Critical Aortic Stenosis in Early Infancy: Surgical Treatment for Residual Lesions After Balloon Dilation

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1 Critical Aortic Stenosis in Early Infancy: Surgical Treatment for Residual Lesions After Balloon Dilation Vladimiro L. Vida, MD, Tomaso Bottio, MD, Ornella Milanesi, MD, Elena Reffo, MD, Roberta Biffanti, MD, Raffaele Bonato, MD, and Giovanni Stellin, MD Departments of Cardiovascular Surgery, Pediatric Cardiac Surgery Unit, Pediatrics, and Anaesthesia, University of Padova Medical School, Padova, Italy Background. The optimal management for critical aortic stenosis in early infancy continues to challenge cardiologists and cardiac surgeons. We present a review of our experience with the surgical treatment of residual aortic valve disease after percutaneous balloon dilation for critical aortic stenosis in early infancy. Methods. Since 1989, 11 of the 38 patients who survived aortic balloon dilation (28.9%) have undergone surgical treatment for residual aortic valve dysfunction. Median time from aortic balloon dilation to surgical intervention was 7 months (range 1 to 56 months). Residual aortic stenosis was the predominant problem in 8 patients and aortic regurgitation was predominant in 2 patients. Results. Aortic valvuloplasty was possible in 5 children; pulmonary autograft replacement of the aortic valve was performed in 6 children. Two children underwent a Ross-Konno procedure because of annulus hypoplasia and severe left ventricular outflow tract obstruction. Two early deaths occurred after a Ross-Konno procedure, both with findings of severe left ventricular fibroelastosis at the pathologic examination. Median follow-up time was 5 years (range 1 month to 11.9 years). No late deaths occurred. One patient with moderate-severe aortic valve regurgitation after aortic valvuloplasty underwent a successful Ross operation. All 9 patients are asymptomatic and are in good clinical condition. Conclusions. We are convinced that the best aortic valve in the pediatric age group is the native one, provided it can function acceptably. However, in cases where conservative surgical treatment fails to yield a functional aortic valve, replacement of the valve is indicated, and the best aortic valve substitute in infants is the pulmonary autograft because of its potential for growth. (Ann Thorac Surg 2005;79:47 52) 2005 by The Society of Thoracic Surgeons The treatment of critical aortic stenosis in early infancy continues to be a challenge for pediatric cardiologists and cardiac surgeons, and the optimal management strategy remains controversial [1]. Aortic valve balloon dilation has become the procedure of choice in many centers for the treatment of critically ill infants with severe aortic valve disease [2]. However, reports of surgical results in infants indicate that repair of the aortic valve can be performed with low risk and with 85% freedom from reintervention at 5 years [3]. Some have suggested that these infants should be treated only by surgery, because it allows more precise plasty of the valve and may prolong the interval before a valve replacement must be attempted [3]. We present a study of our recent experience with infants who were treated surgically after aortic valve balloon dilation for severe aortic valve stenosis in the first 3 months of life. Accepted for publication Feb 3, Address reprint requests to Dr Vida, Department of Cardiovascular Surgery, Pediatric Cardiac Surgery Unit, University of Padova Medical School, Via Giustiniani, Padova, Italy; vladimirovida@ interfree.it. Material and Methods Since 1989, 40 infants ( 3 months of age) have undergone primary percutaneous balloon dilation with a transcarotid approach (direct puncture of the right carotid artery) for severe aortic valve stenosis (peak aortic transvalvar gradient 75 mm Hg). Two other infants were considered for valve dilation during this period, but instead underwent a univentricular repair [4, 5] because the left ventricle was hypoplastic (left ventricular enddiastolic volume 20 ml/m 2 ). Median age at the balloon dilation procedure was 17 days (range 1 to 80 days). There was one death (2.6%) from ventricular fibrillation related to the procedure and one serious complication (2.6%), a fistula between the aorta and the right atrium that was closed surgically 2 days later. No complications were related to the transcarotid approach, and a right carotid Doppler at discharge was normal in all patients. One patient died 3 months after the procedure with findings of severe endocardial fibroelastosis at the postmortem examination. Between January 1990 and April 2001, 11 of the 38 patients who survived aortic balloon dilation (28.9%) underwent surgical treatment for residual aortic valve disfunction. The median time from aortic balloon dilation 2005 by The Society of Thoracic Surgeons /05/$30.00 Published by Elsevier Inc doi: /j.athoracsur

2 48 VIDA ET AL Ann Thorac Surg SURGICAL TREATMENT FOR RESIDUAL LESIONS 2005;79:47 52 to surgical intervention was 7 months (range, 1 to 56 months). The median age at surgical treatment was 7 months (range, 2 to 59 months). Four children presented with congestive heart failure, the remaining 7 were asymptomatic and underwent elective valve repair. The electrocardiogram showed sinus rhythm in all. Mean cardiothoracic ratio was 0.57, ranging from 0.51 to All of the children were evaluated preoperatively by means of two-dimensional echocardiography and color flow Doppler. Aortic stenosis was the primary residual problem in 8 patients. The transaortic gradient was between 50 and 70 mm Hg (median, 56 mm Hg). Aortic regurgitation was the predominant problem in 3 patients (moderate in 2 and severe in 1). Left ventricular hypertrophy was present in all. Preoperatively, 4 patients had severe left ventricular dysfunction, and signs of left ventricular fibroelastosis were present in 2 patients. Associated cardiac lesions that were repaired at the same operation included subaortic discrete fibrous membrane (3 patients), mitral valve dysplasia with predominant stenosis (2 patients), and aortic arch hypoplasia (1 patient). Two patients had undergone cardiac surgery previously. Patient 6 (Table 1) had coarctation repair and patient 11 (Table 1) had aorto-right atrial fistula closure. Twenty-seven of the 38 long-term survivors of aortic valve dilation have had no surgical intervention on the aortic valve. All are followed regularly with clinical and echocardiographic monitoring. Seven patients underwent further balloon valvuloplasty of the aortic valve for restenosis (transaortic gradient 50 mm Hg). All were asymptomatic at the last follow-up. The peak transaortic gradient was less than 40 mm Hg in all. Aortic regurgitation was moderate in 6 patients and mild in 1 patient. None of them is awaiting surgical repair. Surgical Technique All patients underwent intraoperative transesophageal or epicardial (patients 6 kg body weight) echocardiography [6]. Particular attention was paid to the aortic valve morphology and the mechanism of valve dysfunction. After aorto-bicaval cardiopulmonary bypass with moderate systemic hypothermia was established, aortic crossclamping and antegrade/retrograde blood cardioplegia was employed in all. The aortic valve was exposed through a transverse aortotomy and carefully inspected. The aortic valve was bicuspid in 8 patients and tricuspid in the other 3 patients. Valve dysfunction was because of combined anatomic factors such as dysplastic and thickened leaflets (6 patients), leaflet fusion at the commissures (5 patients), annulus hypoplasia (2 patients), torn leaflet after balloon valvuloplasty (2 patients), fibrous subaortic stenosis causing aortic valve leaflet distortion (1 patient), and pseudocommissure distorting the valve leaflet (1 patient). Figure 1 shows the surgical findings for these patients. Details of the surgical techniques that were used in each patient are summarized in Table 1 and shown in Figure 2. Fig 1. Surgical findings: (1) bicuspid aortic valve with congenital (2) bicuspid aortic valve with torn leaflet after balloon valvuloplasty, (3) bicuspid aortic valve with dysplastic and thickened leaflet, (4) fibrous subaortic valve membrane causing aortic leaflet distortion, (5) bicuspid aortic valve with a pseudocommissure distorting the valve leaflet. Results Conservative treatment of the aortic valve was possible in 5 children, although in 6 a pulmonary autograft replacement of the aortic valve was performed. Two children, patients 6 and 11 (Table 1), also underwent a ventriculoseptoplasty in association with the Ross procedure (Ross-Konno procedure) because of annulus hypoplasia and severe left ventricular outflow tract obstruction. The Z-value of the aortic valve annulus was 1.5 in patient 6 and 1.8 in patient 11. No deaths occurred among the reconstruction group (5 patients). Two early deaths occurred in the valve replacement group (6 patients); both had undergone a Ross-Konno procedure. The postmortem examination in both infants disclosed severe endocardial fibroelastosis. No child underwent early reoperation. The final decision whether to perform an aortic valvuloplasty or a Ross operation was made after direct inspection of the aortic valve to evaluate its potential for repair.

3 Table 1. Patients: Preoperative, Operative, and Follow-Up Data Pt Age (mos) Sex AOV disfunction after BAV Interval between BAV and surgery (mos) Surgical aortic valve findings Type of operation 1 59 male Aortic regurgitation 56 Bicuspid aortic valve, Torn leaflet, Pseudocommissure distorting valve leaflet 2 3 male Aortic stenosis 2 Bicuspid aortic valve, 3 34 female Aortic stenosis 33 Tricuspid aortic valve, 4 38 male Aortic stenosis 36 Bicuspid aortic valve, thickened Leaflets 5 7 female Aortic stenosis 6 Bicuspid aortic valve, commissural fusion 6 8 female Aortic stenosis 8 Bicuspid aortic valve, Aortic valve annulus hypoplasia, LV fibroelastosis 7 7 male Aortic regurgitation 6 Tricuspid aortic valve, 8 8 male Aortic stenosis 7 Bicuspid aortic valve, thickened leaflets 9 2 male Aortic stenosis 1 Bicuspid aortic valve, female Aortic regurgitation 10 Bicuspid aortic valve, torn leaflet 11 5 male Aortic stenosis 5 Tricuspid aortic valve, Aortic valve annulus hypoplasia, LV fibroelastosis thickened leaflets Pt patient; mos months; BAV balloon aortic valvuloplasty; PM papillary muscles; LV left ventricle. Cusp repair, Cusp resuspenction, pseudocommissure release Associated procedures Subaortic stenosis resection Outcome Survived Follow-up (years postop.) Asymptomatic (0.1) Commissurotomy Coarctation repair Survived Asymptomatic (11.9) Commissurotomy, Subaortic stenosis Survived Asymptomatic freeing of aortic resection, (5.2) valve leaflet from mitral valve subaortic commissurotomy membrane and PM splitting Commissurotomy, leaflet shaving Subaortic stenosis resection Survived Asymptomatic (6.8) Commissurotomy... Survived Asymptomatic (11.4) Ross-Konno... Died... (3.2) (3.7) (4.3) (5.0) Ross-Konno Mitral valve PM Died... splitting Ann Thorac Surg VIDA ET AL 2005;79:47 52 SURGICAL TREATMENT FOR RESIDUAL LESIONS 49

4 50 VIDA ET AL Ann Thorac Surg SURGICAL TREATMENT FOR RESIDUAL LESIONS 2005;79:47 52 outflow tract obstruction was detected in the patients who underwent a Ross procedure, and none had more than mild homograft regurgitation. Fig 2. Surgical procedures: (1) surgical commissurotomy, (2) aortic valve leaflet repair with direct suture, (3) aortic valve leaflet resuspension at the commissure, (4) freeing of the aortic valve leaflet from the subaortic membrane, (5) pseudocommissure release with mobilization of the valve leaflet, (6) aortic valve leaflet shaving (removal of accessory fibrous tissue from aortic valve leaflet). When the valve was judged severely dysplastic, we did not attempt repair but performed a Ross operation. In our series, no Ross procedures were performed after attempted conservative surgery on the aortic valve. Follow-Up A complete clinical and echocardiographic follow-up was obtained in all 9 survivors. No late deaths occurred. One patient with residual moderate-severe aortic valve regurgitation after surgical aortic valvuloplasty underwent a successful Ross operation 6 years after the initial surgical repair (patient 1, Table 1). Median follow-up time was 5 years, ranging from 1 month to 11.9 years. All patients are asymptomatic and in good clinical condition. Eight patients have mild aortic valve regurgitation and 1 patient, who underwent a Ross operation, has moderate regurgitation. No patient has residual stenosis of the aortic valve (gradient 15 mm Hg in all). No right ventricular Comment Even today, no consensus exists as to the best treatment for critical aortic stenosis in newborns and infants. Aortic valve balloon dilation has become the procedure of choice in many centers [2]. However, incomplete relief of the valvar stenosis and significant aortic regurgitation are well-documented residua after percutaneous balloon dilation [7]. In our institution, critical aortic stenosis in early infancy has been treated routinely with primary balloon dilation since 1989, with a low early mortality (2.9%) and a low incidence of complications (2.9%). However, significant valve dysfunction remains in about 30% of patients. Recent reports in the literature show that in newborns and infants with critical aortic stenosis, the aortic valve can be exposed by conventional cardiopulmonary bypass and that precise commissurotomy, shaving of thickened leaflets, excision of obstructive myxomatous nodularities, and mobilization of leaflets can be performed with a very low surgical risk and 85% freedom from reoperation at 5 years [3, 8 10]. In our experience with the complementary use of balloon dilation and surgical valvuloplasty in the management of infantile critical aortic stenosis, nearly all of the patients could be successfully managed by balloon dilation alone, with low mortality and morbidity. In the patients that did not respond as favorably to balloon dilation, subsequent surgical intervention was successful in 80%, and valve repair was done in nearly half of the patients. We believe this cooperative approach between interventional cardiologists and cardiac surgeons provided excellent results in this group of very difficult patients. Further, our experience demonstrates that primary balloon dilation does not reduce the likelihood of subsequent successful surgical repair or replacement of the valve. In some cases, surgical treatment fails to adequately improve valve function, and aortic valve replacement is indicated. The selection of the most appropriate substitute in infants with irreparable aortic valve lesions remains controversial. Prosthetic valve replacement in infants requires an extensive aortoventriculoplasty (Konno procedure) to insert even the smallest size of prosthetic valve available (16 mm). The mechanical prosthesis imposes the risk of thromboembolism and the need for anticoagulation, which is particularly cumbersome in infants and children. Repeated prosthetic valve replacement will be needed during childhood because of somatic growth [11]. The Ross procedure has been suggested recently as the treatment of choice in infants with critical aortic stenosis, particularly when it is associated with other left-sided heart anomalies. Although we, and others, [12] prefer this approach in infants with unsuitable anatomy for valvesparing surgery, it is clearly not a curative operation.

5 Ann Thorac Surg VIDA ET AL 2005;79:47 52 SURGICAL TREATMENT FOR RESIDUAL LESIONS Some pulmonary autograft valves deteriorate and must be replaced. Further, the homograft in the pulmonary position does not grow and in infants, inevitably becomes stenotic and must be replaced [13 16]. Because there is no long-lasting solution for aortic valve replacement in infants, conservative surgical aortic valve treatment has enjoyed a revival recently [17]. Undoubtedly, the best aortic valve in children is the natural one, provided the valve functions adequately. For this reason, pediatric cardiac surgeons must concentrate their efforts on preserving the native valve, whenever possible. Careful intraoperative epicardial or transesophageal two-dimensional echocardiography and Doppler were performed in all of our patients. The preoperative evaluation led to a better understanding of the valve morphology and pathology and helped us to plan the most appropriate surgical reconstruction. The postoperative echocardiogram confirmed the results of the surgical reconstruction. Any type of treatment for aortic stenosis in newborns and infants is palliative, and future aortic valve replacement is inevitable. In light of the actual results with aortic valve replacement, reconstructive surgery must be the primary objective for any valve with the aim of postponing aortic valve replacement until adolescence or adulthood. We thank Professor Stephen Pruett Sanders for kindly reviewing the manuscript. References 1. Hawkins JA, Minich LL, Shaddy RE, et al. Aortic valve repair and replacement after baloon aortic valvuloplasty in children. Ann Thorac Surg 1996;61: Jindal RC, Saxena A, Juneja R, Kothari SS, Shrivastava S. Long-term results of balloon aortic valvulotomy for congenital aortic stenosis in children and adolescents. J Heart Valve Dis 2000;9: Alexiou C, Langley SM, Dalrymple-Hay MJR, et al. Open commissurotomy for critical isolated aortic stenosis in neonate. Ann Thorac Surg 2001;71: Hammon JW, Lupinetti FM, Maples MD, et al. Predictors of operative mortality in critical valvular aortic stenosis presenting in infancy. Ann Thorac Surg 1988;45: Rhodes LA, Colan SD, Perry SB, Jonas RS, Sanders SP. Predictors of survival in neonates with critical aortic stenosis. Circulation 1991;84: Ungerleider RM, Greeley WJ, Sheikh KH, et al. Routine use of intraoperative echocardiography and Doppler color flow imaging to guide and evaluate repair of congenital heart lesions. A prospective study. J Thorac Cardiovasc Surg 1990;100: Bacha EA, Satou GM, Moran AM, et al. Valve-sparing operation for balloon-induced aortic regurgitation in congenital aortic stenosis. J Thorac Cardiovasc Surg 2001;122: Lamberti JJ. The aortic valve: to dilate, repair or replace that is the question. Ann Thorac Surg 1996;61: Detter C, Fischlein T, Feldmeier C, Nollert G, Reichart B. Aortic valvotomy for congenital valvular aortic stenosis: a 37 years experience. Ann Thorac Surg 2001;71: Gaynor JW, Bull C, Sullivan ID, et al. Late outcome of survivors of intervention for neonatal aortic valve stenosis. Ann Thorac Surg 1995;60: Alexiou C, McDonald A, Langley SM, Dalrylmple-Hay MJ, Haw MP, Monro JL. Aortic valve replacement in children: are mechanical prostheses a good option? Eur J Cardiothorac Surg 2000;17: Laudito A, Brook MM, Suleman S, et al. The Ross procedure in children and young adults: a word of caution. J Thorac Cardiovasc Surg 2001;122: Solymar L, Sudow G, Holmgren D. Increase in size of the pulmonary autograft after the Ross operation in children: growth or dilatation? J Thorac Cardiovasc Surg 2000;119: Simon P, Ashauer C, Moidl R, et al. Growth of the pulmonary autograft after the Ross operation in childhood. Eur J Cardiothorac Surg 2001;19: David TE, Omran A, Ivanov J, et al. Dilation of the pulmonary autograft after the Ross Procedure. J Thorac Cardiov Surg 2000;119: Ishizaka T, Devaney EJ, Ramsburgh SR, Suzuki T, Ohye RG, Bove EL. Valve sparing aortic root replacement for dilatation of the pulmonary autograft and aortic regurgitation after the Ross procedure. Ann Thorac Surg 2003;75: Bogers AJJC, Takkenberg JJ, Kappetein JP, de Jong PL, Cromme-Dijkhuis A, Witsenburg M. Is there a place for pediatric valvotomy in the autograft era? Eur J Cardiothorac Surg 2001;20: INVITED COMMENTARY As with so many things in life, the outcome depends on what you start with. Young infants with aortic stenosis most commonly have bicuspid valves with cuspal fusion, or the valves may be tricuspid or even monocuspid. A perfect result is unlikely to be achieved with any intervention. This interesting article from Padova describes 40 infants who had balloon valvotomy in a 13-year period. Of the 38 survivors, 11 required aortic valve surgery (with good results) within a mean of 7 months and 8 within 1 year. A further 7 patients had repeat ballooning. This compares unfavorably with the best reports of open surgical valvotomy in neonates, where freedom from reoperation on the aortic valve has been reported as 85% and 50% at 5 and 10 years, respectively. It is not surprising that a longer-lasting result can be achieved by direct surgical intervention, where exact splitting of fused commissures and shaving off of obstructing nodules can produce the maximum valve orifice without causing regurgitation. Ballooning has become the method of choice in most units throughout the world. However, the devastating results of a torn leaflet causing early severe regurgitation will require emergency surgery. It may not be possible to repair the valve, and the only realistic treatment is a Ross procedure. Therefore, all balloonists should have surgical backup with surgeons experienced with the Ross procedure. It is interesting that of the 11 patients in this series, only 2 had torn leaflets; the others mostly had residual stenosis. This would suggest that the cardiologists erred on the side of caution and a good thing too. It is clear 2005 by The Society of Thoracic Surgeons /05/$30.00 Published by Elsevier Inc doi: /j.athoracsur