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Eur J Cardiothorac Surg 2001;20:89-94
© 2001 Elsevier Science NL

Is there a place for pediatric valvotomy in the autograft era?

A.J.J.C. Bogersa, J.J.M. Takkenberga, A.P. Kappeteina, P.L. de Jonga, A.H. Cromme-Dijkhuisb, M. Witsenburgb

a Department of Cardiothoracic Surgery, Bd 156 University Hospital, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
b Department of Pediatric Cardiology, University Hospital, Erasmus Medical Center, Rotterdam, The Netherlands

Received 6 October 2000; received in revised form 13 March 2001; accepted 23 March 2001.

Corresponding author. Tel.: +31-10-4635411; fax: +31-10-4633993
e-mail: klomp{at}thch.azr.nl


   Abstract
Top
 Abstract
1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
 Appendix A. Conference...
 References
 
Objective: Valvotomy and the autograft procedure are the most common surgical treatment options for children with valvular aortic stenosis. We evaluated the results of these surgical procedures in our institution. Methods: Retrospective analysis was done of all patients presenting with aortic stenosis and operated upon before the age of 18. In 11 patients a valvotomy was performed and in 36 an autograft procedure. Results: There was no hospital mortality. Mean follow-up in the valvotomy group was 4.8 years (SD 3.3), in the autograft group 4.5 years (SD 3.3). During follow-up one patient died suddenly 2 months after valvotomy. Two patients in the autograft group died (not valve-related). After valvotomy three patients underwent a balloon valvotomy, in one followed by an autograft procedure and one patient had a repeat valvotomy. In the autograft group one patient was reoperated for severe aortic regurgitation and moderate pulmonary stenosis. At last echocardiography after valvotomy (eight remaining patients) in only two patients (25%) no aortic stenosis or regurgitation was present. In the remaining six patients aortic stenosis is mild in two and moderate in three, including one with moderate aortic regurgitation. In one patient without stenosis, moderate aortic regurgitation was seen. No pulmonary stenosis or regurgitation is present. Echocardiography after autografting (33 remaining patients) showed no aortic stenosis. Aortic regurgitation was mild in seven patients, moderate in two, severe in one. Pulmonary stenosis was present in two patients (16%). Pulmonary regurgitation was mild in three patients and moderate in one. Conclusions: In selected patients with valvular aortic stenosis who are beyond infancy, valvotomy may be adequate and may postpone further surgery for a significant length of time. After valvotomy the main problem is residual aortic stenosis while after autografting a shift occurs to aortic regurgitation and problems related to the pulmonary valve. Careful clinical and echocardiographic follow-up is therefore warranted in young patients after the autograft procedure.

Key Words: Aortic stenosis • Valvotomy • Autograft procedure


   1. Introduction
Top
 Abstract
 1. Introduction
2. Materials and methods
 3. Results
 4. Discussion
 Appendix A. Conference...
 References
 
Currently balloon valvotomy is considered the initial treatment of choice for valvular aortic stenosis in the pediatric age group, especially in neonates and infants. In addition balloon valvotomy is also used in selected cases of valvular stenosis in multilevel disease and in restenosis [1]. However, in a number of patients the balloon valvotomy is not indicated, unsuccessful or even failing [1–5]. These patients require surgical treatment. The most common surgical alternatives are valvotomy and the autograft procedure. The number of comparative studies evaluating the results of these two methods is limited and there are no randomized investigations [3–7]. In order to provide further information in this regard we present our experience with valvotomy and autografting for aortic stenosis in children.


   2. Materials and methods
Top
 Abstract
 1. Introduction
 2. Materials and methods
3. Results
 4. Discussion
 Appendix A. Conference...
 References
 
2.1. Study population
All patients younger than 18 years of age, who initially presented with aortic stenosis and who were consequently operated between September 1988 and May 2000, were analyzed. In 11 patients a valvotomy was performed and in 36 an autograft procedure. In four more pediatric patients an autograft procedure was done for primary isolated aortic valve regurgitation and in 11 additional pediatric patients an allograft root replacement was performed because no adequate autograft was present. No mechanical or biological aortic valve prostheses were implanted in this era in this age group. In the same time span 80 percutaneous balloon valvotomy procedures were done for valvular aortic stenosis in 72 patients in this age group. We limited our analysis to those patients presenting with aortic stenosis who underwent either valvotomy or an autograft procedure.

Patient characteristics, prior treatment, hemodynamic diagnosis and clinical condition at surgery are displayed in Table 1. In the autograft group 13 patients had prior balloon dilatation of the aortic valve. Prior surgery in the left ventricular outflow tract was performed in 17 patients in the autograft group and consisted of single or combined enucleation of discrete subaortic stenosis in four patients, of valvotomy in 14 patients and of aortic valve repair in two patients. In the valvotomy group three patients had a previous unsuccessful balloon dilatation. In one of the three patients in the valvotomy group who had coarctation repair this procedure was combined with closure of a patent arterial duct. Other prior cardiac surgery consisted in the valvotomy group of one-stage repair of an atrial septal defect and aortic arch interruption in one patient and in the autograft group of closure of ventricular septal defect in two patients.


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  		Table 1. Patient characteristics, prior treatment, hemodynamic diagnosis and clinical condition at surgerya

 
2.2. Peri-operative data (Table 2)
All patients were operated with standard cardiopulmonary bypass techniques using bicaval cannulation, moderate hypothermia and cardioplegic arrest. Cross-clamp and perfusion times were significantly longer in the autograft group, and are displayed in Table 2. Additional circulatory arrest (mean duration 29 min; SD 14, range 28–36 min) was used only in the valvotomy group in the three patients who had one-stage procedures. Valvotomy was done sharply through the opened ascending aorta and according to the anatomy of the valve at the discretion of the attending surgeon. The modified Ross procedure with autograft aortic root replacement with reimplantation of the coronary arteries and pulmonary artery replacement with an allograft was used in all autograft patients.


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  		Table 2. Peri-operative dataa

 
Twenty-nine cryopreserved allografts were obtained from the heart valve bank in Rotterdam (Heart Valve Bank Rotterdam, Rotterdam, The Netherlands), four from Barcelona (Transplant Services Foundation, Hospital Clinic I Provincial de Barcelona, Barcelona, Spain), and two from Berlin (Homograft Laboratory, Deutsches Herzzentrum Berlin, Berlin, Germany). One fresh allograft was obtained from London (National Heart Hospital, London, UK). Allograft characteristics are displayed in Table 2.

Concomitant procedures in the valvotomy group consisted of closure of ventricular septal defect in three patients, one of which was a one-stage procedure including coarctation repair, an enucleation of discrete subaortic stenosis was performed in one patient and coarctation repair in two more patients. In the autograft group concomitant procedures were enucleation of discrete subaortic stenosis in two patients, enlargement of the left ventricular outflow tract in four patients, enlargement of the ascending aorta in one and ligation of a patent arterial duct in one.

Operative mortality was absent. There were no bleeding complications necessitating rethoracotomy in either group. One patient in the autograft group needed a permanent pacemaker postoperatively because of total heart block.

2.3. Follow-up
Clinical follow-up was obtained by collecting information from the patient records. Data on death, reoperation, occurrence of valve-related events [8] and NYHA classification were extracted. Autograft failure was defined as observed valve failure at death, reoperation or at echocardiographic examination.

Echocardiography during follow-up was compiled from all records of postoperative echocardiographic examinations. Valve function was assessed by echo Doppler studies including color flow mapping. Aortic regurgitation was scored using a jet length grading system of 0–4. Grade 0 was defined as no regurgitation, grade 1 as trivial, grade 2 as mild, grade 3 as moderate and grade 4 as severe. Aortic stenosis was scored in four grades. No or trivial stenosis was defined as a gradient up to 10 mmHg, mild as gradient of 10 to 30 mmHg, moderate as gradient of 30–50 mmHg, severe as a gradient over 50 mmHg. Autograft failure was defined as aortic regurgitation of more than grade 2 or aortic stenosis of more than 50 mmHg. Pulmonary regurgitation was also scored using a jet length grading system of 0–4. Grade 0 was defined as no regurgitation, grade 1 as trivial, grade 2 as mild, grade 3 as moderate and grade 4 as severe. Pulmonary stenosis was scored in four grades. No or trivial stenosis was defined as a gradient up to 10 mmHg, mild as gradient of 10–30 mmHg, moderate as gradient of 30–50 mmHg, severe as a gradient over 50 mmHg.

2.4. Statistical analysis
All data were entered into a relational database, MS Access 97 (Microsoft, Redmond, WA) and all analyses were done using SPSS 9.0 for Windows (SPSS, Chicago, IL). Means were compared using one way analysis of variance. Proportions were compared using the chi-square test. Cumulative survival analysis was conducted according to the method of Kaplan and Meier [9].

To study the progression of echocardiographic aortic regurgitation over time after autograft procedure, for each patient (n=32) who had at least two post-operative echocardiographic examinations a linear regression function was constructed of the relationship between time and the grade of their aortic regurgitation. In addition an overall linear regression function was constructed for all 32 patients combined, in order to illustrate the overall progression of aortic regurgitation over time in the whole group.


   3. Results
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
4. Discussion
 Appendix A. Conference...
 References
 
3.1. Follow-up
No patients died during hospitalization or within 30 days after the procedure. Follow-up was 100% complete at the closing date of the study (August 2000) with a total follow-up of 161 patient years. Mean follow-up in the valvotomy group was 4.8 years (SD 3.3, range 0.1–10.8 years, 53 patient years), in the autograft group 4.5 years (SD 3.3, range 1 week–11.5 years, 161 patient years).

During follow-up one patient died suddenly 2 months after valvotomy. Two patients in the autograft group died, one after 1.5 months as a result of a systemic Candida infection (not valve-related), one after 21 months due to progressive congestive heart failure (aortic regurgitation 1+ after 17 months; not valve-related).

After valvotomy one patient had a balloon valvotomy after 1 month and eventually an autograft procedure after 1.3 years, two patients had a balloon valvotomy after 3.3 and 9.5 years, respectively. In one patient valvotomy was repeated after 9.2 years. In the autograft group one patient was reoperated after 7.5 years for severe aortic regurgitation and moderate pulmonary stenosis. A bileaflet mechanical aortic valve prosthesis (St. Jude, St. Paul, MN) was implanted in the autograft root and the pulmonary allograft was replaced by a new pulmonary allograft (Heart Valve Bank Rotterdam, Rotterdam, The Netherlands). In addition one patient was reoperated after 9.8 years for severe pulmonary stenosis, a new pulmonary allograft (Heart Valve Bank Rotterdam, Rotterdam, The Netherlands) was inserted. One patient was re-operated after 6.9 years for mitral valve replacement and tricuspid valve repair. Neither thrombo-embolic events nor endocarditis were recorded after valvotomy or autografting.

Cumulative survival (Fig. 1) after valvotomy was 90% at 5 and 8 years (SEM 9%), reintervention-free survival was 56% at 5 and 8 years (SEM 17%. Survival after autografting was 94% at 5 and 8 years (SEM 4%), reintervention-free survival was 94% at 5 years (SEM 4%) and 84% at 8 years (SEM 10%) see Figs. 1 and 2 .



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  		Fig. 1. Cumulative survival in autograft and valvotomy patients who presented with the diagnosis of aortic stenosis.

 


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  		Fig. 2. Reintervention-free survival in autograft and valvotomy patients who presented with the diagnosis of aortic stenosis.

 
3.2. Functional class
At last follow-up all patients after valvotomy are in NYHA class I. After autografting all patients are in NYHA class I, except for one patient in class II.

3.3. Echocardiography (Table 3)
At last echocardiographic examination after valvotomy (eight remaining patients) aortic stenosis is absent in three patients, including one patient with moderate aortic regurgitation. Aortic stenosis is mild in two and moderate (systolic Doppler gradient over 40 mmHg) in three, including one with moderate aortic regurgitation. In only two patients no stenosis or regurgitation is present. No pulmonary stenosis or regurgitation is present in this group.


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  		Table 3. Echocardiographic findings at last examination

 
In the autograft group 34 patients had at least one echocardiographic examination postop. In total 129 echocardiographic examinations were performed. At last echocardiographic examination no aortic stenosis was observed. Aortic regurgitation was none or trivial in 22, mild in eight, moderate in three, severe in one (this patient was reoperated shortly thereafter), not recorded in two. Pulmonary stenosis was present in two patients (systolic Doppler gradient 40 mmHg). Pulmonary regurgitation was none or trivial in 13, mild in three, moderate in one, severe in one, not recorded in 16.

Thirty-two patients had two or more echocardiographic examinations. Fig. 3 displays for each patient the linear regression line that reflects the progression of echocardiographic aortic regurgitation over time. The bold line represents the overall progression of echocardiographic aortic regurgitation of the whole autograft group over time, which can also be described by the equation: y=0.1572xx+0.4998.



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  		Fig. 3. Progression of echocardiographic aortic regurgitation (jet length) over time in 32 patients after autograft procedure. For each patient the linear regression function that reflects the individual progression of aortic regurgitation over time is displayed (grey lines). The bold line represents the overall progression of echocardiographic aortic regurgitation for the whole group.

 

   4. Discussion
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
Appendix A. Conference...
 References
 
This study describes our institution's experience with valvotomy and autografting in children with valvular aortic stenosis. When comparing the patients undergoing valvotomy or autografting, it is noted that the valvotomy group is much younger at the time of operation. The valvotomy group also had less prior surgery on the left ventricular outflow tract. Furthermore, in the valvotomy group the indication for surgery was exclusively aortic stenosis while in the autograft group most patients were diagnosed with combined aortic stenosis and regurgitation. This is in concordance with previous observations [7].

Concomitant procedures are also different between the two groups. In the valvotomy group resection of coarctation and closure of ventricular septal defect were done with some frequency. In the autograft group additional left ventricular outflow tract operations were done more frequently. Intra-operative analysis led to more of these interventions than preoperative diagnosis. Overall, autograft procedures took longer perfusion and cross-clamp times than aortic valvotomy.

There was no hospital mortality in either group. Late mortality occurred once after valvotomy and twice after autografting. In this respect the groups are comparable.

At medium term follow-up the remaining (n=9) patients in the valvotomy group are asymptomatic (all NYHA class I), but a substantial number will probably require reoperation or balloon valvotomy in the future mainly because of considerable residual or recurrent valvular aortic stenosis and in some patients because of post-interventional aortic regurgitation. This concurs with previous observations [6]. In our series after valvotomy a reoperation on the aortic root took place in two patients and balloon dilatation of the aortic valve in two more patients.

In the autograft group (n=33) most patients are also doing well (91% in NYHA class I), although 12 patients have mild or moderate aortic regurgitation at the last echocardiographic examination. In one patient a prosthetic aortic valve replacement of the regurgitant autograft (echo aortic regurgitation 4+) was performed, while simultaneously the pulmonary allograft was replaced with a new allograft valved conduit because of moderate valvular and severe supravalvular pulmonary stenosis. Isolated pulmonary stenosis developed in two patients, requiring replacement of the allograft in one.

Several groups have reported that the autograft conveniently increases in diameter in children, mostly concordant with growth [10,11]. This diameter increase takes place for about half in the first few days after operation and for the last half in the further first year after operation [10,12]. However, the diameter increase also takes place in adults where this is not appropriate and is associated with a higher incidence of aortic regurgitation [10,12]. For these reasons close follow-up after autografting is necessary to monitor the value of this procedure [9]. According to the serial analysis of echocardiographic aortic regurgitation over time in patients after the autograft procedure, there is indeed reason to be cautious. Although initial aortic regurgitation is minimal (0.5 grade directly postop), there is clearly progression of aortic regurgitation over time. The clinical relevance of these observations will become clear in the next 5–10 years.

A limitation of the study is that this comparison of two surgical treatments is hampered by the retrospective nature of the study, by the difference in indication for surgery in both patient groups, and by the evolving experience with the autograft procedure during the study time period.

In conclusion, there is indeed a place for pediatric valvotomy in the autograft era. In children with valvular aortic stenosis, selected by unsuccessful balloon valvotomy or by concomitant cardiac anomalies such as ventricular septal defect, discrete subaortic stenosis or coarctation of the aorta, valvotomy may be adequate and will postpone further surgery for a significant length of time. After valvotomy the main problem is residual aortic stenosis while after autografting the problem shifts towards aortic regurgitation and problems related to the pulmonary valve. The autograft procedure may very well solve problems at the left ventricular outflow tract, but is not yet the perfect solution.


   Acknowledgments
 
In part supported by grant number 99141 of the Board of Health Care Insurance (College voor Zorgverzekeringen).


   Footnotes
 
Presented at the 14th Annual Meeting of the European Association for Cardio-thoracic Surgery, Frankfurt, Germany, October 7–11, 2000.


   Appendix A. Conference discussion
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
 Appendix A. Conference...
References
 
Dr E. Baudet (Bordeaux, France): You mentioned valvotomy at the mean age of 2.7 years and autografting at the mean age of 9.8 years. Would you consider to perform primary autografting, instead of valvotomy, in younger patients?

Dr Bogers: Yes, we would consider that, but that was not the point of this study. This was a retrospective observational study looking at the strategy that was applied to the children in the previous 12 years. By now, if we meet a patient after valvotomy where the failure includes also aortic regurgitation, the Ross procedure is the procedure of choice. We select patients for valvotomy if there is only stenosis.

Dr Baudet: That means that you could consider a young patient for autografting?

Dr Bogers: Yes, certainly.


   References
Top
 Abstract
 1. Introduction
 2. Materials and methods
 3. Results
 4. Discussion
 Appendix A. Conference...
 References
 

  1. Witsenburg M., Cromme-Dijkhuis A.H., Frohn-Mulder I.M.E., Hess J. Short- and midterm results of balloon valvuloplasty for valvular aortic stenosis in children. Am J Cardiol 1992;69:945-950.[Medline]
  2. Kirklin J.W., Barratt-Boyes B.G. Congenital aortic stenosis. In: Kirklin J.W., Barratt-Boyes B.G., eds. Cardiac surgery, 2nd edition New York: Churchill Livingstone, 1993:1195-1237.
  3. Schoof P.H., Cromme-Dijkhuis A.H., Bogers A.J.J.C., Thijssen E.J.M., Witsenburg M., Hess J., Bos E. Aortic root replacement with pulmonary autograft in children. J Thorac Cardiovasc Surg 1994;107:367-373.[Abstract/Free Full Text]
  4. Hokken R.B., Cromme-Dijkhuis A.H., Bogers A.J.J.C., Spitaels S.E.C., Witsenburg M., Hess J., Bos E. Clinical outcome and left ventricular function after pulmonary autograft implantation in children. Ann Thorac Surg 1997;63:1713-1717.[Abstract/Free Full Text]
  5. Lofland G.K., McCrindle B.W., Williams W.G., Blackstone E.H., Tchervenkov C.I., Sittiwangkul R., Jonas R.A. Critical aortic stenosis in the neonate: a multi-institutional study of management, outcomes, and risk factors. Congenital Heart Surgeons Society. J Thorac Cardiovasc Surg 2001;121:10-27.
  6. Cobanoglu A., Dobbs J.L. Critical aortic stenosis in the neonate, results of aortic commissurotomy. Eur J Cardio-thorac Surg 1996;10:116-119.[Abstract]
  7. Van Son J.A., Reddy V.M., Black M.D., Rajasinghe H., Haas G.S., Hanley F.L. Morphologic determinants favoring surgical aortic valvuloplasty versus pulmonary autograft valve replacement in children. J Thorac Cardiovasc Surg 1996;111:1149-1156.[Abstract/Free Full Text]
  8. Edmunds L.H., Jr, Clark R.E., Cohn L.H., Grunkemeier G.L., Miller D.C., Weisel R.D. Guidelines for reporting morbidity and mortality after cardiac valvular operations. Eur J Cardio-thorac Surg 1996;122:708-711.
  9. Kaplan E.L., Meier P. Nonparametric estimation from incomplete observations. J Am Stat Ass 1958;53:457-481.
  10. Hokken R.B., Bogers A.J.J.C., Taams M.A., Willems T.P., Cromme-Dijkhuis A.H., Witsenburg M., Spitaels S.E.C., van Herwerden L.A., Bos E. Aortic root replacement with a pulmonary autograft. Eur J Cardio-thorac Surg 1995;9:378-383.[Abstract]
  11. Snider A.R., Enderlein M.A., Teitel D.F., Juster R.P. Two-dimensional echocardiographic determination of aortic and pulmonary artery sizes from infancy to adulthood in normal subjects. Am J Cardiol 1984;53:218-224.[Medline]
  12. Hokken R.B., Bogers A.J.J.C., Taams M.A., Schiks-Berghout M.B., van Herwerden L.A., Roelandt J.R.T.C., Bos E. Does the pulmonary autograft in the aortic position in adults increase in diameter? An echocardiographic study. J Thorac Cardiovasc Surg 1997;113:667-674.[Abstract/Free Full Text]



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