insufficiency; 16 had significant mitral valve stenosis. Mitral valve ... replacement and resection of a subaortic membrane. .... Subvalvular aortic stenosis. 6.
Clinical Investigation
Repair of Congenital Malformations of the Mitral Valve in Children Early and Long-term Results
Giovanni Stellin, MD Alessandro Mazzucco, MD Uberto Bortolotti, MD Aldo Milano, MD Giuseppe Faggian, MD Ornella Milanesi, MD Vincenzo Gallucci, MD
in
34 Cases
From March 1972 through December 1986, 34 children underwent surgical treatment of mitral valve dysplasia at our institution. There were 14 males and 20 females, with a mean age of 6 years (range, 5 months to 15 years). Eighteen patients had significant mitral valve insufficiency; 16 had significant mitral valve stenosis. Mitral valve reconstruction was possible in 30 patients (88.2%); replacement of the mitral valve with a mechanical prosthesis was necessary in the other 4 patients (1 1.8%), after at least 1 attempted reconstruction. Five patients died in the hospital (14.7%). 4 after conservative surgery, and 1 after mitral valve replacement. A 6th patient died 26 months after mitral valve replacement and resection of a subaortic membrane. Four patients required reoperation 2 to 66 months after conservative treatment: in 3 of these, the mitral valve was replaced; in the 4th, additional reconstruction was successful. Upon follow-up (range, 3 months to 14 years after surgery), 26 of the 28 surviving patients were asymptomatic; 2-dimensional and Doppler echocardiographyperformed in 22 patients after mitral valve repair showed normal pulmonary artery pressure in all, and moderate mitral valve dysfunction in 2. Our results indicate that reconstructive surgery for mitral valve dysplasia may prove effective and reliable in children, despite the frequent severity of valve malformation. We believe, therefore, that mitral valve repair should always be attempted in the pediatric population to avoid the disadvantages of prosthetic valve replacement. (Texas Heart Institute Journal 1989;16:102-6)
S
Key words: Mitral valve repair; mitral valve insufficiency; mitral valve stenosis; heart defects, congenital; heart valve diseases; heart valve prosthesis; child From: The Department of Cardiovascular Surgery
(Drs. Stellin, Mazzucco, Bortolotti, Milano, Faggian, and Gallucci) and Pediatrics (Dr. Milanesi), University of Padua Medical School, Padua, Italy This work was supported by the National Council of Research; Rome, Italy; Target Project, "Perinatal Pathology and Its Sequelae. "
Address for reprints: Giovanni Stellin, MD, Istituto Chirurgia Cardiovascolare, Universita di Padova, via Giustiniani 2, 35128 Padua, Italy
102
urgical treatment of mitral valve (MV) dysplasia is a continuing therapeutic challenge, mainly because of the young age of patients when the condition becomes evident and because of the high incidence of associated complex cardiac anomalies. Problems related to the use of most of the currently available mechanical and bioprosthetic valves in the pediatric age group"'- justify a broad effort towards reparative surgery of the native valve.-,' Because information on the surgical treatment of congenital MV malformations in children is limited, we have reviewed our experience on this subject.
Patients and Methods Patient Population Between March 1972 and December 1986, 34 children underwent consecutive surgical correction of MV dysplasia. We treated 14 boys and 20 girls, with a mean age of 6 years (range, 5 months to 15 years) (Fig. 1). This review excludes patients with such complex lesions as atrioventricular (AV) septal defects (partial or complete AV canal), corrected transposition of the great arteries, left ventricular hypoplasia, and univentricular AV connection (single ventricle). Indications for operation included preoperative functional class, symptoms (chronic congestive heart failure, exertional dyspnea, retarded growth, and frequent chest infections), and presence of increased pulmonary artery pressure and associated intracardiac lesions. In 4 patients, the valvular anomaly (supravalvular membrane in 2, isolated cleft of the anterior MV leaflet in 1, and hammock MV in 1) was discovered incidentally during surgery. Patients with MV dysplasia were classified using Carpentier's criteria9 and were divided into 2 groups. The 1st group included 18 patients with clinical and hemo-
Mitral Valve Repair in Children
l'oliiine 16. Number 2. 1989
TABLE 1. Classification of Cases with Mitral Valve Incompetence* (18 patients)
10
Type l: Normal leaflet motion (n = 9) - Annulus dilatation - Leaflet defect - Cleft leaflet - Accessory orifice and commissural leaflet
C,,
C0
0
.0
1 1 6 1
5
E
Type II: Prolapsed leaflet (n = 4)
z
- Elongated chordae - Absent chordae
3 1
Type IlIl: Restricted leaflet motion (n = 5) O
Eo 0
60
m
0
0
oo
74.5±11.8 21 19 17I 13 11I 6I 6I 5I 3I 2I 2I 1 I 1 26 .I 1 2 3 4 5 6 7 8 9 10 1112 1314 Years after Surgery
Fig. 3 Actuarial survival and actuarial freedom from reoperation after conservative treatment of mitral valve dysplasia in 26 children. No deaths occurred in the follow-up period (100% survival rate). At 14 years, 74.5% of patients are free from reoperation. Operative deaths are excluded; numbers on the horizontal axis indicate patients at risk.
Reoperation Reoperation was necessary in 4 (13.3%) of the 30 MV repair patients. The 1st was an 11-year-old boy who had undergone splitting of papillary muscles and insertion of a Carpentier ring. Twenty-two months later, persistent mitral regurgitation necessitated replacement of the repaired valve with a 29-mm Sorin tilting disc prosthesis. The 2nd patient was a 15-yearold girl in whom a cleft of the anterior leaflet and annular dilatation had been repaired by suturing the cleft and inserting a Carpentier ring. She also underwent mitral valve replacement with a 29-mm Sorin prosthesis, 22 months later, because of persistent mitral regurgitation. The 3rd patient was an 8-yearold girl who had undergone chordae elongation and commissure annuloplasty. Because of persistent regurgitation, her natural valve was explanted 2 months after repair and replaced with a 29-mm Sorin prosthesis. Finally, in a 3-year-old girl who had recurrent MV stenosis and a subaortic obstructive ring that was not present at the time of 1st operation, further repair was possible after 66 months, in association with a subaortic membrane resection. The *
According to the classification of Heath and Edwards (circulation 1958; 18:533-47)
Texas HearT Institutejoumal
actuarial freedom from valve reoperation at 14 years is 74.5% ± 11.8% (Fig. 3).
Long-term Follow-up Reevaluation of the 28 survivors was obtained from 3 months to 14 years after surgery. All but 2 children were asymptomatic. Of the latter, 1 has been recently discharged from the hospital after resection of a subaortic membrane and further reconstruction of the MV because of recurrent stenosis. The 2nd, a mentally retarded child, shows signs of persistent cardiomegaly with moderate MV incompetence. Three years ago he underwent repair of a severely malformed parachute-type MV together with resection of a supravalvular membrane. His parents have refused further treatment. A Doppler evaluation of MV function was performed at the time of follow-up examination in 22 out of 23 patients who had received conservative treatment. Among 21 asymptomatic children, 12 showed good MV performance; trivial-to-mild MV incompetence or stenosis was detected in 7, and signs of moderate valve dysfunction were seen in 2. Pulmonary artery pressure was normal in all. The 5 children with prosthetic valves were also asymptomatic; none experienced any prosthesis-related complications.
Discussion Little experience has been reported in the surgical literature regarding the effectiveness and the technical aspects of surgical repair of MV dysplasia in children.i 8 Patients with this condition have frequently been given a prosthetic valve to avoid residual dysfunction. We believe that reconstruction of the natural MV should always be attempted in infants and young children because of the unfavorable flow patterns of small-sized prostheses, the problems of anticoagulant therapy for active children, and the accelerated degeneration of biological valve substitutes in the young. However, when the whole valve apparatus appears to be severely malformed, and an initial attempt fails to achieve a satisfactory result, prompt replacement is recommended. Our experience with 2 patients will serve as an example. The 1st, an 8-year-old boy, died intraoperatively of low output syndrome after repeated attempts to preserve an undiagnosed, severely dysplastic, hammock MV. The 2nd, an 8-year-old girl, had an unsatisfactory reconstruction of a very dysplastic MV apparatus, characterized by absence of tissue at the commissures and short chordae. Two months later, her MV was replaced because of persistent signs of significant mitral regurgitation. She is now alive and well. When the native MV cannot be preserved, our current policy is to replace it with a tilting-disc or a Mitral Valve Repair in Children
105
bileaflet mechanical prosthesis. When small sizes are required, we usually implant the bileaflet prosthesis because it provides better hemodynamic performance. Although no major prosthesis-related complications occurred in the 5 children with a mechanical valve who received sodium warfarin, we are concerned about the high risk of anticoagulation to the pediatric population.3'1 We are aware of reports that show promising results from antiplatelet treatment used alone, and used with prosthetic valves implanted in the mitral position.12 At present, clinicians in our institution use such therapy only in children with prosthetic valves implanted in the aortic position. A longer follow-up and more widespread use of such thromboembolic prophylaxis will give us more reliable information. Even though our patient population was small, our series suggests good overall results from conservative treatment: a 77% long-term survival rate and a promising 74.5% freedom from reoperation after 14 years. This compares favorably with results presented in previous reports.78 Of 23 children in whom the natural valve was preserved, 21 remain asymptomatic. This confirms the success of reconstruction, despite the possible presence of residual valve dysfunction detected in our patients by 2-dimensional echocardiography and Doppler studies. Of the 5 children who underwent MV annuloplasty with a Carpentier ring, 2 required reoperation; in both of these, it was most likely scar tissue caused by the sutures and the ring itself that limited adequate annulus growth and leaflet motion, leading to recurrent MV dysfunction. Consequently, when the annulus is dilated, we now prefer to repair the MV by plication of the mural leaflet at 1 or both commissures (Fig. 2). This technique does not require the use of prosthetic material and has proved, so far, to be effective. Our results indicate that MV reconstruction is the treatment of choice in children, even in the presence of severe valvular dysplasia. These findings encourage us to attempt reparative surgery in order to forestall replacement with prosthetic valves.
106
Mitral Valve Repair in Children
Acknowledgments The authors wish to thank Miss Anna Rambaldo, Mr. Gian Carlo Pengo, and Mrs. Lorella Molena for their technical assistance.
References 1.
2.
3.
4. 5.
6. 7.
8.
9.
10. 11.
12.
Borkon AM, Soule L, Reitz BA, Gott VL, Gardner TJ. Five year follow-up after valve replacement with the St. Jude medical valve in infants and children. Circulation 1986;74(Suppl I): 110-5. Elliott MJ, de Leval M. Valve replacement in children. World J Surg 1985;9:568-78. Milano A, Vouhe PR. Baillot-Vernant F, et al. Late results after left-sided cardiac valve replacement in children. j Thorac Cardiovasc Surg 1986:92:218-25. Miller DC. Stinson EB, Oyer PE, et al. The durahility of porcine xenograft valves and conduits in children. Circulation 1982;66(Suppl I):172-85. Sanders SP, Levy RJ, Freed MD, Norwood WI, Castaneda AR. Use of Hancock porcine xenograft in children and adolescents. Am j Cardiol 1980;46:429-38. Spevak PJ. Freed MD. Castaneda AR, Norw%ood WI, Pollack P. Valve replacement in children less than 5 years of age. J Am Coll Cardiol 1986;8:901-8. Carpentier A, Branchini B, CourjC, et al. Congenital malformations of the mitral valve in children: pathology and surgical treatment. J Thorac Cardiovrasc Surg 1976;72:854-66. Lessana A, Tran-Viet T, Ades F, et al. Mitral reconstructive operations: a series of 130 consecutive cases. J Thorac Cardiovasc Surg 1983;86:553-61. Carpentier A. Congenital malformations of the mitral valve. In: Stark J, de Lev-al NI, eds. Surgery for congenital heart defects. London: Grune & Stratton, 1983:467-82. Kaplan EL, Meier P. Nonparametric estimation from incomplete observations. j Am Stat Assoc 1958:53:457-81. Human DG, Joffe HS, Fraser CB, Barnard CN. Mitral valve replacement in children. j Thorac Cardiovasc Surg 1982;83: 873-7. Pass HI, Sade R-M, Crax-ford FA. Hohn AR. Cardiac valve prostheses in children without anticoagulaltion. J Thorac Cardiovasc Surg 1984:87:823-35.
l'ollitiie 16, A'umber 2. 1989
