferred because its shape can be slightly modified and adapted to the peculiar configuration of the anterior leaflet: bending the two extremities of the ring makes it possible to increase its vertical diameter. With regard to your comment on systolic anterior motion, it was appropriate for you to remind us that systolic anterior motion is mainly due to excess tissue of the posterior leaflet and that it can be prevented by the sliding leaflet technique. May I just add that systolic anterior motion is also possible when the anterior leaflet has not been carefully measured, leaving the height of the anterior leaflet greater than the vertical diameter of the ring. With regard to left ventricular dysfunction, we have shown that both ventricular end-diastolic and systolic volumes returned to normal after Physio-Ring annuloplasty. Indeed, myocardial protection is important in this regard, and we use topical cooling and a jacket adapted to our economic situation, that is to say a glove, to protect the phrenic nerve.
Doctor Cleveland, you have been surprised by the small incidence of ischemic valve disease in this series. This is because, contrary to you, we reserve this terminology to mitral valve insufficiencies due to, and not associated with, ischemic myocardial diseases. These true ischemic mitral valve diseases are actually rare today, most of them being moderate and partially reversible after myocardial revascularization. Therefore, they should not be corrected. Finally, with regards to the Duran ring, may I remind you that this ring is deformable and not distensible. It does not preserve annulus diastolic function if you size it properly and select it, as you should, to restore the systolic coaptation of the leaflets. In any ring annuloplasty either you choose to fix the annulus in the systolic position and then you do not preserve diastolic function, or you want to preserve diastolic function by using a larger ring and then you compromise systolic coaptation. Doctor Starr and Dr Scott, thank you for your comments. I do share your opinion that the Physio-Ring may improve the coaptability. It also reduces the stress on sutures, which may lead to improved long-term stability of the results.
Related Article
Ann. Thorac. Surg. 1995 60: 1177-1185.
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