Patent Application
20100234861
This invention relates to surgical fastener, and to buttress materials adapted to be used in combination with such surgical fasteners.
Surgical fasteners are commonly used in surgeries to perform a variety of functions, for example to remove parts of organs (e.g., to resect tissue), to cut through organs and tissues (transection), and to create connections between structures (to create anastomes). A variety of surgical fasteners are currently in use and include clip appliers, surgical staplers and other devices.
Surgical staplers are commonly used in a variety of surgical procedures including vascular, bariatric, urologic, gynecologic, thoracic and pediatric surgeries. For example, one such thoracic procedure is lung volume reduction, which resects a portion of lung to treat emphysema or other conditions. Also, one such bariatric procedure is the gastric bypass procedure, which resects a portion of the stomach to create a smaller stomach to aid in weight loss.
Surgical staplers are also provided in many forms, including linear staplers, circular staplers, and contoured or curved staplers. Surgical staplers commonly include a pair of apposed working surfaces. In the case of a linear stapler, two apposing jaws are provided, one holding a cartridge of staplers and the other being an anvil member against which the staples are to be fired. When the stapler is fired, it simultaneously emits a plurality of rows of closely spaced staples from the cartridge, and through the patient's own tissue.
In some instances, air and/or fluid leaks and/or excessive bleeding in the staple line have been reported. The term “staple line” is used herein to refer to any row of stapled tissue, and the staple line can be linear, circular or curved, depending on the type of stapler used. Leaks can occur in the cut line, and/or in the staple holes themselves. Frequently in the case of thoracic procedures, the diseased lung tissue is thin and friable and can tear at the staples as the lungs re-inflate. These air leaks can be persistent and can extend the hospital stay for a patient by weeks. As a means to alleviate these leakage problems, surgeons often reinforce the staple line by applying a buttress or pledget material to the desired stapling site, and stapling through the buttress material. The buttress material provides reinforcement to the friable tissue as it reduces the changes of tissue tearing at the staple line, and reduces staple pullout in friable tissue. The buttress material also creates a stronger staple line for increase security against air and/or fluid leaks and/or excessive bleeding both during surgery and in the crucial weeks that follow.
A variety of materials have been described for use as staple line buttress materials, including those formed of specially treated tissue (e.g., bovine pericardial tissue), alginate, polyglycolic felt, and Teflon brand materials, however only a handful have been found suitable for commercial use. These buttress materials are typically mounted in a releasable manner onto the working surfaces of a surgical stapler such that upon firing, the patient's tissue is sandwiched between the strips of buttress material.
Buttress materials are typically releasably mounted upon the working surfaces of a surgical stapler by either mechanical and/or chemical means. In some instances, an adhesive is applied to one or both surfaces of the stapler itself, or to a surface of a buttress material strip, and the strip is then applied to the corresponding working surface. For example, in the case of linear staplers, the buttress material is often attached with an adhesive to each apposing jaw. Current adhesives are typically biocompatible gels that are applied to the buttress material itself in order to hydrate the material and to create a temporary bond between the material and the stapler.
In many cases, it is generally necessary to properly align and position the buttress material strip onto the working surfaces of the stapler. An improperly aligned buttress material often results in a failed staple line. Apparatuses that include an alignment feature have been developed to aid a user in properly aligning a buttress material onto working surfaces of a stapler. For example, such an apparatus is described in Applicant's U.S. Pat. No. 5,752,965, the entire contents of which are herein incorporated by reference.
The invention provides an improved buttress material. Current methods of positioning the buttress material onto a working surface of a stapler typically involve at least two steps, a step of applying an adhesive material to the buttress material (or to the working surface of the surgical stapler) and then applying the buttress material to the working surface. The invention makes possible a one-step method of applying a buttress material to a working surface of a stapler. Also, current methods of aligning the buttress material onto a working surface of a stapler are not fail proof, even with the use of aligning devices. Often times, when a user applies an adhesive to either the buttress material or to the working surface of the stapler, too much adhesive is applied. This excess adhesive often causes the working surface to become slippery and the buttress material itself slides along the surface and becomes misaligned. Thus, the invention also provides a method of applying a buttress material to a working surface of a stapler that substantially reduces misalignments resulting from the user misapplication of the adhesive.
a is a partially exploded view of an aligning apparatus adapted to incorporate two articles of buttress material according to an embodiment of the invention.
b is a cross sectional view of the apparatus in
a is a perspective view illustrating the method of engagement between a surgical stapler and an aligning apparatus which incorporates two articles of buttress material according to an embodiment of the invention.
b is a cross sectional view of the apparatus in
In some embodiments, the invention provides a suture line buttress material having at least one adhesive surface, the material being packaged and provided in a manner that permits the surface to be aligned with and releasably cover the working surface of a surgical fastener. The term “suture line” is used herein to refer to any row of sutured tissue. The suture line can be sutured using staples, clips and the like. Also, the suture line can be linear, circular, curved or of any other suitable pattern or design depending on the type of surgical fastener used. The buttress material is adapted for use with any surgical fastener known in the art. In preferred embodiments, the surgical fastener preferably comprises a surgical stapler, and more preferably comprises a linear stapler.
Buttress materials are often provided in the form of a strip or other configuration where there are two major surfaces, one surface adapted to come into contact with a working surface of a surgical fastener and another surface adapted to be positioned against body tissue. The adhesive surface of the buttress material is provided on a surface that will come into contact with the working surface of the surgical fastener. The adhesive is also sufficiently tacky to permit the material, preferably without extraneous means such as removable sleeves, strings or added gels, to be retained upon the working surface of the surgical fastener in the course of the surgical fastener being positioned within the surgical site, and then to be removed from the working surface upon application of the surgical fastener.
Buttress materials having at least one adhesive surface provide several advantages, including the ability to avoid the need for a separate step for applying an adhesive gel. This improves the ease-of-use of loading the buttress material within the surgical fastener because currently used two-step loading processes are now converted to a one-step loading process. Furthermore, this elimination of the second step helps to reduce user misapplication of the adhesive.
The buttress material having at least one adhesive surface can be comprised of a single material or a composite of two or more of the same or different materials. In preferred embodiments, the buttress material includes at least one material having sufficient mechanical strength to reinforce a suture line (hereinafter “reinforcing material”). The composite of materials can be provided as a laminate of materials, a homogenous mixture of materials, a graded mixture of materials or as other suitable formations.
The reinforcing material can also be formed from synthetic or natural tissue. In certain embodiments, the reinforcing material is formed from natural animal tissue. In some cases, the natural animal tissue is a fibro-serous or serous membrane. In preferred cases, the natural animal tissue is a fibro-serous membrane comprising pericardium, preferably bovine pericardium. In some embodiments, the natural animal tissue can be a tissue of the type described in any of Applicant's own U.S. Pat. Nos. 5,503,638, 5,575,803, 5,549,628, 6,468,313, 6,312,474 and 6,652,594, the entire contents of each of which are herein incorporated by reference.
In particularly preferred cases, the reinforcing material comprises treated bovine pericardium available from the applicant's assignee and sold under its trademark Peri-Strips Dry®. The use of this particular type of material is advantageous in that it has a much higher density of collagen than most other connective tissues and is cross linked with glutaraldehyde. The high density of the bovine pericardium provides increased structural integrity about the suture line and he cross linking with glutaraldehyde is advantageous in that it decreases the antigenicity of the tissue, thereby resulting in little or no inflammatory reaction with the adjoining body tissue. In another preferred embodiment of the invention, the reinforcing material comprises treated bovine pericardium available from the applicant's assignee and sold under its trademark Veritas®. While the preferred embodiment of the present invention employs bovine pericardium as the buttressing biomaterial, it is to be readily understood that other suitable pericardium or dura mater may be employed, including but not limited to equine, porcupine, ovine, and human, as well as bio-compatible synthetic materials.
In a preferred embodiment of the present invention, the reinforcing material comprises a smooth, dense, nonporous membrane. A tissue of cross-linked bovine pericardium, e.g., Peri-Strips Dry® material is an example of a such a dense membrane. In other embodiments, the reinforcing material resists or substantially resists degradation in vivo. For example, such a reinforcing material preferably undergoes little or no hydrolysis once in contact with bodily fluid or saline solution. Cross-linked bovine pericardium, e.g., Peri-Strips Dry® material is also an example of a material which resists degradation in vivo. In other cases, a remodelable material is provided which is integrated into the surrounding body tissue over time. Preferably, the remodelable material comprises non-crosslinked animal tissue, for example bovine pericardium. Veritas® material is an example of a such a remodelable material.
In additional embodiments, the reinforcing material exhibits superior tensile strength, leak resistance and burst resistance. For example, the material preferably has a pre-implant tensile strength wherein the peak load is at least about 2000 grams, more preferably at least about 3000 grams and optimally at least about 4000 grams. In other cases, the material has a pre-implant tensile strength which does not significantly decrease over time once implanted in vivo. The pre-implant tensile strength of a material can be measured using an MTS Q45 uniaxial tensile tester. The reinforcing material also preferable has a leak pressure of at least about 90 mm Hg, more preferably at least about 150 mm Hg. In other embodiments, the reinforcing material has a burst pressure of at least about 90 mm Hg, more preferably at least about 150 mm Hg and optimally at least about 200 mm Hg. The leak pressure and burst pressure can be measured by introducing blue dye onto one side of the suture line at a constant rate and then introducing pressure. The leak pressure is the pressure at which leaking of the blue dye through the suture line is observed. The burst pressure is recorded when the pressure reaches a plateau or drops abruptly as the suture line bursts. Cross-linked bovine pericardium, e.g., Peri-Strips Dry® material is also an example of a material exhibiting superior tensile strength, leak resistance and burst resistance.
The buttress material can be provided with an adhesive surface in a variety of ways. In some embodiments, the buttress material includes a single material having adhesive properties in its own right. The single material also preferably has sufficient mechanical strength to reinforce a suture line. For example, a hydrogel film can be provided as the single material, wherein the hydrogel is itself provided with sufficient mechanical strength. In this case, any surface of the buttress material could be provided as the adhesive surface to be contacted with a working surface of a surgical fastener.
In other embodiments, an adhesive material is pre-applied upon a surface of the buttress material (which can include a single material or composite of one or more materials). In these cases, the one or more materials comprising buttress material generally have reinforcing and buttressing properties rather than adhesive properties, since a separate adhesive is pre-applied to a surface. However, this is by no means required and the one or more materials can certainly include a material having adhesive properties. In this case, the surface of the buttress containing the pre-applied adhesive is provided as the adhesive surface. The adhesive material is preferably formed upon a surface via a layer of film, although other configurations are also possible.
The adhesive can be pre-applied upon one or more surfaces of the buttress material according to any known methods in the art using conventional coating equipment and materials. Suitable coating methods include, for instance, air knife, brush, calendar, casting, curtain, dip, extrusion, blade, knife, gravure, kiss roll, knife over blanket, knife over roll, offset gravure, reverse roll, reverse smoothing roll, rod, sprays, squeeze roll, in vivo polymerization, and powdered resin coating. In turn, the coated material can be in any suitable form, e.g., the form of a powdered resin composition, aqueous or solvent based lattice, emulsion or dispersion.
The adhesive can be applied to one surface, two or more surfaces, or to all surfaces of the buttress material. In cases where the buttress material is porous or otherwise capable of being saturated, the adhesive can be applied to saturate the entire buttress. Preferably the hydrogel is applied to only one side, with the opposite side being left uncoated, or itself treated or provided with a suitable coating or properties. The adhesive is preferably applied to one or more surfaces as a thin layer, e.g., between about 0.1 mm and about 1.0 mm in nominal thickness, and more preferably between about 0.25 mm and about 0.75 mm nominal thickness.
A variety of materials can be provided as the adhesive material. In preferred embodiments, the adhesive material comprises a biocompatible gel. In particularly preferred embodiments, the adhesive material comprises a hydrogel, which can also be described as a polymeric water-containing gel. Suitable hydrogels include those based on natural hydrogels (e.g., artificial silk, cellulosic materials) and synthetic hydrogels, such as methacrylic and acrylic esters, acrylamide hydrogels, hydrogels based on N-vinyl-2-pyrrolidone, and polyelectrolyte complexes and charged hydrogels, including blends, mixtures and copolymers thereof. The inventors have discovered that suitable hydrogels provide an optimal combination of such properties as adhesion to the buttress material of choice, adhesion to the working surfaces of a surgical fastener, flexibility, contour formation, biocompatibility, biostability, and the ability to be sterilized.
Examples of suitable hydrogels include those available under the tradename Aquatrix II™ from Hydromer, Inc., a corporation located at Branchburg, N.J. In a particularly preferred embodiment, the hydrogel comprises a poly(N-vinyl lactam)-chitosan gel. Such gels ar described in U.S. Pat. Nos. 6,379,702, 6,365,664, 6,121,375, 5,420,197, 5,258,421, and 5,156,601, the entire contents of each of which are herein incorporated by reference. Chitosan is a deacetylated chitin, and is a linear polysaccharide of deacetylated N-acetyl-D-glucosamine. Poly(N-vinyl lactam) s such as polyvinylpyrrolidone (PVP) have been used in pharmaceuticals, in certain types of films, and in some cosmetic products. They can be used to provide dermatologically-compatible gels having a hydrophilic absorbent property and K values of less than 60. Such materials are preferably stable, hydrophilic gels which comprise a blend of acid-neutralized chitosan and a poly(N-vinyl lactam), with or without a plasticizer, the poly(N-vinyl lactam) having a K value of less than about 60 and mole equivalents of acid groups of at least about 1.4.
Such preferred gels can be prepared by mixing aqueous poly(N-vinyl lactam) solution and acid neutralized chitosan in aqueous solution at a poly(N-vinyl lactam)/chitosan weight ratio of from about 12/1 to about 1/1, preferably from about 10/1 to about 5/1, to form a blend at about 5 wt. % to 40 wt. % total polymer concentration, preferably from about 12.5 wt. % to about 25 wt. % polymer concentration, and allowing the blend to cure until a gel is formed.
In some embodiments, the adhesive surface has a predetermined adhesive strength or tack, the predetermined adhesives strength being reduced when the adhesive surface is hydrated. The terms “tack” and “adhesive strength” are used herein to describe the stickiness of the adhesive. The tack of an adhesive is typically the pull resistance (measured in dynes) exerted by the adhesive completely adhering to two surfaces being pulled apart. The higher the pull resistance, the higher the tack of the adhesive. Thus, when the adhesive material is outside of the body and in a dry form, it has sufficient tack to prevent the buttress material from being removed or realigned along the working surfaces of the surgical fastener. However, when the buttress material is placed in vivo where it comes into contact with tissue and body fluids, it is hydrated and this causes the surface to be easily removed from the working surfaces of the surgical fastener. Therefore, in preferred cases, the adhesive surface is packaged and provided in a manner that has sufficient tack to be securely applied to a working surface of a surgical fastener, this tack being reduced when the adhesive surface is positioned within the surgical site.
In preferred embodiments, the adhesive material of this invention can be used to deliver one or more bioactive agents, including both locally at the site of placement, or more broadly, including systemically through the patient. Such bioactive agents can serve to improve the function of the adhesive itself and/or they can serve related or unrelated functions within the body. In one embodiment, for instance, the adhesive can itself be used largely as a bioactive delivery device, with its function as a buttress material being ancillary to that. In preferred cases, one or more bioactive agents are provided that would improve healing of the stapled or otherwise sutured tissues. Examples of suitable healing bioactive agents include, but are not limited to antibiotics, anti-inflammatory agents, growth factors, and cytokines. Coagulants can also be provided to reduce the bleeding and radioactive sees can be provided to monitor the location of the buttress material within the body.
In some embodiments, the invention also provides surgical combinations, which include a buttress material according to any of the embodiments already described. For example, in some cases, a combination including a surgical fastener and at least one article of buttress material is provided. Any surgical fastener known in the art can be used with this combination. In preferred embodiments, the surgical fastener preferably comprises a surgical stapler, and more preferably comprises a linear stapler. In other cases, a combination including an apparatus for equipping a surgical fastener with a buttress material and at least one article of buttress material is provided. Suitable apparatuses for equipping a surgical fastener with a buttress material are described in U.S. Pat. Nos. 5,752,965 and 6,656,193 and in U.S. Publication Nos. 20040093029, 20030120284 and 20020165563, the entire contents of each of which are herein incorporated by reference. Such apparatuses are useful for disposing one or more articles of buttress material in releasable attachment with working surfaces of a surgical fastener such that the articles are automatically lined up with those surfaces. The at least one article of buttress material can be provided as installed within a buttress material or as a separate component that is part of a surgical kit in which the buttress material is inserted within the apparatus at the surgical site.
In certain embodiments, the invention provides surgical methods of using the buttress material. Buttress materials of the invention can be used in a variety of surgeries, including vascular, bariatric, urologic, gynecologic, thoracic and pediatric surgeries. Common bariatric surgeries include gastric bypass and gastric bending. Gastric bypass surgeries also include the following types of surgeries: roux-en-y gastric bypass (RYGB), vertical banded gastroplasty, and biliopancreatic diversion. Common thoracic surgeries include blebectomies, bullectomies, wedge resections, segmentectomies, lobectomies, pneumonectomy, lung volume reduction surgery, and other resections of the lung and bronchus.
A surgical method of the invention generally includes providing one or more articles of buttress material to a working surface of a surgical fastener, positioning the surgical fastener about a section of body tissue, and applying the fastener to form a reinforced suture line. In cases where the adhesive material loses adhesive strength when hydrated in vivo, it is desirable to position the surgical fastener about a section of body tissue for a period of time long enough to hydrate the adhesive material so that the articles of buttress material will be easily released from the surgical fastener working surfaces.
The use of a buttress material of this invention will now be described with respect to a preferred embodiment of the invention, which is illustrated by the Figures.
a-3b show an apparatus 10 for equipping a surgical fastener with a buttress material. The apparatus is adapted to incorporate articles of buttress material 100a and 100b in accordance with a particularly preferred embodiment. In this embodiment, the apparatus 10 is configured for use with a linear stapler.
Referring collectively to
The first guide channel 24 and the second guide channel 26 are dimensioned to regulate the engagement of the apposed working surfaces of a surgical stapler and the aligning apparatus. Articles 100a and 100b are designed to be positioned within the receiving area 40 so as to be generally in line with the first and second guide channels 24, 26, respectively. The guide channels 24, 26 will automatically direct the apposed jaws of a surgical stapler into contact with the adhesive surface 105 of each buttress material 100a and 100b when the surgical stapler is clamped down onto the apparatus 10.
With reference now to
In order to equip a surgical stapler to produce reinforced staple line, the apposed working surfaces of the surgical stapler are positioned within the first and second guide channels 24, 26, respectively, and clamped down into contact with the adhesive layers 105 of the articles 100a and 100b. The surgical stapler is maintained in this closed position for a given period of time and then pulled away from the alignment frame 18 to remove the pressure equalization means 20, along with the articles of buttress material 100a and 100b from within the receiving area 40. The adhesive layer 105 forms a sufficient bond between articles 100a and 100b and the apposed working surfaces of the surgical stapler such that, when the surgical stapler is opened from the previously clamped position, the articles 100a and 100b remain releasably attached to the apposed working surfaces of the surgical stapler and the pressure equalization member 20 may be removed from between the articles 100a and 100b. The surgical stapler is then fully equipped with articles 100a and 100b such that the apposed working surfaces thereof may be positioned about a section of body tissue to form a reinforced staple line in accordance with the present invention.
While a preferred embodiment of the present invention has been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11047477 | Jan 2005 | US |
| Child | 12728993 | US |
