Intraoperative rupture of the endoaortic clamp balloon in a patient undergoing port-access mitral valve repair

Abstract

A 66-year-old man (t65 cm, 71 kg) had a 10-year history of mitral valve disease with minimal symptoms. Over the last year, he developed increased shortness of breath and fatigue with physical activity; in the last several months, he was unable to climb a flight of stairs without dyspnea. He underwent a cardiac catheterization, which showed a mildly dilated left ventricle (LV) with an estimated ejection fraction of 83%, 3 + to 4+ mitral regurgitation with a flail posterior mitral leaflet, and a mean pulmonary capillary wedge pressure of 13 mmHg, increasing to 24 mmHg with a V wave to 45 mmHg. Coronary anatomy was normal. He was referred for mitral valve repair or replacement, and a Port-Access, minimally invasive procedure using the Heartport EndoCPB system (Heartport Inc, Redwood City, CA) was planned, The patient was admitted on the same day of surgery. Bilateral radial artery catheters and a pulmonary artery catheter (Swan-Ganz; BaxterEdwards Inc, Deerfield, IL) were inserted. Midazolam, 5 rag, was administered intravenously for sedation. On arrival in the operating room, arterial blood pressure was 125165 mmHg (mean arterial pressure, 80 mmHg); mean pulmonary artery pressure, 30 mmHg; cardiac index, 2.2 L/min/m 2, and heart rate, 60 beats/rain. After preoxygenation, general anesthesia was induced with fentanyl, 500 pg; midazolam, 5 rag; and cisatracurium, 16 mg. The trachea was intubated, and the lungs were ventilated with isoflurane in oxygen. A biplane transesophagoal echocardiography (TEE) probe (Hewlett-Packard, MA) was inserted. The baseline two-dimensional and color-flow Doppler examination confirmed severe mitral regurgitation and valvular changes suggestive of myxomatous degenerative disease, with ruptured chordae and a flail posterior leaflet. The aortic valve appeared normal without regurgitant flow, and the ascending and descending parts of the thoracic aorta were without echocardio~:aphic evidence of significant atheromatous disease. Access to the heart was achieved through a 6-era submammary incision, and the chest was entered through the fourth right intercostal space. The left femoral vessels were exposed through a groin incision, and after systemic anticoagulation with heparin, the Heartport Endoarterial Return cannula was inserted into the femoral artery. A guidewire was advanced from the femoral vein to the right atrium, visualized by TEE, and the Heartport Endovenous Drainage cannula was advanced into the fight atrium with the tip at the superior caval atrial junction. The Heartport Endoaortic Clamp was advanced over a guidewire and positioned in the ascending aorta with the tip slighdy above the sinotubular ridge, as seen by TEE. The surgeon inserted a retrograde cardioplegia catheter through a right atrial purse-string cannulation site into the coronary sinus, guided by TEE and pressure waveform.