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a Department of Cardiovascular Surgery, University Hospital, Berne, Switzerland
b Department of Pediatric Cardiac Surgery, Hôpital Necker Enfants-Malades, Paris, France
c Department of Pediatric Cardiology, Hôpital Necker Enfants-Malades, Paris, France
Accepted for publication July 18, 2007.
* Address correspondence to Dr Kadner, Department of Cardiovascular Surgery, University Hospital, Berne, Freiburgerstrasse, Berne, 3010, Switzerland (Email: a.kadner{at}web.de).
| Pediatric cardiac surgery:
The Annals of Thoracic Surgery CME Program is located online at http://cme.ctsnetjournals.org. To take the CME activity related to this article, you must have either an STS member or an individual non-member subscription to the journal.
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Abstract |
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Methods: From September 1993 to September 2004, 52 children less than 15 years of age underwent a Ross procedure. The patients ranged in age from 4 days to 15 years old (median, 5 years). Fifteen patients (29%) were less than 2 years of age. The predominant indication for the Ross procedure was aortic stenosis. Sixteen patients underwent a Ross-Konno procedure for severe left ventricular outflow tract obstruction. Thirty-four patients had 48 previous interventions. Preoperatively, 6 patients showed severe left ventricular dysfunction, and 2 of the patients required ventilation and inotropic support. Concomitant procedures were performed in 8 patients. Three patients had a mitral valve replacement, 2 patients had a ventricular septal defect closure and an aortic arch reconstruction, 2 patients had aortic arch reconstructions, and 1 patient had resection of a coarctation and a ventricular septal defect closure.
Results: Patients were followed up for a median of 43 months (range, 1 to 130). Overall survival was 85% ± 5% at 1 and 82% ± 5% at 2, 5, and 10 years. Hospital mortality was 5 of 52 patients (9.6%). All deaths occurred in neonates or infants less than 2 months of age, who needed urgent surgery. Three patients died late of noncardiac causes. At last follow-up, all patients were classified in New York Heart Association functional class I or II. No patient had endocarditis of the autograft or the right ventricular outflow tract replacement. During the follow-up, no event of thrombembolism was observed. No patient required the insertion of a permanent pacemaker. Overall freedom from reoperation is 57% ± 15% at 10 years. One patient required the replacement of the autograft at 6 months postoperatively. The development of mild aortic insufficiency was observed in 24 patients, and moderate aortic insufficiency in 1 patient during follow-up. Freedom from reoperation for the right ventricular outflow tract replacement is 60% ± 15% at 10 years.
Conclusions: The Ross procedure represents an attractive approach to aortic valve disease in young children. However, a high early mortality rate has to be considered when performing this procedure in neonates or infants who present in critical preoperative condition.
Surgical therapy of aortic valve disease in children remains challenging and controversial. Valve replacement therapy with mechanical or biological prostheses, as the standard approach in adult patients, is unsatisfactory owing to its various drawbacks in children [1]. The anticoagulation therapy after mechanical valve replacement interferes with the active life style of this patient group and its reduced compliance with a strict therapeutic regimen. In addition, the teratogenic effects of a long-term warfarin therapy present a contraindication for later pregnancies of young women [2]. The application of a bioprosthesis or a homograft valve is hampered by an accelerated calcification and degeneration process in this age group [3]. Furthermore, mechanical, biological, and homograft prostheses lack the capability of growth.
Considering these limitations, the Ross operation appears to be an attractive solution for the management of aortic valve disease in children and teenagers. Most importantly, growth of the autograft is reported to occur, and the burden of anticoagulation therapy can be avoided [4, 5]. However, unlike other aortic valve replacement options, it is argued that the Ross procedure turns a single valve disease into a double-valve pathology [6, 7]. Multiple reinterventions are still necessary for the replacement of the right ventricular outflow tract (RVOT) substitute. An excessive dilatation of the neoartic root has also been described leading to a progressive regurgitation [8, 9]. Hence, it has been concluded that the long-term performance of the Ross procedure, when performed as an aortic root replacement, remains unclear and the application of aortic valve repair techniques or even the application of mechanical or bioprosthetic or homograft valve replacement has been suggested [7, 10–12].
Given this controversy about the management of aortic valve disease in children and teenagers, we analyzed retrospectively our experience with the Ross and the Ross-Konno procedure in patients younger than 15 years of age. The results are presented in this study.
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Material and Methods |
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Thirty-four of the 52 patients had previously undergone one or more interventions. These procedures are listed in Table 1. Preoperatively, 6 patients showed severe left ventricular dysfunction, with 2 of the patients requiring intubation and inotropic support.
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A standard technique of complete root replacement with coronary transfer was used for the Ross procedure with running sutures. No pledgets were used. The neoaortic root was reinforced with a circumferentially placed glutaraldehyde-tanned strip of autologous pericardium. Sixteen patients with LVOT obstruction underwent a Ross-Konno procedure. The ventriculoplasty incision was closed with a glutaraldehyde-tanned heterologous pericardial patch and in smaller children by using the muscular wall of the autograft.
A pulmonary homograft was preferentially used for pulmonary valve replacement when available in the appropriate size. Twenty-five patients received a pulmonary homograft, 5 patients received an aortic homograft, and 22 patients received heterografts. The diameters of the pulmonary valve replacements ranged from 11 to 28 mm (median, 18 mm). Allografts were not matched for blood group type of the recipient. For a harmonious enlargement of the RVOT and to avoid a buldging of the autograft into the RVOT, two small triangulated pericardial patches were implanted bilaterally to the septal patch enlargement during the Ross-Konno procedure, as shown in Figure 2. That allowed a more circular shaping of the RV ostium.
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The immediate postoperative result was assessed by echocardiography in all patients in the intensive care unit on the day of surgery. Further echocardiography studies were obtained preoperatively, early postoperatively, before discharge, and annually thereafter. Autograft valve function, homograft or RVOT conduit valve function, and left ventricular function were assessed by M-mode, two-dimensional echocardiography and by color flow Doppler.
Statistical analysis was performed using SPSS-11 (SPSS, Chicago, Illinois). Descriptive statistics are expressed as median and range. The Kaplan-Meier method was used to determine event-free survival curves.
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Results |
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Patients were followed up to 10 years with a median follow-up of 43 months (range, 1 to 130). For 14 patients (27%), follow-up was not complete owing to their postoperative return to their home countries overseas. Twenty-one patients were followed up for more than 3 years, 15 for more than 5 years, 9 for more than 8 years, and 3 for more than 10 years.
Overall survival was 85% ± 5% at 1 and 82% ± 5% at 2, 5, and 10 years (Fig 3). Six patients died in the group of 36 patients undergoing a Ross procedure (17%; 95% confidence interval: 6.4% to 33%), whereas 2 patients died after a Ross-Konno procedure (12.5%; 95% confidence interval: 1.5% to 39%). Five patients (9.6%; 95% confidence interval: 3.2% to 21%) were in-hospital deaths. Two of these patients underwent a Ross-Konno procedure. All deaths occurred in neonates or infants younger than 2 months of age. Details are given in Table 2. Three patients died late (7, 11, and 24 months postoperatively) of noncardiac causes. Consequently, the survival from cardiac causes of death was 90% ± 4% at 1, 5, and 10 years.
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Overall freedom from reoperation was 97% ± 2% at 1, 84% ± 7% at 4, 69% ± 12% at 8, and 57% ± 15% at 10 years.
Reoperation on the pulmonary autograft was required in 1 patient at 6 months after a Ross procedure for progressive aortic insufficiency and root dilatation. The patient underwent a Bentall procedure with implantation of a mechanical valve prosthesis. The development of mild aortic insufficiency was observed in 24 patients (16 patients after the Ross procedure, 8 patients after the Ross-Konno procedure) and moderate aortic insufficiency in 1 patient (Ross procedure) during follow-up.
Freedom from reoperation for the RVOT replacement was 96% ± 3% at 2, 87% ± 7% at 4, 72% ± 12% at 8, and 60% ± 15% at 10 years (Fig 4).
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Comment |
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The excellent 0% rate for early mortality reported by Hraska and associates [16] was found in a group of 66 patients with a median age of 13 years. Marino and associates [17] also report an early mortality rate of only 1.5% in a group of 66 patients but with a mean age of 10.8 years. Similarly, Elkins and associates [15] report an operative mortality of 3% of a cohort of 178 children with a median age of 10 years, excluding 3 patients operated on urgently. Comparable to this series in regard to age, Al-Halees and associates [18] report a group of 136 patients with a median age of 5.5 years and find also a much lower mortality rate of 5.5%. However, only 7.3% of those patients were less than 2 years of age compared with 32% of patients in our report. Furthermore, the number of previous interventions was lower when compared with our patient group (29 of 136 [21%] versus 34 of 52 [65%]).
It appears that young age represents a risk factor for mortality among patients undergoing the Ross procedure. All 5 in-hospital deaths in this study were of patients less than 2 months of age, and all of these patients were operated on urgently with the majority (3 of 5) for severe aortic insufficiency after percutaneous balloon valvuloplasty (PBV). During recent years, the strategy at our institution regarding the management of severe aortic stenosis in neonates and infants has changed by avoiding PBV and by preferably performing surgical valvulotomy [19]. We are aware that this strategy is controversial, and that other groups report excellent results using PBV as the first approach to aortic stenosis [20, 21]. If the patients operated on urgently in this study (all 5 patients in the 30-day-mortality group) were excluded, early mortality would approach lowest values. In general, we believe that a individualized strategy for the management of congenital aortic stenosis, with its options of PBV or surgical valvulotomy, might provide better results in neonates and infants. This strategy could reduce the need for emergent interventions due to severe aortic insufficiency after PBV and might also provide better long-term performance of the aortic valve, permitting delay of the Ross procedure. As shown in a study by our group on the results of surgical valvulotomy in 36 neonates over a period of 15 years, especially the outcome of neonates with a poor left ventricular function is difficult to predict, and it might be the case that the result one achieves depends more on what one starts with than on the initial management by PBV or surgical valvulotomy [19, 22].
An additional potential risk factor for mortality after the Ross procedure in infants might be the existence of multilevel left heart obstructions with mitral valve involvement. The outcome of such patients is generally poor [23]. Of the 4 patients diagnosed with a Shone complex in this study, 2 patients aged 4 days and aged 2 months died on postoperative days 0 and 10, respectively.
The Ross procedure is an advantageous approach to the management of patients with a hypoplastic aortic annulus or diffuse LVOT. The excellent exposure of the LVOT and the ventricular septum facilitates the performance of the septal incision and the enlargement of the Konno modification. None of the 16 patients undergoing a Konno modification has had a restenosis of the LVOT.
The concept of the Ross procedure jeopardizes two valves by potentially creating a "two-valve disease" for a single-valve problem. The arguments against the Ross procedure as the procedure of choice for young patients requiring aortic valve replacement are strengthened by a number of reports describing the dilatation of the autograft as a significant cause of aortic insufficiency and necessity for reinterventions [24, 25]. On the contrary, other studies have not observed any such progression of aortic insufficiency despite finding the dilatation of the autograft annulus, sinuses of Valsalva, and of the sinotubular junction [9, 26–28].
Reoperation for progressive aortic insufficiency and root dilatation was required in 1 patient of this study at 6 months after the Ross procedure; but a morphologically abnormal pulmonary valve was utilized in this patient. Such an early development of significant neoaortic regurgitation has been described to be associated with using a morphologically abnormal pulmonary valve for the Ross procedure [17]. The development of mild aortic insufficiency was observed in 24 of the 52 patients (46%), and only in 1 patient was moderate aortic insufficiency found. There was no difference found between patients who had undergone a Ross or a Ross-Konno procedure (47% versus 50%). In all other patients, long-term autograft function has been excellent with no evidence of deterioration at as long as 10 years of follow-up.
Given these findings, we think that the functional long-term outcome of the neoaortic valve is encouraging, and we are supported by similar data from others. Al-Halees and associates [18] reported on the development of moderate aortic insufficiency in 3 of 136 patients (mean follow-up, 4 years), Hraska and associates [16] in 2 of 66 patients (median follow-up, 2.4 years), and Williams and associates [29] found no significant autograft insufficiency in their series of 27 infants (median follow-up, 6.1 years). Elkins and associates [15] reported 12 autograft valve reoperations (6.7%) in a group of 178 children. For 8 of these patients, the indication for reoperation was progressive autograft insufficiency, and in 2 of the patients, aneurysmal dilatation of the root. Interestingly, among the 8 patients with autograft valve insufficiency, 4 patients underwent intra-aortic implants. The other autografts were performed as root replacements, of which 2 used bicuspid pulmonary valves. Such findings might have to be considered when thinking about performing the Ross procedure as an inclusion type procedure (ie, freehand subcoronary aortic valve replacement) to avoid late autograft insufficiency. In the present study, the root replacement technique was used in all patients with additional reinforcement of the aortic annulus with a strip of autologous pericardium. We believe that this technique might help to prevent annular dilatation.
Freedom from pulmonary valve replacement after the Ross procedure was 60% ± 15% at 10 years of follow-up. Six patients underwent the replacement of stenotic valves. The median time to reoperation was 45 months. One patient underwent a percutaneous balloon dilatation of the RVOT conduit at 7 years after the implantation. Elkins and associates [15] report freedom from reoperation of 90% ± 4% at 12 years of follow-up. However, these results have to be tempered for young patients, who are fast growing, and the placement of the homograft is limited by the thoracic volumen. Our data indicate that reoperation for exchange of the pulmonary conduit is likely to be necessary in many patients during their later childhood or adolescence. Significant differences of the durability of the various applied conduits could not be found. Among the 7 patients requiring interventions or replacements were 4 pulmonary homografts showing durability between 24 to 42 months, and 2 xenograft conduits with a durability of 49 and 97 months. In general, our preference is to utilize a pulmonary homograft for RVOT reconstruction and to place the largest conduit possible at the time of the operation.
Summarizing our 10-year experience, we think that the Ross operation presents an attractive option for the management of aortic valve disease and complex LVOT obstruction in young children. However, a high early mortality rate might have to be considered when performing this procedure in infants who present in critical preoperative condition or who have multilevel left heart obstructions with mitral valve involvement. The reintervention rate was found to be low, and no significant autograft insufficiency has developed. Given the limitations of this study, the retrospective nature of data collection, and the incomplete follow-up, however, a continued monitoring of the neoaortic function is warranted in these young patients to assess the future development of the autograft.
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