Saddle-shaped mitral valve annuloplasty prostheses with asymmetry, and related methods
A mitral valve annuloplasty prosthesis (ring or C) has a generally saddle shape, i.e., portions of the prosthesis that are or will be adjacent the anterior and posterior commissures of the valve are relatively low as compared to at least some other portions of the prosthesis that are or will be between the commissures. However, the saddle shape is asymmetrical, in that the portion that is or will be adjacent the posterior commissure is lower than the portion that is or will be adjacent the anterior commissure.
1 . A mitral valve annuloplasty ring having an anterior portion including A 1 , A 2 , and A 3 segments, and a posterior portion including P 1 , P 2 , and P 3 segments, the segments being connected in a closed loop series in the order A 1 , A 2 , A 3 , P 3 , P 2 , and P 1 , the ring having an AP axis that extends from the anterior portion to the posterior portion, a first reference point located on the anterior portion to one side of the AP axis, a second reference point located on the anterior portion to the other side of the AP axis, and a third reference point located on the posterior portion to one side of the AP axis, the AP axis being perpendicular to a line between the first and second reference points, and the first and second reference points and the AP axis being located so that the AP axis bisects a greatest width dimension of the ring that is measured perpendicular to the AP axis, each of the first through third reference points being spaced from the AP axis by 0.5 mm, and the first through third reference points lying in and thereby defining a reference plane, the ring further having a fourth reference point where the A 1 and P 1 segments meet, and a fifth reference point where the A 3 and P 3 segments meet, the fourth and fifth reference points being spaced from the reference plane to one side of that plane, and spacing of the fifth reference point from the reference plane being greater than spacing of the fourth reference point from the reference plane.
2 . The ring defined in claim 1 wherein the first and third reference points are both on the side of the AP axis that is closer to the fourth reference point.
3 . The ring defined in claim 1 wherein at least a portion of the P 3 segment is spaced from the reference plane to the one side of the reference plane by an amount greater than the spacing of the fifth reference point from the reference plane.
4 . The ring defined in claim 3 wherein at least a portion of the P 1 segment is spaced from the reference plane to the one side of the reference plane by an amount greater than the spacing of the fourth reference point from the reference plane.
5 . The ring defined in claim 4 wherein the spacing of the fifth reference point from the reference plane is greater than spacing of any portion of the P 1 segment from the reference plane.
6 . A mitral valve annuloplasty prosthesis having a posterior portion including P 1 , P 2 , and P 3 segments, and an anterior portion including A 1 and A 3 segments and a gap intermediate the A 1 and A 3 segments, the segments being connected in a series in the order A 1 , P 1 , P 2 , P 3 , and A 3 , the prosthesis having an AP axis that extends from the anterior portion to the posterior portion, a first reference point located to one side of the AP axis on a trajectory that includes a smooth continuation, across the gap, of both the A 1 and A 3 segments and that follows a path through the gap that would be occupied by material of the prosthesis if the prosthesis were a complete prosthetic ring, a second reference point located on the trajectory to the other side of the AP axis, and a third reference point located on the posterior portion to one side of the AP axis, the AP axis being perpendicular to a line between the first and second reference points, and the first and second reference points and the AP axis being located so that the AP axis bisects a greatest width dimension of the ring that is measured perpendicular to the AP axis, each of the first through third reference points being spaced from the AP axis by 0.5 mm, and the first through third reference points lying in and thereby defining a reference plane, the prosthesis further having a fourth reference point where the A 1 and P 1 segments meet, and a fifth reference point where the A 3 and P 3 segments meet, the fourth and fifth reference points being spaced from the reference plane to one side of that plane, and spacing of the fifth reference point from the reference plane being greater than spacing of the fourth reference point from the reference plane.
7 . The prosthesis defined in claim 6 wherein the first through third reference points are all located in material of the prosthesis.
8 . The prosthesis defined in claim 6 wherein the third reference point is located in material of the prosthesis and the first and second reference points are located in the gap.
9 . The prosthesis defined in claim 6 wherein the gap is located approximately centrally in the anterior portion.
10 . The prosthesis defined in claim 6 wherein the first and third reference points are both on the side of the AP axis that is closer to the fourth reference point.
11 . The prosthesis defined in claim 6 wherein at least a portion of the P 3 segment is spaced from the reference plane to the one side of the reference plane by an amount greater than the spacing of the fifth reference point from the reference plane.
12 . The prosthesis defined in claim 11 wherein at least a portion of the P 1 segment is spaced from the reference plane to the one side of the reference plan by an amount greater than the spacing of the fourth reference point from the reference plane.
13 . The prosthesis defined in claim 12 wherein the spacing of the fifth reference point from the reference plane is greater than spacing of any portion of the P 1 segment from the reference plane.
14 . A method of treating a patient's mitral valve comprising:
applying an annuloplasty prosthesis to the mitral valve adjacent the annulus of the mitral valve, the annuloplasty prosthesis dipping down adjacent the anterior and posterior valve commissures relative to at least some other portions of the annulus between the commissures, the prosthesis pushing down the portion of the annulus that is adjacent to the posterior commissure farther than the prosthesis dips down adjacent the anterior commissure.
15 . The method defined in claim 14 wherein the prosthesis comprises a ring.
16 . The method defined in claim 14 wherein the prosthesis is a C-shaped prosthesis having a gap adjacent at least a portion of the A 2 segment of the valve leaflets.
17 . The method defined in claim 14 wherein the other portions of the annulus include at least a portion of the annulus that is adjacent the A 2 segment of the valve leaflets and at least a portion of the annulus that is adjacent the P 2 segment of the valve leaflets.
18 . The method defined in claim 15 wherein the ring also dips down adjacent at least a portion of each of the A 1 , A 3 , P 1 , and P 3 segments of the valve leaflets relative to said portion of the annulus that is adjacent the A 2 segment of the valve leaflets and said portion of the annulus that is adjacent the P 2 segment of the valve leaflets.