JP2012191963A - Prosthetic valve cusp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prosthetic valve cusp which can be used in various forms of a valve cusp with versatility, can be mounted without excising a valve cusp of a patient as much as possible, and applies small burden on the body of the patient.SOLUTION: The prosthetic valve cusp 1 is provided with a membranous valve cusp section 10 having: a sewing region 14 that comes in contact with the anterior or posterior cusp of a mitral valve to be sewed; and a contact region 16 that is a peripheral surface of a free margin 15 and comes in and out of contact with the other valve cusp of the mitral valve to suppress the reverse flow of blood.

Description

  The present invention relates to an artificial leaflet.

  Blood flows from the left atrium to the left ventricle as the mitral valve between the left ventricle and the left atrium of the heart repeatedly closes and opens.

  Lesions in the mitral valve, annulus, or left ventricle can cause mitral insufficiency and blood flows back from the left ventricle into the left atrium. The backflow of blood places a heavy burden on the left atrium and causes pulmonary congestion and atrial fibrillation.

  In the treatment of mitral insufficiency, valve replacement or valvuloplasty is generally performed. In valve replacement, the mitral valve is removed, and an artificial mechanical valve or biological valve is attached instead of the removed mitral valve. Although the leaflets may be preserved, the leaflets are evacuated to the surroundings by the artificial valve, and the function is lost.

  For example, Patent Document 1 discloses an artificial mitral valve and a leaflet (leaflet). The artificial mitral valve and leaflets disclosed in Patent Document 1 are sewn to the annulus after all the mitral valves of the patient have been excised.

JP 2010-148633 A

  When the artificial leaflet of Patent Document 1 is attached to the annulus, the patient's leaflet is removed. Even when there is no abnormality in the valve leaflet itself, such as insufficiency due to the expansion of the annulus, it is necessary to remove all the valve leaflets.

  On the other hand, when the leaflet is mildly deformed, a part of the leaflet is resected and sewn up, or supplemented with the pericardium, or applied with an artificial chordae. Distortion may leave a back flow and force valve replacement.

  The present invention has been made in view of the above circumstances, and can be used in various forms of valve leaflets with versatility, can be mounted without excising the patient's leaflets as much as possible, and has a small burden on the patient's body. The purpose is to provide a leaflet.

The artificial leaflet according to the present invention is
The sewing area that is sewn in contact with the anterior or posterior leaflet of the mitral valve, and the surface around the free edge that contacts and separates the other leaflet of the mitral valve to suppress blood backflow A membranous leaflet having a region,
It is characterized by that.

  In addition, a chordae portion extending from the free edge and connected directly or indirectly to the papillary muscle of the left ventricle may be provided.

  In addition, an artificial chord to be connected to the papillary muscle of the left ventricle may be provided in the chord chord.

  Further, a suturing needle may be provided on the chordae portion or the artificial chordae.

  Moreover, you may provide the artificial chordae connection part to which an artificial chordae is attached to the vicinity of the said free edge.

  In addition, a hole may be formed in the artificial chordal connection part.

  Moreover, it is preferable that the mechanical strength of the artificial chordae connection portion is higher than the mechanical strength of other parts of the valve leaflet.

  The film thickness of the artificial chordae connection part may be thicker than the film thickness of other parts of the valve leaflet.

  In addition, an artificial chordae may be connected to the artificial chordae connection part.

  Further, a suture needle may be provided on the artificial chord.

  The contact area is preferably smooth.

  Further, the valve leaf portion may include a reinforcing portion.

  Moreover, the said reinforcement part is fiber shape, and it may be stretched around the surface on the opposite side of the said contact area | region in the shape of a grid | lattice.

  According to the prosthetic valve leaflet of the present invention, it is possible to perform good formation regardless of various leaflet shapes during the operation, and there are not many foreign substances like the artificial valve. The operation time can be shortened, and the burden on the patient's body can be reduced without excising the patient's valve leaflets or minimizing the site to be excised.

It is a top view which shows the artificial leaflet which concerns on Embodiment 1, (A) is the top view which looked at the surface which has a contact area, (B) is the top view which looked at the surface which has a sewing area | region. It is sectional drawing of the left ventricle and a mitral valve in a normal heart, (A) is sectional drawing at the time of opening of a mitral valve, (B) is sectional drawing at the time of closing of a mitral valve. (A) is a developed view of the mitral valve, and (B) is a schematic diagram of the mitral valve as viewed from the left atrial side. (A) is sectional drawing of the left ventricle and the mitral valve in the heart which developed the mitral regurgitation resulting from the expansion of the annulus, (B) is a schematic view seen from the left atrial side. (A) is sectional drawing which showed typically the artificial leaflet sewn on the front leaflet of the mitral valve, (B) is the schematic diagram which shows sewing of a chordal part and a papillary muscle. It is an expanded view of the mitral valve which sewn the artificial valve leaflet to the front leaflet. It is the schematic diagram which looked at the mitral valve which sewn the artificial valve leaflet from the left atrium side. It is the perspective view which showed typically the mitral valve which sewn the artificial valve leaflet from the left ventricle side. It is a top view of the artificial leaflet which concerns on another form. (A) is a plan view of an artificial leaflet according to another embodiment, (B) is a developed view of a mitral valve having a perforation in the anterior leaflet, and (C) is a mitral valve in which an artificial leaflet is sewn on the anterior leaflet. FIG. (A) is a top view of the artificial leaflet provided with a reinforcing member, (B) is C-C 'sectional drawing of (A). It is a top view which shows the artificial leaflet which concerns on Embodiment 2. FIG. It is a schematic diagram of an artificial leaflet provided with a suture needle at the end of an artificial chord. It is a top view which shows the artificial leaflet which concerns on Embodiment 3. FIG. (A), (B) is A-A 'sectional drawing of FIG. 14, respectively. It is a top view of the artificial leaflet which has an artificial chordal connection part in a free rim zone. It is a top view which shows the artificial leaflet provided with the hole in the artificial chordae connection part.

(Embodiment 1)
The artificial leaflet according to the first embodiment will be described with reference to the drawings. The artificial leaflet 1 includes a leaflet portion 10 and a chordal portion 20 as shown in FIGS.

  The leaflet 10 is in the form of a membrane, and includes a sewing region 14 that is in contact with the anterior or posterior leaflet of the mitral valve and is sewn, and a surface around the free edge and the other leaflet of the mitral valve. And a contact region 16 that suppresses the backflow of blood by contacting and separating.

  The leaflet 10 is a single membrane-like member that functions to prevent the backflow of blood in the same manner as the anterior and posterior leaflets of the mitral valve, and the outer edge of the leaflet 10 is a circular arc that is convexly curved. , And an arcuate sewing edge 13 curved in a concave shape.

  As shown in FIGS. 1A and 1B, the sewing region 14 is located on the surface opposite to the surface having the contact region 16. The sewing area 14 is an area located in the vicinity of the sewing edge 13, and overlaps and contacts the anterior or posterior cusp of the mitral valve, and is sewn with a surgical thread or the like. The contact region 16 in the vicinity of the free edge 15 is a region that contacts the other leaflet when the mitral valve is closed, as will be described later. The free edge 15 of the valve leaflet 10 is formed in substantially the same shape as the free edge of the front leaflet.

  The chord 20 is a band-like portion extending from the free edge 15 of the leaflet 10. The chordae portion 20 is a member in which the chordae end portion 21 is sewn to the papillary muscle of the left ventricle and connects the leaflet portion 10 and the papillary muscle of the left ventricle. It is desirable to have a plurality of chords 20. As will be described later, the chord 20 is tensioned when the mitral valve is closed. When the plurality of chords 20 are provided, the tension is dispersed in each chord 20 and the chords 20 can be prevented from being torn. Moreover, since the tension | tensile_strength which acts on the valve cusp part 10 is also disperse | distributed, damage to the valve cusp part 10 is also prevented.

  The artificial leaflet 1 is formed from a single film-like material. The leaflet 10 is required to be in close contact with the contralateral leaflet and receive the left ventricular pressure in the same manner as the anterior and posterior leaflets of the mitral valve. For this reason, the valve leaflet portion 10 can receive the pressure when the left ventricle contracts, and the suture portion with the front leaflet or the rear leaflet cannot be broken, and has antithrombogenicity (no thrombus is formed on the surface). When the left ventricle expands, it is necessary to have the flexibility to allow blood to flow into the left ventricle as well as the leaflets, and to have biocompatibility that does not cause harm to the human body. Is done. In addition, the chordae portion 20 is required to receive the pressure of the left ventricle and not to tear, to be torn off from the leaflet portion 10, and to have antithrombogenicity.

  Examples of the material having the above characteristics include PTFE (polytetrafluoroethylene). PTFE is a material that has been used so far for artificial blood vessels, artificial chords, etc., and does not cause any obvious harm to the living body even if it is in contact with blood for a long period of time. Moreover, PTFE is covered with an intima-like membrane structure over time, and it is difficult for thrombus to be formed, and it is not necessary to administer an anticoagulant such as warfarin to a patient wearing the artificial valve leaflet 1. .

  Next, treatment of mitral insufficiency using the artificial leaflet 1 will be described. Here, a heart that has developed insufficiency will be described in comparison with a normal heart. Although insufficiency can occur for a variety of reasons, here we describe the case of insufficiency due to the expansion of the mitral valve annulus.

  The mitral valve 40 is located between the left ventricle 30 and the left atrium (not shown), and includes an anterior leaflet 41 and a posterior leaflet 42 (FIG. 2). The tips of the anterior cusp 41 and the posterior cusp 42 are each connected to a plurality of chords 50, and the chords 50 are connected to the papillary muscle 60. The annulus (not shown) is a region around the mitral valve.

  When the mitral valve 40 is released, the anterior leaflet 41 and the posterior leaflet 42 are separated (FIG. 2A), and blood flows from the left atrium to the left ventricle. Further, when the mitral valve is closed, the tips of the anterior leaflet 41 and the posterior leaflet 42 are in contact with each other (FIG. 2B), and blood is prevented from flowing back from the left ventricle to the left atrium. When the mitral valve 40 is closed, tension is applied from the chord 50 to the anterior leaflet 41 and the posterior leaflet 42 to prevent the valve from turning to the left atrium, whereby blood flows from the left ventricle to the left atrium. Not flowing.

  Further, as shown in the development view of the mitral valve in FIG. 3A, there are a front apex contact area 43 and a rear apex contact area 44 in the vicinity of the front end portions of the front apex 41 and the rear apex 42, respectively. These regions contact when the mitral valve 40 is closed, and as shown in FIG. 3B, the contact regions 43 and 44 come into contact with each other to close the mitral valve.

  When the annulus enlargement has occurred, the anterior leaflet 41 and the posterior leaflet 42 are not in contact with each other, and thus the mitral valve is incompletely closed (FIG. 4A). As can be seen from the left atrial side, a gap is formed between the anterior leaflet 41 and the posterior leaflet 42 (FIG. 4B). Through this gap, blood flows back from the left ventricle to the left atrium.

  An example in which the prosthetic valve leaflet 1 is attached to a mitral valve that has developed such an insufficiency will be described. First, as shown in FIGS. 5A and 6, the valve edge 10 has a free edge 15 and its periphery protrudes from the anterior leaflet 41, and the sewing region 14 overlaps the anterior leaflet 41 of the mitral valve. The apex 10 is disposed on the front apex 41. Then, the sewing region 14 is sutured to the front leaflet 41 with a surgical thread or the like so that the valve leaflet portion 10 and the front leaflet 41 are integrated.

  Further, the chord end portions 21 of the two chords 20 are brought into contact with the papillary muscles 60 (anterior lateral papillary muscles and posterior medial papillary muscles), respectively, and as shown in FIG. Then, it is sutured with a surgical thread or the like, and the chord end 21 and the papillary muscle 60 are connected.

  As shown in the development view of the mitral valve to which the artificial leaflet 1 is sewn (FIG. 6), when the artificial leaflet 1 is attached to the front leaflet 41, the length in the direction perpendicular to the annulus is the length of the front leaflet 41 alone. Longer than the case. For this reason, as shown in FIG. 8, when the mitral valve is closed, the contact region 16 of the artificial leaflet 1 and the contact region 44 of the posterior leaflet contact each other. A schematic view of the mitral valve in the same state as seen from the left atrial side is shown in FIG. The mitral valve is closed by contact between the contact region 16 (not shown) of the valve leaflet 10 and the contact region 44 (not shown) of the posterior leaflet.

  When the artificial leaflet 1 is sewn on the mitral valve, the operation of the heart is as follows. When the left ventricle contracts, the blood pressure in the left ventricle increases, and the anterior leaflet 41 and the posterior leaflet 42 to which the artificial leaflet 1 is attached are pushed toward the left atrium. The contact region 16 of the prosthetic valve leaflet 1 and the contact region 44 of the posterior leaflet are in contact with each other, and the mitral valve is closed, preventing blood from flowing back to the left atrium. At this time, since the free edge of the artificial leaflet 1 is pulled toward the left ventricle by the chordal cord portion 20, the anterior leaflet 41 to which the artificial leaflet 1 is attached is prevented from being turned into the left atrium. In addition, when the left ventricle is expanded, the left ventricle becomes negative pressure with respect to the left atrium, pressure is applied to the mitral valve from the left atrium side, the mitral valve is opened, and blood flows from the left atrium to the left ventricle. Thus, by attaching the artificial valve leaflet 1, it is possible to treat insufficiency due to annulus enlargement.

  Mitral valve insufficiency has various factors, including annulus enlargement, tendon rupture, leaflet perforation, anterior cusp deviation, posterior cusp deviation, and withdrawal of both cusps due to left ventricular enlargement. The valve leaflets 1 can be used to treat any insufficiency.

  For example, when the cause of mitral regurgitation is a chordal rupture, an artificial leaflet 2 having a narrow leaflet 10 can be used as shown in FIG. In the case of rupture of the chordae, it is not necessary to enlarge the area of the leaflet, and it is only necessary to repair the chordae. Therefore, the leaflet portion 10 only needs to have an area that can be sewn.

  Further, although the arc-shaped valve leaflet 10 having the sewing edge 13 curved in a concave shape has been described, the sewing edge 13 may have a shape other than the arc shape. For example, the artificial valve shown in FIG. Like the point 3, the sewing edge 13 may be curved in a convex shape. Depending on the cause of the insufficiency, the stitching edge 13 side of the leaflet 10 can be appropriately trimmed and used.

  For example, as shown in the development view of FIG. 10B, when the cause of mitral regurgitation is in the mitral valve perforation 90, the valve leaflet 10 is placed in front of the cusp so as to close the perforation 90. The valve leaflet 10 and the front leaflet 41 may be integrated with each other. In this case, as shown in the development view of FIG. 10 (C), the leaflet 10 may be trimmed into a shape that can close the perforation 90 of the anterior leaflet.

  Further, the contact region 16 is in contact with other leaflets of the mitral valve when the mitral valve is closed to suppress the backflow of blood, and contact / separation with other leaflets is performed smoothly. Is required. For this reason, it is desirable that the contact area 16 is smooth.

  Further, when the mitral valve is closed, that is, when the left ventricle is contracted, a pressure corresponding to the blood pressure in the left ventricle is applied to the valve leaflet, and the valve leaflet 10 is more resistant to this pressure. May have a reinforcing part. For example, as shown to FIG. 11 (A), the form in which the fiber-shaped reinforcement part was formed is mentioned. The filaments of the reinforcing portion 11 are formed along the sewing edge 13 and the free edge 15 of the valve leaflet portion 10, and are also formed in a direction crossing the stitched edge 13 and the free edge 15, and are stretched around in a lattice shape. FIG. 11B shows a configuration in which the reinforcing portion 11 protrudes from the leaflet portion 10 as shown in the A-A ′ cross section of FIG. The reinforcing portion 11 may be formed integrally with the valve leaflet portion 10 or may be formed integrally by attaching the reinforcing portion to the valve leaflet portion 10. In addition, since it is desirable that the surface having the contact region 16 is smooth as described above, the reinforcing portion 11 is preferably disposed on the surface having the sewing region 14.

  Moreover, although the form which sews the valve cusp part to the front leaflet was demonstrated above, it is also possible to sew to the back leaflet. What is necessary is just to trim and use a leaflet part according to the shape of a posterior leaflet.

  In the above description, the example in which the sewing region 14 and the contact region 16 are located on different surfaces has been described. However, in the case where the sewing region 14 is brought into contact with the valve leaflet from the left ventricle side and stitched, the sewing region 14 is used. And the contact area 16 exists on the same plane.

(Embodiment 2)
As shown in FIG. 12, the artificial leaflet 5 according to the second embodiment includes a leaflet portion 10, a chord cord portion 20, and an artificial chord cord 70. The chord 20 of the prosthetic leaflet 5 is shorter than the chord 20 of the prosthetic leaflet 1 according to Embodiment 1, and the chord 70 is connected to the chord end 21. Two artificial chords 70 are attached to the two chords 20 respectively.

  When the artificial chord 70 of the artificial leaflet 5 is sewn to the papillary muscle, it can be sewn as follows. One of the two artificial chords 70 is passed through the papillary muscle using a needle, and the artificial chord 70 and the other artificial chord 70 are attached by a method such as tying a knot. Can be sewn to the muscle.

  Examples of the artificial chord 70 include a PTFE thread generally used in mitral valvuloplasty.

  In this embodiment, the example in which the artificial chord 70 is integrally formed has been described. However, the artificial leaflet 5 that does not include the artificial chord 70 may be used. When using the artificial leaflet 5, a separately prepared artificial chord may be attached to the chord end 21 and used.

  Furthermore, in order to easily sew the artificial chord and the papillary muscle, a sewing needle 71 may be provided on the artificial chord 70 as in the artificial leaflet 6 shown in FIG.

  About another structure, since it is the same as that of the artificial leaflet 1 which concerns on Embodiment 1, description is abbreviate | omitted.

(Embodiment 3)
As shown in FIG. 14, the artificial leaflet 7 according to the third embodiment has an artificial chordae connection portion in which the leaflet portion 10 does not include the chordae portion 20 and the artificial chordae 70 can be connected in the vicinity of the free edge 15. 80.

  The artificial chordae connection part 80 is a reinforced part so as not to be broken by a force applied via the artificial chordae 70. As shown in the cross-sectional views of FIGS. 15A and 15B, the artificial chordae connection portion 80 is thicker than the other portions of the valve leaflets 10. For this reason, the artificial chordal connection portion 80 has higher mechanical strength such as tensile strength than other portions of the leaflet portion 10.

  As shown in FIG. 15A, the leaflet portion 10 having the artificial chordae connection portion 80 may have a form in which the artificial chordae connection portion 80 is integrally formed by injection molding or the like, as shown in FIG. As shown, a form in which a member having a predetermined shape is bonded to the surface of the leaflet portion 10 in the vicinity of the free edge 15 may be integrally formed.

  Further, the artificial chordae connection part 80 may be partially provided in the vicinity of the free edge, or may be continuously provided in the vicinity of the free edge as in the artificial leaflet 8 shown in FIG. Good.

  Moreover, you may provide the hole 81 for a connection in the artificial chordae connection part 80 like the artificial leaflet 9 shown in FIG. The artificial chords 70 can be easily attached to the artificial chordae connection portion 80.

  About another structure, since it is the same as that of the artificial leaflet 1 which concerns on Embodiment 1, and the artificial leaflet 2 which concerns on Embodiment 2, description is abbreviate | omitted.

DESCRIPTION OF SYMBOLS 1 Artificial leaflet 2 Artificial leaflet 3 Artificial leaflet 4 Artificial leaflet 5 Artificial leaflet 6 Artificial leaflet 7 Artificial leaflet 8 Artificial leaflet 9 Artificial leaflet 10 Valve leaflet 11 Reinforcement part 13 Sewing edge 14 Sewing Region 15 Free edge 16 Contact region 20 Tendon cord portion 21 Tendon cord end 22 Cloth 30 Left ventricle 40 Mitral valve 41 Anterior leaflet 42 Rear leaflet 43 Front leaflet contact region 44 Rear leaflet contact region 45 Annulus 50 60 Papillary muscle 70 Artificial chord 71 71 Needle 80 Artificial chord connection 81 Hole 90 Drilling

Claims (13)

The sewing area that is sewn in contact with the anterior or posterior leaflet of the mitral valve, and the surface around the free edge that contacts and separates the other leaflet of the mitral valve to suppress blood backflow A membranous leaflet having a region,
An artificial leaflet characterized by that. A chordae extending from the free edge and connected directly or indirectly to the papillary muscle of the left ventricle,
The prosthetic valve leaflet according to claim 1. Artificial chords connected to the papillary muscle of the left ventricle are provided in the chordae portion,
The prosthetic valve leaflet according to claim 2. A suture needle is provided on the chordae part or the artificial chordae,
The artificial valve leaflet according to claim 2 or 3, wherein An artificial chordae connection part to which an artificial chordae is attached in the vicinity of the free edge,
The prosthetic valve leaflet according to claim 1. A hole is formed in the artificial chordae connection part,
The prosthetic valve leaflet according to claim 5. The mechanical strength of the artificial chordae connection part is higher than the mechanical strength of other parts of the valve leaflets,
The prosthetic valve leaflet according to claim 5 or 6. The film thickness of the artificial chordae connection part is thicker than the film thickness of other parts of the valve leaflets,
The prosthetic valve leaflet according to claim 7. Artificial chordae are connected to the artificial chordae connection part,
The prosthetic valve leaflet according to any one of claims 5 to 8. A suture needle is provided on the artificial chord,
The prosthetic valve leaflet according to claim 9. The contact area is smooth;
The prosthetic valve leaflet according to any one of claims 1 to 10, wherein: The valve leaflet includes a reinforcing portion;
The artificial valve leaflet according to any one of claims 1 to 11, wherein: The reinforcing portion is in a fiber shape, and is stretched around in a lattice shape on the opposite surface of the contact area,
The prosthetic valve leaflet according to claim 12.