This invention relates to a vessel closure device, and more particularly to a device for effecting the closure of a vessel by delivering a fluent closure composition precursor and converting the composition in situ to a non-fluent closure composition.
A wide variety of surgical procedures are performed by the introduction of a catheter into a vessel. After the surgical procedure is completed, closure of the vessel at the site where the catheter was introduced is needed. Vessel punctures formed in the process of performing a catheter based surgical procedure are commonly 1.5 mm to 7.0 mm in diameter and can be larger. Closure of these punctures is frequently complicated by anticoagulation medicine given to the patient that interferes with the body's natural clotting abilities.
Closure of a vessel puncture has traditionally been performed by applying pressure to the vessel adjacent the puncture site. This procedure requires the continuous attention of at least one medical staff member to apply pressure to the vessel puncture site and can take as long as 30 minutes.
Devices have been developed for effecting the closure of vessel punctures through the application of energy. See U.S. Pat. Nos. 5,626,601; 5,507,744; 5,415,657; and 5,002,051. Devices have also been developed for effecting the closure of vessel punctures through the delivery of a mechanical mechanism which mechanically seals the puncture. See U.S. Pat. Nos.: 5,441,520; 5,441,517; 5,306,254; 5,282,827; and 5,222,974. Devices have also been developed for effecting the closure of vessel punctures through the delivery of a composition to block the vessel puncture. See U.S. Pat. Nos. 5,601,602; 5,591,205; 5,441,517; 5,292,332; 5,275,616; 5,192,300; and 5,156,613. Despite the various devices that have been developed for closing vessel punctures, a need still exists for a simple, safe and inexpensive device and method for closing vessel punctures.
The present invention relates to a device and method for sealing a puncture in a body vessel. In one embodiment, the device has an elongated body having a proximal end and a distal end sized to be positioned within a lumen of the body vessel; at least one closure composition precursor lumen within the elongated body having a entrance port adjacent the proximal end of the elongated body through which one or more fluent closure composition precursors can be delivered into the closure composition precursor lumen and an exit port adjacent the distal end of the elongated body through which the one or more fluent closure composition precursors can be delivered outside the vessel adjacent the vessel puncture; and at least one position sensing mechanism positioned distal relative to the exit port such that the exit port is outside the vessel when the at least one position sensing mechanism is detected to be outside the vessel.
The closure device of this embodiment may optionally further include an energy delivery device for delivering energy adjacent the distal end of the elongated body to the fluent closure compound precursor. In one variation, the device includes a microwave antenna for delivering microwave energy adjacent the distal end of the elongated body to the fluent closure compound precursor. In another variation, the device includes a waveguide for delivering light energy adjacent the distal end of the elongated body to the fluent closure compound precursor. In yet another variation, the device includes a RF electrode for delivering RF energy adjacent the distal end of the elongated body to the fluent closure compound precursor.
In another embodiment, the device includes an elongated body having a proximal end and a distal end sized to be positioned within a lumen of the body vessel; at least one closure composition precursor lumen within the elongated body having a entrance sport adjacent the proximal end of the elongated body through which one or more fluent closure composition precursors can be delivered into the closure composition precursor lumen and an exit port adjacent the distal end of the elongated body through which the one or more fluent closure composition precursors can be delivered outside the vessel adjacent the vessel puncture; and a microwave antenna for delivering microwave energy adjacent the distal end of the elongated body to the fluent closure compound precursor. The microwave antenna according to this embodiment is preferably incorporated onto the elongated body adjacent the body distal end.
In another embodiment, the device includes an elongated body having a proximal end and a distal end sized to be positioned within a lumen of the body vessel; at least one closure composition precursor lumen within the elongated body having a entrance port adjacent the proximal end of the elongated body through which one or more fluent closure composition precursors can be delivered into the closure composition precursor lumen and an exit port adjacent the distal end of the elongated body through which the one or more fluent closure composition precursors can be delivered outside the vessel adjacent the vessel puncture; a guidewire lumen within the elongated body; and a guidewire including microwave antenna for delivering microwave energy adjacent the distal end of the elongated body to the fluent closure compound precursor.
The present invention also relates to a method for sealing a puncture in a body vessel. In one embodiment, the method includes the steps of delivering a distal end of an elongated body into a lumen of the body vessel, the elongated body having at least one closure composition precursor lumen with a entrance port adjacent the proximal end of the elongated body through which one or more fluent closure composition precursors can be delivered into the closure composition precursor lumen and an exit port adjacent the distal end of the elongated body through which the one or more fluent closure composition precursors can be delivered outside the vessel adjacent the vessel puncture, and at least one position sensing mechanism positioned distal relative to the exit port such that the exit port is outside the vessel when the at least one position sensing mechanism is detected to be outside the vessel; withdrawing the elongated body until the at least one position sensing mechanism is positioned outside the vessel lumen; delivering one or more fluent closure composition precursors outside the vessel adjacent the vessel puncture; and transforming the one or more fluent closure composition precursors into a non-fluent closure composition which seals the vessel puncture.
In one variation, the method further includes the step of delivering energy adjacent the distal end of the elongated body to the fluent closure compound precursor to transform the one or more fluent closure composition precursors into the non-fluent closure composition. The energy may be microwave energy and the at least one of the one or more fluent closure composition precursors may optionally include a microwave energy absorbing material.
The present invention also relates to a non-fluent closure composition for closing a puncture in a vessel. In one embodiment, the non-fluent closure composition is formed by delivering a fluent closure composition precursor to a position outside the vessel adjacent to the puncture; and transforming the fluent closure composition precursor in situ to a non-fluent closure composition. In another embodiment, the non-fluent closure composition is formed by delivering two or more fluent closure composition precursors to a position outside the vessel adjacent to the puncture; and mixing the two or more fluent closure composition precursors to form a non-fluent closure composition in situ adjacent the vessel puncture.
Transforming the fluent closure composition precursor in situ may include solidifying the closure composition precursor or causing the closure composition precursor to chemically react with itself to form a non-fluent composition, the chemical reaction optionally being catalyzed by a catalyst or by energy. Energy used in the method may be any form of energy including, for example, RF energy and microwave energy. When microwave energy is used, the closure composition precursor includes a microwave energy absorbing material.
The present invention also relates to a method for improving the adhesiveness of tissue surfaces to sealants and adhesives by applying energy to a surface of tissue to which a sealant or adhesive is to be applied. The energy thermally modifies the tissue surface and causes the tissue to be more adherent to sealants and adhesives, such as closure composition used in the present invention. The thermal modification preferably includes blanching the tissue surface. The thermal modification is believed to reduce the water content at the tissue surface, remove materials at the tissue surface which interfere with the adhesiveness of tissue surfaces to sealants and adhesives, change the topography at the tissue surface, and preferably increase the surface area at the tissue surface, all of which serve to increase the tissue surface's ability to adhere sealants and adhesives. Thermal modification of the tissue surface may be performed with any suitable form of energy, including for example, electromagnetic energy (RF energy, light, and microwave energy), ultrasound, and other thermal heat sources.
The present invention also relates to a method for improving the adhesiveness of tissue surfaces to sealants and adhesives by applying a chemical agent to a surface of tissue to which a sealant or adhesive is to be applied. The chemical agent modifies the tissue surface such that the tissue surface is more adherent to sealants and adhesives, such as closure composition used in the present invention. The chemical modification preferably includes denaturing the tissue surface.
In one variation, basic chemical agents (i.e., having a pH greater than 7) capable of modifying a tissue surface are used. Examples suitable basic chemical agents include but are not limited to aqueous sodium bicarbonate, aqueous sodium carbonate, water solutions or suspensions of alkali or alkali earth oxides and hydroxides, aqueous ammonia, water soluble amines such as alkanol amines, basic amino acids such as lysine and poly(lysine), aqueous sodium lysinate, and basic proteins such as albumin.
In another variation, acidic chemical agents (i.e., having a pH less than 7) having an osmolality above that of blood are used which are capable of modifying a tissue surface.
In yet another variation, a chemical agent which can serve as a tissue etchant is used. Examples of suitable tissue etchants include, but are not limited to salicylic acid, carboxylic acids, α-hydroxy carboxylic acids, and peroxides.
The closure device 10 includes an elongated body 12 with a proximal end 14 and a distal end 16 sized to be inserted into a lumen of a vessel 60. The surface of the elongated body 12 is preferably made of a non-stick material, such as TEFLON, or coated with a biocompatible lubricant. Positioned within the elongated body 12 are one or more closure lumens which extend from adjacent the proximal end 14 of the device 10 to the distal end 16 of the device 10 for introducing a closure composition precursor 70 adjacent the vessel puncture 62 site. Illustrated in
The closure composition precursor 70 can be formed of one or more fluent materials that can be flowed from the closure composition precursor source 24 to adjacent the device distal end 16 through the first closure lumen 18. The fluent closure composition precursor 70 is transformed into a non-fluent closure composition in situ to effect closure of the puncture 62. In a preferred embodiment, energy is applied to the closure composition precursor 70 to accelerate its transformation into the non-fluent closure composition. The transformation of the fluent precursor 70 to a non-fluent closure composition may be the result of a phase change (i.e. solidification) of the precursor 70 or a chemical modification of the precursor 70. For example, the precursor 70 may be formed from multiple components which react with each other, optionally accelerated by a catalyst or energy. Alternatively, the precursor 70 may be formed from a single component which reacts with itself, also optionally accelerated by a catalyst or energy.
In embodiments where energy is applied, the body 12 includes an energy delivery device 28 adjacent the distal end 16. The energy delivery device 28 may be designed to deliver one or more different types of energy including but not limited to electromagnetic radiation (RF, microwave, ultraviolet, visible light, laser), ultrasound, resistive heating, exothermic chemical heating, and frictional heating. The energy source 32 may also function to withdraw energy, i.e., perform cooling. The closure device 10 may also include an energy source attachment mechanism 30 for placing the energy delivery device 28 in energetic communication with an energy source 32.
The body 12 further includes at least one position sensing mechanism 34 adjacent the distal end 16 of the closure device 10 for indicating whether the position sensing mechanism 34 is located within or outside of the vessel 60. The position sensing mechanism 34 should be positioned on the body 12 distal to the precursor exit port 22 so that when the position sensing mechanism 34 is outside the vessel 60 the precursor exit port 22 is also outside the vessel 60.
Other sensors (not shown) may also be positioned on the body 12. For instance, a temperature sensor for measuring temperature adjacent the distal end 16 of the body 12 and/or an impedance sensor may be positioned at the distal end 16 of the closure device 10.
The body 12 can include two or more closure lumens for the introduction of closure composition precursor 70. For example, as illustrated in
The closure composition precursor 70 may be introduced adjacent the vessel puncture 62 as a single composition through a first closure lumen 18. Alternately, a first precursor component 113 may be introduced through the first closure lumen 18 and a second precursor component 112 can be introduced through the second closure lumen 42, as illustrated in
As illustrated in
As illustrated in
As illustrated in
In
The body 12 can optionally further include a locking mechanism 76 for coupling the closure device 10 to the sheath 52. For example, as illustrated in
As illustrated in
Pressure is applied to the skin 56 upstream from the puncture 62 as shown by arrow 76 in
As illustrated in
As illustrated in
As illustrated in
The energy delivery device 28 can be optionally used to deliver a form of energy which functions to accelerate the transformation of the fluent closure composition precursor 70 to non-fluent closure composition. Alternatively or in addition, a catalyst can be added to catalyze the conversion of the fluent precursor 70 to a non-fluent closure composition. Most commonly, energy is used to increase the temperature of the closure composition precursor 70. In one embodiment, the energy delivery device 28 is a microwave antenna positioned on or within the body 12.
The guidewire 82 can also include a microwave antenna. When microwave energy is employed, the closure composition precursor 70 preferably includes materials capable of absorbing microwave energy. Examples of such materials include, but are not limited to, hematite (α-Fe203), maghemite (γ-Fe203), magnetite (Fe304), geothite (α-FeOOH), lepidocrocite (γ-FeOOH), ferrihydrite, feroxyhyte (σ-FeOOH), akageneite (β-FeOOH) graphite and amorphous carbon.
The energy delivery device 28 may also be a wave guide 88 for delivery of UV, visible light or laser energy as illustrated in
The energy delivery device 28 may also be an electrode for delivering RF energy. The electrode can be a ring electrode encircling the body 12 as illustrated in
Referring again to
The position sensing mechanism 34 can also be a contact switch 96 as illustrated in
In a preferred embodiment, the closure device 10 includes two or more position sensing mechanisms 34 positioned around the closure device 10 where a reading that the sensing mechanisms 34 is outside the vessel 60 occurs when all of the sensing mechanisms 34 are outside of the vessel 60. By having more than one position sensing mechanisms 34 around the closure device 10, false readings from one of the position sensing mechanisms 34 are reduced or avoided. For instance, if a single position sensing mechanism 34 is used, the position sensing mechanism 34 may become pressed against the vessel 60 wall resulting in a pressure drop at the position sensing mechanism 34. The position monitor 40 would falsely provide a signal indicating that the position sensing mechanism 34 is outside the vessel 60. When a second position sensing mechanism 34 is included, the second position sensing mechanism 34 would still be exposed to the pressure within the vessel 60. As a result, the position monitor 40 would not provide a false signal.
When the position sensing mechanism 34 is a contact switch 96 or a pressure port, the position sensing mechanism 34 is preferably positioned at least 25 mm from the distal end 16. This positioning assures that the distal end 16 of the closure device 10 remains within the vessel 60 when the closure device 10 is positioned to deliver the closure composition precursor 70. This feature reduces the risk of delivering the closure composition precursor 70 to an improper location on the vessel or within the vessel 60.
The balloon 98 is deflated when the closure device 10 is positioned within the vessel 60. Once the balloon 98 enters the vessel 60, the balloon 98 is inflated to a diameter greater than the diameter of the sheath 52 and thus the puncture 62. The closure device 10 is then withdrawn until the resistance of the balloon 98 against the puncture 62 is felt-as illustrated in
Each position sensing mechanism 34 can be distally positioned 0.5-30 mm from the precursor exit port 22 and more preferably 3.0-9.0 mm from the precursor exit port 22. These distances allow the closure composition precursor 70 to be reliably delivered outside the vessel 60 once the closure device 10 is positioned for delivery of the closure composition precursor 70.
A variety of additional sensors may be used in combination with the present invention. For example, temperature sensors may be positioned adjacent the distal end 16 of the closure device 10 for detecting the temperature adjacent the distal end 16. The temperature sensors may be a thermocouple positioned on the surface of the body 12 (not shown) and hardwired to electrical contacts within a sensor monitor attachment port (not shown). These sensors are useful for regulating the amount of energy being delivered to the vessel 60 and tissue site 54 adjacent the closure device 10 and for preventing tissue damage and ablation due to excess heat application.
Impedance sensors may also be employed when RF is used in order to monitor the amount of energy being delivered to the tissue site 54.
When the closure composition precursor 70 is formed of two or more components, the closure device 10 can optionally include a static mixer 108 for mixing different closure composition precursor components before the closure composition precursor 70 exits the precursor exit port or ports 22.
The configuration of precursor exit ports 22 can also serve to assure adequate mixing of the first precursor component 113 and second precursor component 112. As illustrated in
An anti-backflow valve 26 which is suitable for use in a closure lumen 18 or 42 illustrated in
An example of a suitable anti-backflow valve 26 for use in the guidewire lumen 48 adjacent the distal end 16 of the device 10 is a flapper valve 120 as illustrated in
The body 12 is formed of any suitable, relatively flexible material. Suitable materials include, but are not limited to, polyethylene, PEBAX, polytetrafluroethylene (TEFLON) and polyurethane.
A variety of different closure composition precursors 70 and non-fluent closure compositions can be used in the present invention. The fluent closure composition precursor 70 and non-fluent closure composition should be biocompatible and preferably bioresorbable. The closure composition should be also capable of forming a strong puncture seal and be able to seal larger sized vessel punctures 62, e.g., punctures 62 formed by 8 french or larger needles.
Examples of closure compositions that can be used with the device 10 and method of the present include, but are not limited to sealants and adhesives produced by Protein Polymer Technology; FOCALSEAL produced by Focal; BERIPLAST produced by Centeon (JV Behringwerke & Armour); VIVOSTAT produced by ConvaTec (Bristol-Meyers-Squibb); SEALAGEN produced by Baxter; FIBRX produced by CyoLife; TISSEEL AND TISSUCOL produced by Immuno AG; QUIXIL produced by Omrix Biopharm; a PEG-collagen conjugate produced by Cohesion (Collagen); HYSTOACRYL BLUE produced by Davis & Geck; NEXACRYL, NEXABOND, NEXABOND S/C, and TRAUMASEAL produced by Closure Medical (TriPoint Medical); OCTYL CNA produced by Dermabond (Ethicon); TISSUEGLU produced by Medi-West Pharma; and VETBOND produced by 3M. Examples of two part closure compositions which may be used are listed in Table 1.
Another aspect of the present invention relates to a method for improving the adhesiveness of a surface of living tissue by treating the tissue surface with a form of energy which thermally modifies the tissue surface and renders the surface more readily bonded or adherent to tissue adhesives, sealants, glues and the like. The thermal modification preferably includes blanching the tissue surface. The thermal modification is believed to reduce the water content at the tissue surface, remove materials at the tissue surface which interfere with the adhesiveness of tissue surfaces to sealants and adhesives, change the topography at the tissue surface, and preferably increase the surface area at the tissue surface, all of which serve to increase the tissue surface's ability to adhere sealants and adhesives.
In one embodiment, the method includes exposing a tissue surface to be so treated, which optionally includes the action of forming new tissue surfaces such as by cutting tissue with a scalpel or tool, or by introducing a medical instrument into previously continuous tissue such as with a cannula, introducer, catheter, or trocar, to provide new tissue surface(s) surrounding the instrument. For example, this step is encompassed by the step of introducing a closure device of the present invention into tissue.
After a tissue surface to be treated has been exposed, the tissue surface is contacted with a source of energy that functions to heat the surface of the tissue. Examples of suitable forms of energy include but are not limited to electromagnetic energy (RF energy, light, and microwave energy), ultrasound, and other thermal heat sources. In one particular embodiment, RF energy may be delivered to the tissue surface from a metallic electrode (monopolar) of any convenient shape, such as ring or needle. In another particular embodiment, RF energy is delivered through a saline solution provided by a microporous membrane (MPM). In yet another particular embodiment, the RF energy has an intermittent and variable waveform, such as so-called “coagulation” waveforms, which can serve to increase the bondability of the tissue surface.
Energy is applied until a degree of “blanching” has been achieved and the ability to bond to the tissue surface is increased. It is believed that the energy thermally modifies the tissue surface and causes the tissue to be more adherent to sealants and adhesives, such as closure composition used in the present invention.
While the pretreatment method is being described herein with regard to its use in combination with a closure device of the present invention, it is envisioned that the pretreatment method is a tissue priming method which may be used to enhance the adhesiveness of any tissue surface to which a tissue glue or sealant is to be applied and thus may be used with other methods for joining tissues other than those described in this application. It is believed that this method can be beneficially used in a variety of protocols or procedures that use non-mechanical agents such as glues, adhesives and sealants to join tissue. It is also believed that this method can be beneficially used in protocols or procedures that use mechanical mechanisms, such as mechanical fasteners, to join tissue. Further, it is believed that the pretreatment method will be beneficial for improving bonding strength to and between tissue surfaces in procedures relying on chemical adhesion, including covalent bonding, as well as mechanical interlocking.
Illustrated in
The closure composition precursor 183 can be formed of one or more fluent materials that can be flowed from the closure composition precursor source 154 to adjacent the device distal end 146 through the closure lumen 148, such as the closure composition precursors described in this application. The fluent closure composition precursor is transformed into a non-fluent closure composition in situ to effect closure of the puncture 181.
The sealer/dilator 142 includes an energy delivery device 158 adjacent the distal end 146 for pretreating the tissue site 184 prior to delivering the closure composition precursor 183 to the tissue site 184. The energy delivery device 158 may be designed to deliver one or more different types of energy including but not limited to electromagnetic radiation (RF, microwave, ultraviolet, visible light, laser), ultrasound, resistive heating, exothermic chemical heating, and frictional heating. The closure device 140 also includes an energy source attachment mechanism 160 for placing the energy delivery device 158 in energetic communication with an energy source 162.
A plugging catheter 163 sized to fit within a vessel lumen extends from the distal end 146 of the sealer/dilator 142. In one embodiment, the sealer/dilator 142 is actually a cylindrical, tubular element having a lumen within which the plugging catheter 163 can be moved axially. The plugging catheter 163 includes at least one position sensing mechanism 164 for indicating whether the position sensing mechanism 164 is located within or outside of the vessel 166. The position sensing mechanism 164 should be positioned on the plugging catheter 163 distal to the precursor exit port 152 so that when the position sensing mechanism 164 is outside the vessel 166 the precursor exit port 152 is also outside the vessel 166.
The sealer/dilator 142 and plugging catheter 163 also include a guidewire lumen 169 configured to accommodate a guidewire 179. The guidewire lumen 169 can include an anti-backflow valve or hemostasis valve.
Other sensors (not shown) may also be positioned on the plugging catheter 163 or the sealer/dilator 142. For instance, a temperature sensor for measuring temperature adjacent the distal end 146 of the sealer/dilator 142 and/or an impedance sensor may be positioned at the distal end 146 of the sealer/dilator 142.
The sealer/dilator 142 can include two or more closure lumens for the introduction of closure composition precursor 183. For example, a second closure lumen may be coupled to a second closure composition precursor source by a second precursor entrance port (not shown). The second closure lumen may also contain an anti-backflow valve to prevent blood flow through the second closure lumen.
The closure composition precursor 183 may be introduced adjacent the vessel puncture 181 as a single composition through a single closure lumen 148. Alternately, a first composition may be introduced through the closure lumen 148 and a second composition can be introduced through the second closure lumen. The first and second compositions can be the same or different and can be introduced simultaneously or at different times. The first and second compositions may interact to accelerate the transformation to the non-fluent closure composition at the tissue site 184, for example, by reacting with each other or by one catalyzing the solidification of the other.
In a preferred embodiment, the closure device 140 also includes an energy source 162 for applying energy 167 to the closure composition precursor 183 to accelerate its transformation into the non-fluent closure composition. The transformation of the fluent closure composition 183 precursor to a non-fluent closure composition may be the result of a phase change (i.e. solidification) of the precursor 183 or a chemical modification of the precursor 183. For example, the precursor 183 may be formed from multiple components which react with each other, optionally accelerated by a catalyst or energy 167. Alternatively, the precursor 183 may be formed from a single component that reacts with itself, also optionally accelerated by a catalyst or energy 167.
In embodiments where energy 167 is applied, the energy delivery device 158 on the elongated body or an additional energy delivery device 158 is used to deliver one or more different types of energy 167 including but not limited to electromagnetic radiation (RF, microwave, ultraviolet, visible light, laser), ultrasound, resistive heating, exothermic chemical heating, and frictional heating which serves to accelerate the conversion of the closure composition precursor 183 to a non-fluent closure composition.
The sealer/dilator 142 includes an energy delivery device 158 adjacent the distal end 146 for pretreating the tissue site 154 prior to delivering the closure composition precursor 183 to the tissue site 154. The energy delivery device 158 is energetically connected via a conductive metal tube 155 and a wire 151 to an energy source attachment mechanism 160 for placing the energy delivery device 158 in energetic communication with an energy source 162 (not shown).
The sealer/dilator 142 also includes threading 177 adjacent its proximal end 144 for attaching a hemostasis/lock valve 176 to the sealer/dilator distal end 146.
A plugging catheter 163 sized to fit within a vessel lumen extends through the central lumen 145 and out the distal end 146 of the sealer/dilator 142. The proximal end of the plugging catheter 163 includes a guidewire Luer 157 for positioning a guidewire 179 within a guidewire lumen 169. The plugging catheter 163 can optionally include a locating mark 178 which can be used to indicate how far the plugging catheter 163 is extending from the distal end 146 of the sealer/dilator 142.
The plugging catheter 163 includes first and second position sensing mechanisms 164A, 164B for indicating whether the first and second position sensing mechanisms 164A, 164B are located within or outside of the vessel 166. As can be seen, the first position sensing mechanism 164A is distal relative to the second position sensing mechanism 164B. This enables the plugging catheter 163 to be positioned such that the first position sensing mechanism 164A is inside the vessel 166 and the second position sensing mechanism 164B is outside the vessel 166.
One example of a position sensing mechanism 164 is a pressure port coupled to the position monitor attachment port 168 by a position lumen.
As illustrated in
As can be seen from
Also illustrated in
Other sensors may also be positioned on the plugging catheter 163. For instance, as illustrated in
As illustrated in
As illustrated in
As illustrated in
Another aspect of the present invention relates to a method for improving the adhesiveness of a surface of living tissue by treating the tissue surface with a chemical agent which modifies the tissue surface and renders the surface more readily bonded or adherent to tissue adhesives, sealants, glues and the like. The chemical modification may optionally include a degree of surface denaturization, a reduction in the water content at the tissue surface, removal of materials at the tissue surface which interfere with the adhesiveness of tissue surfaces to sealants and adhesives, a change the topography at the tissue surface, and preferably an increase in the surface area at the tissue surface, all of which serve to increase the tissue surface's ability to adhere sealants and adhesives.
In one embodiment, the method includes exposing a tissue surface to be so treated, which optionally includes the action of forming new tissue surfaces such as by cutting tissue with a scalpel or tool, or by introducing a medical instrument into previously continuous tissue such as with a cannula, introducer, catheter, or trocar, to provide new tissue surface(s) surrounding the instrument. For example, this step is encompassed by the step of introducing a closure device of the present invention into tissue.
After a tissue surface to be treated has been exposed, the tissue surface is contacted with a suitable chemical agent. In one variation, a basic chemical agent (i.e., having a pH greater than 7) capable of modifying a tissue surface is used. Examples of suitable basic chemical agents include but are not limited to aqueous sodium bicarbonate, aqueous sodium carbonate, water solutions or suspensions of alkali or alkali earth oxides and hydroxides, aqueous ammonia, water soluble amines such as alkanol amines, basic amino acids such as lysine and poly(lysine), aqueous sodium lysinate, and basic proteins such as albumin. In another variation, an acidic chemical agent (i.e., having a pH less than 7) having an osmolality above that of blood is used which is capable of modifying a tissue surface. In yet another variation, a chemical agent which can serve as a tissue etchant is used. Examples of suitable tissue etchants include, but are not limited to salicylic acid, carboxylic acids, α-hydroxy carboxylic acids, and peroxides.
While the chemical pretreatment method is being described herein with regard to its use in combination with a closure device of the present invention, it is envisioned that the chemical pretreatment method is a tissue priming method which may be used to enhance the adhesiveness of any tissue surface to which a tissue glue or sealant is to be applied and thus may be used with other methods for joining tissues other than those described in this application. It is believed that this method can be beneficially used in a variety of protocols or procedures that use non-mechanical agents such as glues, adhesives and sealants to join tissue. It is also believed that this method can be beneficially used in protocols or procedures that use mechanical mechanisms, such as mechanical fasteners, to join tissue. Further, it is believed that the pretreatment method will be beneficial for improving bonding strength to and between tissue surfaces in procedures relying on chemical adhesion, including covalent bonding, as well as mechanical interlocking.
The following example provides an exemplary procedure for pretreating tissue with energy in order to enhance the adhesiveness of the pretreated tissue to an adhesive material.
Tissue samples were prepared by cuffing beef flank steak into specimens about 35 mm long by 8 mm wide by 2 mm thick with a scalpel. Care was taken to ensure that the muscle fibrils were aligned lengthwise and the connective tissue between fibrils was intact. A set of 12 specimens was soaked in physiologic saline (NaCI; equal to about 0.9% wt.) for 30 minutes just prior to use. The saline soaked tissue was used as a model for living tissue, which would contain intercellular fluid and blood encountered during any tissue sealing or wound closure medical procedure.
An electrode comprised of a metal cap 6 mm in diameter and 2 mm deep on the end of a plastic wand was fitted with a thermocouple for measuring the temperature at the electrode surface. The electrode was connected to an Apical, Inc. (Menlo Park, Calif.) Radio Frequency (RF) generator.
Some of the tissue samples were treated with RF energy immediately prior to bonding with a tissue adhesive by the following method:
a) an aluminum pan containing a porous towel saturated with a physiologic saline solution was electrically connected to the RF generator via a standard electrosurgical grounding pad;
b) a tissue sample to be treated was laid onto the moist towel and the electrode wand touched endwise to one end of the tissue sample such that a circular area approximately 6 mm in diameter was in contact with the electrode and could be treated;
c) RF energy at a power of 10 wafts in the frequency range of 300-700 kHz was applied to the electrode and to the tissue surface;
d) the electrode temperature was monitored during the application of energy and increased about I-2° C./second in the temperature range of 25-65° C.;
e) the electrode treatment temperature was maintained at the desired level by the Apical RF Generator until treatment was manually stopped after the desired time at temperature; and
f) the twelve energy treated tissue samples were set up in pairs to form six lap shear specimens.
The energy treated tissue samples were then evaluated for the shear strength of the resultant lap bond. A standard gelatin/aldehyde two part tissue adhesive was spread onto the treated portion of one energy treated tissue sample and then compressed against a second energy treated tissue sample to form a lap shear specimen assembly. Bond area was calculated as the product of the bond width and the overlap of the tissue surfaces.
Lap shear bond strength evaluation was done on the six replicate specimen assemblies prepared for each set of control and RF treatment conditions. Bond strength was measured using a Chatillion Stress-Strain instrument. Bond strengths were taken as the average of the six replicates.
Experimental results from this experiment are tabulated in Table 2. As can be seen from the data presented in the table, pre-treatment of tissue with RF energy to a temperature of 50° C. for 5 seconds increased the average lap shear bond strength by 34% and increased the greatest observed strength in the sample population by 66%. These results demonstrate the efficacy of the pre-treatment method for increasing the bond strength of energy treated tissue relative to non-energy pretreated tissue.
While the present invention is disclosed by reference to the preferred embodiments and examples detailed above, it is to be understood that these examples are intended in an illustrative rather than limiting sense, as it is contemplated that modifications will readily occur to those skilled in the art, which modifications will be within the spirit of the invention and the scope of the appended claims.
This application is a divisional of co-pending application Ser. No. 10/803,229 filed 18 Mar. 2004, which is a divisional of application Ser. No. 09/548,145, filed Apr. 13, 2000, which is continuation-in-part of application Ser. No. 09/140,017, now U.S. Pat. No. 6,475,182, and which is a divisional application of application Ser. No. 09/021,708, filed Feb. 10, 1998, now U.S. Pat. No. 6,302,898, which is a continuation-in-part of application Ser. No. 08/963,033, filed Nov. 3, 1997, entitled “Vascular Sealing Device,” now abandoned, application Ser. No. 08/963,082, filed Nov. 3, 1997, entitled “In Situ Formed Non-fluent Closure Composition,” now abandoned, and application Ser. No. 08/963,408, filed Nov. 3, 1997, now U.S. Pat. No. 6,033,401, which each claim the benefit of Provisional U.S. Application Ser. No. 60/036,299, filed Mar. 12, 1997.
Number | Date | Country | |
---|---|---|---|
60036299 | Mar 1997 | US | |
60036299 | Mar 1997 | US | |
60036299 | Mar 1997 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10803229 | Mar 2004 | US |
Child | 11986470 | Nov 2007 | US |
Parent | 09548145 | Apr 2000 | US |
Child | 10803229 | Mar 2004 | US |
Parent | 09021708 | Feb 1998 | US |
Child | 09140017 | Aug 1998 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 09140017 | Aug 1998 | US |
Child | 09548145 | Apr 2000 | US |
Parent | 08963033 | Nov 1997 | US |
Child | 09021708 | Feb 1998 | US |
Parent | 08963082 | Nov 1997 | US |
Child | 09021708 | US | |
Parent | 08963408 | Nov 1997 | US |
Child | 09021708 | US |