Transaortic Double Valve Replacement

Abstract

Very few cases of transaortic double valve replacement have been reported in the literature. A 26-year-old man presented to us with severe aortic regurgitation, mitral valve thickening, and mild mitral regurgitation 6 years after he had undergone a Ross procedure and open mitral commissurotomy. At his 2nd operation, he underwent transaortic double valve replacement with total chordal preservation of the mitral apparatus.

Due to recurrent rheumatic activity, this patient had experienced a recurrence of valvulopathy. Because we have observed this in other young patients with rheumatic heart disease, we no longer perform the Ross procedure in such patients, especially if there is associated mitral valve disease.

In selected patients with dilated aortic annulus, the transaortic approach provides excellent access for safe mitral valve replacement with total chordal preservation. The surgical technique and a brief review of the literature are presented. (Tex Heart Inst J 2002;29:133–5)

Mitral and aortic valve replacement through the aorta was 1st reported by Carmichael and colleagues ¹ in 1983. Since then, a few other cases of transaortic double valve replacement have been reported in the English medical literature. It is not clear whether total chordal preservation has been performed during mitral valve replacement surgery in these cases reported to date. Here we present the details of a case in which the patient underwent aortic and mitral valve replacement through an aortotomy, with total chordal preservation.

Case Report

A 26-year-old man presented at our institution in August 2001 with palpitations and progressively increasing dyspnea on exertion.

In January 1995, this patient had undergone aortic valve replacement with a pulmonary autograft (the Ross procedure) and open mitral commissurotomy. The diagnosis at this 1st surgery had been rheumatic heart disease with severe aortic regurgitation and a thickened mitral valve with moderate mitral regurgitation. At surgery, his aortic root size had measured 28 mm. The pulmonary autograft that was used in the aortic position had also measured 28 mm in diameter, and the right ventricular outflow tract had been reconstructed with a pulmonary homograft.

On follow-up, the patient showed progressive aortic regurgitation, which became severe by August 2001, with enlargement of the left ventricle. His symptoms progressed from New York Heart Association functional class I to class III, although left ventricular function remained normal. Echocardiography performed in August 2001 revealed thickening of the mitral valve and mild mitral regurgitation.

In view of the severe aortic regurgitation, cardiomegaly, and the finding of thickened mitral valve with mild mitral regurgitation, we planned replacement of both valves. The aortic root size (sinotubular) before this present surgery was 45 mm, as determined by transesophageal echocardiography.

A mid-sternotomy was performed with an oscillating saw. There were dense adhesions between the heart and pericardium (the pericardium was closed at the 1st surgery). Most of the adhesions were released, exposing the aorta, the right ventricle, the right atrium, part of the left ventricle, the left atrium, superior vena cava, and inferior vena cava. The left ventricle was hugely dilated, but the left atrium was small. The sinuses of the autograft were also greatly dilated, while the pulmonary homograft was soft and appeared normal. Cardiopulmonary bypass was established using aortic and bicaval cannulation. For myocardial protection, we used moderate hypothermia, topical ice slush, and cold blood cardioplegic solution administered antegrade. The valve cusps of the autograft were thick and retracted, and there was annular dilatation. We excised the cusps and reduced the diameter of the annulus to 33 mm. The mitral valve with its subvalvular apparatus could be seen clearly through the aortotomy. We excised the anterior mitral leaflet, separated the chordal apparatus on either side, and affixed the chordae to the trigones (Miki's technique of chordal preservation ^2,3). A radial incision was made in the mid-posterior mitral leaflet. The mitral valve annulus was sized to 31 mm. A 31-mm St. Jude mechanical prosthesis (SJM Master's Series, St. Jude Medical; St. Paul, Minn) was used for replacing the mitral valve. Interrupted mattress sutures were taken from the posterior mitral leaflet to the sewing ring of the valve. The valve was released from its holder, pushed into the mitral annulus, and then seated by tying the posterior mitral leaflet sutures on the left atrial side. The anterior sutures were then placed through the valve ring and tied down in such a way that the knots were facing the left ventricular side. Valve-leaflet movements were checked. A 31-mm St. Jude aortic mechanical prosthesis (SJM Master's Series) was used in the aortic position. This was sutured in position by using interrupted simple sutures. There was no obstruction to the leaflets of the aortic valve by the mitral valve or by the preserved chordal apparatus. The dilated sinuses of the aorta were plicated, and the aortotomy was closed. Routine de-airing and rewarming was done. The patient was weaned from cardiopulmonary bypass without difficulty.

Postoperative transesophageal echocardiography showed normal functioning of the mitral and aortic prostheses, together with good left ventricular function. No left ventricular outflow tract obstruction or gradient was noted. The patient's postoperative recovery was uneventful. Cinefluoroscopy on the 5th postoperative day showed normal movements of both valves' leaflets. The patient was discharged on the 7th postoperative day. He is currently doing well.

Discussion

Combined aortic and mitral valve replacement is a common operation. Aortic and mitral valve replacement through an aortotomy was described as early as 1983 by Carmichael and colleagues ¹ of the Texas Heart Institute. Since then, a few cases have been reported in which both mitral and aortic valves were replaced through the aorta. Crawford and Coselli ⁴ performed 2 cases of double valve replacement through the aorta: 1 in a patient with Marfan syndrome and another in a case of chronic subacute bacterial endocarditis. Dodge and Najafi ⁵ described the procedure in 1998. In Marfan syndrome, the hugely dilated aorta and aortic annulus enable easy placement of the mitral valve without much retraction. ^4,6 Unfortunately, the published reports do not emphasize the desirability of chordal preservation as part of these transaortic mitral valve replacements. Crawford and Coselli ⁴ removed the entire anterior mitral leaflet and its chordae, even though they preserved the posterior mitral leaflet chordal apparatus.

Our patient had undergone the Ross procedure and open mitral commissurotomy in 1995, for rheumatic heart disease. Due to recurrent rheumatic activity, there was a recurrence of aortic root dilatation with severe aortic regurgitation, mitral valve thickening, and mild mitral regurgitation. Because we have observed this in young patients with rheumatic heart disease, we no longer perform the Ross procedure in this group of patients, especially if there is associated mitral valve disease. ⁷ Histopathologic examination of excised aortic and mitral valves in our patient showed rheumatic valvulitis with no fresh activity. The aortic root and annulus were dilated, possibly due to rheumatic involvement and progressive aortic regurgitation; this dilatation enabled good visualization of the mitral valve and subvalvular apparatus.

Previous reports ^5,6 have listed the advantages of transaortic mitral valve replacement. They are 1) elimination of the need for a 2nd atrial incision, 2) avoidance of extensive dissection, which minimizes trauma and perioperative bleeding, and 3) reduction of myocardial ischemic time. Because this was a reoperation, the transaortic approach was especially advantageous; also, the left atrium was not dilated. The exposure during surgery was excellent. No difficulty was encountered in preserving all chordal attachments. We conclude that, in selected patients with dilated aortic annulus, the transaortic approach provides excellent access for safe mitral valve replacement with total chordal preservation.

Addendum

Since submitting this case report, we have operated on 3 additional patients (48, 34, and 26 years of age), who also underwent double valve replacement with full chordal preservation through the transaortic route. All 3 patients were doing well as of May 2002.