Echocardiographic Appearance of Normally Functioning Sorin Bicarbon Valve Prostheses

A clinical and echocardiographic study was carried out to evaluate the performance of the Sorin Bicarbon bileaflet valve. From December 1990 to December 1994, 100 patients underwent isolated mitral (64) or aortic (36) valve replacement. There were 39 males and 61 females, with ages ranging from 21 to 73 years (mean 62 ± 9.6 years). Forty-three patients underwent a transthoracic continuous pulsed color Doppler echocardiogram at 3 and 6 months postoperatively. For mitral prostheses, the parameters calculated were valve area, pressure half-time and mean gradient; for aortic prostheses, peak and mean gradients were measured. Results were compared by analysis of variance to those obtained in patients matched for sex, body surface area, cardiac rhythm, site, and size of the prosthesis who had St. Jude Medical or CarboMedics valves implanted. No statistically significant differences were found among the 3 prosthetic heart valves. The operative mortality was 7%; 3 cases of fatal cerebral hemorrhage occurred in the early postoperative period. There was 1 late mortality, 1 case of transient cerebral ischemia, and 1 of gastric bleeding, all occurring inpatients with mitral prostheses. Midterm follow-up was satisfactory, although a larger series is required to confirm these results.

Relationship between Some Design Characteristics and Wear in the Bicarbon Heart Valve Prosthesis

The hinge design of a new bileaflet valve (Bicarbon) is presented in relation to the long-term durability characteristics. Theoretical considerations supported by experimental findings, lead to the identification of two different wear mechanisms acting in bileaflet valves, i.e. impact and friction wear. Impact wear, caused by the collision between the hinge stops and inflow surface of the leaflet pivots, is the predominant phenomenon; it is mostly influenced by the design of the coupling elements. The wear due to friction is significantly less important, given a proper kinematic coupling and a thorough washout. These different mechanisms can significantly affect the wear resistance and long-term reliability of bileaflet valves; therefore, they have been properly taken into account in designing the new valve model. The safety of the overall material and design solutions adopted in the Bicarbon valve has been confirmed by extensive accelerated durability tests resulting in no mechanical failure or loss of functionality