Beating heart mitral valve repair for a patient with previous coronary bypass: a case report and review of the literature

The number of patients undergoing cardiac reoperations continues to increase. Redo procedures usually involve sternal reentry, which has the potential for hazardous injuries to the important structures and subsequent morbidity and mortality [1]. In the case of a patient who has poor ventricular function for a long-standing valve disease, cardiac arrest may predispose the dilated myocardium to ischemia-reperfusion injury and postoperative low cardiac output [2]. We describe a case in which we performed a redo mitral valve repair after coronary bypass surgery using a beating heart approach via a limited right thoracotomy. Advantages and disadvantages of the procedure are discussed.

A 76-year-old Japanese male who underwent quadruple coronary artery bypass surgery 3 years before had developed shortness of breath, and visited our clinic for checkups. His postoperative course was significant for mediastinal wound infection, which was treated by local debridement and antibiotics. Upon examination, a loud systolic murmur was noted at the apical area. Chest roentgenogram showed mild cardiomegaly. Electrocardiogram showed sinus rhythm and no evidence of myocardial ischemia. Echocardiogram demonstrated severe mitral regurgitation due to torn chorda of the posterior leaflet (P2), which was not noted at the initial operation (Figure 1A, B). Otherwise, severe tricuspid and mild to moderate aortic insufficiency were noted. Cardiac computed tomography demonstrated that all bypass grafts were patent. The right internal mammary artery ran across the front of the heart and was connected to the left anterior descending branch (Figure 1C). Written informed consent was obtained from the patient and his family, and the patient was taken to the operating room for a corrective surgery.

The patient was intubated with a double-lumen endotracheal tube. The patient was placed in a left hemi-decubitus position. Heart rate was maintained around 40 beats/minute throughout the procedure by remifentanyl and a short-acting beta-blocker (Landiolol) infusion. A 10 cm skin incision was made and the right lateral thoracotomy was performed via the 4th intercostals space. The lateral aspect of the ascending aorta was easily dissected and was cannulated. In order to avoid injury to the vein grafts, care was taken not to dissect the anterior aspect of the ascending aorta. The right femoral vein was cannulated with a 25 Fr. venous cannula (QuickDraw™, Edwards Lifesciences, Irvine, CA), and cardiopulmonary bypass was initiated. The superior vena cava was cannulated for additional venous drainage. Vacuum-assisted venous drainage was used to establish a full flow cardiopulmonary bypass. Carbon dioxide gas was insufflated into the pleural cavity. An aortic root vent needle was inserted. It was ensured that the aortic valve was not open by transesophageal echocardiogram. The patient was placed in the Trendelenburg position, and the left atrium was opened. Two drop-in suckers were placed, one in the left atrium and the other in the left ventricle to maintain a bloodless operative field. The mitral valve was exposed using a handheld retractor, and P2 prolapse due to torn chordae was evident (Figure 2). A standard triangular resection and suture technique was performed. A 26-mm Cosgrove-Edwards band (Edwards Lifesciences) was secured onto the posterior annulus for annuloplasty. The valve was verified competent under physiologic condition and a saline injection test was not necessary. The left atrium was closed using a standard technique. The tricuspid annuloplasty was performed using a 26 mm MC3 ring (Edwards Lifesciences). After de-airing, competency of the valve was checked by transesophageal echo (Additional file 1). The operation time and cardiopulmonary bypass time were 300 minutes and 163 minutes, respectively. Intraoperative blood loss was 320 ml, and no transfusion was required. The postoperative course was uneventful and the patient discharged on postoperative day 10. After 6 months, the patient remains asymptomatic with no evidence of recurrence of mitral regurgitation by echocardiogram.

The beating heart mitral valve repair via a limited right thoracotomy is a valid option in terms of less blood loss and lower risk of injury to the hazardous vascular structures and the grafts compared to a sternal reentry option. Further studies are warranted to validate the potential benefits and the limitations of this technique.

Written informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.