Aortic Root Dissection after Coronary Artery Bypass Graft Operation

Abstract

Dissection of aorta after coronary artery bypass operation is a rare and a potentially lethal complication, usually diagnosed postmortem. Aortic root dissection usually occurs as a result of intimal tear of heavily calcified aorta during the clamping procedure We present the case of a 44-year old man in whom aortic root dissection occurred one month after the bypass operation. A 44-year-old man with a history of chronic kidney disease and hemodialysis presented to our emergency department with the complaint of chest pain associated with fever and dyspnea. One month ago he had underwent triple vessel coronary artery bypass operation in our hospital. His blood pressure was 166/64 mm Hg, the heart rate 93 beats per minute and the respiratory rate 14 breaths per minute, the temperature 37.8°C. White blood cell count was 15,000 per microliter. The level of high sensitive troponin was 27,860 pg per mililiter, CRP 140 mg per deciliter, creatinin 14,8 mg per deciliter, NT-proBNP > 35,000 pg per mililiter. An electrocardiogram was unremarkable. Echocardiogram despite having poor echogenicty revealed mild left ventricular systolic dysfunction with an ejection fraction of 45% and moderate aortic regurgitation and a mobile mass in the aortic root prolapsing into the left ventricle. With the diagnosis of acute coronary syndrome, heart failure and infective endocarditis, the patient was treated with heparin, antiischemic treatment and ampiric antiobiotic as well as undergone hemodialysis with effective fluid removal. Transesophageal echocardiography was scheduled. On the third day of his hospitalization, he developed asystolic cardiac arrest which responded to resuscitation. After a successful resuscitation, he was treated with dobutamine and dopamine. He had constant fever with persistent high CRP levels. He was undergone transesophageal echocardiography( TEE) with the suspicion of Aortic abscess. TEE demonstrated severe aortic regurgitation and a dissection flap on the aortic root prolapsing into the left ventricle (Figure 1 and Figure 2). Computed tomographic angiographic studies of chest revealed dilated ascending aorta with a diamater of 4,25 cm and a dissection flap starting on the aortic root and extending to the beginning of arcus aorta. Upon diagnosis of type A Aortic dissection, he immediately underwent ascending aorta replacement operation which lasted 11 hours. The patient left the operation room unstable on dopamine and dobutamine as well as intraaortic balloon pump. Hemodynamic deterioration continued and he died within 8 hours after the operation.