The present invention provides a shaped balloon catheter for use in a variety of surgical procedures. The shaped balloon is able to obtain large outer diameters while sustaining high inflation pressures. The balloon may be attached to a catheter and is comprised of at least two passes of a balloon material.
The balloon material of the present invention is a composite film comprising a porous reinforcing layer and a continuous polymer layer. The porous reinforcing polymer layer is preferably a thin, strong porous membrane that can be made in sheet form. The porous reinforcing polymer can be selected from a group of polymers including, but not limited to, olefin, PEEK, polyamide, polyurethane, polyester, polyethylene, and polytetrafluoroethylene. The porous reinforcing polymer is preferably expanded polytetrafluoroethylene (ePTFE) made in accordance with the teachings of U.S. Pat. No. 5,476,589 or U.S. patent application Ser. No. 11/334,243 to Bacino.
In one preferred embodiment, the ePTFE membrane is anisotropic such that it is highly oriented in the one direction. An ePTFE membrane with a matrix tensile value in one direction of greater than 690 megapascals is preferred, and greater than 960 megapascals is even more preferred, and greater than 1,200 megapascals is most preferred. The exceptionally high matrix tensile value of ePTFE membrane allows the composite material to withstand very high hoop stress in the inflated balloon configuration. In addition, the high matrix tensile value of the ePTFE membrane makes it possible for very thin layers to be used which reduces the deflated balloon profile. A small profile is necessary for the balloon to be able to be positioned in small arteries or veins or orifices. In order for balloons to be positioned in some areas of the body, the balloon catheter must be able to move through a small bend radius, and a thinner walled tube is typically much more supple and capable of bending in this manner without creasing or causing damage to the wall of the vessel.
In another preferred embodiment, the ePTFE membrane is relatively mechanically homogeneous. The mechanically balanced ePTFE membrane can increase the maximum hoop stress that the composite film made therefrom can withstand.
The continuous polymer layer of the present invention is coated onto at least one side of the porous reinforcing polymer. The continuous polymer layer is preferably an elastomer, such as, but not limited to, aromatic and aliphatic polyurethanes including copolymers, styrene block copolymers, silicones, preferably thermoplastic silicones, fluoro-silicones, fluoroelastomers, THV and latex. In one embodiment of the present invention, the continuous polymer layer is coated onto only one side of the porous reinforcing polymer. The continuous polymer layer is coated onto both sides of the porous reinforcing polymer. In a preferred embodiment, the continuous polymer layer is imbibed into the porous reinforcing polymer and the imbibed polymer fills the pores of the porous reinforcing polymer.
The continuous polymer layer can be applied to the porous reinforcing polymer through any number of conventional methods including, but not limited to, lamination, transfer roll coating, wire-wound bar coating, reverse roll coating, and solution coating or solution imbibing. In a preferred embodiment, the continuous polymer layer is solution imbibed into the porous reinforcing polymer. In this embodiment, the continuous polymer layer is dissolved in a suitable solvent and coated onto and throughout the porous reinforcing polymer using a wire-wound rod process. The coated porous reinforcing polymer is then passed through a solvent oven and the solvent is removed leaving a continuous polymer layer coated onto and throughout the porous reinforcing polymer. In some cases, such as when silicone is used as the continuous polymer layer, the coated porous reinforcing polymer may not require the removal of solvent. In another embodiment, the continuous polymer layer is coated onto at least one side of the porous reinforcing polymer and maintained in a “green” state where it can be subsequently cured. For example, an ultraviolet light (UV) curable urethane may be used as the continuous polymer layer and coated onto the porous reinforcing polymer. The composite film comprising the porous reinforcing polymer and the UV curable urethane continuous polymer layer can then be wrapped to form at least one layer of the balloon and subsequently exposed to UV light and cured.
An individual pass is comprised of one or more layers of balloon material which are laid at a similar angle in relation to the longitudinal axis of the balloon. A layer is considered to be one thickness of balloon material which may be wrapped, folded, laid or weaved over, around, beside or under another thickness. A longitudinal pass comprises a distinctive layer or series of layers of material which are wound to form a region or area distinct from surrounding or adjoining parts. For instance a pass may comprise multiple layers of balloon material wrapped at a 90 degree angle relative to the longitudinal axis. This exemplary pass may then be flanked by layers of balloon material wrapped at dissimilar angles in relation to the longitudinal axis, thus defining the boundary of the pass.
A pass of balloon material may be oriented helically, radially or longitudinally. By layers of balloon material it is meant to include pieces, threads, layers, filaments, membranes, or sheets of suitable balloon material. In helically oriented layers, the material is oriented so to form a balanced force angle in relation to each other upon inflation. The layers may further be wound upon themselves in subsequent passes.
The inflated shaped balloon 1, as depicted in
The shaped balloon of the present invention comprises a plurality of wrapped balloon passes 2. The passes are made up of one or more layers of film or membrane wrapped at similar angles. The layers may be built up upon each other to a desired thickness. The wrap layers are comprised of film or membrane. The composite film 8 of the present invention may comprise a porous reinforcing polymer 9 and a continuous polymer layer 10 as depicted in
The continuous polymer layer 10 is preferably an elastomer, such as but not limited to, aromatic and aliphatic polyurethanes including copolymers, styrene block copolymers, silicones, thermoplastic silicones, fluoro-silicones, fluoroelastomer, THV, and latex. In one embodiment of the present invention, the continuous polymer layer 10 is coated onto only one side of the porous reinforcing polymer 9, as shown in
In this preferred embodiment, the ePTFE membrane is anisotropic such that it is highly oriented in the one direction. An ePTFE membrane with a matrix tensile value in one direction of greater than 690 megapascals is preferred, and greater than 960 megapascals is even more preferred, and greater than 1,200 megapascals is most preferred. The exceptionally high matrix tensile value of ePTFE membrane allows the composite material to withstand very high hoop stress in the inflated balloon configuration. In addition, the high matrix tensile value of the ePTFE membrane makes it possible for very thin layers to be used which aid in a reduced balloon profile. As depicted in
The segmented, hollow balloon tube is then formed into a shape and fixed into that shape through heating or over-wrapping with an outer configuration layer(s) 19 as depicted in
In another embodiment, the hollow balloon tube is wound into a spiral wound shaped balloon 20 and fixed into that shape through heating or over-wrapping with an outer configuration layer 19 as depicted in
In another embodiment, the hollow balloon tube is formed into a coil shaped balloon 21 around a center axis and fixed into that shape through heating or over-wrapping with an outer configuration layer 19 as depicted in
In yet another embodiment, a portion of the length of the hollow balloon tube is attached to a treatment device 18 and subsequently spiral wound as depicted in
A small profile is necessary for the balloon to be able to be positioned in small arteries or veins or orifices. In order for balloons to be positioned in some areas of the body, the balloon catheter must be able to move through a small bend radius, and a thinner walled tube is typically much more supple and capable of bending in this manner without creasing or causing damage to the wall of the vessel.
In another embodiment, the ePTFE membrane used in the configuration layers are relatively mechanically isotropic or homogeneous. The mechanically balanced ePTFE membrane can increase the maximum hoop stress that the composite film made therefrom can withstand, such as discussed in Example 3.
The inflated shaped balloons 1 of the present invention comprise wrapped balloon layers 2 and non-distensible regions 6 and can be further reinforced with the addition of an outer configuration layer 19 as depicted in
The shaped balloon of the present invention can withstand high inflation pressures relative to the outer diameter achieved due to the outer diameter 3 being larger than the inflated balloon diameter 5, as shown in
The balloons of the present invention can be attached to a catheter through any number of conventional means. In a preferred embodiment as depicted in
The balloons of the present invention, when attached to a catheter, are capable for use in various surgical procedures including but not limited to angioplasty, stent or graft delivery and distention, valvuloplasty, aortic stent graft deployment, pediatric coarctation, sizing balloon for ASD/PFO, endocardial procedures, stent deployment, temporary brachytherapy, vertebrae compression and compaction, as well as intestinal procedures. The shaped balloons of the present invention are particularly useful in procedures requiring a large diameter elastomeric balloon catheter. In a preferred embodiment, the balloon is made with an open region 7 that allows for flow 17 through the inflated shaped balloon 1, deployed in a vessel 16 as depicted in
In yet another embodiment of the present invention as depicted in
In another embodiment of the present invention, the open region 7 can be made to close upon inflation of the balloon. This would allow the balloon to be positioned in a vessel and then decrease flow upon inflation. In a preferred embodiment, the balloon is used to control the flow rate through a vessel through the use of inflation pressure. In yet another embodiment, the shaped balloon of the present invention is used to increase the flow through a vessel. When increased flow in a vessel is desired, the shaped balloon of the present invention is configured with an open region and is positioned in the vessel and inflated. The shaped balloon expands and increases the diameter of the vessel allowing an increased flow through the open region 7. In another embodiment, the balloon with a closing open region 7 during inflation is used to secure devices or tissue for placement, delivery into or removal from the body.
In another embodiment of the present invention, bioresorbable polymer is used as the porous reinforcing polymer in the construction of the balloon. Bioresorbable polymer can also be used as the continuous polymer layer and would leave behind the porous reinforcing polymer after being absorbed by the body. This use of the present invention may be of particular value in intestinal or abdominal hernia applications, or aneurysm applications. In yet another embodiment of the present invention, a bioresorbable polymer is used in the construction of the composite film and is used as an inflation fluid to deploy the balloon.
In another embodiment, the balloon of the present invention can be made to detach from the catheter after location in the body, and subsequent inflation. In this embodiment it is preferred that the composite film be made to be self sealing such that the balloon stays inflated after removal of the inflation tube. In another embodiment, the inflation tube can be sealed and the catheter can be made to detach from the inflation tube after locating and inflating the balloon.
In yet another preferred embodiment, the shaped balloon of the present invention is able to realize an inflated outer diameter of at least 10 mm at an inflation pressure of at least 10 atmospheres and maintain the shape profile. In another preferred embodiment, the shaped balloon of the present invention is able to realize an inflated diameter of at least 20 mm, and an axial length of 5 mm at an inflation pressure of at least 10 atmospheres and maintain the shape profile.
While particular embodiments of the present invention have been illustrated and described herein, the present invention should not be limited to such illustrations and descriptions. It should be apparent that changes and modifications may be incorporated and embodied as part of the present invention within the scope of the following claims. The following examples are further offered to illustrate the present invention.
Tensile break load was measured using an INSTRON 1122 tensile test machine equipped with flat-faced grips and a 0.445 kN load cell. The gauge length was 5.08 cm and the cross head speed was 50.8 cm/min. The sample dimensions were 2.54 cm by 15.24 cm. For longitudinal MTS measurements, the larger dimension of the sample was oriented in the machine, also known as the down web direction. For the transverse MTS measurements, the larger dimension of the sample was oriented perpendicular to the machine direction, also known as the cross web direction. Each sample was weighed using a Mettler Toledo Scale Model AG204, then the thickness of the samples was taken using the Kafer FZ1000/30 thickness gauge. The samples were then tested individually on the tensile tester. Three different sections of each sample were measured. The average of the three maximum load (i.e., the peak force) measurements was used. The longitudinal and transverse MTS were calculated using the following equation:
MTS=(maximum load/cross section area)*(bulk density of PTFE)/density of the porous membrane),
wherein the density of PTFE is taken to be 2.2 g/cc.
The inflatable balloon of the present invention was made by wrapping a composite film of Tecothane TT-1085A polyurethane (Thermedics, Inc, Woburn, Mass.), and ePTFE membrane over a urethane-coated Tefzel core wire (Putnam Plastics LLC, Dayville, Conn.). The wrapped core wire was heat treated and the center wire were subsequently removed to provide a hollow composite balloon tube.
The core wire was a (nominal) 0.74 mm diameter Tefzel 280 wire with a (nominal) 0.05 mm Tecothane TT-1074A coating. The ePTFE membrane used to make the composite film was made in accordance with the teaching in U.S. Pat. No. 5,476,589 to Bacino, incorporated herein by reference. Specifically, the ePTFE membrane was longitudinally expanded to a ratio of 55 to 1 and transversely expanded approximately 2.25 to 1, to produce a thin strong membrane with a mass of approximately 3.5 g/m2 and a thickness of approximately 6.5 micrometers.
The composite film was made by using a wire-wound rod coating process whereby a solution of Tecothane TT-1085A polyurethane and tetrahydrofuran (THF) was coated onto an ePTFE membrane. A 3% to 8% by weight solution of Tecothane TT-1085A polyurethane in THF was coated onto the ePTFE membrane to produce a composite film with approximately equal amounts of Tecothane TT-1085A polyurethane on either side and throughout the ePTFE membrane and a total polymer weight application of approximately 40% to 60% of the total final composite film weight.
The composite film described in Example 1 was slit to 12 mm wide and helically wrapped around the core wire described in Example 1 at a 4 to 5 degree angle from the longitudinal axis of the wire. The wrapped core wire was heated for approximately 5 to 30 seconds at 180° C. after wrapping. The core wire was then wrapped with the composite film in the opposite direction at a 4 to 5 degree angle from the longitudinal axis of the wire and subsequently heated for approximately 5 to 30 seconds at 180° C. The process of wrapping the core wire with this first wrap material in opposite directions and heating after each pass was repeated until a total of twelve passes of wrapping was complete. A second wrap material was made from a mechanically balanced composite film using a wire-wound rod coating process whereby a solution of Tecothane TT-1085A polyurethane and tetrahydrofuran (THF) was coated onto an ePTFE membrane. The ePTFE membrane used to make the composite film was made in accordance with the teachings of U.S. patent application Ser. No. 11/334,243 to Bacino et al. incorporated herein by reference. Specifically, the ePTFE membrane was longitudinally expanded to a ratio of 15 to 1 and transversely expanded approximately 28 to 1, to produce a thin strong membrane with a mass of approximately 3.5 g/m2 and a thickness of approximately 8 micrometers. A 3% to 8% by weight solution of Tecothane TT-1085A polyurethane in THF was coated onto the ePTFE membrane to produce a composite film with Tecothane TT-1085A polyurethane on one side of the ePTFE membrane and throughout of the ePTFE membrane, and a total polymer weight application of approximately 40% to 60% of the total final composite film weight. This second wrap layer material was slit to approximately 7.6 mm wide.
The wrapped core was mounted onto a wrapper station, comprising chucks for clamping the ends of the wire, and a variable speed rotation control. The 7.6 mm wide second wrap layer material was wrapped at approximately 90 degrees from the longitudinal axis of the wrapped wire, in eight locations 36 mm apart from each other. The second layer wrap material was wrapped approximately ten times revolutions around the circumference of the wrapped wire to produce an approximately 10 mm wide over-wrapped section. The non-distensible regions were then heated using a Weller WSD81 solder gun (Cooper Industries, Inc. Raleigh, N.C.), with a large blunt solder tip heated to a set-point of 315. The wrapped wire was slowly rotated and the blunt solder tip was pressed onto the over-wrapped non-distensible regions.
The core wire was removed from the composite balloon construction. Approximately a 2.54 cm long section of the composite hollow balloon tube was removed from either end of a 30.5 cm long section of the balloon over wire construction. The exposed ends of the wire were clamped with hemostats and pulled by hand until the wire had been stretched approximately 30 cm, at which point it was removed from the center of the tube. A composite hollow balloon tube was produced with a first layer helically wrapped composite film wrapped at a low (4 to 5 degree) angle of wrap and six 10 mm wide over-wrapped sections with 36 mm spaces between them and two non-distensible seals at the end.
One end of the composite hollow balloon tube was tied into a knot and clamped with a hemostat and the opposite end was slipped through a Qosina male touhy borst with spin lock fitting (#80343, Qosina Corporation, Edgewood, N.Y.), and a Monoject blunt needle with Aluminum luer lock hub (model # 8881-202389, Sherwood Medical, St. Louis, Mo.) was inserted approximately 2.0 cm into the balloon. The hemostatic valve was tightened to seal the balloon, and was then attached to an Encore 26 inflation device (Boston Scientific Scimed, Maple Grove, Minn., catalog #15-105) and inflated to approximately 18 atmospheres with saline solution. The inflation created seven balloon sections or segments separated by non-distensible regions.
The inflated balloon sections were then folded or over-layed with the first balloon section in the center and the remaining six around the circumference of the first section as depicted in
The composite film described in Example 1 was slit to nominally 23 mm wide and helically wrapped around the core wire described in Example 1 at a 10 to 12 degree angle from the longitudinal axis of the wire. The wrapped core wire was heated for approximately 5 to 30 seconds at 180° C. after wrapping. The core wire was then wrapped with the composite film in the opposite direction at a 10 to 12 degree angle from the longitudinal axis of the wire and subsequently heated for approximately 5 to 30 seconds at 180° C. The process of wrapping the core wire in opposite directions and heating after each pass was repeated until a total of four passes of wrapping was complete. The wrapped core wire was then wrapped around a pin frame with approximately 30 cm spaces between pins and approximately 180 degrees of wrap around each pin and tied at the ends before being placed into an oven and heated for approximately 30 minutes at 150° C.
The core wire was removed from the composite balloon construction. Approximately a 2.54 cm long section of the composite hollow balloon tube was removed from either end of a 30.5 cm long section of the balloon over wire construction. The exposed ends of the wire were clamped with hemostats and pulled by hand until the wire had been stretched approximately 30 cm, at which point it was removed from the center of the tube. A composite hollow inflatable balloon resulted. One end of the composite hollow balloon tube was closed with a knot, and the other end was inserted with a Monoject blunt needle and secured to a Encore 26 inflation device (Boston Scientific Scimed, Maple Grove, Minn., catalog #15-105) via Qosina male touhy borst.
The balloon was inflated and, starting from the center-point, manually coiled into a planar disc-shape having an inflated outer diameter of 1.5 inches and height of 3.5 mm. The coiled, inflated balloon was then over-wrapped with a second wrap layer to form the outer configuration layer. This second wrap material was made from a mechanically balanced composite film using a wire-wound rod coating process whereby a solution of Tecothane TT-1085A polyurethane and tetrahydrofuran (THF) was coated onto an ePTFE membrane. The ePTFE membrane used to make the composite film was made in accordance with the teachings of U.S. patent application Ser. No. 11/334,243 to Bacino et al. incorporated herein by reference. Specifically, the ePTFE membrane was longitudinally expanded to a ratio of 15 to 1 and transversely expanded approximately 28 to 1, to produce a thin strong membrane with a mass of approximately 3.5 g/m2 and a thickness of approximately 8 micrometers. A 3% to 8% by weight solution of Tecothane TT-1085A polyurethane in THF was coated onto the ePTFE membrane to produce a composite film with Tecothane TT-1085A polyurethane on one side of the ePTFE membrane and throughout of the ePTFE membrane, and a total polymer weight application of approximately 40% to 60% of the total final composite film weight.
The coiled, inflated, over-wrapped balloon was then heated using a Weller WSD81 solder gun (Cooper Industries, Inc. Raleigh, N.C.), with a large blunt solder tip heated to a set-point of 315. The blunt solder tip was pressed gently against the wrapped outer configuration layer of the balloon and traversed along the balloon surface. This process produced a disc shaped balloon with approximately a 38 mm outer diameter and approximately 3.5 mm in height.