We report the case of a 24-year-old man who presented progressive precordial pain and dyspnea that had worsened in the last six months prior to the consultation with no previous history of arterial hypertension, dyslipidemia, smoking habits, or infectious diseases, such as syphilis or immunodeficiency syndrome. The physical examination showed no signs of congenital syndromes and revealed only severe systolic murmur in the aortic focus. Preoperative examinations were conducted as routine. Laboratory tests as well as the chest radiograph were unchanged. The electrocardiogram showed sinus rhythm, incomplete right bundle branch block and moderate left ventricular hypertrophy. The echocardiogram revealed aortic stenosis caused by a thickened aortic valve, which determined a gradient of 65 mmHg, left ventricular ejection fraction of 0.63, ascending aortic diameter of 30 mm, and systolic and diastolic diameters of 32 and 48 mm, respectively. Then, we proposed the surgery for aortic valve replacement. The procedure was performed by median sternotomy. After the pericardiotomy, we noticed an uncommon aspect of the ascending aorta, with an irregular surface and thinned dilated areas with soft superficial texture (Figure 1). Aortic cannulation was performed above and medial to the innominate artery, and right atrial cannulation was performed through the right atrial appendage. A left ventricular vent was placed via the right superior pulmonary vein. After total heparinization, cardiopulmonary bypass was then established, the aorta was cross-clamped and a transverse aortotomy was performed. The internal aspect of the vessel was thickened, with multiple focal cavities of different sizes corresponding to the external dilatations; no thrombi were found (Figure 2).
Antegrade cold blood cardioplegic solution was infused every twenty minutes. The three thickened aortic leaflets, as well as the anterolateral convexity and anteromedial concavity of the aorta were excised, leaving the posterior one third, macroscopically normal, to serve as support tissue to the vascular prosthesis that would be placed. Samples were submitted for histological study, and the procedure was completed. The prosthesis implanted was a mechanical no. 21; a Dacron tube prosthesis (no. 24) was positioned in replacement of the ascending aorta above the coronary ostia. De-airing was performed through a catheter placed in the tube; the aortic cross-clamp was removed. As the heartbeats became effective, the cardiopulmonary bypass was ended, and the surgery was finalized as usual. The patient was sent to the intensive care unit, where he remained for one day. He was then discharged by the tenth day in good health. He recovered and has lived until the present moment without complications.
The histopathological findings were ascending aorta with areas of intimal fibrosis with dystrophic calcification consistent with arteriosclerosis. Areas of medial cystic degeneration with saccular dilations were observed to be diffusely distributed; inflammation was absent (Figure 3-A,B,C). The aortic leaflets were fibrous with myxomatous degeneration and dystrophic calcification. The loss of smooth muscle cells was markedly important, as was the deposition of extracellular matrix following the degeneration.
Angiotomography of the aorta was performed post-operatively and showed no other injuries in the aorta. Furthermore, the prosthetic graft in the ascending aorta and the mechanic valve prosthesis in the aortic position were properly positioned (Figure 4).
Some laboratory tests were performed in order to try to identify infectious diseases, such as syphilis and HIV, and autoimmune diseases, such as vasculitis, with no positive results.