Transesophageal echocardiography assessment of severe aortic regurgitation in type a aortic dissection caused by a prolapsed circumferential intimal flap.

A 61-year-old obese man, with a history of hypertension, presented with acute onset of substernal chest pain and associated diaphoresis. Significant physical findings included a rapid irregularly irregular rhythm (heart rate 126 beats/min), a blood pressure differential between the left (125/45 mmHg) and right (165/52 mmHg) arms, and a grade 3 diastolic murmur at the right upper sternal border. Electrocardiogram showed atrial fibrillation with diffuse repolarization abnormality. An initial chest x-ray revealed a widened superior mediastinum. A CT angiogram of the chest, abdomen, and pelvis showed a 7 7 cm type A aortic dissection originating at the aortic root and involving the coronary sinuses and coronary ostia with complete intimal disruption of the mid-ascending aorta. The dissection extended to the right brachio- cephalic artery, left common carotid artery, left subclavian artery, and terminated at the left common iliac artery. There was a small hemo- pericardium. After sedation and tracheal intubation, the patient was transferred to this hospital for emergency surgery. On arrival to the OR, the patient was treated with an intravenous infusion of esmolol for heart rate and blood pressure control. The patient was anesthetized with incremental dosing of midazolam, fent- anyl, isoflurane, and pancuronium. Once the patient was stabilized under anesthesia, intraoperative TEE was performed using a Hewlett- Packard Sonos 5500 ultrasonograph (Andover, MA) with a 5-MHz multiplane TEE probe. Initially, 2-dimensional study revealed a dilated aortic root measuring 7.2 cm in diameter with proximal ascending dissection that extended into the distal ascending aorta. The dissection involved the coronary sinuses and all three vessels of the aortic arch. In addition, a small pericardial effusion, bilateral pleural effusions, and moderately depressed biventricular function were found. These find- ings were discussed with the surgeons and confirmed the planned surgical approach to repair the aortic arch under profound hypothermic circulatory arrest. Detailed assessment of the AV and aortic root with the midesophageal short-axis and long-axis views revealed a circum- ferential intimal dissection flap in the proximal ascending aorta. The flap was oscillating en masse in and out of the LVOT during systole (Fig 1A) and diastole (Fig 1B). The prolapsed flap intussuscepted into the LVOT precluding proper AV leaflet coaptation and resulting in severe AR. This was confirmed by a color Doppler flow study showing a4 central aortic regurgitant jet (Fig 2). The redundant dissected wall was plicated to produce a convoluted image in the AV short-axis view (Fig 3). Findings of diastolic fluttering of the mitral valve anterior leaflet and premature mitral valve closure were consistent with severe AR. Further examination of the AV showed no evidence of leaflet prolapse or disruption of the tricuspid leaflets or their commissures. These findings were discussed with the surgeons, and AV repair was thus deemed unnecessary and avoided. The patient underwent repair of the type A aortic dissection with a Dacron graft (Vascutek, Renfrewshire, Scotland) sized to match the diameter of the reconstituted sinotubular junction and anastomosed to the distal ascending aorta. The total bypass time was 207 minutes, the aortic cross-clamp time was 107 minutes, and the circulatory arrest time was 34 minutes. The patient was then weaned from cardiopulmo- nary bypass uneventfully. Immediate postrepair TEE assessment re- vealed normal aortic leaflet coaptation without residual AR. The patient was transferred to the intensive care unit in stable condition, and his trachea was extubated on postoperative day 3. Before his discharge from the hospital on postoperative day 10, a transthoracic echocardio- gram showed an intact aortic graft with no evidence of AR.