Ann Thorac Surg 1999;68:1843-1845
© 1999 The Society of Thoracic Surgeons
Case Reports
Intraatrial mitral valve insertion with native valve preservation in children
Serafin Y. DeLeon, MDa,
Frank Cetta, MDa,
Thyyar M. Ravindranath, MDa,
Patrick T. Roughneen, FRCSa,
Elizabeth A. Fisher, MDa
a Departments of Pediatrics and Thoracic-Cardiovascular Surgery, Stritch School of Medicine, Maywood, Illinois, USA
Address reprint requests to Dr DeLeon, Department of Surgery, Tulane University School of Medicine, 1430 Tulane Ave, SL22, New Orleans, LA 70112
 |
Abstract
|
|---|
Two patients underwent intraatrial mitral valve insertion for an unsuccessful valvotomy for severe mitral stenosis and left-sided atrioventricular valve insufficiency associated with corrected transposition utilizing a porcine valve from a valved conduit with preservation of the native valve. The valves were inserted using continuous suture distally at the mitral annulus and proximally at the pulled atrial wall distal to the pulmonary veins. Both patients had uneventful hospital course and are doing well at up to 6 months postoperatively. This apporach provides a viable option for congenital mitral stenosis or insufficiency in children.
|
Introduction
|
|---|
Management of congenital mitral stenosis or insufficiency that causes significant hemodynamic problems in early infancy or childhood is difficult. Valvotomy, valve repair, or valve replacement are often unsuccessful and carry significant risk in this age group [1–4].
During a 2-month period, we inserted a porcine valve from a valved conduit intraatrially in series with the intact native mitral valve in 2 patients. This is a report of our experience.
One patient was a 3-month-old boy with failure to thrive from a severe congenital mitral stenosis. Preoperative echocardiography showed a double orifice mitral valve with shortened chordae, mitral gradient of 17 mm Hg, and pulmonary artery pressure of 74 mm Hg. The other patient was a 2.5-year-old boy with corrected transposition of the great arteries who underwent ventricular septal defect closure at 7 months of age. Mild left-sided (tricuspid) atrioventricular valve insufficiency, which was present at that time, progressed to a severe degree.
Cardiopulmonary bypass and moderate hypothermia (28°C) were accomplished through an ascending aorta and bicaval cannulation. Antegrade followed by retrograde blood cardioplegia at 10 to 15-minute intervals was used. The valve graft was performed through an atrial septal incision in both patients. Warm antegrade cardioplegia was given before release of the aortic cross-clamp.
In the first patient, mitral valvotomy was attempted by opening the medial commissure and splitting the major papillary muscle. Postvalvotomy echocardiography with the patient off cardiopulmonary bypass showed moderately severe mitral insufficiency with several jets of insufficiency. The gradient, however, was reduced to 4 to 5 mm Hg from 17 mm Hg. Cardiopulmonary bypass was reinstituted. A no. 14 porcine valve was taken from a valved conduit by cutting the proximal and distal part of the conduit as close to the valve as possible. The distal anastomosis was accomplished first (Fig 1) with continuous 4-0 monofilament suture at the mitral annulus. The proximal continuous suture line was performed by pulling the atrial wall to the valve. Because of the potential space between the valve and the atrial wall, a hole in the atrial septum was made to drain any fluid accumulation in this space into the right atrium. The atrial septum proximal to the valve was enlarged with a polytetrafluorethylene patch.
View larger version (33K):
[in this window]
[in a new window]
|
Fig 1. (A) Illustration showing the porcine valve cut from a valved conduit being aligned in the left atrium (LA). Dotted lines indicate the proximal and distal suture line. (B) The porcine has been implanted. Arrow indicates the hole created in the atrial septum to drain any fluid accumulation between the valve and the atrial wall. The left atrium is enlarged with a patch in the atrial septum proximal to the valve. (RA = right atrium; RV = right ventricle.)
|
|
In the second patient, mild downward displacement of the septal leaflet of the tricuspid valve was found. Annuloplasty was performed but failed to result in reasonable coaptation of the leaflets. An unstented porcine valve was inserted using the technique similar to the first patient. The porcine valve wall, however, buckled causing significant gradient across the valve determined by transesophageal echocardiography done after coming off cardiopulmonary bypass. The unstented porcine valve was replaced with a no. 20 valve from a conduit. The porcine aortic wall rigidity from the glutaraldehyde preservation was not enough to avoid distortion in contrast to the porcine valve taken from a valved conduit.
Both patients had uneventful postoperative course and went home at 7 and 10 days after the operation, respectively.
The immediate postoperative transesophageal echocardiography in the first patient showed a valve mean gradient of 6 mm Hg (Fig 2) of the prosthetic and native valve in series and right ventricular pressure of 31 mm Hg. Postoperative transthoracic echocardiography at 5 months showed mitral valves gradient of 10 mm Hg and right ventricular pressure of 40 mm Hg. The other patient had a mean gradient of the mitral valves of 6 to 7 mm Hg on immediate postoperative transesophageal echocardiography. Two months postoperatively, transthoracic echocardiography showed negligible gradient across the mitral valves in this patient.
View larger version (62K):
[in this window]
[in a new window]
|
Fig 2. (A) Echocardiogram of patient 1 showing the porcine valve in the left atrium (open arrow) and the intact native mitral valve (solid arrows). (B) Echocardiogram of patient 2 with corrected transposition also showing the intraatrial porcine valve (open arrow) and intact native systemic tricuspid valve (solid arrows).
|
|
|
Comment
|
|---|
Mitral valve replacement in infants and small children is nearly improbable because the size of the mitral annulus is not big enough for the smallest available metallic or stented porcine valve. Although the porcine valve taken from small-valved conduit can be used, its high profile will cause obstruction of the left ventricular outflow tract if inserted in the mitral annulus [4]. Even if the smallest metallic valve can be used, anticoagulation in children is difficult to control.
There is increasing evidence that preservation of the chordae and papillary muscle in mitral valve replacement maintains the geometry and function of the left ventricle [5]. The systemic ventricle geometry and function was well preserved in both of our patients.
Most prosthetic valves will have some flow gradients. Although both of our patients are doing well postoperatively, the patient with mitral stenosis has a mean gradient across the mitral valves in series that is relatively high. In retrospect, the native mitral valve should have been opened further after the initial attempt to open the valve, because any worsening of the mitral insufficiency will be relieved by the prosthetic valve.
Leaving the native mitral valve intact makes repair of the mitral valve possible as the child gets older. Even if repair of the valve is not possible, valve replacement and anticoagulation are better tolerated in older patients.
|
References
|
|---|
-
Kadoba K., Jonas R.A., Mayer J.E., Castaneda A.R. Mitral valve replacement in the first year of life. J Thorac Cardiovasc Surg 1990;100:762-768.[Abstract]
-
Coles J.G., Williams W.G., Watanabe T., et al. Surgical experience with reparative techniques in patients with congenital mitral valvular anomalies. Circulation 1987;76(suppl 111):111-117.
-
Stellin G., Bortolotti V., Mazzucco, et al. Repair of congenitally malformed mitral valve in children. J Thorac Cardiovasc Surg 1988;95:480-485.[Abstract]
-
Kirklin J.W., Barratt-Boyes B.G. Congenital mitral valve disease. In: Kirklin J.W., Barratt-Boyes B.G., eds. Cardiac surgery. New York: Churchill Livingstone, 1993:1343-1359.
-
Hennein H.A., Swain J.A., McIntosh C.L., Bonow R.O., Stone C.D., Clark R.E. Comparative assessment of chordal preservation versus chordal resection during mitral valve replacement. J Thorac Cardiovasc Surg 1990;99:828-837.[Abstract]
Accepted for publication April 14, 1999.
Top
Abstract
Introduction
