Ann Thorac Surg 1999;67:1355-1358
© 1999 The Society of Thoracic Surgeons
Original Articles
The Ross operation: mid-term results
Jean E. Rubay, MD, PhDa,
Michel Buche, MDa,
Gébrine A. El Khoury, MDa,
Jean-Louis J. Vanoverschelde, MD, PhDb,
Thierry Sluysmans, MD, PhDc,
Baudouin Marchandise, MD, PhDb,
Jean-Claude Schoevaerdts, MDa,
Robert A. Dion, MDa
a Division of Cardiovascular and Thoracic Surgery, Catholic University of Louvain, Brussels, Belgium
b Division of Cardiology, Catholic University of Louvain, Brussels, Belgium
c Division of Pediatric Cardiology, Catholic University of Louvain, Brussels, Belgium
Accepted for publication November 21, 1998.
Address reprint requests to Dr Rubay, UCL St-Luc, 10 ave Hippocrate, 1200 Brussels, Belgium
 |
Abstract
|
|---|
Background. The Ross operation, although more demanding, is now widely accepted as an alternative solution for aortic valve replacement in young adults and children. A review of our experience to assess the mid-term results with the Ross operation is presented.
Methods. From June 1991 through October 1997, 80 patients (mean age, 31 years) underwent aortic valve or root replacement with pulmonary autografts. Indications for operation were predominant aortic stenosis in 38 patients, aortic incompetence in 42 patients including endocarditis in 3 patients. Congenital lesions were present in 57 patients, either at pediatric (27 patients) or adult age (30 patients). Transthoracic echocardiography was performed preoperatively in all patients and serially after operation with the aims of measuring aortic and pulmonary annuli, evaluating transvalvular gradients and incompetence, and studying the left ventricular function. Intraoperative transesophageal echocardiography was used routinely. Complete root replacement was performed in 52 patients, intraluminal cylinder in 25 patients, and subcoronary implantation in 3 patients.
Results. One patient died in the early postoperative period (1.2%). There was no late death. The actuarial survival at 5 years was 98% ± 1%. All survivors remained in New York Heart Association functional class I and were free of complications and medications. No gradient or significant aortic incompetence could be demonstrated in 73 patients. One patient developed late aortic incompetence grade 3 and reoperation is considered. On the pulmonary outflow tract, 6 patients had gradients between 20 and 40 mm Hg as calculated on echocardiography.
Conclusions. The pulmonary autograft gives excellent mid-term results with low mortality and no morbidity. It completely relieves the abnormal loading conditions of the left ventricle, resulting in a complete recovery of left ventricular function in most patients.
|
Introduction
|
|---|
The replacement of the diseased aortic valve by the pulmonary autograft, a procedure initially described by Ross [1], has been shown to provide excellent hemodynamic results, both in children and young adults, and to be associated with low morbidity and mortality rates [2–4]. The intraluminal cylinder and root replacement is usually preferred to the subcoronary technique, because it results in lower transvalvular gradients as well as fewer valvular regurgitations [5–7]. As the pulmonary autografts retain their potential for growth [8], and their use eliminates the risk of thromboembolic events and hence the need for anticoagulation, the Ross procedure has gained increasing popularity and is now considered as a valuable alternative to the use of mechanical valves, xenografts, and homografts. In this report, we describe our experience with the replacement of aortic valves by pulmonary autografts in 80 consecutive patients.
|
Patients and methods
|
|---|
Patient population
From June 1991 through October 1997, 80 consecutive patients (mean age, 31 years; range, 5 months to 60 years) underwent replacement of their aortic valve or root by a pulmonary autograft. Indications for operation were aortic stenosis in 38 patients and aortic regurgitation in 42 patients, including 3 patients with aortic valve endocarditis. Congenital lesions including aortic valvular or subvalvular stenosis, valvular aortic regurgitation, and bicuspid aortic valves, were present in 57 patients (mean age, 30 years; range, 5 months to 52 years). Previous procedures (operations or balloon dilatation) had been performed in 18 patients and are as follows: interrupted aortic arch repair, 1 patient; subvalvular aortic stenosis resection and associated ventricular septal defect, 1; aortic balloon dilatation, 2; commissurotomy, 2; ventricular septal defect closure, 3; aortic valve repair, 1; aortic valve replacement with homograft, 1; with heterograft, 1; and with mechanical valve, 5 patients. Associated procedures were undertaken in 3 patients, including a Konno ventriculoplasty [9] in 1 patient, a mitral valve repair in another patient, and a saphenous vein coronary artery bypass grafting in one additional patient.
Operative techniques and echocardiographic methodology have been described previously [10]. In adult patients, we recently introduced a protocol of normothermia and warm cardioplegia as described by Calafiore and colleagues [11]. The choice of the surgical technique was guided by both the patient’s age and the geometry of the aortic annulus and root. In children and in adults with distorted roots, the only technique used was the root replacement. In adults with symmetrical roots, both the subcoronary implantation and the intraluminal cylinder technique were used. The autografts were secured by interrupted or continuous running sutures with 4-0 polypropylene. Eighty cryopreserved pulmonary homografts from the European Homograft Bank (Brussels, Belgium) were implanted as roots [12]. Their mean diameter was 23 mm (range, 16 to 29 mm).
Statistical analysis
Variables are expressed as mean ± one standard deviation unless otherwise specified. Continuous variables were compared by use of the Student’s t test for unpaired data. All test were two-tailed and values of less than 0.05 were considered indicative of a statistically significant difference.
|
Results
|
|---|
Operative data
Mean aortic cross-clamping time was 132 minutes (range, 100 to 180 minutes). One patient (1.2%) died at the end of the operation from cardiac arrest during a maneuver to control a bleeding. The patient had had a previous aortic arch repair and a subsequent restenosis at the level of the ascending aorta that was successfully dilated but led to severe aortic regurgitation.
Three patients had to be reoperated because of early (2 patients) or delayed bleeding (1 patient). One patient who had prolonged aortic cross-clamping (3 hours) could not be weaned from the extracorporeal circulation and requested circulatory support by use of an extracorporeal membrane oxygenator for 5 days. He recovered successfully. Additional procedures were required in 3 patients (mitral valve repair in 1, a Konno ventriculoplasty in 1, and a saphenous vein coronary artery bypass graft in 1 patient.
Peroperative transesophageal echocardiography was performed in 78 patients. This examination revealed no residual aortic regurgitation in 65 patients, trivial amounts of regurgitation in 12 additional patients, and mild aortic regurgitation in the remaining patient.
Long-term follow-up
Patients were followed-up for a mean of 32 ± 16 months (range, 1 to 76 months). No patient was lost during follow-up. There has been no late death. As shown in Figure 1, the 5-year actuarial survival rate was 98% ± 1%. At 5 years, all survivors were in New York Heart Association functional class I and were free of medications. No single episode of endocarditis or thromboembolism was noted during follow-up.
On echocardiography, no significant aortic valve gradients were noted. The majority of patients had no (n = 37) or trivial (n = 35) aortic regurgitation. Among the 8 remaining patients, 6 had mild degrees of regurgitation, 1 had moderate aortic regurgitation, and another patient showed severe regurgitation. In this patient reoperation is currently being contemplated. As shown in Figure 2, at 5 years, freedom from significant aortic regurgitation (grade 2 or more) was 92% ± 4%, mortality included. It was 20% ± 6% when considering grade 1 of aortic regurgitation.
View larger version (16K):
[in this window]
[in a new window]
|
Fig 2. The freedom from aortic incompetence grade 2 or more was 92% ± 4% at 5 years. Mortality was included.
|
|
In the pediatric group, the mean values for annular diameter of the autograft soon after the operation was 19 ± 3 mm as compared 20 ± 4 mm at the most recent visit (p = not significant). A significant enlargement of the aortic annulus ranging from 4 to 8 mm was observed in only 5 patients. In one of them, it was associated with the occurrence of a trivial autograft regurgitation.
Six patients (4 children and 2 adults) exhibited pulmonary gradients of 20 to 40 mm Hg, and in 10 other patients gradients of 10 to 20 mm Hg. Freedom from significant pulmonary homograft stenosis (defined as a pulmonary gradient >20 mm Hg) was 73% ± 9% at 5 years (Fig 3).
View larger version (17K):
[in this window]
[in a new window]
|
Fig 3. The freedom from significant pulmonary homograft stenosis (equal or superior to 20 mm Hg) was 73% ± 9% at 5 years. Mortality was included.
|
|
|
Comment
|
|---|
Clinicians taking care of children or young adults with significant aortic valve disease often face the difficult dilemma of when to operate and what graft material to implant. Practically, the choice is usually between mechanical prostheses, which are long lasting but require anticoagulation, expose to a continuous infectious threat [13], and may display suboptimal hemodynamic performance particularly on exertion [13, 14], xenografts, which do not require anticoagulation but often exhibit worse hemodynamic performances than the former [15] and frequently degenerate particularly in the young [16], and homografts, which also have limited durability, do not grow, and hence often require reoperation (as in one of our patient). Because of these challenges, the decision to resort on operation is often delayed, particularly in pediatric patients, which exposes the patient to a potential risk of permanent left ventricular damage.
The Ross procedure was introduced in 1967 [1] as a possible alternative for aortic valve replacement. However, it is only recently that the pulmonary autograft replacement of the diseased aortic valve gained interest among cardiovascular surgeons, probably because of the many technical difficulties inherent to this procedure and the unknown outcome of the double valve replacement. Despite these initial concerns, results of large-scale clinical studies have indicated that this procedure was safe, with favorable short- [17–19] and long-term results [19, 20]. The present data are thus in agreement with these earlier reports. In our series, the hospital mortality was quite low (1.2%) and there was no late death. In addition, there has been no thromboembolic events or endocarditis. We also confirmed our initial findings concerning the superiority of the intraluminal cylinder and the root replacement over the subcoronary technique in terms of functional results [7].
Because of its potential for growth and annular enlargement, we chose to always perform the root procedure in children [21]. Previous reports using echocardiography had suggested that continuing enlargement of the pulmonary autograft, probably related to growth was possible [17, 22]. This was subsequently confirmed by Elkins and colleagues [8] for the intraluminal cylinder technique as well. Although attractive, the concept that progressive dilatation of the annulus after root replacement represents growth and not a pathologic process that could lead to the development of subsequent valvular regurgitation remains speculative. In our series, annulus enlargement was observed in a minority of patients, all belonging to the pediatric group. In only one child, this was associated with the onset of a mild aortic regurgitation. Although in adults with aortic root replacement, annular dilatation was not observed, we cannot rule out the possibility that this complication could occur in the future. Accordingly, our current policy is to prefer the intraluminal cylinder technique over the root replacement each time it is possible (ie, in the presence of a symmetrical root).
Our data also demonstrate that some degree of aortic regurgitation eventually develops during follow-up. Although a minority of these aortic regurgitations were probably related to the surgical technique itself, the vast majority developed despite any apparent technical cause. It is probable that the late occurrence of aortic regurgitation after the Ross operation somehow reflects the relative inability of the autologous pulmonary valve to adapt to systemic pressure. Similar observations have been made in up to 40% of the patients undergoing the arterial switch procedure [23]. Even if this risk is real, the hemodynamic profile of the pulmonary autograft is far better than that of any of the currently available alternatives. In our series, aortic gradients were always lower than 10 mm Hg, thus much lower than those reported for mechanical valves and bioprostheses, at rest and during exercise [15, 24].
The fate of the pulmonary homograft represents the second unresolved issue. In this regard, the results of follow-up studies [19] on the long-term outcome of patients in whom a large variety of pulmonary valve substitutes, including the fascia lata, irradiated or ethylene oxide-treated valves, antibiotics-stored and frozen aortic homografts, and some pulmonary homografts were used, are quite encouraging, freedom from reoperation being more than 80% at 20 years. Cryopreservation and the more liberal use of pulmonary homografts might thus be beneficial. In our series, among the 79 survivors with a pulmonary homograft, only 16 exhibited pulmonary gradients. These gradients were considered to be significant in only 6 of them, none being more than 40 mm Hg, the limit beyond which reoperation should be contemplated.
Finally, in a previous study we had demonstrated [10] that the Ross procedure permitted recovery of left ventricular function, particularly when it had been altered by a long-standing aortic regurgitation. The present study demonstrates that this benefit persists over time. Our results are thus in agreement with those of Moidl and colleagues [25], who demonstrated that the Ross procedure results in more complete and more rapid return of left ventricular function and volumes than with other substitutes.
In conclusion, our current experience with the Ross procedure suggests that replacement of the aortic root by a pulmonary autograft can be safely performed in infants, children, and young adults, and is associated with low mortality and morbidity rates. So far, inappropriate enlargement of the autograft was not observed in adults. Although in children some degree of annular enlargement could be observed, it was not associated with an increasing incidence of aortic regurgitation. Therefore, we believe it reflects more annular growth than pathologic annular dilatation. The Ross procedure does not require permanent anticoagulation and is associated with low rates of endocarditis, thromboembolism, and degeneration. It constitutes an elegant alternative to the use of prosthetic valves in the treatment of aortic valve diseases.
|
Acknowledgments
|
|---|
We thank Professor Yves Goffin from the European Homograft Bank for his contribution by supplying high quality level homografts.
|
References
|
|---|
-
Ross D.N. Replacement of aortic and mitral valves with a pulmonary autograft. Lancet 1967;2:956-958.[Medline]
-
Ross D.N., Jackson M., Davies J. The pulmonary autograft—a permanent aortic valve. Eur J Cardio Thorac Surg 1992;6:113-117.[Abstract]
-
Elkins R.C. The Ross operation: applications to children. Semin Thorac Cardiovasc Surg 1996;8:345-349.[Medline]
-
Kouchoukos N.T., Davila-Roman V.G., Spray T.L., Murphy S.F., Perrillo J.B. Replacement of the aortic root with a pulmonary autograft in children and young adults with aortic valve disease. N Engl J Med 1994;330:1-6.[Abstract/Free Full Text]
-
O’Brien M.F. Aortic valve implantation techniques. Should they be any different for the pulmonary autograft and the aortic homograft?. J Heart Valve Dis 1993;4:385-387.
-
Daicoff G.R., Botero L.M., Quintessenza J.A. Allograft replacement of the aortic valve versus the miniroot and valve. Ann Thorac Surg 1993;55:855-859.[Abstract]
-
Rubay J.E., Raphael D., Sluysmans T., et al. Aortic valve replacement with allograft/autograft: subcoronary versus intraluminal cylinder or root. Ann Thorac Surg 1995;60:S78-S82.
-
Elkins R.C., Knott-Craig C.J., Ward K.E., McCue C., Lane M.M. Pulmonary autograft in children: realized growth potential. Ann Thorac Surg 1994;57:1387-1394.[Abstract]
-
Konno S., Imai Y., Nakajima M., Tatsuno K. A new method for prosthetic valve replacement in congenital aortic stenosis associated with hypoplasia of the aortic valve ring. J Thorac Cardiovasc Surg 1975;70:909-917.[Abstract]
-
Rubay J.E., Sluysmans T. The pulmonary autograft: results and left ventricular function. Semin Thorac Cardiovasc Surg 1996;8:362-368.[Medline]
-
Calafiore A.M., Mezzetti A. Intermittent antegrade normothermic blood cardioplegia. In: Salerno T.A., ed. . Warm heart surgery. London: Arnold Hodder Headline Group, 1995:77-89.
-
Goffin Y., Grandmougin D., Van Hoeck B. Banking cryopreserved heart valves in Europe: assessment of a 5-year operation in an international tissue bank in Brussels. Eur J Cardiothorac Surg 1996;10:505-512.[Abstract]
-
Baudet E.M., Puel V., McBride J.T., et al. Long-term results of valve replacement with the St. Jude medical prosthesis. J Thorac Cardiovasc Surg 1995;109:858-870.[Abstract]
-
Laske A., Jenni R., Maloigne M., Vassali G., Bertel O., Turina M. Pressure gradients across bileaflet aortic valve by direct measurement and echocardiography. Ann Thorac Surg 1996;10:1097-1106.
-
Jaffe W.M., Coverdale H.A., Roche A.H.G., Whitlock R.M.L., Barratt-Boyes B.G. Rest and exercise hemodynamics of 20–23 mm allograft, Medtronic intact (porcine) and St-Jude Medical valves in aortic position. J Thorac Cardiovasc Surg 1990;100:167-174.[Abstract]
-
Sanders S.P., Levy R.J., Freed M.D., et al. Use of Hancock porcine xenografts in children and adolescents. Am J Cardiol 1980;46:429-438.[Medline]
-
Elkins R.C., Santangelo K., Randolph J.D., et al. Pulmonary autograft replacement in children. The ideal solution?. Ann Surg 1992;216:363-371.[Medline]
-
Hokken R.B., Bogers A.J., Trams M.A., et al. Aortic root replacement with a pulmonary autograft. Eur J Cardiothorac Surg 1995;9:378-383.[Abstract]
-
Chambers J.C., Somerville J., Stone S., Ross D.N. Pulmonary autograft procedure for aortic valve disease. Long-term results of the pioneer series. Circulation 1997;96:2206-2214.[Abstract/Free Full Text]
-
Elkins R.C., Knott-Craig C.J., Ward K.E., Lane M.M. The Ross operation in children: 10-year experience. Ann Thorac Surg 1998;65:496-502.[Abstract/Free Full Text]
-
Daenen W., Gewillig M. Extended aortic root replacement with pulmonary autografts. Eur J Cardiothorac Surg 1993;7:42-46.[Abstract]
-
Gerosa G., McKay R., Ross D.N. Replacement of the aortic valve or root with a pulmonary autograft in children. Ann Thorac Surg 1991;51:424-429.[Abstract]
-
Jenkins K.J., Hanley F.L., Colan S.D., Mayer J.E., Castaneda A.R., Wernovsky G. Function of the anatomic pulmonary valve in the systemic circulation. Circulation 1991;84(suppl 3):173-179.
-
Hasegawa J., Kitamura S., Taniguchi S., et al. Comparative rest and exercise hemodynamics of allograft and prosthetic valves in the aortic position. Ann Thorac Surg 1997;64:1753-1756.[Abstract/Free Full Text]
-
Moidl R, Chevtchik O, Simon P, et al. Early reversal of ventricular dilatation after correction of isolated aortic incompetence: comparison between mechanical and human aortic valves. Abstract, 167; VII International Symposium Cardiac Bioprostheses, Sitges, Spain 1997.
This article has been cited by other articles:
|
|
|
|
 
R. D. Stewart, C. L. Backer, N. D. Hillman, C. Lundt, and C. Mavroudis
The Ross Operation in Children: Effects of Aortic Annuloplasty
Ann. Thorac. Surg.,
October 1, 2007;
84(4):
1326 - 1330.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
