Evaluation of Two Different Ross Techniques: In Vitro Full-Root versus Graft-Inclusion

Background: The Ross procedure is a widely accepted surgery for treating patients with aortic valve stenosis. There is currently lack of knowledge regarding the optimal among its different techniques, which may influence the long-term success. In a bench in vitro study, we compared two Ross techniques (graft-inclusion versus full-root technique) according to their hemodynamic characteristics.

Methods: In a total of n = 20 porcine autografts two different techniques of the Ross procedures were performed: the full aortic root replacement (n = 10; full-root group) and the graft-inclusion technique (n = 10; graft inclusion group). In the valve tester the mean pressure gradient (mmHg), the effective orifice area (EOA, cm²), and the regurgitant volume (mL) were evaluated under four defined settings with increasing stroke volumes. Furthermore, we evaluated the closing volume (mL) for each group. Testing was conducted using physiological saline at 37°C, at a heart rate of 64 beats per minute and a baseline pressure of 120/80 mm Hg.

Results: Hydrodynamic assessment revealed that the EOA and the mean pressure gradient were lower in the full-root group compared with the graft-inclusion group (full-root group: 4.016 ± 0.899 mm Hg versus graft inclusion group: 6.446 ± 2.544 mm Hg, p < 0.001). The leakage volume between the two groups showed no difference (full-root: 2.6 ± 0.991 mL/stroke versus graft-inclusion: 3.681 ± 3.562 mL/stroke, p = 0.3192). Remarkably, the closing volume and in consequence the dilatation of the aortic root were significantly higher in the full-root group (full-root: 9.08 ± 3.13 mL versus graft-inclusion: 5.44 ± 2.39 mL, p < 0.001).

Conclusion: Though the hemodynamic properties tended toward the full-root technique, the lower closing volume for the graft-inclusion technique may prevent long-term autograft and root pathologies after the Ross procedure. Our in vitro study suggests further clinical studies to evaluate the effects of the different techniques on the long-term course after Ross.

NB: This abstract was presented in a similar form at a previous meeting.

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Artikel online veröffentlicht:
11. Februar 2025