WO2021214705A1

WO2021214705A1 - Calibrating mitral rings and related surgical kit

Info

Publication number: WO2021214705A1
Application number: PCT/IB2021/053324
Authority: WO
Inventors: Luca Deorsola
Original assignee: Cd Med S.R.L.
Priority date: 2020-04-23
Filing date: 2021-04-22
Publication date: 2021-10-28
Also published as: IT202000008698A1

Abstract

The present invention describes a calibrating ring for mitral valve surgery with an annular body made of a rigid and sterilizable material which is shaped like a saddle, with a median axis which intercepts on said annular body a posterior midpoint and an anterior midpoint, and which comprises a plurality of slits separated by a plurality of bridges located so as to be positioned, in use, at said posterior and anterior midpoints and at the regions of anterior commissure, posterior commissure, anterior pseudo-commissure, and posterior pseudo-commissure of said mitral valves.

Description

CALIBRATING MITRAL RINGS AND RELATED SURGICAL KIT

FIELD OF THE INVENTION

The present invention relates to the field of surgical instruments; in particular, calibrating mitral rings for mitral valve repair/stabilization surgeries.

BACKGROUND ART

The mitral valve, also known as bicuspid, is one of the four heart valves, is located at the base of the left ventricle, of which it forms an integral part. The left ventricle is the heart cavity which receives oxygenated blood from the left atrium (in turn received from the lungs) to pump it throughout the body. In order to perform this function, the ventricle has an inlet and an outlet with a valve: thereby the hematic flow (i.e., the blood flow) always and only moves in the proper direction. The mitral valve forms the entryway to the left ventricle and therefore directs the blood flow. As the ventricle dilates to receive oxygenated blood from the left atrium, the valve opens to allow passage. When the ventricle contracts to pump the received blood, the valve closes to prevent it from returning to the atrium, so that it can only proceed to the aorta.

Like a valve, the bicuspid structure comprises an orifice and a shutter. The orifice is the mitral ring the perimeter of which has an approximately oval shape, the shutter comprises two leaflets, defined by a layer of tissue which extends from the mitral ring. Two bundles of tendon cords are connected to the leaflets to open and close them in the proper direction, i.e., only towards the ventricle. Furthermore, the mitral ring has a particular saddle shape.

With reference to Figure 1 , it diagrammatically shows a mitral valve, generally indicated with the reference numeral 100.

The mitral valve 100 comprises a valve ring 110 and a pair of leaflets, namely an anterior leaflet 120 and a posterior leaflet 130, for opening and closing the valve ring 110.

More specifically, the anterior leaflet 120 has a semi-circular shape and occupies two fifths of the entire annular circumference, while the posterior leaflet 130 has a substantially quadrangular shape and is attached to three fifths of the annular circumference. The valve ring 110 is therefore divided into an anterior portion 111 , occupied by the anterior valve leaflet 120, and a posterior portion 112, occupied by the posterior valve leaflet 130.

The anterior 120 and posterior 130 valve leaflets are joined together, and to the valve ring 110, at two regions, said anterior commissure CA and posterior commissure CP, respectively.

The free margin of the anterior 120 and posterior 130 valve leaflets corresponds to the margin which is not connected to the valve ring 110 and the height of the leaflet is defined as the distance between the free edge and the valve ring 110. Furthermore, the line of contact between the free edges of the anterior 120 and posterior 130 valve leaflets is referred to as the coaptation line. When the mitral valve 100 is in the closed condition thereof, shown in Figure 1 , the anterior 120 and posterior 130 leaflets are in contact with each other along the coaptation line (they coaptate), thus preventing the regurgitation of blood in the left atrium.

The posterior leaflet 130 also has two typical indentations referred to as pseudo commissures, CA’, CP’ which divide it into three portions or scallops. According to Carpenter’s nomenclature, the portions of the posterior leaflet 130 are divided into anterolateral portion P1 , median portion P2 and posteromedial portion P3. The anterior leaflet 120 has no indentations, but is equally divided, on the basis of the proximity to the indentations of the pseudo-commissures, CA’, CP’ of the posterior leaflet 130, into an anterolateral portion A1 , a median portion A2 and a posteromedial portion A3.

As shown in Figure 2, when the valve ring 110 is viewed from the atrial side, it appears to be of an irregularly ellipsoidal or “D” shape. For this reason, the extension thereof is characterized by the main diameters thereof, i.e., the anteroposterior diameter AP and the commissure-commissure diameter CC.

More in particular, the anteroposterior diameter AP is the line connecting the center point A of the anterior ring 111 with the center point P of the posterior ring 112; the commissure-commissure diameter CC is the line connecting the anterior CA and posterior CP commissures.

The anterior-posterior diameter AP and the commissure-commissure diameter CC form two characteristic measures of the valve ring 110. Many patients suffer from ailments or disorders related to this important portion of the heart. Surgery is very often required to correct these disorders, occurring with a stopped heart with imposed extracorporeal circulation. The heart has a very different shape, size, and volume in vivo from those in the conditions of an operation. In other words, the surgeon operates on a “deflated” heart which will take quite different dimensions in vivo. The corrective actions of the surgeon on a mitral valve in these conditions are always a bit approximate, his/her experience and dexterity are highly important for the success of the operation. The operation further includes the positioning of a stabilization ring, which is sutured to the mitral ring by the surgeon to keep the desired shape and size of the mitral valve over time. There are multiple shapes and sizes of these stabilizing rings available to adapt to different sizes of the native valve ring.

In WO/2018/162949 a repairing mitral ring is described, which has a particular geometric configuration close to that of an in vivo valve ring. Although the choice of the size suited to the patient can be predicted to a certain extent by echocardiographic investigations, it is not possible to establish a priori the exact measure required, which must be decided by the surgeon during the operation.

It is the object of the present invention to provide a surgical instrument which ensures the cardio surgeon the possibility of establishing the exact size of a repairing mitral ring suited to each individual patient during the operation and facilitates the correct and rapid conduct of the surgery.

SUMMARY OF THE INVENTION

With reference to figure 1 , the present invention solves the aforementioned problems by means of a surgical instrument consisting of a calibrating mitral ring 50 made of a rigid and sterilizable material, having a geometric configuration substantially with an ovoid or “D” perimeter and a saddle shape, consisting of a structure inside which there are 6 slits of adequate width to allow the easy passage of some stitches, said slits identifying 6 full portions in the structure, referred to as “bridges”, placed at the 6 key points (A, P, CA, CP, CA’ and CP’) of the valve anatomy or the points adapted to identify the anteroposterior diameter (AP), the intercommissural diameter (CA-CP) and the anterior and posterior pseudo commissures (CA’ and CP’). For a correct positioning of a repairing mitral ring (as described, for example, in WO/2018/162949) it is useful to have a surgical instrument consisting of a corresponding calibrating mitral ring according to the present invention. The calibrating mitral ring is a surgical instrument, made of a rigid and resterilizable material, which allows the surgeon to temporarily stabilize the valve and perform the calculations necessary for the repair thereof during operations. It is positioned and fixed on the native valve ring and is then removed at the end of the procedure to make room for a similar ring, with identical shape and size, but suitably manufactured for a definitive implant.

The use of the calibrator requires that the surgeon, after passing a series of stitches on the native valve ring (the same points which will then be used to fix the final ring), passes the aforesaid points into the slits of the calibrator and drops the latter onto the valve ring, resting it on top thereof and fixing it simply by applying a slight pull towards the outside of the stitch threads. It is obviously essential that the calibrator is oriented correctly, and this is achieved by making sure that the six bridges coincide with the respective key points of the valve. Through such a positioning, the valve takes the correct shape and dimensions, and the repair can be carried out with greater precision and with better spatial references.

The present invention also relates to a surgical mitral surgery kit comprising a plurality of calibrating mitral rings according to the present description and each having different scalar dimensions identified by the anteroposterior diameter, preferably in the range 20-30 mm. The aforementioned kit can be advantageously completed by a collector of said calibrating mitral rings made of a rigid and sterilizable material and adapted to neatly collect said plurality of calibrating mitral rings in ascending order by size of the anteroposterior diameter, and a container made of a rigid and sterilizable material, said container adapted to contain said collector.

By means of the kit of the invention, the surgeon can easily and quickly have calibrating rings of each size and can thus quickly and easily check which is the most suitable size for each individual patient directly on the patient’s valve. The kit, made of a rigid and sterilizable material, can conveniently be sterilized in bulk and reused countless times. BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will become apparent from the following detailed description provided by way of non-limiting example, with the aid of the figures shown in the accompanying drawings, in which:

- Figure 1 diagrammatically shows the structure of a mitral valve;

- Figure 2 is a diagrammatic plan view of a valve ring observed from the atrial side;

- Figure 3 is a diagrammatic three-dimensional view of the valve ring in Figure 2;

- Figure 4 shows plan and perspective views of a preferred embodiment of the calibrating ring of the present invention;

- Figure 5 shows plan and perspective views of another preferred embodiment of the calibrating ring according to the present invention, and

- Figure 6 shows the container and the collector of the kit according to the present invention.

The following description of exemplary embodiments refers to the accompanying drawings. The same reference numerals in the various drawings identify the same or similar elements. The following detailed description does not limit the invention. The scope of the invention is defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

As shown in figure 4 attached to the present description, the calibrating ring of the present invention preferably consists of a structure with an approximately rectangular section, with rounded edges (to avoid surgical trauma), and inside which “slits” 51 have been obtained of adequate width to allow the easy passage of some stitches.

The calibrating ring for mitral valve surgery according to the present invention also has an annular shaped body, preferably having an ovoid or “D” shape, shaped like a saddle with a median area 68 raised over the two side parts, and a median axis 69 which intercepts on said body a posterior midpoint P and an anterior midpoint A. Said annular shaped body comprises a plurality of said slits 51 separated by a plurality of solid areas, referred to as bridges 52, placed at said posterior P and anterior A midpoints and, in use, at the anterior commissure CA, posterior commissure CP, anterior pseudo-commissure CA’ and posterior pseudo commissure CP’ regions of said mitral valves. In preferred embodiments of the calibrating ring according to the present description, the structure of the calibrating ring can comprise a pair of concentric rings, joined by some bridges 52.

In further detail, the positions of the bridges 52 preferably correspond to the 6 key points of the valve anatomy:

- A first and a second bridge are placed at points A and P and are therefore located respectively at about halfway of the anterior and posterior part of the ring, in those which are the highest points of the ring itself, and each identify the center of the two valve leaflets and correspond to the extremes of the so-called “anteroposterior diameter” one of the key measures of the valve anatomy.

- A third and a fourth bridge are placed, in use, at the anterior commissure and posterior commissure points CA and CP and are placed on the sides of the anterior part of the ring. These bridges are located at the level of the two lower points of the ring, and as mentioned, they are located, in use, at the so-called “commissures”, i.e., the two points which delimit the border between the two valve leaflets of the mitral valve. Said bridges CA and CP also define the extremes of the so-called “intercommissural diameter”, another important measure in mitral geometry.

- A fifth and a sixth bridge are placed, in use, at the anterior pseudo-commissure and posterior pseudo-commissure points CA ’and CP’, they are also placed on the sides of the ring, but in the posterior part. They are found, as mentioned, at the level of the so-called “pseudo-commissures”, i.e., the two points which divide the posterior valve leaflet into three portions known as “scallops” and form two other useful references for correct valve repair.

For the purposes of the present invention, rigid and sterilizable material means any metal or polymer material which can be used for the manufacture of surgical instruments and which can be sterilized countless times. Preferably, the calibrating rings and the components of the kit of the present invention are made of surgical steel.

The calibrating ring according to the present description is made in various dimensions which refer to the inner and/or outer lumen of the ring at said anteroposterior diameter; With reference to Figure 5, a preferred embodiment of the ring according to the present description has a body having a “D” shape with a linear anterior part 58 and the remaining circular arc shaped part in which: the length of said linear part 58 is 13.8 mm ± 0.2 mm, and in particular, it can preferably take the measure of 13.83 ± 0.10 mm; the inner diameter 60 of the circular arc shaped part is 23.4 mm ± 0.2 mm, and in particular, it can preferably take the measure of 23.42 mm ± 0.15 mm; the width 59 of said body is 3 mm ± 0.2 mm, and in particular, it can preferably take the measure of 3 mm ± 0.1 mm; the thickness 64 of said body is 2 mm ± 0.2 mm, and in particular, it can preferably take the measure of 2 mm ± 0.1 mm; the difference 65 between the highest dimension and the lowest dimension of the ring is 6.7 mm ± 0.2 mm, and in particular, it can preferably take the measure of 6.73 mm ± 0.1 mm; the width 57 of the bridges is 3 mm ± 0.20 mm, and in particular, it can preferably take the measure of 3 mm ± 0.1 mm; the positions of said third and fourth bridge lie at an angle 62 between 75° and 77° and which, in particular, can preferably take the measure of 76.35° with respect to the direction of the anteroposterior diameter; the positions of said fifth and sixth bridges lie at an angle 63 between 45° and 47° and which, in particular, can preferably take the measure of 46.37° with respect to the direction of the anteroposterior diameter; the width of said slits 51 is 1 mm ± 0.2 mm, and in particular, it can preferably take the measure of 1 mm ± 0.1 mm;

The inner lumen 55 at the anteroposterior diameter is 20 mm ± 0.20 mm, and in particular, it can preferably take the measure of 20 mm ± 0.10 mm;

The outer lumen 56 at the anteroposterior diameter is 26 mm ± 0.20 mm, and in particular, it can preferably take the measure of 26 mm ± 0.10 mm;

Calibrating rings having an inner lumen 55 at the anteroposterior diameter of 21 , 22, 23, 24, 25, 26, 27, 28, 29 and 30 mm ± 0.20 mm can be made by keeping said angles 62 and 63 fixed and increasing the aforesaid size in a scalar manner.

Claims

1. A calibrating ring (50) for mitral valve surgery, comprising an annular body made of a rigid and sterilizable material and shaped like a saddle with a median area (68) raised over the two side parts, and a median axis (69) which intercepts on said body a posterior midpoint (P) and an anterior midpoint (A), said body comprising a plurality of slits (51) separated by a plurality of bridges (52) located so as to be positioned, in use, at said posterior (P) and anterior (A) midpoints and at the regions of anterior commissure, CA, posterior commissure CP, anterior pseudo-commissure CA’, and posterior pseudo commissure CP’ of said mitral valves.

2. A calibrating ring (50) according to claim 1 , characterized in that said annular body is ovoid-shaped.

3. A calibrating ring (50) according to claim 1 , characterized in that said annular body is “D”-shaped with a linear anterior part (58) and the remaining part having a circular arc shape.

4. A calibrating ring (50) according to one or more of the preceding claims, characterized in that said rigid and sterilizable material is of the metal or polymer type.

5. A calibrating ring (50) according to one or more of claims 3 to 4, characterized in that the length of said linear anterior part (58) is of 13.8 mm ± 0.2 mm; the inner diameter (60) of the circular arc part is of 23.4 mm ± 0.2 mm; the width (59) of said body is of 3 mm ± 0.2 mm; the thickness (64) of said body is of 2 mm ± 0.2 mm; the difference (65) between the highest and lowest elevations of said ring is of 6.7 mm ± 0.2 mm; the width (57) of the bridges is of 3 mm ± 0.2 mm; the positions of the bridges corresponding, in use, to said anterior CA and posterior CP commissure regions, are arranged at an angle (62) between 75° and 77° with respect to the direction of the anteroposterior diameter; the positions of the bridges corresponding, in use, to said anterior CA’ and posterior CP’ pseudo-commissure regions, are arranged at an angle (63) between 45° and 47° with respect to the direction of the anteroposterior diameter; the width of said slits (51 ) is of 1 mm ± 0.2 mm; the inner lumen (55) at the anteroposterior diameter is 20 mm ± 0.2 mm; the outer lumen (56) at the anteroposterior diameter is of 26 mm ± 0.2 mm.

6. A mitral surgery kit comprising a plurality of calibrating rings according to one or more of claims 1 to 5, having inner lumens (55) of different sizes at the anteroposterior diameter.

7. A mitral surgery kit according to the preceding claim, characterized in that said plurality of calibrating rings comprises eleven calibrating rings having inner lumen (55) at the anteroposterior diameter of 20, 21 , 22, 23, 24, 25, 26, 27 , 28, 29 and 30 mm ± 0.20 mm.

8. A mitral surgery kit according to one or more of claims 6 to 7, characterized in that it comprises a collector (53) for said calibrating mitral rings made of a rigid and sterilizable material and adapted to neatly collect said plurality of calibrating rings (50) in ascending order by the size of the inner lumen (55) at the anteroposterior diameter; a container (54) adapted to contain said collector (53).

9. A mitral surgery kit according to the preceding claim, characterized in that said container (54) is made of a rigid and sterilizable material.

10. A mitral surgery kit according to one or more of claims 8 to 9, characterized in that said rigid and sterilizable material is of the metal or polymer type.