Valve-sparing operation for balloon-induced aortic regurgitation in congenital aortic stenosis

Biofabrication in Congenital Cardiac Surgery: A Plea from the Operating Theatre, Promise from Science

Despite significant advances in numerous fields of biofabrication, clinical application of biomaterials combined with bioactive molecules and/or cells largely remains a promise in an individualized patient settings. Three-dimensional (3D) printing and bioprinting evolved as promising techniques used for tissue-engineering, so that several kinds of tissue can now be printed in layers or as defined structures for replacement and/or reconstruction in regenerative medicine and surgery. Besides technological, practical, ethical and legal challenges to solve, there is also a gap between the research labs and the patients' bedside. Congenital and pediatric cardiac surgery mostly deal with reconstructive patient-scenarios when defects are closed, various segments of the heart are connected, valves are implanted. Currently available biomaterials lack the potential of growth and conduits, valves derange over time surrendering patients to reoperations. Availability of viable, growing biomaterials could cancel reoperations that could entail significant public health benefit and improved quality-of-life. Congenital cardiac surgery is uniquely suited for closing the gap in translational research, rapid application of new techniques, and collaboration between interdisciplinary teams. This article provides a succinct review of the state-of-the art clinical practice and biofabrication strategies used in congenital and pediatric cardiac surgery, and highlights the need and avenues for translational research and collaboration.

The great debate series: surgical treatment of aortic valve abnormalities in children

This article is the latest in an EJCTS series entitled 'The Great Debates'. We have chosen the topic of aortic valve (AoV) surgery in children, with a focus on infants and neonates. The topic was selected due to the significant challenges that AoV problems in the young may present to the surgical team. There are many areas of active controversy, despite the vast accumulated world experience. We have tried to incorporate many of these issues in the questions posed, not claiming to be all-inclusive. The individuals invited to this debate are experts in paediatric valve surgery, with broad and successful clinical experiences on multiple continents. We hope that the facts and opinions presented in this debate will generate interest and discussion and perhaps prove useful in decision-making for future complex valve cases.

Long-term outcome of congenital aortic valve stenosis: predictors of reintervention

OBJECTIVES

To evaluate long-term outcome of initial aortic valve intervention in a paediatric population with congenital aortic stenosis, and to determine risk factors associated with reintervention.

PATIENTS AND METHODS

From 1985 to 2009, 77 patients with congenital aortic stenosis and a mean age of 5.8±5.6 years at diagnosis were followed up in our institution for 14.8±9.1 years.

RESULTS

First intervention was successful with 86% of patients having a residual peak aortic gradient 1 regurgitation increased by 7%. Long-term survival after the first procedure was excellent, with 91% survival at 25 years. At a mean interval of 7.6±5.3 years, 30 patients required a reintervention (39%), mainly because of a recurrent aortic stenosis. Freedom from reintervention was 97, 89, 75, 53, and 42% at 1, 10, 15, 20, and 25 years, respectively. Predictors of reintervention were residual peak aortic gradient (p=0.0001), aortic regurgitation post-intervention >1 (p=0.02), prior balloon aortic valvuloplasty (p=0.04), and increased left ventricular posterior wall thickness (p=0.1).

CONCLUSIONS

Aortic valve intervention is a safe and effective procedure for congenital aortic stenosis with excellent survival results. However, rate of reintervention is high and influenced by increased left ventricular posterior wall thickness pre-intervention, prior balloon valvuloplasty, higher residual peak systolic valve gradient, and more than mild regurgitation post-intervention. The study highlights that long-term follow-up is recommended for these patients.

Mixed aortic valve disease in the young: initial observations

The short-term surgical results for mixed aortic valve disease (MAVD) and the long-term effects on the left ventricle (LV) are unknown. Retrospective review identified patients with at least both moderate aortic stenosis (AS) and aortic regurgitation (AR) before surgical intervention. A one-to-one comparison cohort of patients with MAVD not referred for surgical intervention was identified. The 45 patients in this study underwent surgical management for MAVD. A control group of 45 medically managed patients with MAVD also was identified. Both groups had elevated LV end-diastolic volume (EDV), elevated LV mass, a normal LV mass:volume ratio (MVR), and a normal ejection fraction. Both groups had diastolic dysfunction shown by early diastolic pulsed-Doppler mitral inflow/early diastolic tissue Doppler velocity z-score. The LV end-diastolic pressure (EDP) was correlated with age (R = 0.4; p = 0.03) and LV MVR (R = 0.4; p = 0.03) but not with AS, AR, or the score combining gradient and LV size. As shown by 6- to 12-month postoperative echocardiograms, aortic valve gradients and AR significantly improved (gradient 65 ± 17 to 28 ± 18 mmHg, p = 0.01; median regurgitation grade moderate to mild; p < 0.01), LV EDV normalized, and LV mass significantly improved (p < 0.01). Diastolic dysfunction was unchanged. Symptoms did not correlate with any measured parameter, but the preoperative symptoms resolved. In conclusion, despite diastolic dysfunction, systolic function is invariably preserved, and symptoms are not correlated with aortic valve function or LV EDP. Current surgical practice preserves LV mechanics and results in short-term improvement in valve function and symptoms.

Aortic valve repair and replacement in children

ABSTRACT: Several aortic valve (AV) pathologies might necessitate intervention. Percutaneous or surgical AV repair is generally recommended as the initial management strategy in children with AV disease, offering the advantage of stabilization of the heart dimensions and improvement of patients‘ symptoms. When AV repair is not possible or fails, AV replacement is necessary and is associated with several challenges in children. This review will focus on treatment strategy, AV repair techniques, AV replacement choices and outcomes of AV disease management in children.

Selective tricuspidization and aortic cusp extension valvuloplasty: outcome analysis in infants and children

BACKGROUND

Encouraging early outcomes of emerging aortic cusp extension valvuloplasty techniques have redirected attention to nonreplacement strategies in the management of younger patients with aortic insufficiency or aortic stenosis. Outcome analysis after aortic cusp extension valvuloplasty in infants and children was undertaken.

METHODS

From July 1987 to December 2008, 78 patients younger than 10 years of age underwent aortic cusp extension valvuloplasty in the form of pericardial cusp extension and selective use of tricuspidization. Sixteen (20.5%) patients were younger than 1 year of age. Twenty-seven had bicuspid aortic valve, 34, congenital aortic valve stenosis, and 17, congenital or acquired aortic insufficiency or aortic stenosis. Forty-two patients had balloon valvuloplasty or surgical valvotomy before aortic cusp extension valvuloplasty. Median follow-up was 12.4 years (range, 0.1 to 21.6 years). Freedom from aortic valve replacement (AVR) and determinants of outcome were analyzed.

RESULTS

There were no early or late deaths. During the follow-up period, 23 patients (29.5%) had Ross operation and 8 patients (10.2%) had other AVR. The z values of left ventricular end-diastolic dimension, aortic annulus, aortic sinus diameter, sinotubular junction diameter, and left ventricular wall thickness before AVR were 3.8 +/- 2.95, 2.1 +/- 1.15, 4.2 +/- 1.22, 1.78 +/- 1.24, and 2.92 +/- 1.31, respectively. Actuarial freedom from AVR at 1, 5, and 10 years was 97.3 +/- 2.0%, 71.3 +/- 5.8%, and 55.6 +/- 6.9%, respectively.

CONCLUSIONS

Aortic cusp extension valvuloplasty with tricuspidization allows left ventricular reverse remodeling with satisfactory long-term durability and freedom from AVR. Used selectively, it represents a reliable and effective approach in infants and children with congenital or acquired abnormal aortic valve.

Aortic cusp extension valvuloplasty with or without tricuspidization in children and adolescents: long-term results and freedom from aortic valve replacement

OBJECTIVE

Aortic cusp extension valvuloplasty is increasingly used in the management of children and adolescents with aortic stenosis or regurgitation. The durability of this approach and the freedom from valve replacement are not well defined. A study was undertaken to investigate outcomes.

METHODS

From July 1987 to November 2008, 142 patients aged less than 19 years underwent aortic cusp extension valvuloplasty in the form of pericardial cusp extension and tricuspidization (when needed). Three patients with truncus arteriosus and severe truncal valve insufficiency were excluded. From the available follow-up data of 139 patients, 50 had bicuspid aortic valves, 40 had congenital aortic valve stenosis, 41 had combined congenital aortic valve stenosis/insufficiency, and 8 had other diagnoses. Median follow-up was 14.4 years (0.1-21.4). Long-term mortality and freedom from aortic valve replacement were studied.

RESULTS

There were no early, intermediate, or late deaths. Z-values of left ventricular end-diastolic dimension, aortic annulus, aortic sinus diameter, and sinotubular junction diameter before aortic valve replacement were 4.2 +/- 3.11, 2.3 +/- 1.25, 4.4 +/- 1.23, and 1.84 +/- 1.28, respectively. During the follow-up period, 64 patients underwent aortic valve reinterventions. The Ross procedure was performed in 32 of 139 patients (23%) undergoing aortic cusp extension valvuloplasty. Other aortic valve replacements were undertaken after 16 aortic cusp extension valvuloplasties (11.5%). Freedom from a second aortic cusp extension valvuloplasty or aortic valve replacement at 18 years was 82.1% +/- 4.2% and 60.0% +/- 7.2%, respectively.

CONCLUSION

Aortic cusp extension valvuloplasty is a safe and effective surgical option with excellent survival and good long-term outcomes in children and adolescents. The procedure provides acceptable durability and satisfactory freedom from aortic valve replacement.

Aortic valve repair for congenital and balloon-induced aortic regurgitation

Current techniques for aortic valve replacement in the child carry multiple disadvantages. Longer-term follow-up of the Ross procedure has documented disappointing late results for an increasing proportion of patients. Many challenges continue to face the development of a tissue-engineered valve with growth potential. In this setting, aortic valve repair is a useful temporizing procedure that allows a child to have an excellent quality of life, free from the need for anticoagulation and the risk of thromboembolism. Repair techniques are primarily based on the use of autologous pericardium to extend leaflets and support prolapsing leaflets. These methods appear to be particularly applicable in the setting of balloon-induced aortic valve regurgitation. An increasing number of centers are reporting satisfactory midterm results with aortic valve repair.

Bicuspidization of the unicuspid aortic valve: a new reconstructive approach

BACKGROUND

Unicuspid anatomy of the aortic valve is infrequent but may require intervention by age 40 for severe regurgitation. We propose a new repair technique for the regurgitant unicuspid valve by converting it into a bicuspid aortic valve.

METHODS

Between November 2003 and September 2007, 20 patients underwent regurgitant unicuspid aortic valve repair: 13 had aortic regurgitation (AR) and 7 had combined regurgitation and stenosis. Four patients had previously undergone balloon valvuloplasty for critical aortic stenosis. The aim of the repair was to construct a bicuspid valve with two normal commissures and unrestricted cusp motion. The fused cusp tissue was divided anteriorly and a new commissure of normal height was created. Noncoronary and right coronary cusps were extended with autologous pericardium. Concomitant operations included ascending aortic replacement in 7 and resection of subaortic stenosis in 1.

RESULTS

No early or late deaths occurred. Intraoperative echocardiography revealed minimal or no AR in 19 patients. Follow-up was 4 to 47 months. One patient underwent valve re-repair for recurrent and progressive aortic regurgitation 3 years postoperatively. All other valves remained stable throughout the follow-up period. Freedom from relevant aortic insufficiency (> or = II) at 4 years was 77%; freedom from reoperation was 67%; and freedom from valve replacement was 100%.

CONCLUSIONS

The regurgitant unicuspid aortic valve can be repaired successfully and reproducibly by converting it into bicuspid anatomy. The functional results are comparable with those obtained in reconstructed bicuspid aortic valves. With this approach, replacement can be avoided in most patients with regurgitant unicuspid aortic valves.

Outcome of Surgical Commissurotomy for Aortic Valve Stenosis in Early Infancy

BACKGROUND

The method of treatment of aortic valve stenosis in early infancy is still controversial. This study was performed to evaluate short-term and long-term outcome in our center during a 14-year period.

METHODS

Between 1991 and 2004, 64 consecutive patients younger than 3 months old underwent open surgical commissurotomy because of aortic valve stenosis. Median age was 18 days (range, 1 to 79 days), and median weight was 3.6 kg (range, 1.9 to 6.7 kg). Left ventricular function was good in 44 patients (69%), depressed in 12 (19%), and poor in 8 (12%). The study ended in July 2005. Median follow-up time was 4.1 years (range, 0.4 to 13.6 years).

RESULTS

The 30-day mortality was 3 of 64 patients and late mortality was 3 of 61, and the respective mortality in patients younger than 1 month old was 2 of 41 and 2 of 39. There was no early mortality after 1993 and no late mortality after 1999. Thirteen patients required reoperation. Median time to reoperation was 4.3 years (range, 0.2 to 11.3 years) and to aortic valve replacement (7 Ross and 1 homograft) was 6.9 years (range, 1.6 to 9.7 years). At the last follow-up, all had good left ventricular function and 57 of 58 had an ability index of 1.

CONCLUSIONS

Surgical commissurotomy for aortic valve stenosis during the first 3 months of life can be done with low mortality and morbidity. The risk for early recurrent stenosis or regurgitation is low, and the need for aortic valve replacement can, in most cases, be delayed until the child is older. The long-term functional ability is excellent.

Intermediate-term results of repair for aortic, neoaortic, and truncal valve insufficiency in children

OBJECTIVE

Repair of aortic valve insufficiency is difficult, and durability is relatively unknown in children. This study evaluates the intermediate-term results of repair of the systemic semilunar valve, including the native aortic valve, neoaortic valve (anatomic pulmonary), and truncal valve.

METHODS

We reviewed the records of 54 children (aged 2 days to 18 years) who underwent repair of the functional aortic valve for moderate or greater insufficiency from 1991 to 2005. Valve anatomy was tricuspid aortic in 26 patients, bicuspid aortic in 11 patients, tricuspid neoaortic in 9 patients, bicuspid neoaortic in 1 patient, and truncal valve in 7 patients. Multiple surgical techniques were used in most of the 54 patients, including leaflet plication in 17, leaflet repair in 15, commissuroplasty in 32, pericardial cusp augmentation in 8, and sinus of Valsalva reduction in 3.

RESULTS

There was 1 early death and no late deaths. Actuarial freedom from reoperation was 68% at 5 years and 58% at 10 years. Freedom from aortic valve replacement was 82% at 5 years and 73% at 10 years. Duration of cardiopulmonary bypass was the most significant risk factor for reoperation with multivariate analysis. Of the 40 patients who have not undergone reoperation, 37 have had follow-up echocardiograms with the latest study (4.5 +/- 4.2 years) demonstrating trace to 1+ insufficiency in 23 patients, 1 to 2+ in 12 patients, 2 to 3+ in 1 patient, and 3 to 4+ in 1 patient.

CONCLUSION

Repair of the insufficient systemic semilunar valve offers acceptable 10-year freedom from reoperation and functional results, and should be considered for most children.

Pericardial patch reconstruction of the congenitally diseased aortic valve

Congenital aortic valve disease manifests itself either in the course of its natural history or as a consequence of an intervention (balloon dilatation or surgery). In infancy, a congenital aortic valve presents with stenosis, in childhood and adolescence as slowly evolving regurgitation after primary intervention/surgery and in late adulthood, they re-emerge as stenosis due to natural degeneration and calcification of the fused leaflets. The surgical approach to a congenital aortic valve disease differs depending on whether it is a malformed or a normally laid down (tri-sinusoidal tricuspid) valve; it also differs depending on the type of deformity, dysfunction and valve tissue presenting at surgery. Acutely regurgitant aortic valve in a neonate or an infant after balloon dilatation of congenital aortic stenosis is an infrequently occurring difficult problem with few available options. This video presentation demonstrates a xenopericardial patch repair of the torn fused leaflet (fusion between the right and the noncoronary cusp) of a congenitally stenotic valve, followed by height augmentation of all the three leaflets. Because of the relative hypoplasia of the aortic annulus and the ascending aorta, the aortic root and proximal ascending aorta were enlarged by an oblong xenopericardial patch. The following text includes additional technical issues involved in congenital aortic valve repair. A brief summary of literature is presented.

Is the Ross procedure as good as we thought it would be?

For patients requiring intervention because of progressive disease of the aortic valve, the perfect palliation will provide a valve that produces normal dynamics of flow, will not require anti-coagulation, will grow with the patient, and have long term durability. Current surgical interventions include aortic valvoplasty, or replacement with either a mechanical or tissue prosthesis. Options for tissue valves include insertion of a pulmonary autograft in the Ross procedure, a cadaveric homograft, or porcine or bovine xenograft valves. The optimal option is still debated.

Current Perspective on Aortic Valve Repair and Valve-Sparing Aortic Root Replacement

Aortic valve repair and valve-sparing aortic root replacement are attractive concepts because they offer the possibility of valve competence without structural deterioration due to nonviability and they preclude the need for anticoagulation. Enthusiasm for aortic valve repair has waxed and waned over the past 45 years due in part to the inherent technical difficulties and poor mid-term results. Renewed interest in the concept of aortic valve repair has paralleled the development of valve-sparing aortic root replacement over the last 20 years. A current perspective on aortic valve repair and valve-sparing aortic root replacement is presented in the following review. Historical background, indications for repair, technical considerations, and outcomes data are discussed.

Left heart growth, function, and reintervention after balloon aortic valvuloplasty for neonatal aortic stenosis

BACKGROUND

Transcatheter balloon aortic valvuloplasty (BAVP) has become the first-line treatment for critical aortic stenosis (AS) in neonates. However, little is known about the growth and function of left heart structures or about patterns of reintervention on the left heart after neonatal BAVP.

METHODS AND RESULTS

Between 1985 and 2002, 113 patients underwent neonatal BAVP at < or =60 days of age. There were 16 early deaths (14%), with a significant decrease from 1985 to 1993 (22%) to 1994 to 2002 (4%), and 6 patients had successful early conversion to a univentricular circulation. In the short term, the mean relative gradient reduction was 54+/-26%, and significant aortic regurgitation (AR) developed in 15% of patients. The 91 early survivors with a biventricular circulation were followed up for 6.3+/-5.3 years, during which time there was a steady increase in the frequency of significant AR. Freedom from moderate or severe AR was 65% at 5 years. In almost all patients with a baseline aortic annulus z score less than -1, the annulus diameter increased to within the normal range within 1 to 2 years. Similarly, left ventricular (LV) end-diastolic dimension z scores, which ranged from -5 to 7.5 before BAVP, normalized within 1 to 2 years in nearly all patients with a predilation z score less than -1. Among early survivors with a biventricular circulation, reintervention-free survival on the LV outflow tract was 65% at 1 year and 48% at 5 years, with younger age, higher pre- and post-BAVP gradients, and a larger balloon-annulus diameter ratio associated with decreased reintervention-free survival (P<0.01). Seventeen surgical interventions were performed on the aortic valve in 15 patients, including replacement in 7. Survival free from aortic valve replacement was 84% at 5 years.

CONCLUSIONS

BAVP for AS during the first 60 days of life results in short-term relief of AS in the majority of patients. Among early survivors, initially small left heart structures may be associated with worse subacute outcomes but typically normalize within 1 year. Reintervention for residual/recurrent AS or iatrogenic AR is relatively common, particularly during the first year after BAVP, but aortic valve replacement during early childhood is seldom necessary.

Aortic valve repair

Aortic valve replacement options are limited in children, and all of them have disadvantages. Aortic valve repair techniques have evolved slowly and have not gained wide acceptance; however, large series using a variety of techniques demonstrate that valve repair is possible with excellent early hemodynamics and satisfactory intermediate durability. The results of aortic valve repair at the Children's Hospital of Wisconsin are presented. Simple repairs (blunt valvotomy, commissurotomy, or commissurotomy with leaflet thinning) directed at congenital aortic stenosis resulted in 86% +/- 5% freedom from reintervention at 10 years. Repair of aortic insufficiency with ventricular septal defect (VSD) resulted in 93.3% +/- 6% freedom from reoperation at 10 years. Complex repairs included a combination of techniques and yielded 5-year freedom from reintervention of 83% +/- 7% compared with 73% +/- 11% for patients undergoing aortic valve replacement (P = .62). Aortic valve repair provides an alternative to aortic valve replacement in selected patients. The utility of aortic valve repair and aortic valve replacement must be measured not only in freedom from reintervention but also in regression of left ventricular mass and exercise testing. Improvement in outcome depends on better patient selection and suitable bioprosthetic materials.

The Ross procedure is not the procedure of choice for the teenager requiring aortic valve replacement

The Ross procedure was a remarkable technical achievement when it was introduced in 1967. Although the long-term results for the procedure when performed in adults using the technique of intra-aortic subcoronary freehand implantation have been satisfactory, the results for children using the technique of complete aortic root replacement have been less satisfactory. Not only have early outgrowth, calcification, and shrinkage of the pulmonary homograft used to reconstruct the right ventricular outflow tract been a problem but in addition some children have experienced excessive dilation of the neoaortic root as well as neoaortic valve regurgitation. In contrast to the Ross procedure, aortic valve repair and other forms of aortic valve replacement do not exclude the possibility of reoperation in the future using more advanced options such as tissue engineered leaflets or valves. Until more information is available regarding long-term performance of the pulmonary root when implanted as a neoaortic root, as well as improved results for reconstruction of the right ventricular outflow tract, the Ross procedure should be used rarely.

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

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.

Management of valvar aortic stenosis in children

What is the best treatment for the child with valvar aortic stenosis-balloon or surgical valvotomy?

Balloon aortic valvoplasty in paediatric patients: progressive aortic regurgitation is common

OBJECTIVE

To evaluate immediate and midterm results after balloon valvoplasty in a paediatric population with congenital aortic stenosis, giving special consideration to aortic regurgitation.

DESIGN

Retrospective study.

SETTING

Two tertiary referral centres for paediatric cardiology.

PATIENTS

70 consecutive patients, with an age range of 0-16.4 years. Group A infants < 3 months old (n = 21). Group B children > 3 months old (n = 49). Median follow up time was 19.8 months, range 0-158 months.

INTERVENTION

All patients underwent balloon aortic valvoplasty. The balloon to annulus ratio was selected at a mean of 0.90 (range 0.67-1.0).

MAIN OUTCOME MEASURES

Doppler gradients and degree of aortic regurgitation.

RESULTS

The pressure gradient dropped significantly with the intervention and increased mildly at follow up. Freedom from relevant aortic regurgitation (that is, moderate and severe) was initially lower in group A (75% v 90% after one month) but after two years the difference between the two groups was not significant (50% v 61%). Freedom from reintervention was significantly lower in group A (with 35% v 80%) after three years.

CONCLUSION

Aortic balloon valvoplasty is safe and effective but has a high rate of early reintervention in infants with critical aortic stenosis. The major long term problem is progressive aortic regurgitation, which does not seem to be prevented by the use of small balloons.