Since January 8,1985, three different designs of unstented (type A, n = 9) and partial stented (type B, n = 4; and type C, n = 3) glutaraldehyde preserved porcine aortic valves were used for aortic valve replacement in 16 patients with acquired aortic valve lesions. Type A and type B prostheses were Implanted using a two suture row technique. In type C prostheses, only a single suture row was necessary for implantation, facilitating surgery considerably. In all patients, the fully flexible commissures of the bioprostheses were secured to the aortic wall of the recipient. There was no hospital mortality. Two patients with type A bioprostheses died due to noncardiac causes, 4 and 24 months postoperatively. One bioprosthesis in this group had to be replaced after 3 months because of insufficiency. Serial Doppler echocardiographic studies were performed up to 6 years after implantation. No significant leaflet calcification was observed. In three type A bioprostheses, a mild insufficiency without progression was recorded. The latest mean/peak transprosthetic pressure gradients were: type A: 6 ± 4 mmHg/12 ± 6 mmHg; type B: 6 ± 3 mmHg/14 ± 5 mmHg; and type C: 11 ± 5 mmHg/18 ± 8 mmHg. The functional results of the type A and type B bioprostheses have proven to be satisfactory. The slightly higher pressure gradients in patients with a type C bioprosthesis give rise to further refinements of its design. These results confirm the usefulness of imitating normal anatomy by using unstented or partial stented bioprostheses.
The anatomy of valsalva's sinus is such that it decreases the mechanical stress on the leaflets of the aortic valve. Artificial stents impair the hemodynamic performance of an aortic bioprosthesis and lead to unphysiological functional stresses and may also shorten their durability. Therefore a semi-supported xenograft was developed which can be attached with an one-suture row in subcoronary position. This facilitates surgery considerably. Moreover, the commissures can be attached directly to the patient's aortic wall. The semi-supported valve was successfully implanted in a 69 years old patient with a combined aortic valve lesion. Postoperative invasive investigations, including angiography and videodensitometry, showed a normal performance of the valve and a normal anatomy of the aortic root.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.