Hemodynamic Performance at Rest and During Exercise After Aortic Valve Replacement: Comparison of Pulmonary Autografts Versus Aortic Homografts

Abstract

Background The Ross procedure and aortic homografts have both been shown to have superior hemodynamic performance after valve replacement, but there have been few comparisons. Methods Sequential Doppler echocardiograms were performed up to 5 years after aortic valve replacement in 132 patients with the Ross procedure and 111 patients with an aortic homograft (AH). Measurements included assessment of valvular regurgitation and calculations of valve effective orifice area (EOA) and mean transvalvular gradients; the same measurements were also performed at the level of the pulmonary homograft in the Ross patients as well as during maximum exercise in 20 Ross patients and 14 AH patients. Results Aortic valve hemodynamics were stable during follow-up for both procedures and values at 1 year showed larger indexed EOAs (1.77±0.45 versus 1.42±0.35 cm 2 /m 2 , P <0.001) and lower gradients (2±3 versus 4±3 mm Hg) for the Ross procedure; similar findings were also observed during exercise (1.99±0.44 versus 1.36±0.39 cm 2 /m 2 , P <0.001 and 7±3 versus 17±11 mm Hg). Prevalence and severity of aortic regurgitation were low in both groups, although 4 patients (1 Ross, 3 AH) underwent a second operation for this reason. Also, various degrees of pulmonary homograft stenosis were found in 20% of Ross patients, 4 of which underwent a second operation. Conclusion Both procedures provide continued excellent hemodynamics of the aortic valve. The Ross procedure has a slight advantage, but this is somewhat counterbalanced by the deterioration of the pulmonary homograft in up to 20% of patients. Further studies aimed at clarifying longer-term outcomes as well as preventing pulmonary homograft stenosis with the Ross operation are clearly needed.

Biomechanics of Pulmonary Autograft as Living Tissue: A Systematic Review

“…Although allogenic and autologous substitutes recorded similar hemodynamic performance with mean and peak transaortic gradients <10 mm Hg in the vast majority of individuals [ 97 ], pulmonary autografts revealed minimal calcification or degeneration, whereas many individuals develop high transaortic gradients following bioprosthesis or homograft implantation [ 103 , 104 , 105 , 106 , 107 ]. This implies that the transvalvular gradient remains stable over time with the use of the PAs as reported in long-term follow-ups, whereas it tends to increase after the implantation of homograft or bioprosthetic conduits [ 48 , 108 , 109 , 110 , 111 ]. The presence of low transvalvular gradients is even more significant when we consider the population of young individuals who want to exercise after AVR surgery.…”

Perspective Chapter: Ross Procedure in Adults with Congenital Aortic Valve Stenosis - New Perspectives

“…One study demonstrated autografts have reduced LVOT peak velocities after valve replacement and reduced left ventricular wall thickness, which was not seen in a comparison to patients who receiving aortic homografts [37][38][39]. Beyond these benefits, the Ross procedure is typically used in physically active young adults, and the reason for this is due to the pulmonary autograft's ability to adapt to aerobic exercise without increasing the neo-aortic valve gradient, thus mimicking normal aortic physiology [40,41].…”

Biological Surgical Options in Young Patients for the Treatment of Severe Aortic Stenosis: Is the Jury Still Out? A Review

“…Ross procedure was also associated with a lower mean aortic gradient at follow-up after 13 years in a randomized controlled trial when compared to aortic homograft (5 mmHg versus 30 mmHg) [ 30 ]. Pulmonary autograft has been shown in several studies to mirror the native healthy aortic valve in hemodynamic performance during activity by maintain a low gradient with maximal exercise [ 44 , 45 , 46 ]. Newer bioprosthetic valves have modified designs that allow the placement of a larger valve, that sits in the supra-annular position, while avoiding a high aortic gradient and decreasing the incidence of patient-prosthesis mismatch [ 47 , 48 ].…”