Degenerative valvular disease specific annuloplasty rings
View Patent ↗Annuloplasty rings optimally sized to take into account more of the common degenerative valve pathologies. Each ring has a structural ring body with a shape that complies with predicted shapes of degenerative valvular diseases, such as fibroelastic deficiency (FED), Marfan's or Barlow's. The predicted shapes are obtained through careful echocardiographic and intraoperative measurements, and often differ for different annulus orifice sizes. For instance, in mitral rings the larger rings have larger minor axis and oblique axis dimensions relative to their major axis dimensions, and are more circular as opposed to D-shaped. The rings may also be three-dimensional and the relative heights around the rings may change for different sized rings. A mitral ring may have a higher anterior saddle relative to a posterior saddle, with the relative heights varying across the ring sizes. The ring may have varying flexibility around the ring periphery which also changes for different ring sizes. A bulge on the sewing cuff forms a step on the outflow side for ease of suturing, which may be indicated by a suture line.
1. A mitral annuloplasty ring, comprising:
a ring body defining a periphery with an anterior segment opposite a posterior segment, and two side segments, the ring body in plan view defining a major axis A and a minor axis B extending across from the anterior segment to the posterior segment, the dimensional pairs B and A being selected from the groups consisting of:
A is about 38 mm and B is about 27.2 mm; and
A is about 40 mm and B is about 28.7 mm,
wherein the ring defines a horizontal line segment a 1 -a 2 having a length A along the major axis of the ring, and
wherein the periphery is defined in plan view by four circular arcs, one for each segment, connected at points of tangency, and wherein two of the four circular arcs consist of portions of two congruent circles c 2 , c 3 that include points a 1 and a 2 , respectively, and both have a center along line segment a 1 -a 2 and include a point b 1 at the center of line segment a 1 -a 2 .
2. The mitral annuloplasty ring of claim 1 , wherein the ratio of B/A is greater than or equal to 0.69 and less than or equal to 0.73.
3. The mitral annuloplasty ring of claim 1 , wherein the axial elevation of the anterior segment is higher than the axial elevation of the posterior segment above a common datum plane.
4. The mitral annuloplasty ring of claim 3 , wherein the ring body is three-dimensional with the center of the anterior segment rising to a height C and the center of the posterior segment rising to height D above the common datum plane, wherein the ratio C/D>1.
5. The mitral annuloplasty ring of claim 4 , wherein the ratio C/D is about 3:1.
6. The mitral annuloplasty ring of claim 1 , wherein the ring body has varying flexibility around its periphery with the posterior segment being more flexible than the anterior segment.
7. The mitral annuloplasty ring of claim 1 , wherein the ring body generally defines a D-shape in plan view with a relatively straight anterior segment opposite a curved posterior segment, and wherein as the ring size increases the D-shape diminishes and becomes generally more circular.
8. The mitral annuloplasty ring of claim 1 , wherein the ring further defines:
a vertical line segment b 1 -b 2 extending from center point b 1 and having a length B′=(0.3125·A),
a vertical line segment b 1 -b 3 opposite b 1 -b 2 , wherein the line segment b 2 -b 3 defines the minor axis of the ring and has a length B;
wherein a third one of the four circular arcs defining the ring body periphery consists of an arc T 1 -T 4 that is tangent at both ends to the outer circles c 2 and c 3 and includes point b 2 ; and
wherein a fourth one of the four circular arcs defining the ring body periphery consists of an arc T 2 -T 3 that is tangent at both ends to the outer circles c 2 and c 3 and includes point b 3 .