Incidental TOE finding - Carpentier mitral annuloplasty ring dehiscence during heart transplantation

A 57-year-old male with heart failure from dilated cardiomyopathy was scheduled to undergo heart transplant. Other cardiac comorbidities included chronic atrial fibrillation, severe pulmonary hypertension, severe mitral regurgitation with history of mitral valve repair and implantation of 29-mm annuloplasty ring earlier. The patient also had an automated implantable cardioverter-defibrillator for ventricular tachycardia therapy and termination. The last surgical procedure prior to the heart transplant was laparoscopic cholecystectomy at an outside hospital complicated by intraoperative cardiac arrest, necessitating prolonged cardiopulmonary resuscitation. The trans-thoracic echocardiogram postresuscitation showed severe and worse mitral regurgitation with no mention of mitral ring pathology.

Following the induction of anaesthesia for heart transplant, transoesophageal echocardiographic (TOE) examination revealed severe eccentric mitral regurgitation and the dramatic appearance of a total mitral ring dehiscence with the new appearance of severe dilatation of the mitral annulus. The ring appeared to be freely floating in the left atrium . Following the commencement of cardiopulmonary bypass and recipient cardiectomy, the gross inspection of the transected heart revealed a 29-mm Carpentier-Edwards annuloplasty ring dehisced along the valve circumference . One of the possible etiologies proposed was traumatic dehiscence following protracted chest compressions when the patient arrested intraoperatively during the laparoscopic cholecystectomy. Also likely was primary failure of the ring annuloplasty. This patient went on to have an uneventful heart transplant. The purpose of this brief report is to illustrate the superiority of TOE over transthoracic echocardiography, particularly in the evaluation of mitral valve disease. In this patient, the dehisced annuloplasty ring may have worsened the mitral regurgitation. In this situation, it did not influence the outcomes since the heart was transplanted. The author makes the recommendation that all patients with prosthetic valves and annuloplasty rings should have thorough TOE evaluation following chest compression during cardiopulmonary resuscitation