Summary
Recurrence of mitral regurgitation after mitral valve repair is correlated with unfavourable left ventricular remodelling and poor outcome. This pictorial review describes the echocardiographic features of three types of acute mitral valve repair dysfunction, and the additional value of three-dimensional echocardiography.
Résumé
La récurrence d’une fuite mitrale après plastie mitrale est corrélée à un moins bon remodelage ventriculaire gauche et à un pronostique défavorable. Dans le présent article, nous décrivons trois formes différentes échocardiographiques de dysfonction précoce de plastie mitrale en insistant sur la valeur additionnelle de l’échocardiographie tridimensionnelle.
Background
Mitral regurgitation (MR) is the second most frequent valvular disease requiring surgery, and is classified into two groups. Organic mitral regurgitation (OMR) presents intrinsic lesions of the mitral valve apparatus, and is mostly degenerative. Both the European Society of Cardiology and the American Heart Association/American College of Cardiology favour mitral valve repair over replacement when feasible, because repair has lower perioperative mortality and improved survival, and avoids prosthetic complications . Several repair techniques exist (leaflet resection, neochordae implantation, edge-to-edge repair, etc.), and are systematically associated with an annuloplasty ring . In functional mitral regurgitation (FMR), the valve apparatus is structurally normal, and MR results from leaflet tethering and annular dilatation, secondary to left ventricular systolic remodelling and reduced dysfunction. Operative mortality is markedly higher than in OMR, and whether surgical correction improves, survival is still under debate An undersized mitral ring is usually implanted, but its superiority over replacement is also a matter of debate .
Despite an early reoperation after initial successful mitral valve repair being rare, acute recurrent valvular or paravalvular MR may occur . We report three cases of acute dysfunction of mitral valve repair, and evaluate the additional benefit of three-dimensional (3D) echocardiography in the assessment and management of recurrent MR.
Case presentation
Case n o 1
A 59-year-old man was admitted to our cardiac surgery department for severe symptomatic OMR; he was a current smoker and had a history of hypertension. Preoperative transthoracic echocardiography (TTE) showed an enlarged left ventricle with a left ventricular ejection fraction of 60%. There was isolated P2 prolapse, with normal pulmonary artery pressure. Coronary angiography was also normal. A quadrangular resection on the posterior mitral leaflet was performed, combined with a sliding plasty and implantation of a Carpentier-Edwards Physio II N o 32 ring (Edwards Lifesciences, Irvine, CA, USA). Intraoperative transoesophageal echocardiography (TOE) showed no MR. Atrial fibrillation occurred during the following days. Eight days after the surgery, a 3/6 systolic murmur was audible, while the patient was asymptomatic. Two-dimensional TTE and TOE showed significant MR with a complex mechanism. Finally, 3D TOE showed a tear above the prosthetic ring tissue at the anterior and medial levels, with “paravalvular” MR, despite a persistent successful mitral repair ( Fig. 1 ). The MR mechanism was confirmed intraoperatively ( Fig. 2 ), and the patient underwent a biological valve replacement with an Epic N o 33 prosthesis (St. Jude Medical, Saint Paul, MN, USA).
Case n o 2
A 53-year-old man with known OMR for several years was referred to our hospital for progressive shortness of breath. Preoperative TTE showed severe MR with a P2 flail. The left ventricle was enlarged (left ventricular end-diastolic diameter, 70 mm) and the left ventricular ejection fraction was 60%. Pulmonary artery pressure and coronary angiography were normal. The patient underwent mitral valve repair (quadrangular resection on the posterior mitral leaflet + Carpentier-Edwards Physio II N o 32 ring, combined with implantation of a tricuspid Carpentier-Edwards Physio II N o 28 ring). Intraoperative TOE showed a successful repair, with only mild MR. The patient left the intensive care unit 2 days after surgery. At day 6, systematic echocardiography revealed moderate MR, while the patient was asymptomatic with no systolic murmur, but the mechanism was unclear. 3D TOE showed partial detachment of the prosthetic ring at the medial level above A3, resulting in moderate MR outside the ring. Nevertheless, the dehiscence had no consequence on the repair itself, as the underlying valvular lesion was corrected successfully ( Fig. 3 ). A careful follow-up was advised.
