Ann Thorac Surg 2006;82:761-762
© 2006 The Society of Thoracic Surgeons
How to do it
Application and Adjustment of Artificial Chordae to the Mitral Valve Using an Approach Through the Aortic Valve
René Prêtre, MD*,
Gregory Khatchatourov, MD,
Alexander Kadner, MD,
Michele Genoni, MD
Department of Surgery, Clinic for Cardiovascular Surgery, University Hospital Zürich, Switzerland
Accepted for publication July 19, 2005.
* Address correspondence to Dr Pretre, Department of Surgery, Clinic for Cardiovascular Surgery, University Hospital, Raemistrasse 100, Zürich, CH-8091 Switzerland. (Email: rene.pretre{at}usz.ch).
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Abstract
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Insertion of artificial chordae or shortening of native ones on the mitral valve with precise determination of their length can be done through the aortic annulus. This route was used to correct a prolapse of the anterior leaflet in 7 patients and resulted in stable repair with no residual insufficiency (4 patients) or trivial residual insufficiency (3 patients).
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Introduction
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The aortic access provides an excellent exposure of the anterior structures of the mitral valve and is useful in adjusting the length of chordae. In some circumstances, it can help finalize a valve repair and avoid a replacement.
Mitral valve insufficiency due to prolapsus of the anterior leaflet often requires insertion of artificial chordae or shortening of native ones. Various techniques have been described [1, 2] to adjust the length of the chordae, but none has imposed itself. Secondary adjustment of the length of the chordae is furthermore extremely difficult once an annular ring has been inserted.
We describe a technique in which fine and repetitive adjustments of the chordae set on the anterior leaflet of the mitral valve can be performed, and this is also after insertion of an annular ring. The technique was initially used to save a compromised repair. In view of the ease and reliability of the technique, it was subsequently used to directly support the anterior leaflet.
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Technique
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A salvage procedure was performed on 3 patients and a primary approach on 4. In the salvage group, the mitral valve was approached with an incision in the interatrial groove and repaired according to usual techniques [3], using artificial chordae on the anterior leaflet and a flexible annular ring. Excessive residual prolapsus of the anterior leaflet was then identified. The retractor in the left atrium was removed and the ascending aorta was opened. A Langenbeck retractor (Martin Surgical Instruments, Tuttlingen, Germany) was inserted in the left ventricle along the septum, and it was pulled up to expose the papillary muscles. Native chordae were shortened with a plicature on the papillary muscle (1 patient) or artificial chordae were inserted on the papillary muscle and the anterior leaflet (2 patients). Their length was calibrated to adjacent normal chordae. The artificial chordae were initially locked but not tied down. The mitral valve was inspected again from the atriotomy while saline water was injected through the aortotomy in the left ventricle. The anterior leaflet spread out harmoniously without areas of restriction or prolapsus. The chordae were tied from the aortotomy and the incisions were closed in the usual fashion. This approach was then used primarily on 4 patients. The repair of the posterior leaflet was performed and a ring was inserted (without tying the knots) using a classical atrial incision. The ascending aorta was opened and artificial chordae (or a strip of autologous pericardium) were set on the papillary muscles and the anterior leaflet (Figs 1,
2) and were calibrated. The valve was reinspected through the atriotomy with instillation of saline in the left ventricle for possible adjustment of the chordae until they were definitively secured.
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Fig 1. Implantation of artificial chordae on the anterior leaflet of the mitral valve through the aortic valve. First the threads are locked and then the deployment of the leaflet is controlled through the left atrial incision (see inset). When the length of the artificial chordae is appropriate, the threads are tied. The native chordae can also be shortened using the same approach.
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Fig 2. Operative view of the mitral subvalvular apparatus. A strip of autologous pericardium is inserted on the tip of the anterior papillary muscle and on the border of the anterior leaflet of the mitral valve. An aortic valve preserving procedure is being concomitantly performed. Inset shows the end result with the loose elongated chordae.
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This combined "atrio-aortic" approach was used to save a compromised repair in 3 patients and to primary implant artificial chordae in 4 patients. The first 2 patients in the latter group required a concomitant aortic valve preserving procedure, which made this sequence particularly attractive. In all of the patients the aorta was opened after the posterior leaflet had been repaired and the annular ring was inserted. In the last 2 patients, the combined approach was decided beforehand. The additional time required for changing the exposure, opening and closing the aorta, and exposing the mitral valve did not exceed 25 minutes. In 1 patient, a strip of autologous pericardium (Fig 2) was used instead of artificial chordae. The repair of the anterior leaflet was immediately good in 6 patients and required further adjustment in 1 patient.
The repair was assessed by echocardiography during the operation and 3 months after discharge. Follow-up (median time, 4 months; range, 2 to 23 months) was complete.
The repair was excellent in all the patients with either no residual regurgitation (4 patients) or trivial residual regurgitation (3 patients). There was no systolic anterior motion and no complication (ie, damage of the aortic valve or additional bleeding) related to the additional aortotomy. Rhythm was sinus in 6 patients and junctional in 1 patient after a concomitant maze procedure. The valve repair remained stable with time.
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Comment
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Prolapsus of the anterior leaflet is best treated by transferring chordae, shortening distended ones, or implanting artificial ones. Determination of the chordal length is the most challenging part of the repair. Although many techniques have led to reliable results in experienced hands [1, 2, 4], many surgeons concede that some gut feeling in regard to this determination is required. The discovery of a restriction or prolapsus of the anterior leaflet is always a frustrating experience, especially when this happens after insertion of an annular ring. The ring considerably restricts the access to the subvalvular apparatus and reduces the chances of a successful correction.
In this situation, we have accessed the subvalvular mitral apparatus through the aortic annulus. Our surprise was that the access to the papillary muscle was straightforward, the determination of the chordal length was relatively easy, and the tying down of the knots was less demanding. Furthermore the insulation of saline water in the left ventricle generated enough pressure (even with an opened ascending aorta) to spread out the leaflets of the mitral valve and to allow assessment of their coaptation. Using the locking stitch as described by David and colleagues [4, 5], fine adjustment of the chordae was further possible.
These findings prompted us to test this combined approach in case of mitro-aortic valve surgery and finally in case of isolated mitral valve disease with prolapsus of the anterior leaflet. However, we advocate a conventional approach to patients with isolated mitral valve repair, and we would resort to a combined approach only in the most difficult cases.
One of our initial concerns with the aortotomy approach was the risk of injury to the fragile aortic cusps. Obviously care must be applied to avoid any stretch on the valve leaflets. In this regard, the use of the heart-port instruments was particularly helpful to place the artificial chordae on the tip of the papillary muscle, because these instruments do not get larger along their length. However, classical needle holders were also used with success.
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References
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- El Khoury G, Noirhomme P, Verhelst R, Rubay J, Dion R. Surgical repair of the prolapsing anterior leaflet in degenerative mitral valve disease J Heart Valve Dis 2000;9(1):75-80.[Medline]
- Duran CM, Pekar F. Techniques for ensuring the correct length of new mitral chords J Heart Valve Dis 2003;12(2):156-161.[Medline]
- Carpentier A. Cardiac valve surgery–the "French correction." J Thorac Cardiovasc Surg 1983;86(3):323-337.[Medline]
- David TE. Artificial chordae Semin Thorac Cardiovasc Surg 2004;16(2):161-168.[Medline]
- David TE, Bos J, Rakowski H. Mitral valve repair by replacement of chordae tendineae with polytetrafluoroethylene sutures J Thorac Cardiovasc Surg 1991;101(3):495-501.[Abstract]
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Abstract
Introduction
