Acute Type A dissecting Aortic Aneurysm associated with a right-sided arch and descending Aorta is an extremelly rare situation. One or two such cases have been reported at all times. The situation is fatal especially when it is complicated with acute Aortic Regurgitation and/or myocardial Ischemia.
A 64-year-old man with a known history of Aneurysmal dilation of the descending Thoracic Aorta, presented with acute retrosternal pain and hemodynamic instability, at a rural area Medical center. The patient being in cardiogenic shock was succesfully resuscitated and transported to the University Hospital where the CT scan revealed an acute Stanford A / DeBakey I Aortic dissection with a right-arch and descending Aorta (Fig 1). TTE findings -besides the dissection- were severe Aortic regurgitation, 2+/4+ Mitral regurgitation, LV hypertrophy and apical and inferior wall hypokinesia. ECG revealed obvious new-onset Ischemia. The patient was intubated in the ICU due to hypoxia and hemodynamic instability. Risk factors included known COPD and acute Renal Failure due to involvement of the Right Renal artery. The patient was febrile due to active upper respiratoty Staphylococcal infection as proven by subsequent culture; nevertheless he was scheduled for emergent Surgery which was performed with a median Sternotomy, cannulation of the right subclavian artery and a two staged right Atrial venous cannula and performance of a Bentall procedure with distal reinforcement of the Aortic wall with Teflon-felt rings placed inside the intima and outside the adventitia. Fenestration was also performed distally in order to equalise pressures between true-false lumens. It is worth mentioning that intraoperative bleeding was controlled by felt wrapping of the heart, a technique not known to the new generation of cardiac surgeons. This is obvious as a white substernal rim in the postoperative CT scan (Fig 2) and involves the innominate vein, the superior vena cava, the pericardium next to the pulmonary artery and the epicardium of the right ventricle all along from the superior vena cava to pulmonary artery. The patient recovered during a long ICU stay and was finally discharged and went back to normal life. Chest computed tomography at three months after surgery demonstrated a disappearance of the false lumen of the arch and descending Aorta (Fig 2).
Acute Type A Aortic dissection associated with a right-sided arch and descending Aorta is an extremelly rare situation and to the best of our knowledge only two such cases have been reported worldwide. This condition is fatal when complicated with acute severe Aortic insufficiency and acute myocardial Ischemia. Surgery is idicated unless it is felt to carry a prohibitive risk because of medical debility, extensive renal, myocardial,or bowel infarction, or massive stroke. In our case we believe that surgery was indicated keeping in mind the heavy risk it carried for an unfavorable outcome.
There seem to be some exceptions to the general rules of Cardiothoracic surgery concerning Risk stratification and decision making. The unexpected results of prompt and aggressive Surgical treatment of otherwise fatal situations make out for these exceptions.
Konstantinos Paziouros, None.