A 57-year-old woman (155 cm; 65 kg) with aortic valve stenosis (aortic valve area, 0.77 cm2) and left ventricular pressure overload hypertrophy with a normal systolic function was scheduled to undergo mechanical aortic valve replacement. She had a history of hypertension, hyperlipidemia, and type 2 diabetes mellitus, for which she was being treated with an angiotensin receptor antagonist, statin, and insulin, respectively.
General anesthesia was induced with 4 mg of midazolam, 50 mg of rocuronium, and 0.3 μg/kg/min of remifentanil intravenously. After intubation, an IO-TEE probe was inserted. A central venous catheter and pulmonary artery catheter were placed in the right internal jugular vein. Anesthesia was maintained with sevoflurane 1.5% in oxygen and air and continuous infusions of remifentanil 0.2–0.4 μg/kg/min and propofol 4 mg/kg/h.
IO-TEE showed a thickened tricuspid aortic valve with an immobile cusp and mild aortic regurgitation, with no other valve insufficiency. The aortic annulus diameter was 19 mm.
CPB was performed in a standard manner. After aortic cross-clamping, the native aortic valve was resected and replaced with an 18-mm mechanical aortic valve (ATS-AP360, Medtonic Inc., USA) using the non-evert mattress suture technique. After rewarming, the heart was de-aired and the cross-clamp was removed. After declamping of the aorta, a 3-μg/kg/min dopamine infusion was started. IO-TEE was performed to study the new prosthetic aortic valve before weaning off CPB (Fig. 1).
The mid-esophageal aortic valve short-axis view revealed that the mechanical bileaflet prosthetic valves were inserted in an ordinary position, which indicated that the two hinges were not located on the coronary ostia. The mid-esophageal aortic valve long-axis view revealed the presence of aortic regurgitation jets (Fig. 1), toward the anterolateral papillary muscle. The width of the regurgitation jet was 0.73 cm, indicating severe aortic regurgitation. LIVE xPlane, using a CX50 (Philips Medical Systems, Bothell, WA, USA), revealed that the regurgitation had originated in the intra-sewing ring of a non-coronary cusp and was not located at the point of the hinges (Fig. 2). At the time, the cause of the abnormal severe transvalvular leakage was unknown. Thus, we decided to perform a second CPB. After re-aortic-cross-clamping and aortotomy, residual suture material placed in the sewing ring was observed to be caught in one leaflet, interfering with the closing of the leaflet. Upon cutting the residual suture material, the leaflet began to move appropriately, and non-interference with the leaflet motion was confirmed. Weaning from the second CPB was very smooth. After CPB weaning, IO-TEE showed no transvalvular leakage into the mechanical prosthetic valve. The postoperative course was uneventful.