Surgical instrument for heart valve reconstruction

[0002] The present invention pertains to the field of heart valve repair and reconstruction. More particularly, this invention relates to a surgical instrument for holding tissue used in heart valve reconstruction.

[0003] For nearly forty years, since the advent of the heart-lung machine, it has been possible to repair and reconstruct diseased heart valves. The concept of repairing, rather than replacing, diseased heart valves began with the work of Professor Ake Senning of Zurich in 1960. (Senning A.: Fascia Lata Replacement of Aortic Valves. Journal Thoracic and Cardiovascular Surgery54: 465-70 (1967).) However, until recently, methods for reconstructing semilunar valves have generally been characterized by lack of precision and reproducibility.

[0004] To overcome these and other disadvantages of the prior methods of valve reconstruction, the inventor of the subject invention developed improved, more easily reproducible, less complicated, and generally standardized, methods of reconstructing heart valves. These methods are generally described in Love U.S. Pat. No. 5,716,399 and Love U.S. Pat. No. 6,129,758, and copending U.S. Application Ser. No. 09/330, 689 of Love, et al. (collectively referred to as the “Love Patents”), each of which is incorporated herein by reference in its entirety. The Love Patents generally describe methods for repairing or reconstructing heart valves preferably using a novel unitary trefoil tissue pattern. An embodiment of these methods can preferably include the steps of (a) sizing of the heart valve based on the distance between adjacent commissures of the native valve annulus; (b) cutting a trefoil tissue pattern corresponding in size to the native valve annulus; (c) temporarily mounting the tissue pattern on a surgical instrument for holding the tissue in a configuration of a heart valve to facilitate attachment of the tissue; and (d) suturing the tissue to the native valve annulus.

[0005] The Love Patents disclose an innovative surgical instrument for holding the tissue pattern in a configuration of at least one leaflet of a circulatory system valve. An embodiment of the device described therein is shown in prior art FIG. 1. The instrument generally comprises an upper former 11 having a handle 12, and a lower former 13 having a handle 14. The tissue pattern 15 is placed between upper former 11 and the lower former 13. The formers are brought into complementary engagement by inserting handle 14 into handle 12 and sliding the upper former 11 against the lower former 13. The tissue pattern 15 is held in the configuration of the a closed or partially closed circulatory system valve to allow the tissue pattern 15 to be surgically attached to the native valve annulus.

[0006] The present invention relates to a novel variation of a surgical instrument for holding a piece of tissue in a configuration of a circulatory system valve, which provides a number of desirable features not present in the device described in the Love Patents or any other prior devices. The instrument disclosed herein allows the tissue to be surgically attached in an open valve configuration (rather than in the closed or partially closed configuration required by prior devices). The present invention also avoids rubbing of the two tissue forming surfaces so as to reduce the risk of slippage or damage to the tissue when engaging the tissue forming surfaces. In addition, the tissue holding instrument disclosed herein can be manufactured at relatively low cost because it has few parts, which can be manufactured of low-cost plastic materials. The claimed invention provides a new, useful and unique surgical instrument for holding a piece of tissue in a configuration of one or more leaflets of an open circulatory system valve, which provides these and other advantageous features.

[0007] The present invention relates to a surgical instrument for holding a piece of tissue in a configuration of at least one leaflet of an open circulatory system valve to facilitate surgical attachment of the tissue. The instrument includes an inner member having a proximal end comprising a handle portion and a distal end comprising an inner tissue holding portion. The inner tissue holding portion has of one or more inner leaves. An outer member is disposed about the inner member. The outer member has an outer tissue holding portion comprising one or more of outer leaves. The inner and outer leaves preferably correspond to the shape of leaflets of a circulatory system valve and may be brought together into complementary engagement with a piece of tissue held between the inner and outer leaves. An actuator, such as a collet, moves the outer leaves radially inward and outward with respect to the inner leaves. The outer leaves are separated from the inner leaves to allow placement of the tissue on the inner leaves. The outer leaves are moved radially inward to hold the tissue between the leaves in a configuration of at least one leaflet of an open circulatory system valve to facilitate surgical attachment to the native valve annulus.

[0008] The outer member preferably includes a sleeve slidably disposed about the inner member and one or more arms connecting the outer leaves to the sleeve. The outer member is slid axially toward the proximal end of the inner member to facilitate placement of the tissue on the inner leaves and slid axially toward the distal end to engage the inner and outer leaves.

[0009] Each arm is preferably positioned within a groove on the collet that cooperates with the arm to actuate movement of the outer leaves when the collet is slid axially along the arms.

[0010] The instrument also preferably includes a tissue loading member. One end of the tissue loading member is engaged with the distal end of the inner member. The other end of the tissue loading member includes a rounded portion for facilitating the placement of the tissue on the inner leaves.

[0011] The instrument also preferably includes a locking mechanism for retaining the actuator in place to keep the inner and outer leaves pressed together in complementary engagement, and to prevent linear movement and rotation of the outer member relative to the inner member.

[0012] The instrument is preferably provided in a kit comprising a plurality of instruments. Each instrument is one of a predetermined range of sizes corresponding to a range of anatomical sizes of normal human heart valves.

[0013] These, and other features, aspects and advantages of the present invention will become more fully apparent from the following detailed description, appended claims, and accompanying drawings where:

[0014] FIG. 1 is a partially exploded perspective view of a prior art instrument for holding a piece of tissue in a configuration of a circulatory system valve;

[0015] FIG. 2 is a front view of a preferred trefoil tissue pattern for use with the subject invention;

[0016] FIG. 3 is a perspective view of an embodiment of the surgical instrument of the subject invention in an engaged/closed position;

[0017] FIG. 4 is a perspective view of an embodiment of a surgical instrument of the subject invention showing the leaves in a disengaged/open position;

[0018] FIG. 5 is a side view of an embodiment of a surgical instrument of the subject invention showing the leaves in an engaged/closed position;

[0019] FIG. 6 is a side view of an embodiment of a surgical instrument of the subject invention with the collet removed;

[0020] FIG. 7 is a perspective view of the inner member of an embodiment of the subject invention;

[0021] FIG. 8 is a perspective view of the outer member of an embodiment of the subject invention;

[0022] FIG. 9A is a perspective view of the collet of an embodiment of the instrument of the subject invention;

[0023] FIG. 9B is a top view of the collet of an embodiment of the instrument of the subject invention;

[0024] FIG. 10 is a perspective view of the tissue loading member of an embodiment of the instrument of the subject invention;

[0025] FIG. 11 is a perspective view of the tissue loading member being used to load tissue on the instrument; and

[0026] FIG. 12 is a perspective view of an embodiment of the instrument of the subject invention used to surgically attach tissue to a heart valve annulus.

[0027] The subject invention provides a new, useful and unique surgical instrument for holding a piece of tissue in a configuration of one or more leaflets of an open circulatory system valve to facilitate surgical attachment of the tissue. The instrument is particularly suited for reconstruction of cardiac semilunar valves (aortic and pulmonic) utilizing the methods described in Love U.S. Pat. No. 5,716,399 (incorporated herein by reference in its entirety).

[0028] FIG. 2 illustrates a preferred tissue pattern for use with the subject invention. The tissue pattern is fully described and shown in copending U.S. app. Ser. No. 09/330,689 (incorporated herein by reference in its entirety). The trefoil pattern is used to form the preferred tri-leaflet valve structure. An embodiment of the trefoil valve tissue pattern 15 has three lobes, 16a, 16band 16c, arranged about a center orifice 18. Each of lobes 16a, 16band 16cof the trefoil valve tissue pattern, when oriented in the configuration of a valve and affixed to the native valve annulus, will form one leaflet or lobe of the valve structure. The tissue pattern is preferably cut in a predetermined size that corresponds to the size of the native valve annulus.

[0029] FIGS. 3-12 illustrate an embodiment of a surgical instrument for holding a piece of tissue in a configuration of at least one leaflet of a circulatory system valve to facilitate surgical attachment of the tissue. As shown in FIGS. 3-6, the instrument preferably comprises three principal components: inner member 17, outer member 19, and collet 21.

[0030] FIG. 7 shows an example of inner member 17 of an embodiment of the instrument. Inner member 17 is preferably cylindrical to conform to the shape of the native valve annulus; however, those skilled in the art will appreciate that various other shapes are possible. Inner member 17 has a proximal end 23 and a distal end 25. At the proximal end 23, inner member 17 includes a handle 27. Handle 27 preferably has a circumference that is slightly smaller than the circumference at the distal end 25 of the inner member 17 to provide a comfortable holding area. Inner member 17 has a tissue holding portion 30 (referred to as an inner tissue holding portion) three leaves 29a, 29band 29c(referred to as inner leaves). The leaves are preferably in a shape that conforms to the shape of the leaflets of an open tri-leaflet circulatory system valve. Each of the three inner leaves 29a, 29band 29cpreferably includes a tissue retention region 31, which uses friction to facilitate retention of the tissue on the leaf. The tissue retention region may comprise any of a number of means for retaining the tissue on the leaf, which preferably avoids trauma to the tissue. For example the tissue retention region may comprise a region of dimples, texturing, holes, ridges, pebbling, etches, or grooves to provide a surface to facilitate holding of the tissue.

[0031] FIG. 8 is a perspective view of the outer member 19 of an embodiment of the instrument. Outer member 19 comprises sleeve 37, which slides over the distal end 25 of the inner member 17. In one embodiment, sleeve 37 is a cylindrical portion that slides over a cylindrical inner member 17. Sleeve 37 need not necessarily be cylindrical, but preferably conforms to the shape of inner member 17 so that it can be slid over inner member 17. Outer member 19 includes a tissue holding portion 40 (referred to as an outer tissue holding portion), which comprises three leaves 39a, 39band 39c(referred to a outer leaves). Outer leaves 39a, 39band 39cpreferably conform to the shape of the leaflets of an open circulatory system valve. The outer leaves 39a, 39band 39care complementary and engageable with the inner leaves 29a, 29band 29c(e.g., a convex outer surface of the inner leaf mates with a concave inner surface of the outer leaf). The outer leaves 39a, 39band 39cand the inner leaves 29a, 29band 29cneed not be completely complementary but should possess sufficient complementarity to provide the functions and results disclosed herein. The inner leaves 29a, 29b, 29cand outer leaves 39a, 39b, 39care engaged (i.e., brought together in complementary engagement) while the trefoil pattern of tissue is sandwiched between the inner and outer leaves to form the tri-leaflet valve repair structure. Outer leaves 39a, 39band 39cmay also include a tissue retention region 41 (e.g., dimples, texturing, holes, ridges, pebbling, etches, or grooves to facilitate holding of the tissue) which uses friction to facilitate retention of the tissue on the leaf. Outer member 19 preferably further comprises arms 43a, 43band 43cbetween leaves 39a, 39band 39cand sleeve 37. In the embodiment shown, arms 43a, 43band 43care tapered outward toward sleeve 37 to facilitate radial movement of the outer leaves when engaged with collet 21 as discussed below.

[0032] FIGS. 9A and 9B illustrate the collet 21 of an embodiment of the instrument. The term collet broadly refers to any device disposed about the outer member 19 for actuating movement of the outer leaves 39a, 39band 39cradially inward and outward with respect to the stationary inner leaves 29a, 29b, 29c. In the embodiment shown, collet 21 is a ring-shaped member that that fits over outer member 19. Collet 21 preferably comprises grooves 45a, 45band 45cto facilitate movement of arms 43a, 43band 43c. As shown in FIGS. 3-6, arms 43a, 43band 43cfit within grooves 45a, 45band 45cof collet 21 and are engaged therewith to produce radial movement of outer leaves 39a, 39band 39c. Collet 21 may be slid axially (i.e., back and forth between proximal and distal ends) along arms 43a, 43band 43c. As collet 21 is slid along tapered arms 43a, 43band 43c, grooves 45a, 45band 45ccooperate with arms 43a, 43band 43cto cause outer leaves 39a, 39band 39cto move radially outward and inward with respect to inner 20 member 17. As collet 21 is moved toward sleeve 37, outer leaves 39a, 39band 39cmove radially outward with respect to inner member 17. As collet 21 is moved toward the outer leaves 39a, 39band 39c, outer leaves 39a, 39band 39cmove radially inward with respect to inner member 17 to bring outer leaves 39a, 39band 39cinto complementary engagement with inner leaves 29a, 29band 29c. As those skilled in the art will appreciate, there are numerous other mechanisms that could be employed to actuate radial movement of outer leaves 39a, 39band 39c. The term actuator is used herein to broadly refer to collet 21 and any of various alternative mechanisms for actuating movement of the outer leaves 39a, 39band 39cradially inward and outward with respect to the stationary inner leaves 29a, 29b, 29c.

[0033] In contrast to prior devices such as the device illustrated in FIG. 1, the outer leaves 39a, 39band 39cof the instrument described herein move radially inward and outward with no lateral sliding against the tissue surface. This radial movement provides a number of significant advantages. For example, the radial movement of the leaves avoids the possibility of pushing the tissue off of the forming surfaces when engaging the leaves. The radial movement also avoids the risk of damaging the tissue as a result of sliding action between the forming surfaces.

[0034] Each of arms 43a, 43band 43cpreferably further includes an outer ridge 44 and an inner ridge 46. Outer ridge 44 cooperates with collet 21 to limit the axial sliding of collet 21 along arms 43a, 43band 43cand to lock collet 21 in place to maintain inner leaves 29a, 29band 29c in complementary engagement with outer leaves 39a, 39band 39c. Inner ridge 46 cooperates with groove 26 on inner member 17 to prevent the axial movement of outer leaves 39a, 39band 39cas collet 21 is slid along arms 43a, 43band 43caway from the outer leaves 39a, 39band 39c. Each of arms 43a, 43band 43calso preferably includes a widened proximal portion 48 that is wider than the opening of grooves 45a, 45band 45con collet 21 so as to limit the axial sliding of collet 21 along arms 43a, 43band 43cin the direction of sleeve 37. One of arms 43a, 43band 43calso preferably includes a travel limit slot 50 that cooperates with a travel limit stop 52 on inner member 17 to limit the axial sliding of outer member 19 and along inner member 17 and to prevent the rotation of outer member 19 about inner member 17. Those skilled in the art will appreciate that there are numerous other alternative mechanisms that could be employed to maintain inner leaves 29a, 29band 29cin complementary engagement with outer leaves 39a, 39band 39c, and to limit the axial and rotational movement of collet 21 and outer member 19.

[0035] FIG. 10 illustrates a tissue loading member 51 of an embodiment of the instrument of the present invention. The tissue loading member 51 has a proximal end 53 and a distal end 55. The proximal end 53 of the tissue loading member 51 is preferably a cylindrical portion that is sized to be inserted into the distal end 25 of the inner member 17. The distal end 55 of the tissue loading member 51 is preferably a rounded (e.g., ellipsoidal) portion for facilitating the placement of the tissue 15 on the inner leaves 29a, 29band 29cas is illustrated in FIG. 11. After loading of the tissue on the inner leaves 29a, 29band 29c, the tissue loading member 51 is preferably removed from the inner member 17.

[0036] As illustrated in FIG. 12, the tissue pattern is held between inner leaves 29a, 29band 29cand outer leaves 39a, 39band 39cin a configuration of at least one leaflet of an open circulatory system valve. A margin of tissue pattern 15 (preferably of approximately 3 mm) extending from the edge of the leaves is preferably surgically attached to the native valve annulus 57 with either continuous or interrupted sutures or by other suitable means. One of the many advantages of the device is that the margin of tissue pattern 15 extending from the edge of the leaves and the contour of the leaves can be used to guide placement of sutures or other means for surgically attaching the valve tissue to the native valve annulus 57. Another advantage of the present invention is that it allows the valve leaflets to be surgically attached in an open valve position. Prior devices, such as the instrument disclosed in FIG. 1, require that the valve be surgically attached in a closed or partially closed position.

[0037] The instrument is preferably molded, cast or machined, from a biocompatible thermoplastic material that can be readily sterilized and discarded after single use. All edges that contact tissue are round and smooth to avoid damage to the tissue. One of the many advantages of the instrument of the present invention is that it can be manufactured in four pieces (inner member 17, outer member 19, collet 21 and loading member 51) of low-cost biocompatible thermoplastic material materials with minimal assembly. Thus, this instrument can be manufactured at a relatively low cost as compared to prior devices. This feature of the present invention provides a significant advantage when used in connection with the methods of heart valve reconstruction described in the Love Patents. An initial step of the methods described therein involves sizing of the native heart valve annulus. The preferred tissue pattern is preferably cut size-specific to correspond to the native annulus size. The holding instrument of the present invention is also preferably sized to correspond to the native valve annulus/tissue pattern size. Accordingly, the holding instrument may be distributed in kits comprising a tissue pattern or cutting template that corresponds in size to the tissue holding instrument. Because the devices of the present invention can be constructed using a few low-cost plastic parts, it has the significant practical advantage of allowing the instrument to be produced in a range of sizes at relatively low cost.

[0038] Although the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that the examples are merely illustrative and various changes may be made without departing from the spirit or scope of the invention. For instance, the numerous details set forth herein relating to the configuration and use of the presently preferred embodiment of the instrument with the preferred trefoil tissue pattern, are provided to facilitate the understanding of the invention and are not provided to limit the scope of the invention. It should also be appreciated that the subject invention can be used to repair less than all, i.e., one or two leaflets of a discarded valve, using tissue patterns comprising one or two lobes. Accordingly, the disclosure of embodiments of the invention is intended to be illustrative of the scope of the invention and is not intended to be limiting. It is intended that the scope of the invention shall be limited only to the extent required by the appended claims.