Aortic Root Physiology Late After a “Perfect” Ross Operation: Magnetic Resonance Imaging Study of Three Operative Techniques

In order to define physiological properties of the autograft root, magnetic resonance imaging (MRI) findings relative to three different operative techniques were compared with those of control subjects. Twenty-three patients, 18/5 M/F, aged 32 ± 9 years, underwent MRI assessment of the aortic root. Patients with normally functioning autograft valve and at least 4 years of follow-up (average 5.6 ± 1.9, range 4-10 years) were selected for each technique: six subcoronary (Group 1), nine inclusion (Group 2), and eight freestanding root (Group 3). Results were compared among patient groups and with seven control subjects, 6/1 M/F, aged 30 ± 2 years (P = ns). Morphological and functional properties were defined using transverse and paracoronal views, during systole and diastole. Mean aortic size in each group was greater than control, except for the LV-aortic junction and the sinus of Valsalva in Group 1 (26 ± 5 vs. 23 ± 3 mm, P = 0.2 and 33 ± 6 vs. 30 ± 5 mm, P = 0.3). Aortic valve plane rotation (P = 0.02) and root dilatation (P = 0.02) were more common in Group 3. Altered valve opening dynamics and asymmetrical aortic flow profile were also more common in Group 2 (P = 0.03) and Group 3 (P = 0.04). Distensibility was significantly reduced at sinus level in Group 2 and 3 compared with control (4.1 ± 3.5% and 3.6 ± 4.4% vs. 9.0 ± 4.7%, P = 0.03). Asymmetrical aortic flow profile was more common in patients with aortic dilatation (P = 0.05) and with severely reduced (<4%) root elasticity (P = 0.06). Among the three techniques, only subcoronary grafting allows preservation of physiological autograft valve dynamics, aortic flow and distensibility, at all root levels, late after operation. These findings may have relevant implications in the selection of the ideal Ross technique.