MECHANICAL SEAM SEAL

Description

FIELD

[0001] The claimed invention relates generally to surgical instruments for fastening suture, and more particularly to a mechanical fastener which is suitable for securing suture, particularly of very fine diameter.BACKGROUND

[0002] Malleable suture fasteners such as the sleeves sold under the trademarks Ti-KNOT ®< and COR-KNOT ®< by LSI Solutions, Inc. are a significant improvement over hand or instrument-tied knots in laparoscopic surgical procedures. The sleeves, which are made of a malleable material that has proven safe with prolonged exposure to body tissue, are slid over two or more strands of suture and deformed or crimped to secure the strands of suture.

[0003] An exemplary crimping instrument is shown in U.S. Pat. No. 7,235,086, entitled "CRIMPING INSTRUMENT WITH MOTION LIMITING FEATURE", assigned to LSI Solutions, Inc., of Victor, NY. Such crimping devices have a handle with an actuator lever that is movable relative to the handle. A hollow shaft extends from the handle to a distal end of the shaft. Suture ends can be threaded through a crimping sleeve held between a hammer and an anvil which are located in the distal end of the shaft. The suture ends pass out a hole in the side of the shaft, and the device can be used to position the crimping sleeve at a desired location on the suture relative to a surface through which the suture has been secured (for example, tissue, a replacement anatomical structure such as a heart valve, or an augmentive anatomical structure such as a heart valve annulus).

[0004] Squeezing the actuator lever towards the handle causes a wedge, located in the shaft, to advance and to force the hammer into the crimping sleeve. The hammer crimps the crimping sleeve against the anvil, and the suture is held tightly by the deformed sleeve. A blade may also be incorporated within the shaft and can be simultaneously moveable by the actuator lever in order to trim the suture ends.

[0005] Such instruments for attaching suture fasteners have proven to be very effective for sutures of a 2-0 and a 3-0 size. The United States Pharmacopeia (U.S.P.) specifies suture sizes as follows:

[0006] The 2-0 and 3-0 sutures (0.3mm to 0.2mm diameter) used with existing mechanical fastener products like the COR-KNOT ®< and Ti-KNOT ®< devices, as disclosed in US 2014 / 276979 A1, are useful in a wide range of surgeries where it is desired to approximate soft tissue and prosthetic materials. Unfortunately, these existing products are not indicated for use with smaller diameter sutures, such as, but not limited to 6-0, 7-0, and 8-0 sutures, which are much smaller in diameter (ranging from 0.07mm down to 0.04mm in diameter). These extremely small diameter sutures are useful in a wide variety of surgeries, such as coronary artery bypass graft (CABG) procedures, but it is not possible to use the existing COR-KNOT ®< or Ti-KNOT ®< crimpable sleeves (mechanical fasteners) with these small sutures. While these existing fasteners can be crimped onto such small suture, the sutures slip out of the fasteners under too low of a tension, making them incompatible.

[0007] It has been suggested that the dimensions of the COR-KNOT ®< fasteners simply be scaled down so that a proportionally smaller mechanical fastener could be used to secure smaller sutures, such as 6-0, 7-0, and 8-0 sutures. However, this has been attempted, including scaling down the critical portions of the device which crimps the mechanical fastener, and the results were not ideal. Hammer and anvil profiles, as well as mechanical fastener dimensions have proven not to be directly scalable to smaller suture, and as such design work related to different suture sizes from what is commercially available for mechanical suture fasteners is a non-obvious and highly exploratory endeavor.

[0008] Besides, US 2017 / 049435 A1 discloses a surgical snare assembly having a suture fastener, which have the dimension of the above described COR-KNOT ®< fasteners. US 2012 / 131983 A1 discloses a crimping device in general without specifying specific dimensions for the mechanical fasteners. US 8 349 003 B2 discloses a suture locking assembly for a heart valve repair device having a ring shape. US2014276979 discloses a mechanical suture fastener according to the preamble of claim 1.

[0009] Therefore, there is a need for a mechanical suture fastener which enables reliable suture holding performance when crimped onto 6-0, 7-0, and 8-0 sutures (ranging from 0.07mm down to 0.04mm in diameter).SUMMARY

[0010] The invention is set out in the appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIGS. 1A and 1B are proximal and distal perspective views, respectively, of one embodiment of a mechanical suture fastener. FIGS. 2A, 2B, and 2C are distal, side, and proximal elevational views, respectively, of the mechanical suture fastener of FIGS. 1A and 1B. FIG. 3 is a side cross-sectional view of the mechanical suture fastener of FIGS. 1A and 1B, illustrating relevant dimensions of the mechanical suture fastener. FIGS. 4A and 4B are side partial cross-sectional views of a mechanical suture fastener from two different elevations which are 90 degrees apart.

[0012] It will be appreciated that for purposes of clarity and where deemed appropriate, reference numerals have been repeated in the figures to indicate corresponding features, and that the various elements in the drawings have not necessarily been drawn to scale in order to better show the features.DETAILED DESCRIPTION

[0013] FIGS. 1A and 1B are proximal and distal perspective views, respectively, of one embodiment of a mechanical suture fastener. The mechanical suture fastener 10 ("fastener") has a crimpable sleeve 12 that joins a flange 14 on the distal end 10D of the sleeve 12. The crimpable sleeve 12 defines a proximal opening 16, and the flange 14 defines a distal opening 18. A channel is defined within the fastener, the channel allowing the proximal opening 16 to be in communication with the distal opening 18.

[0014] FIGS. 2A, 2B, and 2C are distal, side, and proximal elevational views of the fastener of FIGS. 1A and 1B.

[0015] FIG. 3 is a side cross-sectional view of a mechanical suture fastener, illustrating some relevant dimensions of the fastener. A longitudinal axis 20 of the fastener 10 is illustrated for an axial reference. A corresponding axial length 22 of the fastener is shown. The fastener also has a flange diameter 24 and a flange thickness 26. The flange 14 has a proximal outer flange radius 28, a distal outer flange radius 30, and an inner flange radius 32 as shown. The flange 14 further has a sleeve length 34 as shown, and a concave transition radius 36 between the flange 14 and the sleeve 12. The sleeve 12 has a sleeve diameter 38 measured on the outside of the sleeve 12, and the sleeve 12 defines a channel 40 having a channel diameter 42 on the inside of the sleeve 12. The crimpable sleeve 12 also has a wall thickness 44.

[0016] The table below illustrates different embodiments of different dimensions which have been discovered to provide suitable holding force and crimpable knot performance when used with 6-0, 7-0, and 8-0 suture. Measurement DescriptionEmbodiment 1 Value (mm)Embodiment 2 Value (mm)Embodiment 3 Value (mm)Embodiment 4 Value (mm)Axial length2.1082.1082.1082.108Channel diameter0.40640.39120.40640.3912Sleeve length1.9051.9051.9051.905Concave transition radius0.07620.07620.07620.0762Proximal outer flange radius0.07620.07620.07620.0762Distal outer flange radius0.07620.07620.07620.0762Inner flange radius0.2790.2790.2790.279Flange diameter1.0161.0161.1431.143Flange thickness0.2030.2030.2030.203Proximal sleeve radius0.05080.05080.05080.0508Sleeve diameter0.6100.6100.6100.610Sleeve wall thickness0.1020.1020.1020.102

[0017] It has been discovered that a crimpable mechanical fastener with an axial length to channel diameter ratio from about 5.19 to about 5.39 results in reliable suture holding force when the mechanical suture fastener is crimped onto 6-0, 7-0, or 8-0 suture. Similarly, it has been discovered that a crimpable mechanical fastener with a sleeve length to channel diameter ratio of about 4.69 to about 4.87 results in reliable suture holding force when the mechanical suture fastener is crimped onto 6-0, 7-0, or 8-0 suture. These ratios may be especially relevant for crimpable fasteners having a sleeve wall thickness of approximately 0.102 mm (0.004 inches), but not necessarily limited to such thickness. The sleeve length to channel diameter ratio may be especially helpful in designing such fasteners, since it appears to be relatively independent of the flange dimensions, which may separately be chosen for criteria such as alignment of the mechanical suture fastener into a crimping device and for non-traumatic tissue interface. Other dimensional ratios and relationships are being explored in order to guide the designs for these types of fasteners, and such discoveries will be pursued in follow-on patent applications.

[0018] It has also been discovered that embodiments having an inner flange radius of approximately about 0.178 to 0.279 mm (0.007 to 0.011 inches) or larger, and preferably 0.279 mm (0.011 inches) or larger, may be helpful in preventing the mechanical suture fastener from cutting the 6-0, 7-0, or 8-0 suture held therein when the fastener has been crimped onto such suture. As mentioned with respect to other design parameters and dimensions of the mechanical suture fastener described herein, simply reducing the size of previously known embodiments of mechanical suture fasteners has proven ineffective in balancing desirable properties and quality measures such as reduced size, sufficient suture holding force while avoiding new issues such as suture cutting or shearing. Therefore, merely proportionally reducing dimensions or scaling down previous embodiments of mechanical suture fasteners resulted in an inner radius between the flange end and the inner channel that resulted in shearing or cutting the thinner 6-0, 7-0, or 8-0 suture which was held and crimped within the mechanical fastener.

[0019] FIGS. 4A and 4B are side partial cross-sectional views of a mechanical suture fastener from two different elevations which are 90 degrees apart. They illustrate a snare wire 46 pulling first 48 and second 50 ends of a suture through the mechanical suture fastener in a proximal direction 52 (from the distal opening towards the proximal opening). Such a snare 46 may be used to load the suture ends 48, 50 (and therefore the suture) through the fastener 10 prior to a crimping action being performed on the fastener 10 in order to secure the suture therein. These views illustrate a design consideration for embodiments of crimpable fasteners which will employ a snare in such a scenario or similar scenarios. It is important to size the channel diameter so it is at least large enough to allow the snare and the doubled-back suture ends to pass therethrough.

Claims

1. A mechanical suture fastener (10) configured to fasten sutures used in surgeries wherein the mechanical suture fastener (10) comprises a crimpable sleeve (12) defining a channel (40) therein, the crimpable sleeve (12) has a sleeve length (34) and a wall thickness (44); and the channel (40) has a channel diameter (42); characterised in that the wall thickness (44) is approximately 0.102 mm (0.004 inches); and the ratio of the sleeve length (34) to the channel diameter (42) is about 4.69 to about 4.87, and wherein the mechanical suture fastener (10) is configured to fasten sutures having a diameter ranging from 0.04 mm to 0.07 mm.

2. The mechanical suture fastener (10) of claim 1, wherein the channel diameter is between 0.3912 mm (0.0154 inch) and 0.4064 mm (0.0160 inch).

3. The mechanical suture fastener (10) of claim 1, wherein the sleeve length (34) is approximately 1.905 mm (0.075 inches).

4. The mechanical suture fastener (10) of claim 1, further comprising a flange (14) that joins the crimpable sleeve (12) on a distal end (10D) of the crimpable sleeve (12).

5. The mechanical suture fastener (10) of claim 4, wherein: the flange (14) defines a distal opening (18); the crimpable sleeve (12) defines a proximal opening (16); and the proximal opening (16) is in communication with the distal opening (18) via the channel (40).

6. The mechanical suture fastener (10) of any one of claims 1 to 4, further comprising an axial length (22), and having an axial length (22) to channel diameter (42) ratio of at least approximately 5.0.

7. The mechanical suture fastener (10) of claim 6, wherein the axial length (22) to channel diameter (42) ratio is about 5.19 to about 5.39.

8. The mechanical suture fastener (10) of claim 4, wherein the flange (14) has a flange diameter (24) of about 1.016 mm (0.040 inches) to about 1.143 mm (0.045 inches).

9. The mechanical suture fastener (10) of claim 4, further comprising an inner flange radius (32) of at least about 0.178 mm (0.007 inches).

10. The mechanical suture fastener (10) of claim 9, wherein the inner flange radius (32) is approximately about 0.178 mm (0.007 inches) to approximately about 0.279 mm (0.011 inches).

11. The mechanical suture fastener (10) of claim 4, wherein the flange (14) has a flange thickness (26), which is greater than the wall thickness (44) of the crimpable sleeve (12); wherein preferably the flange thickness (26) is of 0.203 mm (0.008 inch).

12. The mechanical suture fastener (10) of any one of claims 1 to 11, wherein the crimpable sleeve (12) is configured to be deformed in a crimping operation performed on the crimpable sleeve (12) by a hammer and anvil profile disposed in a distal end of a shaft of a crimping device, the crimpable sleeve (12) being deformed such that the one or more strands of suture extending through the channel (40) are secured within the channel (40) by one or more portions of the deformed crimpable sleeve (12) following the crimping operation.