| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Ann Thorac Surg 1995;60:503-504
© 1995 The Society of Thoracic Surgeons
DR STEPHEN B. COLVIN (New York, NY): I have enjoyed Dr Cosgrove's presentation and greatly appreciate his providing me both with a copy of his manuscript and the video prior to this meeting. This paper focuses on annuloplasty and annular remodeling with a new device. I gather that it was developed because of concerns related to all the annuloplasty rings with possible association with left ventricular outflow tract obstruction, annular narrowing, and ring dehiscences.
In the performance of mitral valve repairs, particularly in the degenerative group, posterior leaflet resection, often up to several centimeters, is quite common, and reduction annuloplasty is carried out by bringing together the edges of the leaflet and the annulus. Annuloplasty support may be carried out to buttress the repair with pledgeted sutures or, most commonly, ring annuloplasty, which we have done exclusively with the Carpentier-Edwards annuloplasty ring and, most recently, the flexible Carpentier-Edwards Physio ring, which we will shortly hear about. I use a ring whenever feasible in all adults for remodeling and support. I do not use any ring in the children. The various techniques of valve repair, leaflet resection, posterior and anterior, chordal transposition, and shortening procedures are clearly supported by a ring. The ring aids in keeping tension off of the sometimes fragile suture lines. The dynamic process of annular contraction, which is not toned down or reduced by Dr Cosgrove's technique, may not aid in prevention of dehiscence of a complex repair. Thus, physiology may be maintained, but there may be more recurrences.
In our initial experience of 100 cases redos were done in the first year or so of the patient's follow-up in less than 3% of such cases. In the total series of 700 cases now, including the early events and all the surgeons at the institution, reoperations have been necessary in only 1.7% of all cases.
In the 620 cases with 98% follow-up, reoperation is quite rare, and there is a lot of patient follow-up; 90 patients have been followed up beyond 10 years.
Reoperation in the nonrheumatic group of patients is 90% free from reoperation now out to 12 years, and with the rheumatics that drops off; they are about 70% free of reoperation at 12 years, as most everybody has reported. Anticoagulation-related problems, bleeding, thromboemboli, and endocarditis are extremely rare.
I took the liberty of extracting from Dr Cosgrove's video several points that I wanted to ask him about. First, in this case where he is putting the annuloplasty sutures in, are those ruptured chordae, and when did he do the repair? Second, was the device that was used to measure the annulus the Carpentier annuloplasty sizer or the Cosgrove sizer? Is this flexibility going to be a problem in terms of support of the complex repairs with time?
In the Cleveland Clinic, with a large number of coronary artery disease patients, I would have expected a greater percentage of his cases to have included mitral insufficiency secondary to coronary artery disease. I wonder whether or not other procedures are done in some of those patients.
Finally, with transesophageal echocardiography being used so widely, were any repairs abandoned and any other procedures done in any patients during this series?
DR D. CRAIG MILLER (Stanford, CA): Doctor Cosgrove asked me to say something about this ring because Scott Mitchell and I have had the opportunity over the last 6 months to use about 20 of them. Doctor Cosgrove has been bending my ear for years, as well as many of you, about how great this device is; however, I never really understood it, probably because it is extremely difficult to articulate how precise and how perfect this device actually is. It is only after using a few that you can appreciate its unique attributes. I do favor this ``annuloplasty system,'' but it is not the band or the flexibility, but more the template that you seat and tie against; it is absolutely precise, and there is just no room for sloppy technique.
Doctor Cosgrove, the number of patients out at 1 year studied with your fascinating three-dimensional echocardiographic reconstructions must be very small, and I would urge caution until you have more data. Second, it looks like there is cardiac translation with the anterior structures moving towards the posterior annulus rather than true sphincteric motion of the posterior annulus moving anteriorly. That, of course, can only be determined with respect to external, fixed laboratory three-dimensional coordinates, not an internal floating reference system such as echocardiography. I can tell you, at least in normal dog hearts, that it is the posterior motion and not cardiac translation that causes size and shape change of the mitral annulus throughout the cardiac cycle.
Finally, I have two quick questions. What was the cardiac rhythm of the patient who showed the annular orifice area change? Was that patient in atrial fibrillation? I did not see any presystolic decrease in size, which is coincident with atrial contraction and the P wave, as shown by Tsakaris and Ormiston and Wong and others many years ago. Finally, was the fascinating increase in fractional area contraction over time due to a smaller end-diastolic area (denominator) later postoperatively or was it perhaps a reflection of better systolic pump mechanics later on?
DR JAMES L. COX (St. Louis, MO): My comments parallel those of Dr Miller in that I had also been less than convinced of this system until I used it. We have now used it in about 20 patients over the last 6 months. Before describing our experience, however, I think that it is worth mentioning that the presentation this morning by Dr Cosgrove will probably be remembered for two things: First, the introduction of his system for repairing mitral valves and second, the rather unique way in which the information was presented.
In the past 20 years we have progressed from black and white slides to color slides to three-dimensional computer slides and now to a combined slide-movie format that I found, particularly for a complex subject like this, to be very informative and effective in making the point.
The Cosgrove annuloplasty system represents another outstanding contribution from Dr Cosgrove and his associates at the Cleveland Clinic. This system seems to be the epitome of the adage that the simplest ideas are frequently the best ones. We have found three advantages of this system over others that are currently available. The first is that the effect of this system is to focus only on the degenerative portion of the mitral annulus and to leave the normal portion of the annulus alone. The second is that they are flexible, as Dr Cosgrove showed in his film. Finally, one of the most important advantages is that these devices are very easy to insert. This has moved mitral valve repair back into the realm of operations that can be handed down to residents.
I do have a couple of questions for Dr Cosgrove. The first is that you mentioned a reoperation rate of 5 patients in a series of 150. That would be a reoperation rate of 2.5%. I noticed Dr Colvin's reoperation rate is in that general range, but the fact is it is difficult to compare results from one institution to another. Therefore, I would be interested in knowing how your own reoperation rate using this system compares with your own reoperation rate using other devices. Second, do you think that the absence of artificial material between the left and right fibrous trigones explains the absence of systolic anterior motion of the mitral valve in this series of patients?
DR DENTON A. COOLEY (Houston, TX): I also congratulate Dr Cosgrove on his presentation and particularly the technique of cine presentation, which certainly will relieve many of us from attempts to present before such a vast audience. I also was interested in knowing if he has extended what we originally reported as a ``collar prosthesis'' some 20 years ago and finally abandoned for a number of disadvantages, one of which is hemolysis. Even a small jet of blood at the lateral commissure against the velour surface will produce hemolysis. We encountered this in a few patients and abandoned the use of this velour collar prosthesis partly for that reason.
Also, it was difficult to estimate the proper extent of reduction in the annular size. This reminds me of gastric stapling for morbid obesity. Nature will compensate for iatrogenic anatomic distortions. The bare area on the anterior leaflet is subject to dilatation, even though it is of a fibrous nature. The collar itself can slip and loosen.
That brings us to my opinion of a suitable prosthesis. In my opinion it should be completely flexible, not partially flexible. I have found in my own experience in more than 150 cases that a simple prosthesis made by the surgeon suffices; a 20-mm Dacron vascular graft cut appropriately into 2- to 3-mm-wide rings suffices very well, in my experience. I know that this will not be very popular with our exhibitors.
Doctor Cosgrove, has this prosthesis passed through the usual Food and Drug Administration investigational device assessment?
DR JOHN C. ALEXANDER, JR (Evanston, IL): We have used this operation for the past 4 years. We have used the Duran prosthesis and cut out the anterior one-third. We agree with everything that Dr Cosgrove has said. We think that this is an excellent approach to repairing what is really wrong with the mitral valve. One of the things that has occurred to me is just what Dr Cooley mentioned, and that is, I wonder about a nice, tightly packed piece of felt cut in a thin strip. My guess is that we could accomplish the same thing if we would just cut it to the right size.
DR COSGROVE: I thank the discussants for their comments. The most important questions deal with the issues of reoperation and physiologic changes of the annulus.
In an effort to evaluate the incidence of reoperations I went to the literature to compare our incidence of reoperation with what had previously been reported by Dr Spencer, by ourselves, and Dr Deloche from Dr Carpentier's group. All of these annuloplasties involved the use of a Carpentier-Edwards ring. The incidence of reoperation within 2 years is roughly the same in the three groups and in this series. It would appear that the reoperations, with very few exceptions, were the result of failure of the primary repair. I would add the caveat that the more difficult procedures you undertake, the higher the incidence of reoperations.
Unfortunately, we only have 5 patients who were studied a year afterward with transesophageal echocardiography. There are two reasons for this. It is difficult to get an asymptomatic patient to come back to have a transesophageal study, and also the transesophageal study takes longer due to the extensive acquisition of data required for this analysis. However, we have noted that the sphincter mechanism and the normal saddle shape of the mitral annulus are preserved at a year. We have discovered that there seems to be some change in postoperative motion of the mitral annulus from postoperative to 1 year. It is too early and there are too few patients to say what this represents. It is an intriguing observation, which we will need to look at further.
Doctor Cooley, some of the thoughts that I had that brought this device to fruition originated from your work. We, for a number of years, used a strip of pericardium around the posterior annulus to plicate the posterior annulus, similar to your collar, but we were concerned we were not providing a measured plication of the posterior annulus. For this reason we developed a template so we could tie down around something that was rigid. We selected the material because of our observations that the St. Jude valve was almost always completely endothelialized and tightly adhered to the annulus.
| ||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
