Mitral annular size and shape in sheep with annuloplasty rings

摘要: Abstract Background: Mitral annuloplasty is an important element of most mitral repairs, yet the effects various types rings on annular dynamics are still debated. Recent studies suggest that flexible preserve physiologic area change during cardiac cycle, while rigid do not. Methods: To clarify ring dynamic geometry, we sutured 8 radiopaque markers equidistantly around anulus in 3 groups sheep (n = 7 each: no ring, Carpentier-Edwards semi-rigid Physio-Ring [Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif], and Duran [Medtronic, Inc, Minneapolis, Minn]). Ring sizes were selected according to anterior leaflet inter-trigonal distance (Physio-Ring 28 mm, n=7; 31 n=5, 29 n=2). After ± 1 days recovery, sedated studied by means biplane videofluoroscopy. was calculated from 3-dimensional marker coordinates without assuming circular or planar geometry. Results: In group, varied cycle 11% 2% (mean SEM; maximum=7.6 0.2, minimum=6.8 0.2 cm 2 ; P ≤ .001). fixed group (4.6 0.1 ) and, surprisingly, also static (4.8 .26 vs Physio-Ring). Furthermore, shape changed no-ring but not groups. Conclusions: did after annuloplasty, regardless type. Thus reduction, independent intrinsic flexibility, chief mechanism responsible for salutary annuloplasty. (J Thorac Cardiovasc Surg 1999;117:302-9)