J Thorac Cardiovasc Surg 2002;124:417-418
© 2002 The American Association for Thoracic Surgery
Reoperation for dilatation of the pulmonary autograft after the Ross procedure
Paul Stelzer, MD
Beth Israel Medical Center, 317 E 17th St, New York, NY 10003
To the Editor:
Sundt and colleagues
1 from St Louis have described a dramatic case of dilatation of the pulmonary artery wall submitted to systemic pressure as a freestanding root replacement Ross procedure. Amazingly, the valve itself was not rendered incompetent despite this degree of dilatation and could be preserved with a Yacoub operation. This was elegantly done and described. The pathology clearly showed "marfanoid" changes of the pulmonary wall.
All 4 of the patients requiring reoperation had primary aortic regurgitation of a bicuspid valve. None had stenosis. The authors are correct to observe that the majority of very young persons requiring aortic valve replacement have bicuspid valve disease. I disagree, however, with their conclusion that bicuspid valve alone is the marker for future dilatation of the autograft. It seems curious that none of these patients had stenosis as the original pathologic condition. Perhaps the marker for histologic abnormality is the regurgitation and not the bicuspid nature of the valve.
The authors rightly point out that a recommendation for prosthetic material support of the proximal autograft suture line might prevent annular dilatation but would have no effect on the remainder of the root. However, I disagree with the suggestion that this problem could be solved by reverting to an intra-aortic (root inclusion) autograft technique. Several important points explain my difference of opinion:
- When should the inclusion technique be used? Clearly, if the root is severely dilated in the native state or severely narrowed, it is unsuitable to accommodate the intra-aortic techniques. The root most likely to allow a good, competent inclusion technique is the normal aortic root. However, the normal root is also the least likely to have the genetic substrate for root dilatation. Thus, a full root replacement would be a very reasonable option in all 3 of these situations.
- The real question is in whom and how best to support the autograft. Clearly, a dilated anulus must be reduced and stabilized at the size of the pulmonary anulus or slightly smaller. The length of the autograft should be limited by cutting it off just beyond the commissures so that the sinotubular junction can be supported by the distal anastomosis.
- The distal anastomosis must not be made unsupported to a dilated distal aorta. Some aortas have mild size discrepancy that can be corrected by incorporating another measured strip of felt into the anastomosis. Others have poststenotic dilatation that lends itself nicely to lateral aortorrhaphy combined with a support strip. A few will require complete resection and replacement with a graft whose size should be appropriate to the sinotubular junction of autograft.
- The sinus portion of the autograft itself can be left alone in most patients, but in those with dilated aortic sinuses or primary regurgitation of either a bicuspid or a 3-leaflet valve this can be externally supported to some extent by leaving the native noncoronary sinus tissue long and incorporating it into the distal anastomosis. The "pillar" of tissue between the right and left coronary "buttons" can also be left long enough to be incorporated as support on the left side of the neo-aortic root. Care must be taken not to shorten the root height by these maneuvers as leaflet prolapse and regurgitation can result.
- If the aortic root is truly aneurysmal (ascending or sinus of Valsalva), I believe this constitutes gross evidence of intrinsic weakness of the proximal great vessel wall and a more aggressive approach is warranted. A very secure external support of vascular prosthetic graft material (2-3 mm larger than internal autograft anulus dimension) can be fashioned as a "jacket" with "armholes" cut for the exit points of the coronary arteries. The proximal end of the graft is tacked to the prosthetic felt strip, which should always be incorporated into the proximal autograft anastomosis in patients with this kind of root. The distal end is trimmed to the exact length to match the autograft and incorporated into the distal suture line. That distal suture line may be to another graft, which has replaced the entire ascending aorta and even proximal arch if need be. All points of potential dilatation can be addressed in this manner. The only unknown variable is the intrinsic histologic characteristics of the pulmonary leaflets themselves.
The real solution, I believe, is not to abandon the root replacement technique, which has reduced the incidence of primary autograft regurgitation, 2,3 but rather to try to predict which patients should have external support of the entire root and provide that in a controlled fashion. Routine histologic studies of pulmonary artery and aortic biopsy specimens from dozens of my own Ross patients have failed to reveal evidence of microscopic abnormality in the absence of grossly recognizable anatomic problems. Ideally, genetic testing will one day accurately predict those patients whose aortic and/or pulmonary leaflets are doomed to fail even with Yacoub or external support techniques and help us to decide whose Ross should wear a "jacket" and whose need not.
12/8/124293
doi:10.1067/mtc.2002.124293
References
- Sundt TM, Moon MR, Xu H. Reoperation for dilatation of the pulmonary autograft after the Ross procedure. J Thorac Cardiovasc Surg. 2001;122:1249-52.[Free Full Text]
- Stelzer P, Weinrauch S, Tranbaugh RF. Ten years' experience with the modified Ross procedure. J Thorac Cardiovasc Surg. 1998;115:1091-100.[Abstract/Free Full Text]
- Elkins RC, Lane MM, McCue C. Pulmonary autograft reoperation: incidence and management. Ann Thorac Surg. 1996;62:450-5.[Abstract/Free Full Text]
