Abstract

In recent years balloon valvuloplasty has gained popularity for congenital aortic stenosis. Aortic complication of the procedure is well known whereas mitral valve injury is an exception. We report a case of surgically repaired mitral valve insufficiency, which was secondary to direct injury during aortic balloon valvuloplasty performed 2 years ago.

Treatment of aortic stenosis in infants and neonates is still controversial. In recent years the balloon aortic valvuloplasty is widely accepted as an alternative to surgery because of its comparable early results [1]. Although several complications have been reported as aortic regurgitation or residual aortic gradient, mitral valve injury is very rarely described [2,3].

We report a case of surgically repaired mitral valve injury secondary to aortic balloon valvuloplasty performed in infancy.

Case Presentation

A 3-year-old boy was referred to our hospital for surgical repair of severe mitral valve regurgitation. He had a history of a percutaneous aortic balloon valvuloplasty for critical aortic stenosis in infancy. Progressive mitral valve regurgitation, which was absent before valvuloplasty procedure, was observed on routine echocardiographic follow-up. After 2 years of medical treatment the patient was referred to our clinic for surgical repair.

His physical examination was unremarkable except an apical grade 3/6 and a grade 2/6 systolic murmur at the aortic area. Electrocardiography shows sinus rhythm with left ventricular hypertrophy. Moderate cardiomegaly was detected on telecardiography. Echocardiography revealed severe mitral valve regurgitation from a tear in the anterior leaflet and enlargement of the left side of the heart, mild aortic stenosis with 27 mm Hg gradient across the valve and mild aortic regurgitation.

The patient was undergone open-heart surgery with median sternotomy and standard cardiopulmonary bypass. Aorto – bicaval cannulation was used. After aortic clamp and isothermic blood cardioplegia, transseptal approach was used for mitral valve exposure. A cleft like tear on the middle of the anterior mitral leaflet with chordal elongation and annular dilatation was detected at surgery (Figure 1). The tear was repaired with interrupted pericardial pledgetted stitches and valve repair was completed with chordal plication and posterior annuloplasty. Perioperative transesophagial echocardiography revealed mild mitral regurgitation with 7 mm Hg mean gradient across the valve at the end of cardiopulmonary bypass.

Figure 1: The tear on the anterior leaflet of the mitral valve

The postoperative course was uneventful and the patient was discharged from hospital at postoperative day 6. The echocardiographic examination after 1 year postoperatively showed trivial or mild mitral regurgitation with mean transvalvular 5 mm Hg, and also mild aortic stenosis with 17 mm Hg systolic gradient and mild aortic regurgitation. He had NYHA class 1 functional capacity without medical treatment.

Discussion

Since the description of aortic balloon valvuloplasty, many studies compared the outcomes of surgical and catheter valvuloplasty techniques [1,4]. In recent years balloon valvuloplasty has gained popularity because of short hospitalisation period and good early results in congenital aortic stenosis [1,3,5]. Aortic complication of the procedure is well known whereas mitral valve injury is very rarely described, in all cases reported, this complication was related to posteriorly positioned guide wire in the left ventricle [2,3]. Brierly et al suggest that this malposition is more likely to occur if the patient has a small left ventricular cavity or an abnormal mitral apparatus. Reposition of the posteriorly positioned wire is necessary if it is noted on lateral screening or on transesophagial echocardiography during the procedure [2]. As in our case, none of the cases reported needed surgery immediately after balloon valvuloplasty [2,3]. It is possible, that the tear becomes excessive over time, or the blood turbulence across the damaged valve may cause secondary injury on other components of the mitral valve apparatus. Many studies demonstrate that surgery for mitral valve can be performed with low risk in pediatric age group [6-8]. Plastic repair is the procedure of choice in children because of its several advantages like avoidance of thromboembolism, no need of long term anticoagulation, preservation of chordal function and a potentially reduced need for reoperation. Different surgical techniques have been used for mitral repair with good early and long-term results [6,8,9]. In this case we performed a successful combination of different techniques (primary repair of tear, chordal plication and annuloplasty) for mitral valve reconstruction.

As a conclusion, mitral injury during aortic balloon valvotomy is a rare complication. But this possible complication must be taken into account during the procedure and close follow up is necessary for eventual surgical repair. PABV procedure should be cautious in patients with small left ventricular cavity and mitral valve anomaly. Lateral screening and TEE may be helpful for proper positioning of the balloon. When mitral valve injury occurs, plastic repair should be performed without delay to prevent excessive degeneration of the valvular apparatus due to chronic blood turbulence across the valve and the left ventricular hypertrophy.

References

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