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J Thorac Cardiovasc Surg 2010;139:933-941
© 2010 The American Association for Thoracic Surgery
Congenital Heart Disease |
a Division of Pediatric Cardiovascular Surgery, Section of Cardiac Surgery, Department of Surgery, The Heart Institute for Children at Advocate Hope Children's Hospital, Oak Lawn, Ill
b Division of Pediatric Cardiovascular Surgery and Thoracic Surgery, Center for Congenital and Structural Heart Disease, Rush University Medical Center, Chicago, Ill
c Department of Cardiovascular and Thoracic Surgery, Rush University Medical Center, Chicago, Ill
Received for publication June 28, 2009; revisions received November 12, 2009; accepted for publication December 13, 2009. * Address for reprints: Anastasios C. Polimenakos, MD, Assistant Professor of Surgery, Rush Center for Congenital and Structural Heart Disease, The Heart Institute for Children, Hope Children's Hospital, Congenital and Pediatric Cardiovascular Surgery, Heart Transplantation, ECMO and Ventricular Assist Devices, Rush University Medical College, 1653 West Congress Parkway, Seven Jones, Chicaco, IL 60612-3244. (Email: anastasios_c_polimenakos{at}rush.edu).
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionConclusionsReferences |
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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.
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Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionConclusionsReferences |
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there have been various techniques described. Available surgical options for the treatment of aortic insufficiency (AI) or aortic stenosis (AS) in young patients include various techniques of aortic valve repair, surgical aortic valvuloplasty, and aortic valve replacement (AVR) with mechanical, bioprosthetic, or autologous pulmonary valves.2-5 Results have been improving with better anatomic understanding and operative and postoperative management. Aortic cusp extension valvuloplasty (ACEV) with tricuspidization (when needed) may have important advantages in children relative to the alternatives, particularly with regard to freedom from reoperation related to a small mechanical prosthesis, avoidance of anticoagulation, and potential mid and late disadvantages of the Ross procedure related to the pulmonary autograft and implanted homograft. Few reports of ACEV in children, most with limited follow-up, have been published.6-12 Clinical analysis on patients who underwent ACEV was conducted. Assessment of valvar morphologic characteristics was performed. The impact of ACEV on survival and freedom from reoperation was assessed, and factors associated with improved outcome were explored. |
Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionConclusionsReferences |
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Preoperative echocardiography was used. AI was graded as (1) none or trace; (2) mild (no left ventricular [LV] dilation, no retrograde flow in the descending aorta, AI vena contracta width < 4 mm); (3) moderate (LV end-diastolic volume or LV end-diastolic dimension [LVEDD] z-value > 2 and < 4, retrograde flow in the descending aorta, vena contracta 4–6 mm); or (4) severe (LV end-diastolic volume or LVEDD z-value > 4, retrograde flow in the descending aorta, vena contracta > 6 mm). AS was estimated by Doppler evaluation, and the peak instantaneous gradient (PIG) was recorded. AS was categorized as mild (PIG < 40 mm Hg), moderate (PIG 41–75 mm Hg), or severe (PIG > 76 mm Hg). Aortic valve annulus and root diameters were measured from parasternal long-axis images, with the root diameter taken as the maximum dimension at the level of the sinuses.
LV dimensions, volumes, and mass were measured and calculated from apical 4-chamber and cross-sectional echocardiographic images. Short-axis LVEDD and LV end-systolic dimension were measured. All data were indexed to body surface area and reported as z-value.
This study was approved by the institutional review board of Advocate Hope Children's Hospital. The institutional review board waived the need for patient consent.
Clinical Management Protocol and Surgical Technique
Patient Characteristics
From July 1987 to November 2008, 142 patients aged less than 19 years underwent ACEV in the form of pericardial cusp extension and tricuspidization (when needed). Three patients with truncus arteriosus and severe truncal valve insufficiency, who require valvuloplasty, were excluded. Patients with isolated commissuroplasty/commissurotomy, isolated cusp tear repair, or annular reduction without alteration of the valve leaflets were excluded. Patients with univentricular pathway, morphologically right ventricle functioning as systemic ventricle, and other associated causes of LV volume overload were excluded. During the same period, 29 patients had AVR without prior ACEV. From the available follow-up data of 139 patients, 50 had an initial diagnosis of bicuspid aortic valves (BAVs), 40 had congenital AS, 41 had combined congenital AS and aortic insufficiency (AI), and 8 had other diagnoses (Table 1
). AI causes were classified as (1) congenital, (2) BAVs, (3) due to trauma during other cardiac interventions, (4) due to transcatheter or surgical treatment of congenital valvular AS, (5) endocarditis related, (6) rheumatic carditis related, or (7) secondary to an abnormal neoaortic (native pulmonary) valve or root after arterial switch operation. Twenty-six patients (18.7%) had associated cardiovascular anomalies, and 1 patient had Turner's syndrome (Table 1). Patients were not initially randomized; rather, each case was managed according to each of 4 surgeons' preference and not on strict anatomic or functional criteria. Later in the series (since 1998), patients selected for ACEV had a normally sized aortic annulus (z-value 
–1.5) without LV hypoplasia or mitral valve hypoplastic annulus (z-value 
–2.0). Assessment of severity of valve dysfunction and timing for ACEV involved several echocardiographic/Doppler-derived indices. Indications for ACEV were moderate or severe AI, moderate AS, or a combination of moderate-to-severe AS and moderate AI. Specifically, patients with isolated AS of 40 mm Hg or greater with a normally sized valve annulus (as described above) associated with progressive LV hypertrophy were considered for ACEV. In isolated AI, a ratio of regurgitant jet/annulus diameter of 35% or greater and progressive increase in LVEDD z-value of +2.5 or greater in 2 consecutive measurements constituted objective indications for intervention. The mean age at the time of ACEV was 9.3 ± 2.7 years. Seventy-five patients were aged less than 10 years. The mean weight of patients undergoing ACEV was 32.71 ± 9.74 kg. The median follow-up was 14.4 years (0.1–21.4 years) (Table 1).
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Aortobicaval cardiopulmonary bypass (CPB) with moderate hypothermia of 32°C is used. The aortic cannula is inserted at the distal aspect of the ascending aorta close to the innominate artery. Myocardial preservation is maintained with antegrade and retrograde cold, mostly continuous, blood cardioplegia.
An oblique aortotomy incision is made, and each valve cusp is evaluated as to the extent of tissue deficiency, the shape, and the irregularities of the free edge. The thickened edges of the cusps are thinned out. The valve is tricuspidized by cutting the fused cusp at the raphae all the way to the aortic wall. The fused portion of the cusps at the commissural level is opened to the wall. Any subcommissural fusion or scar tissue is released to provide maximal mobility of the cusps.
The ACEV technique consists of using a piece of the treated autologous pericardium that is then tailored to fit the specific architecture of each cusp (Figure 1 ), but slightly oversized in depth (10%–15%) and length (up to 25%). In particular, the width should provide enough additional depth to the cusp so that the reconstructed cusp free edge is leveled with the sinotubular bar at the commissures but deeper (more caudad) at the center. It is then sutured to the cusp using continuous 5.0/6.0 polypropylene sutures from its center toward the commissures. The sutures are placed in a radial fashion so the distance between the suture-line on the pericardium is slightly wider than that on the cusp to allow for a generous mural edge.
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In patients with severe dilatation of the ventriculoaortic junction, a reduction annuloplasty at the subcommissural area between right and left cusps is performed to enhance coaptation. When the cusp is prolapsed, no attempt is made to excise any portions, but rather to support the prolapsed segment with a strip of autologous pericardium sutured to the edge of the cusp and consequently suspended to the aortic wall as described.
Intraoperative transesophageal, and recently 3-dimensional, echocardiography is typically used to define the anatomy of the valve and to assess the repair (Figure 3 ).
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The probability of freedom from events was estimated according to the Kaplan–Meier method. The freedom-from-events estimates were compared with the log-rank test. Univariate analysis was carried out using a P value of less than .05 to determine predictors of early and late freedom from valve reoperation or replacement. The Cox proportional hazards regression model was used to identify variables. Significant factors were entered into a multivariate logistic regression model to assess their independent impact. Because of a high degree of covariance of variables, the analysis was performed repeatedly, removing factors stepwise, to identify the most important variables. The Statistical Package for the Social Sciences 15.0.1 for Windows (SPSS Inc, Chicago, Ill) was used for statistical analysis.
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Results |
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Before ACEV, AI was severe in 49 patients (35.2%) and moderate in 9 patients (6.5%). Of those with severe AI, 19 patients had a tricommissural valve with deficiency of 1 or more leaflets (usually right or noncoronary leaflets), 1 patient had a unicommissural valve and central deficiency, and the remaining patients had a bicommissural valve with a central deficiency. In all but 4 of these patients, AI was related to the area of the right or noncoronary cusp. The cause was acquired in 4 patients (2 with endocarditis, 2 with rheumatic carditis).
Among patients with only moderate AI, 2 had post-arterial switch operation AI, 6 had traumatic AI after primary valvuloplasty, and 1 had aortic root abscess.
Moderate AS was present in 39 patients (28%): after previous treatment of AS in 26, 12 with BAVs (1 after primary valvuloplasty for BAVs), and after ventricular septal defect repair in 1.
A combination of moderate-to-severe AS and moderate AI was present in 42 patients (30.2%): 39 with congenital AS/AI, after primary valvuloplasty treatment for BAVs in 2, and after primary valvuloplasty for congenital AS in 1.
There were no early, intermediate, or late deaths. After the Ross operation (previously treated congenital AS with balloon valvuloplasty and ACEV), a patient had intraoperative cardiac arrest and as a result had a devastating irreversible neurologic injury.
Crossclamp and CPB times were 69.6 ± 18.6 and 95.1 ± 27.6 minutes, respectively. More than mild AS, AI, or combined AS/AI, as documented by echocardiogram, were considered nonacceptable intraoperative outcomes and justified reintervention. On this basis, reinstitution of CPB was required after 8 (5.8%) ACEVs for residual moderate or greater AS, AI, or combined-AS/AI. Re-repair was successfully performed in 6 patients (with only trace/mild AI). Two patients underwent AVR.
ACEV was performed in all 139 patients. Tricuspidization was performed in all patients with BAV. Additional procedures were performed in 8 patients. Ten patients had undergone previous aortic coarctation repair (2 with associated ventricular septal defect repair and 2 with subaortic resection), 3 patients underwent an arterial switch operation, and 1 patient underwent repair of an interrupted aortic arch with ventricular septal defect.
Post-ACEV AI or AS was improved in 137 patients. AI or AS was trivial or none in 54 patients (39%), mild in 84 patients (60.3%), and moderate in 1 patient (0.7%) (Table 2 ).
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During a median follow-up of 14.4 years (0.1–21.4 years), 64 patients underwent aortic valve reinterventions. A second ACEV for recurrent AI or combined AS/AI was performed in 16 patients at a median of 40.6 months (11–116). AVR (Ross procedure or mechanical valve prosthesis) was performed in 48 patients at a median of 47.2 months (5–172) after ACEV, at a mean age of 14.1 ± 5.8 years. In 32 of 139 ACEVs (23%), the Ross operation was performed. The Konno operation was added in 2 patients (6.2%) undergoing the Ross operation. Other AVRs were performed after 16 ACEVs (11.5%) (Table 2).
Freedom from any reintervention at 18 years was 50.3% ± 5.3%. Freedom from a second ACEV at 1, 5, 10, and 18 years was 99.1% ± 0.9%, 88.0% ± 3.3%, 82.1% ± 4.2%, and 82.1% ± 4.2%, respectively. Freedom from any type of AVR at 1, 5, 10, and 18 years was 97.6% ± 1.4%, 79.7% ± 4.3%, 71.8% ± 5.1%, and 60.0% ± 7.2%, respectively (Figure 4 ).
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionConclusionsReferences |
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This series was intended to focus on patients with complex anatomy in whom ACEV with tricuspidization (when needed) was exclusively used. Simple lesions, such as isolated AS, less than moderate AI, or simple iatrogenic-associated AI, for which the usual techniques of repair have proved durable, were excluded.11-15 Balloon or surgical aortic valvuloplasty may be an effective and safe initial treatment for patients with AS.16,17 Contrary to other reports,18 no patients had any form of surgical or balloon valvuloplasty after ACEV.
In our experience, ACEV was effective at acutely reducing AI or AS and improving LV wall mass thickness and dimensions in children and adolescents with AI or AS from a variety of causes. Other investigators have reported similarly promising early outcomes after ACEV in children and adolescents with congenital heart disease, although most series are relatively small or include simple and complex repairs.7-14,18,19 Nevertheless, the literature suggests that ACEV is effective in the short term and, as well shown in this study, allows expeditious LV remodeling even in patients with significant LV dilation or wall mass thickness with satisfying long-term durability and freedom from AVR.
Despite the limited data regarding advanced valvuloplasty techniques in children with complex aortic valve disease, the literature concerning the use of pericardial leaflet extension in both children and adults with rheumatic AI and in adults with AI and a structurally normal aortic valve demonstrates that repairs incorporating pericardial augmentation of cusps can be fairly durable.13-15,18,19 There are several important features related to ACEV with tricuspidization. It provides a comprehensive repair and restores all the important anatomic features of the aortic valve. By fashioning the pericardial patch to fit the deficient parts of each cusp, normal depth of the sinuses is reestablished and adequate cusp coaptation is secured. Cusp resuspension at the level of sinotubular bar without central valve crowding and wide subcommissural triangle are essential elements of ACEV. Furthermore, tricuspidization restores central flow characteristics and, thus, decreases turbulence and subsequent trauma to the repaired cusps. The ultimate outcomes are often contingent on the performance of the patch used. We have no experience with patch substitutes other than autologous pericardium at the present time. Autologous pericardium is fairly pliable and easily accessible, and can be fashioned to any shape needed. Concentration of glutaraldehyde solution and duration of preinsertion pericardial treatment have varied throughout the study period. In our early series, the pericardial extensions were often heavily calcified and contracted, presumably contributing to progressive post-ACEV aortic valve dysfunction. Currently, the pericardium is treated with 0.625% glutaraldehyde solution for shorter duration (3 minutes), compared with our early experience,20 and kept moist with normal saline. This might promote increased pericardial pliability and decrease the incidence of restenosis; however, the effect of this modification has yet to be determined.
The optimal timing and method of intervention remain a challenging task. Guidelines for aortic valve surgery in this patient population traditionally have been developed on the basis of those for adults. Results with ACEV encourage earlier and more aggressive management in pediatric patients because the LV has to preserve function for a longer life span. On the basis of our experience and those of others,7,10,13,14,17-19,21 we advocate ACEV in all patients with moderate or severe AI, moderate AS, or a combination of moderate-to-severe AS and moderate AI as long as they have a normally sized aortic annulus (z-value, –1.5 or greater) without LV hypoplasia or mitral valve hypoplastic annulus (z-value, –2.0 or smaller). Timing is rather critical. Several echocardiographic/Doppler-derived indices, such as pressure gradient, LV hypertrophy progression, LVEDD z-value, and ratio of regurgitant jet/annulus diameter (as previously described), may guide optimal timing and strategy.
Mid- and long-term survival varies in the literature.6-15,18,19 There were no early, intermediate, or late deaths in our series.
Although freedoms from any aortic valve reintervention or AVR vary between different series, published studies have demonstrated progressively decreasing freedom from aortic valve reintervention after various surgical valvuloplasty techniques.10-14,18,19,21 Ours is among the longest in the literature.
One of the potential adverse outcomes of ACEV for AI in patients with congenitally abnormal valves is postoperative AS. This is a particular concern in patients in whom AI developed after balloon or surgical valvuloplasty for AS.16,17 In our experience, new or worsening AS after ACEV was rare. However, AS did develop over time. The cause of this progressive AS is not clear, but pericardial calcification or contraction might contribute. In those who underwent AVR, the degree of AS at the most recent follow-up after ACEV was severe in 7.9% and moderate in 19.4%. On the basis of this observation, we have recently favored the Ross procedure over ACEV in patients with moderate/severe AS and aortic annulus with z-value –1.5 because of the concern for early failure and recurrence of AS over time.
In contrast with the findings of others,22 the z-values of LVEDD, aortic annulus, aortic sinus diameter, sinotubular junction diameter, and LV wall thickness, which improved after ACEV, remained relatively stable at follow-up in patients who met no AVR criteria at the latest follow-up after ACEV.
On the basis of multivariate regression analysis, shorter CPB and initial diagnosis of combined congenital AS/AI at the first ACEV increase freedom from AVR. In addition, mild or moderate residual AS or AI after the first ACEV is associated with an elevated risk for AVR. LV dimensions typically normalize or improve substantially after ACEV even when severe dilation is present. ACEV allows substantial delay of AVR for most patients, which may facilitate eventual AVR with a larger prosthesis or Ross procedure. As a result, with improved patient selection and surgical techniques, the durability of ACEV should continue to improve.
There are advocates of the Ross procedure as first-line management in children and adolescents with congenitally abnormal aortic valve disease and a normally sized aortic annulus.3-5,23-25 Our experience with ACEV in this complex population with aortic valve disease suggests that unless certain criteria are fulfilled (as outlined above), and despite certain drawbacks, the Ross procedure or prosthetic AVR remains an alternative to ACEV in our practice. The Ross procedure involves replacement of the entire aortic root, with reimplantation of the coronary arteries, as well as placement of a valved conduit between the right ventricle and the pulmonary arteries. Apart from the need for conduit replacement, there is increasing evidence of significant progressive neoaortic root dilation and autograft failure. As an alternative to the Ross procedure, prosthetic AVR involves a risk of early and late mortality in younger children receiving smaller mechanical valves. It is associated with increased frequency of complications, including morbidity related to long-term anticoagulation if mechanical prosthesis is used, deterioration of ventricular function caused by the development of patient–prosthesis mismatch as the child outgrows the initial valve, and the need for subsequent prosthetic valve replacement.5,23-25
Study Limitations
The limitations of our study involve all the aspects of a clinical retrospective, nonrandomized comparison analysis. This study is limited by the heterogeneous patient population and by the fact that referral for surgery was subjective in most cases. Furthermore, this experience encompasses a period when the techniques of ACEV were under development. Regular serial echocardiographic assessment of pre-ACEV geometry and function was not available, which limits our insight into the evolution of changes in aortic valve function and LV size and function with time. A study is in progress to evaluate the 3-dimensional echocardiographic parameters of an abnormal aortic valve that may help to guide selective intraoperative management. Finally, despite the relative benefits and drawbacks of ACEV in comparison with therapeutic alternatives, this study cannot be considered for direct comparison between ACEV and AVR.
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Conclusions |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionConclusionsReferences |
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–1.5 because of the concern for early failure and recurrence of AS over time. Patients with a normally sized aortic annulus who have moderate or severe AI, moderate AS, or a combination of moderate-to-severe AS and moderate AI should be considered for ACEV with tricuspidization (when needed). Pressure gradient, LV hypertrophy progression, LVEDD z-value, and ratio of regurgitant jet/annulus diameter may guide optimal timing and strategy. ACEV provides acceptable durability and satisfactory freedom from AVR.
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Footnotes |
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References |
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This article has been cited by other articles:
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  H. A. Vohra, L. deKerchove, J. Rubay, and G. ElKhoury A simple technique of commissural reconstruction in aortic valve-sparing surgery J. Thorac. Cardiovasc. Surg., March 1, 2013; 145(3): 882 - 886. [Full Text] [PDF]
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Y. d'Udekem, J. Siddiqui, C. S. Seaman, I. E. Konstantinov, J. C. Galati, M. M. H. Cheung, and C. P. Brizard Long-term results of a strategy of aortic valve repair in the pediatric population J. Thorac. Cardiovasc. Surg., February 1, 2013; 145(2): 461 - 469. [Abstract] [Full Text] [PDF]
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 A. C. Polimenakos, S. Sathanandam, C. Blair, C. ElZein, D. Roberson, and M. N. Ilbawi Selective Tricuspidization and Aortic Cusp Extension Valvuloplasty: Outcome Analysis in Infants and Children Ann. Thorac. Surg., September 1, 2010; 90(3): 839 - 847. [Abstract] [Full Text] [PDF]
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