Total Chordal Augmentation in a Child with Marfan Syndrome and Severe Mitral Insufficiency

Abstract

Mitral valve repair has become an established treatment in adults, but there is limited experience with the procedure in children, in whom the avoidance of a valve prosthesis is particularly advantageous.

Repair of the mitral valve in children who have Marfan syndrome is especially difficult due to the presence of generalized connective tissue disorder, which may lead to future elongation and rupture of chordae tendineae that were unaffected at the time of mitral valve repair. We performed a total augmentation of all segments of the mitral valve, using artificial chordae tendineae. Herein, we describe the procedure and the positive outcome in a 10-year-old girl.

In August 2006, a 10-year-old girl (height, 157 cm; weight, 34 kg) with classic features of Marfan syndrome presented with progressive exercise intolerance. Echocardiography showed severe insufficiency of the mitral valve, with chordal rupture of the P2 segment and prolapse of the A1 and A2 segments. The anterior–posterior dimension of the mitral annulus was 34 mm. The left ventricular end-diastolic dimension was 55 mm; the end-systolic dimension was 39 mm. The aortic valve was competent. The aorta was 24 mm wide at the aortic annulus, 39 mm at the sinuses of Valsalva, 27 mm at the sinotubular junction, 26 mm at the level of the brachiocephalic arterial takeoff, and 16 mm at the level of the diaphragm.

Surgical Technique

The patient underwent mitral valve repair. On intraoperative examination, the mitral valve chordae tendineae were elongated and thin throughout. Substantial prolapse of the A1 and A2 segments, a flail P2 segment, and several ruptured chordae were seen. We measured the distance between the tip of the papillary muscle and the non-prolapsing edge of the mitral valve leaflet, and we prepared 4–0 gore-tex® chordae tendineae (W.L. Gore & Associates, Inc.; Flagstaff, Ariz) by means of a simple, previously described technique.¹ Because of the uniform thinning of all of the chordae, we were concerned that currently competent segments of the mitral valve, if left unsupported, could develop similar prolapse due to future chordal elongation or rupture. The decision was made to augment every segment of the mitral valve and to distribute the artificial chordae at even intervals along the edges of the mitral valve leaflets (Fig. 1). We placed a total of 18 artificial chordal loops (2 sets of 3 loops and 3 sets of 4 loops) of 2 cm in length and secured these at about 2 mm from the edges of the mitral valve leaflets with 5–0 gore-tex® sutures. To prevent further dilation of the mitral annulus, a 32-mm Duran ring was implanted. The aortic cross-clamp time was 143 min at 32 °C; the cardiopulmonary bypass time was 166 min. The pericardium was closed in order to minimize adhesions that could complicate possible future surgery.

Fig. 1 Drawing shows total chordal augmentation of all segments of the mitral valve.

One year after surgery, the patient remained asymptomatic, with stable aortic dimensions and no mitral valve insufficiency.

Discussion

Early and late complications are common in children after mitral valve replacement.² Therefore, valve-sparing mitral and aortic procedures are preferred over replacement.^3,4 In order to prevent future annular dilation in patients who have Marfan syndrome, it is important to stabilize the annulus while performing valve-sparing procedures.⁵ However, in children, stabilization of the mitral or aortic annulus at an adult size is not always feasible.⁴ In our patient, we preferred to avoid a concomitant valve-sparing aortic root replacement, because she did not have aortic insufficiency and because aortic dissection is uncommon in her age group.³ In patients of this age who have a competent aortic valve, thevalue of aortic root-wrapping or stabilization of the sinotubular junction with a strip of artificial material is unclear. Our patient is scheduled to undergo echocardiographic evaluation every 6 months; she may require valve-sparing aortic root replacement in the future.

Total chordal augmentation of the mitral valve as described herein should be performed by 2 experienced cardiac surgeons, one of whom prepares the artificial chordae tendineae while the other evaluates the valve, places the annuloplasty stitches, and begins implanting the artificial chordae. Our simplified method of preparing artificial chordae was of special benefit to our young patient, because 18 artificial chordae for all segments ofthe mitral valve leaflets had to be made during a limited period of time.

Total chordal augmentation provided reliable mitralvalve repair in a child with Marfan syndrome. This technique might be a valuable alternative to mitral valve replacement in children who have complex mitral valve disorders.