MXPA06008653A - Devices and methods for stricture dilation - Google Patents

Abstract

Various methods and devices for dilating strictures in a lumen are provided. In an exemplary embodiment, a stricture dilation device is provided having an elongate shaft with at least one electrically expandable actuator coupled thereto and adapted to radially expand to dilate a stricture in a lumen.

Description

DEVICES AND METHODS FOR THE DILATION OF STENOSIS FIELD OF THE INVENTION The present invention relates broadly to surgical devices, and in particular to methods and devices for dilating stenosis ...

ANTECEDENTS OF THE INNECTION Bariatric surgery is a treatment for morbid obesity that involves the alteration of a patient's digestive tract to stimulate weight loss and to help maintain a normal weight. A common type of bariatric surgery is gastric bypass surgery that helps decrease the size of the patient's stomach. In particular, the stomach is divided into an upper bag and a lower bag using a stapler and / or stitches. The jejunum (the middle section of the small intestine) is also divided into two parts. A part of the jejunum (called the "Roux member") is attracted to the back of the colon of the lower stomach pouch, and is attached or "anastomosed" in the upper stomach pouch. The remaining end of the jejunum is attached to the side of the Roux member. As a result, a new digestive path is created, where food travels down the esophagus, into the upper stomach pouch, and through anastomosis within the Roux limb. The digestive juices of the stomach, liver and pancreas travel through the pouch of the lower stomach, down the duodenum and jejunum, and into the Roux limb where the two parts of the jejunum meet and in addition digestion takes place. Although effective, gastric bypass surgery is not uncomplicated. For example, scar tissue can be developed in the stoma (the intersection between the upper stomach pouch and the Roux limb), creating a stricture that can make digestion difficult. As a result, surgery also needs to be done to remove the stricture. Several devices are available to dilate the stenosis. For example, a tube can be inserted down into the patient's esophagus and manipulated to separate the tissue surrounding the stenosis. While this may be effective, it may be difficult to completely reopen the stricture. The procedure can also be very time consuming. Another common device used to dilate the stenosis is a balloon catheter that is inserted down into the patient's esophagus to place the balloon deflated inside the stenosis. The balloon then expands to expand the stenosis, thereby reopening the passage. Balloon catheters can be effective, however the balloon can rupture when it expands against the stenosis. Accordingly, there is a need for improved methods and devices for dilation of stenosis.

BRIEF DESCRIPTION OF THE INVENTION The present general invention provides various methods and devices for dilating stenoses. In an exemplary embodiment, a device for tissue dilation is provided having a substantially flexible elongate shaft with a proximal end coupled to a handle and a distal end having an activator disposed about a distal portion thereof. The activator is adapted to actually expand after the distribution of energy thereto to dilate a stenosis. The activator can have a variety of configurations, and can be formed from a variety of materials. In an illustrative embodiment, the activator can be an electrically expandable member, and more preferably it can be in the form of an electroactive polymer (EAP). For example, the activator may be in the form of a bundle of fibers having a flexible conductive outer shell with several electroactive polymer fibers and an ionic fluid disposed therein. Alternatively, the activator may be in the form of a laminate having at least one flexible conductive layer, an electroactive polymer layer, and an ion gel layer. Multiple laminated layers can be used to form a composition. The activator may also include a return electrode and a distribution electrode coupled there, with the distribution electrode being adapted to supply energy to the activator from an external energy source.

Methods to dilate stenosis are also provided. In an exemplary embodiment, the method may include inserting a substantially flexible elongate shaft into a lumen, and placing an activator disposed in the distal portion thereof within a stenosis formed in the lumen. The activator can then be electrically activated to expand radially, thereby increasing a diameter of the stenosis. Since the activator can have a variety of configurations, in an illustrative embodiment the activator is substantially cylindrical and adapts to expand at least about 20% in size when energy is distributed thereto.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, wherein: Figure 1A is a perspective view of an illustrative embodiment of a stenosis dilatation device; Figure 1B is a perspective view of a distal portion of the stenosis dilatation device shown in Figure 1A showing an activator disposed there; Figure 1C is a perspective view of a distal portion of the stenosis dilatation device shown in Figure 1B showing the expanded activator; Figure 2A is a cross-sectional view of an EAP activator of the fiber bundle type of the prior art; Figure 2B is a radial cross-sectional view of the prior art activator shown in Figure 2A; Figure 3A is a cross-sectional view of a laminated type EAP activator of the prior art having multiple layers of EAP composition; Figure 3B is a perspective view of one of the composition layers of the prior art activator shown in Figure 3A; Figure 4A is an illustration showing the dilatation device of the stenosis of Figure 1A in use, showing the activator disposed within a stenosis; and Figure 4B is an illustration showing the dilatation device of the stenosis of Figure 4A in use, showing the expanded activator within the stenosis to dilate the stenosis.

DETAILED DESCRIPTION OF THE INVENTION Certain illustrative embodiments will now be described to provide a comprehensive understanding of the principles of structure, function, manufacture, and use of the devices and methods described herein. One or more examples of these modalities are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the appended drawings are non-limiting illustrative embodiments and that the scope of the present invention is defined only by the claims. The features illustrated or described in connection with an illustrative embodiment may be combined with characteristics of other modalities. Said modifications and variations are intended to be included within the scope of the present invention. Methods and devices for dilating stenoses in lumens are described herein, such as stoma, carotid arteries, peripheral vessels, urethra, esophagus, bile duct, jejunum, and duodenum. In an illustrative embodiment, a device may include one or more activators coupled thereto and adapted to radially expand. In use, the radial diameter of the activator expands to effect dilation of a stenosis. One skilled in the art will appreciate that the methods and devices described herein can have a variety of configurations and can be adapted for use in a variety of medical procedures. For example, methods and devices can be used in blood vessels after a stenosis has been compressed through percutaneous transluminal coronary angioplasty (PTCA), percutaneous transluminal angioplasty (PTA), or removed through atherectomy or other means, to help improve the outcome of the procedure and reduce the likelihood of restenosis. further, the methods and devices described herein can be used with any other procedures known in the art that require dilation of the stenosis. The device for dilation of the stenosis can also be incorporated into a variety of other devices that allow dilatation of stenosis to be carried out in conjunction with other procedures. Figures 1A-1C illustrate an illustrative embodiment of the dilatation device 10 that is adapted to dilate a stenosis within a lumen. The device 10 may have a variety of configurations, but in an illustrative embodiment may include an elongated shaft 14 having a proximal end 14a coupled to a handle 14, and a distal end 14b adapted to be placed within a lumen, and an activator 16 coupled to a distal portion of the elongated shaft 14 and adapted to expand to dilate a stenosis. The handle 12 can have any configuration that allows the user to manually control the device 10, and in particular to control the distribution of energy to the activator 16, as will be explained in more detail below. As shown in Figure 1A, the handle 12 has a generally elongated shape to facilitate clamping. The handle 12 also includes features and components to facilitate the operation of the device 10. For example, in an illustrative embodiment, an energy source, such as a battery, may be provided within the handle 12 to distribute energy to the activator 16. Alternatively, the handle 12 can be adapted to be coupled to a power source, such as an electrical output connection.

The Handle 16 may also include a mechanism that allows the user to selectively activate and deactivate the distribution of energy to the trigger 16. For example, the handle 12 may include a button 20 that can be moved or pressed to distribute energy to! activator 16, as shown in Figure 1 A. Alternatively, or in addition to, handle 12 may include a sliding lever, or rotary selector dial that can be used to control the amount of energy being distributed, thereby allowing that the amount of expansion of activator 16 is controlled, as will be explained in more detail below. The elongated shaft 14 extending from the handle 12 can also have a variety of configurations, and the shape and size of the elongated shaft 14 can vary depending on the intended use of the device 10. In an illustrative embodiment, the elongated shaft 14 can have a Generally cylindrical shape and can be flexible to allow insertion into the esophagus. The length of the shaft 14 may vary depending on the particular procedure being carried out. For example, when the stenosis is dilated in a stoma, the shaft 14 may have a length in the scale of about 121.92 cm to 182.88 cm. The elongate shaft 14 may also include several features to facilitate insertion through a lumen, such as a conical distal tip 18. One skilled in the art will appreciate that the shaft may be rigid, and may have a variety of other configurations. For example, although not shown, shaft 14 may include a lumen extending therethrough to provide access to a surgical site, such as for drug delivery, imaging, fluid flow, etc. As previously indicated, the device 10 may also include one or more activators coupled to the flexible elongate shaft 14 to effect dilation of the stenosis. Since the activator (s) can (have) a variety of configurations, a suitable activator is an activator of electroactive polymer. Electroactive polymers (EAOs), also referred to as artificial muscles, are materials that exhibit piezoelectric, pyroelectric, or electrostric properties in response to electrical or mechanical fields. In particular, EAPs are a group of conductive neutralized polymers that change shape when an electrical voltage is applied. The conductive polymer can be equated with some form of fluid or gel using electrodes. After application of a voltage potential to the electrodes, a flow of ions from the fluid / gel into or out of the conductive polymer can induce a change in shape of the polymer. Typically, a voltage potential on the scale of about 1 to 4k V may be applied depending on the particular polymer and the ionic fluid or gel used. It is important to note that EAPs do not change volume when energized, rather they merely expand in one direction and contract in a transverse direction. One of the main advantages of EAPs is the possibility of electrically controlling and fine tuning their behavior and properties. EAPs can be deformed repetitively through the application of external voltage through the EAP, and can quickly recover their original configuration after reversing the polarity of the applied voltage. The specific polymers can be selected to create different kinds of structures in motion, including expansion, linear motion, and flexed structures. EAPs can also be equated with mechanical mechanisms, such as springs or flexible plates, to change the effect of the EAP on the mechanical mechanism when voltage is applied to the EAP. The amount of voltage distributed to the EAP can also correspond to the amount of movement or change in dimension that occurs, and in this way the energy distribution can be controlled to effect a desired amount of change. There are two basic types of EAPs and multiple configurations for each type. The first type is a bundle of fibers that can consist of numerous fibers grouped together to work in cooperation. The fibers typically have a size of about 30-50 microns. These fibers can be woven in a bundle very similar to textiles and are usually referred to as an EAP yarn. When they used, the mechanical configuration of EAP determines the EAP trigger and its capabilities for movement. For example, the EAP can be formed into large strands and wrapped around an individual central electrode. A flexible outer sheath will form the other electrodes for the activator as well as contain the ionic fluid necessary for the function of the device. When voltage is applied to it, the EAP will swell causing the strands to contract or shorten. An example of a commercially available fiber EAP material is manufactured through Santa Fe Science and Technology, and sold as PANION ™ fiber, and is described in U.S. Patent No. 6,667,825, which is incorporated herein by reference herein. whole. Figures 2A and 2B illustrate an illustrative embodiment of an EAP 100 activator formed of a fiber bundle. As shown, the activator 100 generally includes a flexible conductive outer sheath 102 that is in the form of an elongated cylindrical member having opposed insulating end covers 102a, 102b formed therein. The conductive outer sheath 102 may, however, have a variety of other shapes and sizes depending on the intended use. As further shown, the conductive outer sheath 102 is coupled to a return electrode 108a, and an energy distribution electrode 108b extends through one of the insulated end covers, e.g., the end cover 102a, through the inner lumen of conductive outer sheath 102, and within the opposite insulated end cover, for example, end cover 102b. The energy distribution electrode 108b may be, for example, a platinum cathode cable. The conductive outer sheath 102 may also include an ionic fluid or gel 106 disposed there to transfer energy from the energy distribution electrode 108b to the EAP fibers 104, which are disposed within the outer sheath 102. In particular, several EAP fibers 104 are configured in parallel and extend between and within each end cover 102a, 120b. As noted above, the fibers 104 may be configured in various orientations to provide a desired result, for example, radial expansion or contraction, or bending movement. When used, the energy can be distributed to the activator 100 through the active energy distribution electrode 108b and the conductive outer sheath 102 (anode). The energy will cause the ions in the ionic fluid to enter the EAP fibers 104, thereby causing the fibers 104 to expand in one direction, e.g., radially such that the outer diameter of each fiber 104 is increased, and to contract in a transverse direction, for example, axially such that a length of the fibers is decreased. As a result, the end covers 102a, 120b will be attracted towards each other, thereby contracting and decreasing the length of the flexible outer sheath 102. Another type of EAP is a laminated structure, consisting of one or more layers of EAP, a layer of gel or ionic fluid disposed between each EAP layer, and one or more flexible conductive plates attached to the structure, such as a positive plate electrode, and a negative plate electrode. When voltage is applied, the laminated structure expands in one direction and contracts in a transverse or perpendicular direction, thereby causing the flexible plate (s) to engage there to shorten or lengthen, or to bend or flex, depending on the configuration of EAP in relation to the flexible plate (s). An example of a commercially available laminated EAP material is manufactured by Artificial Muscle Inc., a division of SRI Laboratories. The EAP plate material referred to as thin-film EAP is also available from EAMEX of Japan. Figures 3A and 3B illustrate an illustrative configuration of an EAP 200 activator formed from a laminate. Referring first to Figure 3A, the activator 200 may include multiple layers, for example, 5 layers 210, 210a, 210b, 210c, 21 Od are shown, of a laminated EAP composition that is fixed to one another through adhesive layers 103a, 103b, 103c, 103d , arranged among them. One of the layers, i.e., the layers 210, is shown in greater detail in Figure 3B, and as shown, the layer 210 includes a first flexible conductive plate 212a, an EAP layer 214, an ion gel layer 216, and a second flexible conductive plate 212b, all of which are joined to each other to form a laminated composition. The composition may also include an electrode for energy distribution 208a and a return electrode 218b coupled to the flexible conductive plates 212a, 212b, as further shown in Figure 3B. When used, the energy can be distributed to the activator 200 through the active energy distribution electrode 218a. The energy will cause the ions of the ionic gel layer 216 to enter the EAP layer 214, thereby causing the layer 214 to expand in one direction and contract in a transverse direction. As a result, the flexible plates 212a, 212b will be forced to flex or bend, or otherwise change the shape with the EAP layer 214. Referring again to Figures 1A-1C, any of the activating type can be used to effect the Prolapse of a stenosis.

However, in an illustrative embodiment, the activators are in the form of an EAP laminate or composition formed of multiple laminates. Since the number and location of the actuators may vary depending on the intended use in the illustrative embodiment the elongated shaft 14 includes an individual actuator 16 coupled to a distal end portion of the shaft 14 near the conical tip 18. The activator 16 can be equated with axis 14 using a variety of techniques, and the matching technique may depend on the type of activator. When the activator 16 is a laminated activator or of EAP composition, the activator 16 can be wrapped around and adhered to the shaft 14 using an adhesive technique or other matching technique. The orientation of the EAP activator can be configured to allow the activator 16 to radially expand and contract axially when energy is distributed thereto, thereby allowing the diameter of the activator 16 to increase. Although not shown, the trigger 16 may optionally be disposed within an internal lumen of the shaft and / or embedded within the walls of the shaft 14 or alternatively the activator 16 may be formed integrally with the shaft 14. In use, the energy is it can distribute to the activator 16 to cause the activator 16 to expand radially and contract axially. Since various techniques can be used to distribute energy to the activator 16, in one embodiment the activator can be coupled to a return electrode and a distribution electrode that is adapted to communicate energy from an external energy source to the activator. The electrodes may extend through the internal lumen on the elongated shaft 14, be embedded in the side walls of the elongated shaft 14, or may extend along an external surface of the elongated shaft 14. Figures 4A and 4B illustrate a illustrative method for using the device 10 to dilate a stenosis in a lumen. As shown, the device 10 can be inserted into a lumen 60 in the body with the activator 16 being deactivated, i.e., in a configuration at rest without being energized thereto. Once the stenosis 62 is located, for example, through lumen imaging, the activator 16 is brought within the stenosis. Energy can then be distributed to the trigger 16 to cause the trigger 16 to expand radially, as shown in Figure 4B, that is, to increase the diameter of the trigger 16. The amount of radial expansion of the trigger 16 can be controlled through of the adjustment of the amount of energy that is being distributed, and the radial expansion of the activator 16 can be maintained while continuously supplying energy to the activator 16. As a result of the radial expansion of the activator 16, the activator 16 will expand against the fibrous tissue of the stenosis, causing the tissue to break and the stenosis to dilate. Typically the activator 16 can expand at least about 30% of its size when energy is distributed thereto. For example, in certain embodiments the activator 16 may have a diameter on the scale of about 16 mm in an unexpanded condition to about 25 mm in the expanded condition. The shape and size of the activator 16 can, of course, vary depending on the intended use. Once the stenosis is dilated, the energy distribution of the activator may end to cause the activator to return to its resting configuration. If the device includes more than one activator formed there, other activators may also be selectively activated and deactivated, either alone or in combination, to effect dilation. One skilled in the art will appreciate that the additional features and advantages of the invention are based on the above described modalities. Accordingly, the invention is not limited to what has been particularly shown and described, except as indicated by the appended claims. All publications and references cited herein are expressly incorporated by reference in their entirety.

Claims (27)

NOVELTY OF THE INVENTION CLAIMS

1. A device for tissue dilation comprising: a substantially flexible elongate shaft having a proximal end coupled to a handle and a distal end adapted to be placed within a stenosis formed in a lumen; and an activator disposed about the distal portion of the flexible elongated shaft and adapted to expand radially after energy distribution thereto to dilate the stenosis.

2. The device according to claim 1, further characterized in that the activator comprises an electroactive polymer.

3. The device according to claim 1, further characterized in that the activator has a substantially cylindrical shape.

4. The device according to claim 1, further characterized in that the activator is positioned proximate the distal end of the flexible elongate shaft.

5. The device according to claim 1, further characterized in that the activator comprises a flexible conductive outer shell having an electroactive polymer and an ionic fluid disposed therein.

6. - The device according to claim 1, further characterized in that the activator comprises at least one electroactive polymer composition having at least one flexible conductive layer, an electroactive polymer layer and an ion gel layer.

7. The device according to claim 1, further characterized in that the activator is adapted to radially expand to at least 30% in size when energy is distributed thereto.

8. The device according to claim 1, further characterized in that the activator includes a return electrode and a distribution electrode coupled thereto, the distribution electrode is adapted to distribute energy to the activator from a power source.

9. The device according to claim 8, further characterized in that it comprises a power source disposed inside the handle and coupled to the distribution electrode.

10. The device according to claim 1, further characterized in that the flexible elongate shaft has a length that is in the range of approximately 121.92 to 182.88 cm.

11. The device according to claim 1, further characterized in that the activator has a diameter of approximately 16 mm in an unexpanded configuration, and a diameter of approximately 25 mm in an expanded configuration.

12. - A device for dilating a stenosis in a lumen, comprising: a handle; a flexible elongated shaft extending from the handle; and an electrically expandable member disposed about a distal portion of the flexible elongate shaft and configured to radially expand when energy is distributed thereto.

13. The device according to claim 12, further characterized in that the distal portion of the flexible elongate shaft has a conical distal tip adapted to be inserted through the stenosis in a lumen.

14. The device according to claim 12, further characterized in that the electrically expandable member comprises an electroactive polymer.

15. The device according to claim 12, further characterized in that the electrically expandable member is positioned proximate the distal end of the flexible elongate shaft.

16. The device according to claim 12, further characterized in that the member comprises a flexible conductive outer shell having an electroactive polymer and an ionic fluid disposed therein.

17. The device according to claim 12, further characterized in that the electrically expandable member comprises at least one electroactive polymer composition having at least one flexible conductive layer, a layer of the electroactive polymer and an ion gel layer.

18. The device according to claim 12, further characterized in that the electrically expandable member is adapted to radially expand to at least 30% in size when energy is applied thereto.

19. The device according to claim 12 further characterized in that the electrically expandable member includes a return electrode and a distribution electrode coupled thereto, the distribution electrode is adapted to distribute energy to the electrically expandable member from a source of energy.

20. The device according to claim 12, further characterized in that it comprises an energy source arranged inside the handle and coupled to the distribution electrode.

21. The device according to claim 12, further characterized in that the flexible elongated shaft has a length that is on the scale of approximately 121.92 to 182.88 cm.

22. The device according to claim 12, further characterized in that the electrically expandable member has a diameter of approximately 16 mm in an unexpanded configuration and a diameter of approximately 25 mm in an expanded configuration.

23. A method for dilating stenosis, comprising: inserting a substantially flexible elongate shaft into a lumen; placing an activator disposed on the distal portion of the substantially flexible elongate shaft within a stenosis formed in the lumen; and distributing energy to the activator to cause the activator to expand radially to increase a diameter of the stenosis.

24. The method according to claim 23, further characterized in that the activator has a substantially cylindrical shape.

25. The method according to claim 23, further characterized in that the activator expands to at least about 30% in size when energy is distributed thereto.

26. The method according to claim 23, further characterized in that the lumen is an esophagus.

27. The method according to claim 23, further characterized in that the stenosis is formed in a stoma.