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Ann Thorac Surg 1997;64:729
© 1997 The Society of Thoracic Surgeons
DR THOMAS L. SPRAY (Philadelphia, PA): I congratulate Dr Brauner and his associates on an excellent series with quite impressive results in a group of patients that has traditionally represented a very poor surgical outcome.
I have several questions that perhaps are not so much related to the data, which I think speak for themselves, but perhaps to some speculation for future therapy on some of these patients.
First, I noted that in your article, which you kindly provided to me, patients with hypoplastic left heart syndrome were excluded from this study. I wonder with the multiple levels of left heart obstruction what criteria were used to define an adequate left ventricular size and function.
One of the problems with patients with Shone's anomaly is that they tend to present, as in your series, with coarctation. And it is not until after the coarctation is relieved that these patients show their other multiple levels of obstruction. Therefore, I wonder how you define what an adequate left ventricular size and left ventricular function is in a newborn presenting with complex left ventricular outflow tract obstruction.
The second question concerns the average age at repair of the mitral valve, about 2 years, but the two repair failures were in infants. Is age is a relative risk factor for valve repair, as has been suggested by some other investigators?
Along similar lines, Barbero Marcial and Jatene and his associates have reported an apical left ventriculotomy approach to the subvalvar mitral apparatus in this kind of a condition, because these patients generally have abnormal submitral apparatus as the primary component of their valve disease. I wonder whether you would comment on this approach and perhaps comment on your approach to the subvalvar apparatus in these very young and small patients with often a hypoplastic mitral annulus.
Other researchers have also suggested a high incidence of recurrence of supravalvar mitral stenosis in patients when the valve is left unrepaired. This was reported by Martin Elliott and associates. Most of your patients with supravalvar mitral membranes had very little or no obstruction from the membrane itself. I wonder whether you think that aggressive approaches to supraannular mitral membranes in infancy with associated valve repair will prevent recurrence of these membranes. I noticed that there were no recurrences in your series, which is unusual.
It is clear that these patients will require multiple operative procedures with frequent reoperation for left ventricular outflow tract obstruction. But after repair, interestingly, in your series, the mitral component has been relatively stable. I wonder whether you could comment on the possible use of an early Ross procedure with aortoventriculoplasty in these patients. This is especially something to consider as most of these patients have complex left ventricular outflow reconstructions and often they have abnormal aortic valves. Although they are not hemodynamically significant at presentation, the majority of these patients have bicuspid aortic valves, often with commissural fusion. Therefore, perhaps early aggressive intervention on the left ventricular outflow tract may decrease late reoperation.
Although few patients are free of residual hemodynamic defects at follow-up, the investigators have shown that early attention to multiple levels of left ventricular outflow tract obstruction in these children can be associated with surprisingly good long-term results. And I think this justifies a continued aggressive surgical approach for this complex group of patients.
I enjoyed this article very much and again compliment the researchers on their excellent series.
DR BRAUNER: Thank you, Dr Spray. Unfortunately, I did not have the privilege to review those questions beforehand, but I can say that it was our impression that coarctation is the initial presenting symptom in the most severe patients. And indeed, none of the data that I have presented about mitral valve, ventricular size, or subaortic stenosis were applied to the period before repair of the coarctation. First, coarctation was repaired very early. Usually it is even masking intracardiac anomalies because of the lower cardiac output, and therefore all the definitions of our predominant disease and levels of obstruction were done after initial repair of the coarctation.
The appearance of the anomalies in Shone's syndrome is at separate time points, with coarctation usually being first, mitral disease and left ventricular inflow being second, and subaortic stenosis being third, as you can see by the different ages of repair of these anomalies.
Indeed, in mitral disease the technique of repair should be tailored to suit the individual deformity of the valve. In the most frequent parachute anomaly that is found in Shone's syndrome, the mitral annulus is usually not hyperplastic, the defect is mostly, if not totally, subvalvular, and the repair that works, and worked for us, was splitting papillary muscles, and depending on the development of chordae, separation of the chordae to release interchordal spaces.
In the second most common variant, which is the typical congenital mitral stenosis where the papillary muscles are always close together, we often need to do a commissurotomy, and after that it seems that results in the midterm or long-term (7 years of follow-up) are quite good. This is also the case in subvalvular obstructions that needed to be released. Again, our numbers are not very large and we believe that that worked for at least the intermediate term.
About supravalvular mitral rings, going through the literature I have to disagree about the rate of recurrence. We did not observe any recurrence of supravalvular rings, and I do not think anybody did. I did not see such a case in the literature.
We only had 1 case of supraaortic stenosis, which was repaired as part of an aortoventriculoplast, and this worked fine.
Now, it is indeed indicated to do a combined Kono-Ross procedure for severe tunnel-type subaortic stenosis, but I do not think it is warranted for simple bicuspid fused aortic valves that can be released, postponing the need for valve replacements for a long time.
Therefore, we believe that treatment in this disease must be individualized to suit the great anatomic variability. However, with the routine use of transesophageal echocardiography and the safety net that is now provided by the availability of small, 16-mm mitral prosthetic valves, it will be possible to extend event-free long-term survival in these patients.
Footnotes
Presented at the Thirty-third Annual Meeting of The Society of Thoracic Surgeons, San Diego, CA, Feb 3–5, 1997. 
Related Article
Ann. Thorac. Surg. 1997 64: 721-729.
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