The influence of the noduli of Arantii on competent aortic valve closure

Objectives: Aortic valve function is a complex interaction of its different structures. Competent final closure of aortic valves is ensured by the noduli of Arantii. This study was performed to investigate the influence of these noduli on competent aortic valve closure in-vitro.

Methods: Fresh porcine aortic roots (n=39) were selected into three groups according to their number of noduli of Arrantii. Group A (n=20): three noduli, group B (n=11): two noduli, and group C (n=8): one nodulus. Aortic roots were pressurized stepwise (20mmHg steps) with increasing pressures from 20 to 200mmHg. Leakage rate was measured. After resection of the noduli, measurements were repeated. Competent valve closure was defined when no leakage occurred. Moderate valve insufficiency was defined as less than 20ml/10min leakage and severe insufficiency as more than 20ml/10min leakage.

Results: Resencion of noduli in group A resulted in significant higher rates of valve incompetence (p<0.04). In group B, resection of the noduli showed under pressures up to 100mmHg a trend to less valve regurgitation compared to baseline (p=n.s.). In group C, nine valves showed no and six only a moderate rate of incompetence compared to baseline after resection of the nodulus (p=n.s.).

Conclusions: These results give some evidence, that not the presence of noduli of Anrantii, but the symmetry of them play a role in competent valve closure. These findings may have implications for the design of pericardial bioprosthesis, tissue engineered aortic valves, and autograft implantation.