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Artificial Chordae for Mitral Valve Reconstruction in Children
Artificial Chordae for Mitral Valve Reconstruction in Children Takashi Murakami, MD, Toshikatsu Yagihara, MD, Fumio Yamamoto, MD, Hideki Uemura, MD, Katsushi Yamashita, MD, and Toru Ishizaka, MD Department of Cardiovascular Surgery, National Cardiovascular Center, Osaka, Japan
Background. Congenital mitral regurgitation continues to present a challenge for cardiac surgeons because of the diversity of the anatomy of the congenitally malformed mitral valve. We undertook aggressive repair of the mitral valve with artificial chordae for reconstruction of the prolapsed anterior leaflet in some children. The short-term results are reported herein. Methods. Three patients with isolated congenital mitral regurgitation underwent mitral valve repair with use of expanded polytetrafluoroethylene sutures as artificial chordae. Results. There have been no late deaths and no valverelated complications. Serial follow-up echocardiographic
examinations have not revealed any increase in the severity of mitral regurgitation with continuing patient growth up to 39 months after the operation. Conclusions. When combined with other conservative methods of mitral valve repair, chordal replacement with expanded polytetrafluoroethylene sutures in children undergoing mitral valve reconstruction produces good short-term results. We believe that it delays and possibly prevents the need for a mechanical prosthesis with its associated complications in this young patient population. (Ann Thorac Surg 1998;65:1377– 80) © 1998 by The Society of Thoracic Surgeons
C
length was adjusted, both ends of the suture were tied together (Fig 1).
ongenital mitral regurgitation continues to present a challenge for cardiac surgeons [1]. Conventional techniques can have limitations related to the wide spectrum of congenitally malformed lesions and the relatively small size of the valve. Artificial chordae may be an attractive option in some cases but their use in pediatric patients and long-term outcome, after patient growth, have not been reported. We used artificial chordae to reconstruct the prolapsed anterior leaflet in 3 patients undergoing repair of a congenitally malformed mitral valve.
Material and Methods Surgical Technique Mitral valve repair was performed under moderate hypothermic cardiopulmonary bypass with cardioplegic arrest induced by St. Thomas solution. Artificial chordae were constructed of 4-0 expanded polytetrafluoroethylene (ePTFE) in all patients. The mattress ePTFE suture with a Teflon or autologous pericardial pledget was passed through the free margin of the leaflet from the ventricular side to the atrial side. The two arms of the suture then were brought down to the papillary muscle and passed through it, reinforced with pledget. The length of the ePTFE chordae was adjusted by approximating the coapting area of the opposite leaflet. After the
Case Reports A 1.4-year-old girl had a prolapsed anterior mitral valve leaflet. The anterolateral side of the anterior leaflet had only one primary chorda providing support, resulting in prolapse of the leaflet on both sides of this chorda. By the technique described previously, 4-0 ePTFE suture was used as a substitute for the deficient chorda on the medial side of the primary chordae. A bilateral commissural annuloplasty was performed by Reed-type commissuroplasty and included the anterolateral side of the prolapsed leaflet. The diameter of the mitral valve annulus was reduced from 24 mm to 15 mm, which was the normal mitral valve diameter calculated from the body surface area [2].
PATIENT 1.
Accepted for publication Sep 10, 1997.
A 4.6-year-old girl had a cleft on the anterior mitral valve leaflet. There was no chorda attached to this area. One elongated primary chorda was found on the anterolateral side of the cleft. The mitral valve annulus was dilated. The cleft was closed with interrupted sutures and 4-0 ePTFE suture was attached at the free margin of this area. Chordal shortening and bilateral mitral annuloplasty also was performed by Reed-type commissuroplasty, and the diameter of the mitral annulus was reduced from 27 mm to 19 mm, which was 119% of the normal mitral valve diameter calculated from the body surface area.
Address reprint requests to Dr Yagihara, Department of Cardiovascular Surgery, National Cardiovascular Center, 2-5-1 Fujishirodai, Suita, Osaka, 565 Japan.
PATIENT 3. A 5.1-year-old boy had only one thickened dysplastic chorda on the anterolateral side of the anterior
© 1998 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
PATIENT 2.
0003-4975/98/$19.00 PII S0003-4975(97)01441-0
1378
MURAKAMI ET AL ARTIFICIAL CHORDAE FOR CHILDREN
Ann Thorac Surg 1998;65:1377– 80
Fig 1. Surgical technique for mitral valve repair in (A–C) patient 1, (D, E) patient 2, and (F–H) patient 3.
mitral valve leaflet, which restricted the motion of the leaflet. The anterolateral areas of both the anterior and posterior leaflets were sclerosed. Mobilization of the anterior leaflet was obtained by resection of the abnormal chorda, which was replaced with 4-0 ePTFE suture. Unilateral annuloplasty was performed, folding the sclerotic posterior leaflet by Reed-type commissuroplasty, and the diameter of the mitral annulus was reduced from 31 mm to 22 mm, which was 116% of the normal mitral valve diameter calculated from the body surface area.
Results All 3 patients survived the operation without complications and were discharged from the hospital. All the patients received warfarin sodium and dipyridamole after the operation. Warfarin sodium was discontinued after 3 months and dipyridamole was discontinued after 1 year.
Follow-up of the patients ranged from 17 to 39 months. There were no late deaths, no thromboemboli, no anticoagulant-related hemorrhages, and no cases of infective endocarditis. All the patients underwent cardiac catheterization before and 1 year after the operation. Left ventricular angiography showed a totally competent mitral valve in patient 2 and mild mitral insufficiency in patients 1 and 3. Left ventricular volume had returned to normal in all the patients. Serial follow-up echocardiographic examinations have revealed no increase in the severity of mitral regurgitation with continuing patient growth (Fig 2). All the patients have good activity levels without cardiac medication.
Comment Numerous techniques of chordal reconstruction have been proposed for the repair of prolapsed anterior leaflet of the mitral valve, such as chordal shortening [3], trans-
Ann Thorac Surg 1998;65:1377– 80
MURAKAMI ET AL ARTIFICIAL CHORDAE FOR CHILDREN
1379
Fig 2. Serial follow-up of the grade of mitral regurgitation (MR), left ventricular end-diastolic dimension (LVDd) as shown by echocardiography, and body weight (BW) in (A) patient 1, (B) patient 2, and (C) patient 3.
location of the chordae of the posterior leaflet [3], flipover of the posterior leaflet, and the creation of artificial chordae [4]. Because of the diversity of the anatomy of the congenitally malformed mitral valve, a combination of these methods may be required. Chordal reconstruction with ePTFE sutures is a wellestablished technique for the correction of mitral insufficiency in adults [5–7]. We have used this technique in adult patients with mitral valve insufficiency with satisfactory intermediate results [8]. In this report, we describe the early results of this technique used in pediatric patients with various congenital malformations of the mitral valve. The early postoperative results have been satisfactory. However, the long-term results have not yet been con-
firmed, particularly in terms of the reliability of ePTFE sutures as substitute chordae and their continued function as the patients grow. Expanded polytetrafluoroethylene has been reported to be a reliable material for the replacement of mitral valve chordae [9]. In a clinical study, Zussa and associates [7] reported that ePTFE was not associated with either thromboembolic events or degeneration of the material. At reoperation 18 months and 2 years after the initial procedures, these investigators found the artificial chordae covered with fibrous tissue with no evidence of thrombi or calcification. Although the process of fibrous overgrowth has been reported to be slow in adults, the rates of fibrous overgrowth and calcification are not known in pediatric patients.
1380
MURAKAMI ET AL ARTIFICIAL CHORDAE FOR CHILDREN
Theoretic concern exists over the possibility of relative shortening of chordae replaced with ePTFE as the patient grows, resulting in mitral regurgitation. In our limited experience over 3 years, no increase in the severity of mitral valve regurgitation has been detected in patients 1, 2, and 3, who have increased in body weight from 8.7 to 11.8 kg, 11.0 to 14.5 kg, and 22.5 to 35 kg, respectively (Fig 2). Two of our patients have shown dramatically decreased ventricular volume 1 year after the operation, but long-term changes in the longitudinal dimension of the left ventricle and their impact on mitral valve function after repair with the use of artificial chordae are uncertain. We would expect that the effect of relative shortening of the artificial chordae would be compensated for by growth or elongation of the papillary muscle or the mitral valve leaflet tissue, but further follow-up is needed to evaluate the long-term outcome. We conclude that the short-term results of chordal replacement with ePTFE in children undergoing mitral valve reconstruction are satisfactory. We believe that when this technique is combined with other conservative methods of mitral valve repair, it delays and possibly prevents the need for a mechanical prosthesis with its associated complications in this young patient population.
Ann Thorac Surg 1998;65:1377– 80
References 1. Uva MS, Galletti L, Gayet FL, et al. Surgery for congenital mitral valve disease in the first year of life. J Thorac Cardiovasc Surg 1995;109:164–76. 2. Rowlatt JF, Rimoldi JHA, Lev M. The quantitative anatomy of the normal child’s heart. Pediatr Clin North Am 1963;10:499 –588. 3. Carpentier A. Cardiac valve surgery: the “French correction.” J Thorac Cardiovasc Surg 1993;86:323–37. 4. Lessana A, Romano M, Lutfalla G, et al. Treatment of ruptured or elongated anterior mitral valve chordae by partial transposition of the posterior leaflet: experience with 29 patients. Ann Thorac Surg 1988;45:404– 8. 5. David TE, Bos J, Rakowski H. Mitral valve repair by replacement of chordae tendineae with polytetrafluoroethylene sutures. J Thorac Cardiovasc Surg 1991;101:495–501. 6. Frater RWM, Vetter HO, Zussa C, Dahm M. Chordal replacement in mitral valve repair. Circulation 1990;82(Suppl 4): 125–30. 7. Zussa C, Polese E, Col UD, Galloni M, Valfre C. Seven-year experience with chordal replacement with expanded polytetrafluoroethylene in floppy mitral valve. J Thorac Cardiovasc Surg 1994;108:37– 41. 8. Kawazoe K, Eish K, Sasako Y, et al. Clinical experience of mitral valve reconstruction with artificial chordae implantation. Eur J Cardiothorac Surg 1992;6:297–301. 9. Vetter HO, Burack JM, Factor SM, Macaluso F, Frater RWM. Replacement of chordae tendineae of the mitral valve using the new expanded PTFE-suture in sheep. In: Bodnar E, Yacoub M, eds. Biological and bioprosthetic valves. New York: Yorke Medical Books, 1986:772– 84.
Background. Congenital mitral regurgitation continues to present a challenge for cardiac surgeons because of the diversity of the anatomy of the congenitally malformed mitral valve. We undertook aggressive repair of the mitral valve with artificial chordae for reconstruction of the prolapsed anterior leaflet in some children. The short-term results are reported herein. Methods. Three patients with isolated congenital mitral regurgitation underwent mitral valve repair with use of expanded polytetrafluoroethylene sutures as artificial chordae. Results. There have been no late deaths and no valverelated complications. Serial follow-up echocardiographic
examinations have not revealed any increase in the severity of mitral regurgitation with continuing patient growth up to 39 months after the operation. Conclusions. When combined with other conservative methods of mitral valve repair, chordal replacement with expanded polytetrafluoroethylene sutures in children undergoing mitral valve reconstruction produces good short-term results. We believe that it delays and possibly prevents the need for a mechanical prosthesis with its associated complications in this young patient population. (Ann Thorac Surg 1998;65:1377– 80) © 1998 by The Society of Thoracic Surgeons
C
length was adjusted, both ends of the suture were tied together (Fig 1).
ongenital mitral regurgitation continues to present a challenge for cardiac surgeons [1]. Conventional techniques can have limitations related to the wide spectrum of congenitally malformed lesions and the relatively small size of the valve. Artificial chordae may be an attractive option in some cases but their use in pediatric patients and long-term outcome, after patient growth, have not been reported. We used artificial chordae to reconstruct the prolapsed anterior leaflet in 3 patients undergoing repair of a congenitally malformed mitral valve.
Material and Methods Surgical Technique Mitral valve repair was performed under moderate hypothermic cardiopulmonary bypass with cardioplegic arrest induced by St. Thomas solution. Artificial chordae were constructed of 4-0 expanded polytetrafluoroethylene (ePTFE) in all patients. The mattress ePTFE suture with a Teflon or autologous pericardial pledget was passed through the free margin of the leaflet from the ventricular side to the atrial side. The two arms of the suture then were brought down to the papillary muscle and passed through it, reinforced with pledget. The length of the ePTFE chordae was adjusted by approximating the coapting area of the opposite leaflet. After the
Case Reports A 1.4-year-old girl had a prolapsed anterior mitral valve leaflet. The anterolateral side of the anterior leaflet had only one primary chorda providing support, resulting in prolapse of the leaflet on both sides of this chorda. By the technique described previously, 4-0 ePTFE suture was used as a substitute for the deficient chorda on the medial side of the primary chordae. A bilateral commissural annuloplasty was performed by Reed-type commissuroplasty and included the anterolateral side of the prolapsed leaflet. The diameter of the mitral valve annulus was reduced from 24 mm to 15 mm, which was the normal mitral valve diameter calculated from the body surface area [2].
PATIENT 1.
Accepted for publication Sep 10, 1997.
A 4.6-year-old girl had a cleft on the anterior mitral valve leaflet. There was no chorda attached to this area. One elongated primary chorda was found on the anterolateral side of the cleft. The mitral valve annulus was dilated. The cleft was closed with interrupted sutures and 4-0 ePTFE suture was attached at the free margin of this area. Chordal shortening and bilateral mitral annuloplasty also was performed by Reed-type commissuroplasty, and the diameter of the mitral annulus was reduced from 27 mm to 19 mm, which was 119% of the normal mitral valve diameter calculated from the body surface area.
Address reprint requests to Dr Yagihara, Department of Cardiovascular Surgery, National Cardiovascular Center, 2-5-1 Fujishirodai, Suita, Osaka, 565 Japan.
PATIENT 3. A 5.1-year-old boy had only one thickened dysplastic chorda on the anterolateral side of the anterior
© 1998 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
PATIENT 2.
0003-4975/98/$19.00 PII S0003-4975(97)01441-0
1378
MURAKAMI ET AL ARTIFICIAL CHORDAE FOR CHILDREN
Ann Thorac Surg 1998;65:1377– 80
Fig 1. Surgical technique for mitral valve repair in (A–C) patient 1, (D, E) patient 2, and (F–H) patient 3.
mitral valve leaflet, which restricted the motion of the leaflet. The anterolateral areas of both the anterior and posterior leaflets were sclerosed. Mobilization of the anterior leaflet was obtained by resection of the abnormal chorda, which was replaced with 4-0 ePTFE suture. Unilateral annuloplasty was performed, folding the sclerotic posterior leaflet by Reed-type commissuroplasty, and the diameter of the mitral annulus was reduced from 31 mm to 22 mm, which was 116% of the normal mitral valve diameter calculated from the body surface area.
Results All 3 patients survived the operation without complications and were discharged from the hospital. All the patients received warfarin sodium and dipyridamole after the operation. Warfarin sodium was discontinued after 3 months and dipyridamole was discontinued after 1 year.
Follow-up of the patients ranged from 17 to 39 months. There were no late deaths, no thromboemboli, no anticoagulant-related hemorrhages, and no cases of infective endocarditis. All the patients underwent cardiac catheterization before and 1 year after the operation. Left ventricular angiography showed a totally competent mitral valve in patient 2 and mild mitral insufficiency in patients 1 and 3. Left ventricular volume had returned to normal in all the patients. Serial follow-up echocardiographic examinations have revealed no increase in the severity of mitral regurgitation with continuing patient growth (Fig 2). All the patients have good activity levels without cardiac medication.
Comment Numerous techniques of chordal reconstruction have been proposed for the repair of prolapsed anterior leaflet of the mitral valve, such as chordal shortening [3], trans-
Ann Thorac Surg 1998;65:1377– 80
MURAKAMI ET AL ARTIFICIAL CHORDAE FOR CHILDREN
1379
Fig 2. Serial follow-up of the grade of mitral regurgitation (MR), left ventricular end-diastolic dimension (LVDd) as shown by echocardiography, and body weight (BW) in (A) patient 1, (B) patient 2, and (C) patient 3.
location of the chordae of the posterior leaflet [3], flipover of the posterior leaflet, and the creation of artificial chordae [4]. Because of the diversity of the anatomy of the congenitally malformed mitral valve, a combination of these methods may be required. Chordal reconstruction with ePTFE sutures is a wellestablished technique for the correction of mitral insufficiency in adults [5–7]. We have used this technique in adult patients with mitral valve insufficiency with satisfactory intermediate results [8]. In this report, we describe the early results of this technique used in pediatric patients with various congenital malformations of the mitral valve. The early postoperative results have been satisfactory. However, the long-term results have not yet been con-
firmed, particularly in terms of the reliability of ePTFE sutures as substitute chordae and their continued function as the patients grow. Expanded polytetrafluoroethylene has been reported to be a reliable material for the replacement of mitral valve chordae [9]. In a clinical study, Zussa and associates [7] reported that ePTFE was not associated with either thromboembolic events or degeneration of the material. At reoperation 18 months and 2 years after the initial procedures, these investigators found the artificial chordae covered with fibrous tissue with no evidence of thrombi or calcification. Although the process of fibrous overgrowth has been reported to be slow in adults, the rates of fibrous overgrowth and calcification are not known in pediatric patients.
1380
MURAKAMI ET AL ARTIFICIAL CHORDAE FOR CHILDREN
Theoretic concern exists over the possibility of relative shortening of chordae replaced with ePTFE as the patient grows, resulting in mitral regurgitation. In our limited experience over 3 years, no increase in the severity of mitral valve regurgitation has been detected in patients 1, 2, and 3, who have increased in body weight from 8.7 to 11.8 kg, 11.0 to 14.5 kg, and 22.5 to 35 kg, respectively (Fig 2). Two of our patients have shown dramatically decreased ventricular volume 1 year after the operation, but long-term changes in the longitudinal dimension of the left ventricle and their impact on mitral valve function after repair with the use of artificial chordae are uncertain. We would expect that the effect of relative shortening of the artificial chordae would be compensated for by growth or elongation of the papillary muscle or the mitral valve leaflet tissue, but further follow-up is needed to evaluate the long-term outcome. We conclude that the short-term results of chordal replacement with ePTFE in children undergoing mitral valve reconstruction are satisfactory. We believe that when this technique is combined with other conservative methods of mitral valve repair, it delays and possibly prevents the need for a mechanical prosthesis with its associated complications in this young patient population.
Ann Thorac Surg 1998;65:1377– 80
References 1. Uva MS, Galletti L, Gayet FL, et al. Surgery for congenital mitral valve disease in the first year of life. J Thorac Cardiovasc Surg 1995;109:164–76. 2. Rowlatt JF, Rimoldi JHA, Lev M. The quantitative anatomy of the normal child’s heart. Pediatr Clin North Am 1963;10:499 –588. 3. Carpentier A. Cardiac valve surgery: the “French correction.” J Thorac Cardiovasc Surg 1993;86:323–37. 4. Lessana A, Romano M, Lutfalla G, et al. Treatment of ruptured or elongated anterior mitral valve chordae by partial transposition of the posterior leaflet: experience with 29 patients. Ann Thorac Surg 1988;45:404– 8. 5. David TE, Bos J, Rakowski H. Mitral valve repair by replacement of chordae tendineae with polytetrafluoroethylene sutures. J Thorac Cardiovasc Surg 1991;101:495–501. 6. Frater RWM, Vetter HO, Zussa C, Dahm M. Chordal replacement in mitral valve repair. Circulation 1990;82(Suppl 4): 125–30. 7. Zussa C, Polese E, Col UD, Galloni M, Valfre C. Seven-year experience with chordal replacement with expanded polytetrafluoroethylene in floppy mitral valve. J Thorac Cardiovasc Surg 1994;108:37– 41. 8. Kawazoe K, Eish K, Sasako Y, et al. Clinical experience of mitral valve reconstruction with artificial chordae implantation. Eur J Cardiothorac Surg 1992;6:297–301. 9. Vetter HO, Burack JM, Factor SM, Macaluso F, Frater RWM. Replacement of chordae tendineae of the mitral valve using the new expanded PTFE-suture in sheep. In: Bodnar E, Yacoub M, eds. Biological and bioprosthetic valves. New York: Yorke Medical Books, 1986:772– 84.