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Original Articles: Pediatric Cardiac

Neoaortic Root Diameters and Aortic Regurgitation in Children After the Ross Operation

^a Department of Cardiovascular Surgery, German Heart Center Munich at the Technical University, Munich, Germany
^b Department of Cardiac Surgery, University Clinic Schleswig-Holstein, Campus Luebeck, Luebeck, Germany
^c Department of Cardiothoracic Surgery, Erasmus University Medical Center, Rotterdam, the Netherlands
^d Sana Herzchirurgische Klinik, Stuttgart, Germany
^e German Heart Center Berlin, Berlin, Germany
^f Department of Mathematics, School of Science and Technology, University of Sussex, Brighton, United Kingdom

Accepted for publication April 22, 2009.

^_* Address correspondence to Dr Hörer, Department of Cardiovascular Surgery, German Heart Center Munich at the Technical University, Lazarettstrasse 36, Munich, D-80636, Germany (Email: hoerer{at}dhm.mhn.de).

Presented at the Forty-fifth Annual Meeting of The Society of Thoracic Surgeons, San Francisco, CA, Jan 26–28, 2009.

	Abstract

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
Background: For children who require aortic valve replacement, the Ross operation provides a unique advantage of growth potential of the pulmonary autograft in the aortic position. This study assessed the progression of autograft root diameters and its effect on aortic regurgitation (AR).

Methods: Neoaortic echo dimensions from 48 children (<16 years) undergoing Ross operation who had follow-up echocardiograms before age 20 were analyzed (mean follow-up, 5.1 ± 3.3 years).

Results: The mean age at the time of the Ross operation was 10.0 ± 4.3 years. Mean z values of the neoaortic annulus (1.5 ± 0.4), sinus (2.5 ± 0.4), and sinotubular junction (2.6 ± 0.9) when the autograft was implanted were significantly larger compared with normal values (p < 0.001, all). The mean z values significantly increased with follow-up at the level of the sinus (0.5 ± 0.1/year, p < 0.001) and the sinotubular junction (0.7 ± 0.2, p < 0.001), but not at the level of the annulus (0.1 ± 0.1, p = 0.59). AR increased with follow-up time (0.07 ± 0.02 grade/year, p < 0.001). AR increased with sinotubular junction diameter (p = 0.028), but there was not significant evidence of an association with annulus diameter (p = 0.25) or sinus diameter (p = 0.40).

Conclusions: Children undergoing Ross operation have larger neoaortic root dimensions than healthy children. Growth of the annulus matches somatic growth. The diameters of the sinus and the sinotubular junction increase significantly relative to somatic growth. The latter may explain the development of AR.

	Introduction

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
The autograft pulmonary valve may be the ideal substitute for the aortic valve because its hemodynamic performance is excellent, the risk of endocarditis is low, and anticoagulation is not required [1–4]. However, there is concern about an increase of neoaortic root dimensions in patients who undergo operations in adulthood. A worrisome increase of reoperations for aortic regurgitation due to neoaortic root dilatation has been noticed [2, 4, 5].

In children, the increase of neoaortic root dimensions is desirable; therefore, many surgeons prefer the pulmonary autograft to other prostheses because of its alleged growth potential [3, 6]. However, pathologic neoaortic root dilatation in children may also occur out of proportion to somatic growth. In contrast to the studies of adult patients, data on neoaortic dilatation in children are controversial. Growth in proportion to somatic growth as well as pathologic root dilatation has been reported [7–9]. So far, longitudinal parametric analyses of aortic root dimensions in exclusively pediatric patient populations are lacking. In addition, the effect of neoaortic root dimensions on aortic regurgitation is unclear [4, 7, 10]. Therefore, we analyzed longitudinal echocardiographic data of a pediatric Ross operated population to describe the changes of annulus, sinus, and sinotubular junction dimensions with time and to identify the relationship between aortic root dimensions and aortic regurgitation.

	Patients and Methods

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
Institutional Review Board approval was obtained to conduct this prospective follow-up study. The need for patients to provide informed consent was waived.

Study Population and Operative Data
Data from the Dutch-German Ross Registry database were analyzed. The study included all patients who were aged younger than 16 years old at the time of the Ross operation and who had follow-up echocardiograms. Excluded were echocardiographic data from patients aged older than 20 years at the time of the examination. The study population included patient data from three Departments of Cardiac Surgery in Germany, and one Department of Cardiac Surgery in the Netherlands.

The Ross operations were performed between October 1988 and October 2006. The follow-up data from each center were entered into the database, and subsequently, a common systematic, prospective registry was started in January 2002. The responsible surgeon at each center determined the surgical technique. Root replacement was performed in 44 patients, and the subcoronary technique was applied in 4. In 9 patients the autograft implantation technique was modified for size matching purpose. Patients' characteristics and operative data are listed in Tables 1, 2, and 3. Details of the operative techniques have been described elsewhere [11–13].

Echocardiographic Data Acquisition and Measurements
Autograft dimensions were measured as described by Roman and colleagues [14] at three different levels: annulus at the level of the autograft leaflet hinges, sinus of Valsalva at the largest anteroposterior diameter, and sinotubular junction (supraaortic ridge level) at the distal rim of the sinuses of Valsalva. Z values of autograft dimensions were calculated according to the regression equations published by Daubeney and colleagues [15] from the body surface area (BSA) and the echocardiographically derived measurement. Aortic regurgitation (AR) was assessed by multiple techniques with parasternal long-axis and apical 5-chamber views.

Pulsed wave Doppler and color flow Doppler imaging were used for mapping the left ventricular outflow tract, including determination of the ratio of jet height to left ventricular outflow tract height. Continuous Doppler imaging was applied to measure the deceleration slope and pressure half-time of the autograft regurgitation jet. AR was graded with the use of standard criteria in most examinations [16].

Because this was a multicenter study, the final decision of AR grading was left to the decision of the responsible echocardiographer's preference and experience, and AR severity was reported on a scale of grade 0 to 4. Trace (trivial) aortic insufficiency, defined as a very tiny regurgitation jet in early diastole near the detection limit, was included in the analysis as grade 0.5.

We analyzed 129 measurements of the neoaortic root dimensions from 48 patients, and 403 measurements of the neoaortic regurgitation from 135 patients. Mean duration of the echocardiographic follow-up was 5.1 ± 3.3 years (range, 0.2 to 15 years) for the measurements of the dimensions, and 4.4 ± 2.4 years (range, 0.2 to 15 years) for the measurements of the neoaortic regurgitation.

Statistical Analysis
Frequencies are given as absolute numbers and percentages. Continuous data are expressed as means and standard deviation. Statistical analysis of clinical variables and initial fitting was performed using SPSS 16.0 software (SPSS Inc, Chicago, IL). The echocardiographic data of two or more echocardiographic observations per patient were analyzed by using a hierarchical multilevel linear model (MLWin 2.0, Centre for Multilevel Modeling, London, UK) that provides a linear regression line with an intercept and slope for each individual patient. The intercept ± standard error (SE) corresponds to the notional value at the time of surgery; the slope ± SE represents the annual progression of these measurements [17].

	Results

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
Development of the Diameters of the Neoaortic Root With Follow-Up Time
We analyzed 129 measurements of the neoaortic annulus, 96 measurements of the sinus, and 64 measurements of the sinotubular junction of 48 patients. The best fitting regression model to study changes of z values with time was a linear model with the term:

(1)

Hence the terms to estimate changes of z values over time were:

(2)

(3)

(4)

The z values of the diameters were larger compared with healthy children (p < 0.001, all). The z values showed a significant increase with follow-up time at the level of the sinus (p < 0.001), and the sinotubular junction (p < 0.001), but not at the annulus (p = 0.59). For example, the initial annular z value was 1.5, and the estimated annual increase is 0.1 per year. Thus, after 10 years, the estimated z value is presumed to be 2.5. In contrast, the estimated z value after 10 years in the present study was 7.5 for the sinus and 9.6 for the sinotubular junction (Fig 1).

View larger version (8K): [in this window] [in a new window]   Fig 1. Plot of z values of the (A) aortic annulus, (B) sinus, and (C) sinotubular junction against follow-up time.

(5)

(6)

(7)

The analysis revealed an increase of the neoaortic root diameters with increasing BSA (Fig 2). To compare the aortic root dimensions to mean normal values, we calculated the values for healthy children according to the nomograms published by Daubeney and colleagues [15] (Fig 2).

(8)

(9)

(10)

For example, the sinus diameter of a child presenting with a BSA of 1.5 m² after a Ross operation was 33 mm. In contrast, the sinus diameter of a healthy child presenting with a BSA of 1.5 m² was 25 mm.

View larger version (9K): [in this window] [in a new window]   Fig 2. Plot of diameters of the (A) aortic annulus, (B) sinus, and (C) sinotubular junction against body surface area. The solid lines refer to the Ross population. The dotted lines refer to the healthy control population.

(11)

Hence, the term to estimate AR over time is:

(12)

The mean initial AR grade was estimated as 0.69 ± 0.02. There was a slow but significant increase in the grade of aortic regurgitation with follow-up time (0.06 ± 0.02 grade per year, p < 0.001).

AR With Neoaortic Root Diameters
The same measurements as used for the analysis of neoaortic root dimension with follow-up time and BSA were analyzed. A linear model was chosen to model z value of the neoaortic root diameters and AR grade with the term:

(13)

Hence the terms to estimate changes of AR against z value are:

(14)

(15)

(16)

There was significant within-patient evidence that AR increased with sinotubular junction diameter (p = 0.028), but evidence was insufficient to show an association with annulus diameter (p = 0.25) or sinus diameter (p = 0.40, Fig 3). However, the effect was not strong. An increase of the z value from 0 to 10 of the sinotubular junction results in an increase of AR of 0.5 grades.

View larger version (8K): [in this window] [in a new window]   Fig 3. Box and whisker plot of z values of the (A) aortic annulus, (B) sinus, and (C) sinotubular junction stratified by groups of patients presenting with different grades of aortic insufficiency. The horizontal line in the box represents the median, the box represents the interquartile range, and the vertical line indicates the range.

Reoperations
AR at the final follow-up of the studied 48 patients was none or trivial in 18 (38%), mild in 18 (38%), moderate in 8 (17%), severe in 1 (2%), and severest in 3 (6%). The 4 patients who presented with more than moderate AR required autograft explantation at a mean of 13.0 ± 3.7 years after the Ross operation.

	Comment

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
Data on growth of the aortic root after the Ross operation in children are rare and inconsistent. Most previous studies include patients that were grown at the time of the Ross operation [4, 10]. They also mix follow-up data of adults with those of children [6, 18]. However, to assess proportional or disproportional growth of the aortic root, only data from a pediatric population should be analyzed. Furthermore, previous studies analyze freedom from events, such as freedom from z value exceeding 4 [10], or compare means from different follow-up intervals [18].

Because aortic root dimensions and regurgitation develop with time, parametric analyses of repeat longitudinal echo data may be more appropriate to describe changes of dimensions and regurgitation. Following these prerequisites in the present parametric analysis of a pediatric population, we obtained the following results: The aortic root dimensions immediate after the Ross operation are larger than in healthy children, and the annulus grows in proportion to the somatic growth of the child. In contrast, the sinus and the sinotubular junction dilate with time. AR develops slowly but significantly and is associated with a dilated sinotubular junction.

The initial dimensions of the neoaortic root immediately after the autograft implantation are determined by the size of the pulmonary autograft. However, previous studies reported different root dimensions immediately after the operation. Elkins and colleagues [8] found a mean z value of the annulus of –0.5, and thus almost normal dimensions. In contrast, Tantengco and colleagues [18] observed a mean z value of the annulus of 1.4. Our data support this observation, with a mean z value of the annulus of 1.5. This is not surprising, because the pulmonary autograft is usually larger than the aortic valve. In fact, the initial diameters of the neoaortic root were slightly larger compared with normal values obtained from the pulmonary root of healthy individuals. This may be due to immediate dilatation of the pulmonary autograft when transferred into the systemic circuit [18]. Hence, the mean initial diameters of the aortic root immediately after implantation are already larger than in healthy children.

Most studies that included adolescent patients and young adults reported dilatation of the aortic root during follow-up. Tantengco and colleagues [18] noticed pathologic dilation according to z values up to the first year after the Ross procedure, but without progress thereafter. Pasquali and colleagues [10] demonstrated a significant increase in z values of the annulus, sinus, and sinotubular junction over time. Kouchoukos and colleagues [4] observed a consistent increase of the sinus and sinotubular junction dimensions over time, but not of the annulus dimensions; however, their measurements were not indexed to the patients' BSA measurements.

Inconsistent data are reported with regard to proportional or disproportional growth of the neoaortic root in children. Simon and colleagues [7] observed growth parallel to somatic growth without undue dilatation. Elkins and colleagues [8] reported 10 of 23 patients presenting with pathologic annular dilatation after root replacement. In contrast, Solowiejczyk and colleagues [9] observed a disproportionate increase in the size of the sinus but minimal change in the z scores of the annulus.

Our observations affirm this difference in growth pattern between the annulus and the sinus: The curve depicting the z values of the annulus against the follow-up time (Fig 1A) parallels the x-axis. The curves displaying the annular dimension of the Ross population and the control population do not diverge with increasing BSA (Fig 2A). Hence, the annulus grows in proportion to somatic growth. In contrast, the curves depicting the z values of the sinus and the sinotubular junction increase over time (Fig 1B and C). The curves displaying the sinus and the sinotubular junction dimension of the Ross population and the control population diverge with increasing BSA (Fig 2B and C). Hence, there is dilatation of the sinus and the sinotubular junction, but not of the annulus.

According to previous studies, progressive neoaortic regurgitation and neoaortic root dilatation occurs over time in adolescents and adults; however, the correlation between AR and aortic root dilatation is not clear. In the large cohort reported by Pasquali and colleagues [10], freedom from moderate or more AR at 6 years was only 60%, and the freedom from sinus z value exceeding 8 was less than 40% at 6 years. Nevertheless, neoaortic root dilatation was not a significant predictor for AR in univariate or multivariate analysis. In the cohort reported by Kouchoukos and colleagues [4], the autografts in 11 of 119 patients required reoperation. At last follow-up, 8 of 97 patients presented with moderate AR. A consistent and substantial increase of the sinus and sinotunular junction dimensions occurred over time. The authors identified dilatation of the sinotubular junction as an independent predictor for progression of AR.

Do these data apply to children as well? Simon and colleagues [7] observed no dilatation of the aortic root over time and no increase in AR. In contrast, Takkenberg and colleagues [3] observed a significant increase in AR of 0.08 grades per year. In the present study population, AR increased with 0.06 grades per year. We observed a significant dilatation of the sinus and the sinotubular junction over time. In particular, the z values of the sinotubular junction increased with 0.7 per year. There was significant evidence that AR increases with increasing sinotubular junction diameters. Although the average effect was not strong, the mean z value of the sinotubular junction of patients exhibiting moderate or more AR during follow-up was 7.1 ± 3.3. In these patients, the mean sinotubular junction diameter was 38 mm with a maximum of 50 mm. This is worrisome, because the patients were younger than 20 years at the latest follow-up examination. Four patients required autograft explantation at a mean time of 13.0 ± 3.7 years after the Ross operation for severe AR. The mean z value of the sinotubular junction before autograft explantation was 8.8 ± 2.6. Hence, dilatation of the sinotubular junction that is out of proportion may be the cause for AR in children after the Ross operation.

This study has some limitations. The study design was a retrospective follow-up study covering a long period of patient inclusion. Changes in preoperative, operative, and postoperative management may have affected the outcome variables in a way not covered by our analysis.

The comparability of the echocardiographic findings at the time of final follow-up is limited because these data were obtained by various pediatric cardiologists in different outpatient clinics.

The graphs depicting the neoaortic root dimension against BSA do not consider different follow-up times after the Ross operation. Because there is dilation of the sinus and the sinotubular junction with time, the predicted dimensions for a grown patient who underwent a neonatal Ross operation may be underestimated by the graphs. The predicted dimensions for a grown patient who underwent the Ross procedure as an adolescent may also be overestimated.

Finally, the analysis included 4 patients in whom subcoronary technique was used, 5 in whom various techniques of annular enlargement were used, and 2 who underwent replacement of the ascending aorta. These modifications of the Ross operation may have affected AR grade and root dimension. However, the small number of patients precluded a meaningful subanalysis.

In conclusion, dilatation of the sinotubular junction and the sinus occurs after the Ross operation in children. The degree of aortic root enlargement is bothersome because it results in progressive AR and reoperations. Serial echocardiographic follow-up examinations are warranted and should include careful assessment of neoaortic root dimensions and monitoring of AR.

	Discussion

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
DR JOSEPH FORBESS (Dallas, TX): I may have missed it early on, but did you talk about how many of your patients had root inclusion vs how many had root replacement as part of the Ross procedure?

DR HÖRER: Four patients with the use of the subcoronary technique were included. These modifications of the Ross operation may have an impact on aortic regurgitation grade and root dimension. However, due to the small number of patients, a meaningful subanalysis was not possible.

DR FRANK PIGULA (Boston, MA): And could you just clarify, were there any efforts made to fix either the annulus or the sinotubular junction in these patients?

DR HÖRER: There were no additional procedures at the annulus.

DR PIGULA: So there weren't Teflon [DuPont, Wilmington, DE] strips or anything?

DR HÖRER: There were no Teflon strips. There were some enlargement procedures. Five patients underwent enlargement of the left ventricular outflow tract, but there were no enforcements of the annulus.

DR MARSHALL JACOBS (Newtown Square, PA): That was a very elegant and informative analysis. Some previous analyses have related the acquisition of increasing aortic valve insufficiency to the primary lesion or indication for surgery; AI [aortic insufficiency]; for example, isolated AI. Did you stratify the analysis to see if there was a relationship between primary type of aortic valve abnormality and rate of dilatation of the sinotubular junction or acquisition of insufficiency?

DR HÖRER: These are only 48 patients, so there was no significant impact of potential influencing factors like aortic regurgitation or bicuspid valve on outcomes. However, when we looked at the overall cohort of 180 patients, and checked the potential influencing factors for endpoints such as autograft reoperation, we also found a significant influence of predominant aortic regurgitation for autograft reoperation.

DR PIGULA: I just have one other question. Has this changed your practice in your institutions? Do you now consider doing some of the modifications, such as using a tube graft around the autograft, to support the sinuses or the sinotubular junction or any other modifications to avoid this?

DR HÖRER: When the Ross operation is applied to small children, the growth potential of the autograft is desired. So there is no sense in placing a tube graft around. But in those children with an already dilated aorta with the size of a grown-up patient, we place Teflon strips around the distal autograft anastomosis or we replace the ascending aorta with an adult-sized tube graft.

	Acknowledgments

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
We thank Katrin Meyer for her excellent data management and secretarial support at the Registry Site in the Department of Cardiac Surgery, University Hospital Schleswig-Holstein, Campus Lübeck.

	Footnotes

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 
^_* Both authors contributed equally to the study.

	References

Top Abstract Introduction Patients and Methods Results Comment Discussion Footnotes Acknowledgments References

 

1. Moidl R, Simon P, Aschauer C, et al. Does the Ross operation fulfill the objective performance criteria established for new prosthetic heart valves? J Heart Valve Dis 2000;9:190-194.[Medline]
2. Elkins RC, Thompson DM, Lane MM, Elkins CC, Peyton, MD. Ross operation: 16-year experience J Thorac Cardiovasc Surg 2008;136:623-630630 e1–5.[Abstract/Free Full Text]
3. Takkenberg JJ, Kappetein AP, van Herwerden LA, Witsenburg M, Van Osch-Gevers L, Bogers AJ. Pediatric autograft aortic root replacement: a prospective follow-up study Ann Thorac Surg 2005;80:1628-1633.[Abstract/Free Full Text]
4. Kouchoukos NT, Masetti P, Nickerson NJ, Castner CF, Shannon WD, Davila-Roman VG. The Ross procedure: long-term clinical and echocardiographic follow-up Ann Thorac Surg 2004;78:773-781discussion 773–81.[Abstract/Free Full Text]
5. Pasquali SK, Shera D, Wernovsky G, et al. Midterm outcomes and predictors of reintervention after the Ross procedure in infants, children, and young adults J Thorac Cardiovasc Surg 2007;133:893-899.[Abstract/Free Full Text]
6. Elkins RC, Knott-Craig CJ, Ward KE, Lane MM. The Ross operation in children: 10-year experience Ann Thorac Surg 1998;65:496-502.[Abstract/Free Full Text]
7. Simon P, Aschauer C, Moidl R, et al. Growth of the pulmonary autograft after the Ross operation in childhood Eur J Cardiothorac Surg 2001;19:118-121.[Abstract/Free Full Text]
8. Elkins RC, Knott-Craig CJ, Ward KE, McCue C, Lane MM. Pulmonary autograft in children: realized growth potential Ann Thorac Surg 1994;57:1387-1393discussion 1393–4.[Abstract/Free Full Text]
9. Solowiejczyk DE, Bourlon F, Apfel HD, et al. Serial echocardiographic measurements of the pulmonary autograft in the aortic valve position after the Ross operation in a pediatric population using normal pulmonary artery dimensions as the reference standard Am J Cardiol 2000;85:1119-1123.[Medline]
10. Pasquali SK, Cohen MS, Shera D, Wernovsky G, Spray TL, Marino BS. The relationship between neo-aortic root dilation, insufficiency, and reintervention following the Ross procedure in infants, children, and young adults J Am Coll Cardiol 2007;49:1806-1812.[Abstract/Free Full Text]
11. Sievers HH, Hanke T, Stierle U, et al. A critical reappraisal of the Ross operation: renaissance of the subcoronary implantation technique? Circulation 2006;114:I504-I511.[Medline]
12. Duebener LF, Stierle U, Erasmi A, et al. Ross procedure and left ventricular mass regression Circulation 2005;112:I415-I422.[Medline]
13. Bohm JO, Botha CA, Rein JG, Roser D. Technical evolution of the Ross operation: midterm results in 186 patients Ann Thorac Surg 2001;71:S340-S343.[Medline]
14. Roman MJ, Devereux RB, Kramer-Fox R, O'Loughlin J. Two-dimensional echocardiographic aortic root dimensions in normal children and adults Am J Cardiol 1989;64:507-512.[Medline]
15. Daubeney PE, Blackstone EH, Weintraub RG, Slavik Z, Scanlon J, Webber SA. Relationship of the dimension of cardiac structures to body size: an echocardiographic study in normal infants and children Cardiol Young 1999;9:402-410.[Medline]
16. Perry GJ, Helmcke F, Nanda NC, Byard C, Soto B. Evaluation of aortic insufficiency by Doppler color flow mapping J Am Coll Cardiol 1987;9:952-959.[Abstract]
17. Takkenberg JJ, van Herwerden LA, Galema TW, et al. Serial echocardiographic assessment of neo-aortic regurgitation and root dimensions after the modified Ross procedure J Heart Valve Dis 2006;15:100-106discussion 106–7.[Medline]
18. Tantengco MV, Humes RA, Clapp SK, et al. Aortic root dilation after the Ross procedure Am J Cardiol 1999;83:915-920.[Medline]

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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Thorsten Hanke Johanna J.M. Takkenberg Ad J.J.C. Bogers Wolfgang Hemmer Joachim G. Rein Roland Hetzer Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hörer, J. Articles by Lange, R. Search for Related Content PubMed PubMed Citation Articles by Hörer, J. Articles by Lange, R. Related Collections Congenital - acyanotic Valve disease