ECG-gated multidetector computed tomography for the assessment of the postoperative ascending aorta
Purpose: This study was undertaken to define the role of electrocardiographically (ECG)-gated multidetector computed tomography (MDCT) in the assessment of the postoperative ascending aorta. Materials and methods: From November 2006 to June 2007, 21 patients, [11 men, ten women; age ± standard deviation (SD): 62.7±10.8 years] with a history of ascending aorta replacement underwent ECG-gated MDCT and were prospectively included in our study. Ascending aorta replacement had been performed with different surgical techniques: Bentall-De Bono (four patients, 19%), Tirone-David (five patients, 23%), and modified Tirone-David with creation of aortic neosinuses (12 patients, 57%). Two patients were excluded from MDCT evaluation because they failed to fulfil the inclusion criteria. Transthoracic echocardiography was used as the reference standard. All patients provided informed consent. Results: In all patients, ECG-gated MDCT provided a clear depiction of the aortic annulus, aortic root and ascending aorta, enabling accurate measurements in all cases. The aortic valve area (3.4±0.2 cm2), the diameter of the sinotubular junction (31.6±1.8 mm), the diameter of the neosinuses in the case of modified Tirone-David procedures (37.3±2.1 mm) and the distance between the cusps and the graft wall during systole (3.1±0.7 mm) fell within standard ranges and showed a good correlation (r=0.89) with the values obtained with transthoracic echocardiography. Conclusions: MDCT is currently considered a compulsory diagnostic step in patients with suspected or known aortic pathology. MDCT is a reliable technique for anatomical and functional assessment of the postoperative aortic root and provides cardiac surgeons with new and detailed information, enabling them to formulate a prognostic opinion regarding the outcome of the surgical procedure.