METHOD AND APPARATUS FOR GASTROINTESTINAL TRACT ABLATION FOR TREATMENT OF OBESITY

• US 20080275445A1
• Filed: 05/02/2008
• Published: 11/06/2008
• Est. Priority Date: 05/04/2007
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: BARRX Medical LLC
• Inventors: Utley, David S., Wallace, Michael P., Ganz, Robert A., Every, Nathan, Kelly, Douglas
• Granted Patent: US 8,641,711 B2
• Time in Patent Office: Days
• US Class Current: 606/45
• CPC Class Codes: A61B 18/04 by heating by applying electromagnetic radiation A61B18/18; hyperthermia using electric or magnetic fields, radiation or ultrasound A61N
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 18/18 by applying electromagnetic radiation, e.g. microwaves radiation therapy A61N5/00
• CPC Class Codes: A61B 2018/0022 Balloons
• CPC Class Codes: A61B 2018/0212 using an instrument inserted into a body lumen, e.g. catheter
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe

Abstract

Devices and methods for ablating tissue in the wall of various organs of the gastrointestinal tract of a patient in order to cure or ameliorate metabolic pathophysiological conditions such as obesity, insulin resistance, or type 2 diabetes mellitus are provided. Ablational treatment of target areas may be fractional or partial, rendering a post-treatment portion of target tissue ablated and another portion that is substantially intact. Fractional ablation is achieved by controlling the delivery of ablational energy across the surface area being treated, and controlling the depth of energy penetration into tissue. Surface area control of energy delivery may controlled by the spatial pattern of distributed ablation elements or by the selective activation of a subset of a dense pattern of ablation elements. Embodiments of the device include an ablational electrode array that spans 360 degrees and an array that spans an arc of less than 360 degrees.

Claims

1. A method of ablationally-treating tissue at a target area in a gastrointestinal tract of a patient with a pathophysiological metabolic condition comprising:

delivering radiofrequency energy from a non-penetrating electrode pattern on an ablation structure to a tissue surface within the target area, the target area being a contiguous radial portion of the gastrointestinal tract; and

controlling the delivery of radiofrequency energy across the tissue surface within the target area and into a depth of tissue within the target area such that some portion of the tissue is ablated and some portion of the tissue is not ablated.

2. The method of claim 1 wherein controlling the delivery of radiofrequency energy across the tissue surface within the target area includes delivering sufficient radiofrequency energy to achieve ablation in one portion of the tissue target area to achieve ablation and delivering insufficient radiofrequency energy to another portion of the surface to achieve ablation.

3. The method of claim 1 wherein controlling the delivery of radiofrequency energy into depth of the tissue includes controlling the delivery of radiofrequency energy inwardly from the tissue surface such that sufficient energy to achieve ablation is delivered to some layers and insufficient energy is delivered to other layers to achieve ablation.

4. The method of claim 1 wherein controlling the fraction of the target area surface that receives sufficient radiofrequency energy to achieve ablation includes configuring the electrode pattern such that some spacing between electrodes is sufficiently close to allow conveyance of a level of energy sufficient to ablate and other spacing between electrodes is insufficiently close to allow conveyance of the level of energy sufficient to ablate.

5. The method of claim 1 wherein controlling the fraction of the target area surface that receives sufficient radiofrequency energy to achieve ablation includes operating the electrode pattern such that the energy delivered between some electrodes is sufficient to ablate and energy sufficient to ablate is not delivered between some electrodes.

6. The method of claim 1 wherein controlling the delivery of energy into inwardly from the surface of the tissue consists of ablating some portion of tissue within the epithelial layer.

7. The method of claim 1 wherein controlling the delivery of energy into inwardly from the surface of the tissue consists of ablating some portion of tissue within the epithelial layer and the lamina propria.

8. The method of claim 1 wherein controlling the delivery of energy into inwardly from the surface of the tissue consists of ablating some portion of tissue within the epithelial layer, the lamina propria, and the muscularis mucosae.

9. The method of claim 1 wherein controlling the delivery of energy into inwardly from the surface of the tissue consists of ablating some portion of tissue within the epithelial layer, the lamina propria, the muscularis mucosae, and the submucosa.

10. The method of claim 1 wherein controlling the delivery of energy into inwardly from the surface of the tissue consists of ablating some portion of tissue within the epithelial layer, the lamina propria, the muscularis mucosae, the submucosa, and the muscularis propria.

11. The method of claim 1 wherein the pathophysiological metabolic condition includes any one or more of type 2 diabetes, insulin resistance, obesity, or metabolic syndrome.

12. The method of claim 1 further comprising restoring the pathophysiological metabolic condition of the patient toward a normal metabolic condition.

13. The method of claim 12 wherein restoring the metabolic condition toward a normal metabolic condition includes any of decreasing blood glucose levels, decreasing blood insulin levels, decreasing insulin resistance, decreasing body weight, or decreasing body mass index.

14. The method of claim 1 wherein the ablation target area includes cells that support the secretion of insulin in the patient, and wherein upon receiving transmitted energy from the ablation structure are rendered at least partially dysfunctional.

15. The method of claim 14 wherein the cells supporting the effect insulin are endocrine cells.

16. The method of claim 14 wherein the cells supporting the effect of insulin are nerve cells.

17. The method of claim 1 wherein the ablation target area includes cells that support the response of the patient to insulin, and wherein upon receiving transmitted energy from the ablation structure are rendered at least partially dysfunctional.

18. The method of claim 17 wherein supporting the response to insulin includes any of promoting the greater effectiveness of secreted insulin or decreasing the effect of agents that have an anti-insulin effect.

19. The method of claim 17 wherein the cells supporting the effect insulin are endocrine cells.

20. The method of claim 17 wherein the cells supporting the effect of insulin are nerve cells.

21. The method of claim 1 wherein the target area is located in the gastric antrum.

22. The method of claim 1 wherein the target area is located in the pylorus.

23. The method of claim 1 wherein the target area is located in any of the duodenum or the jejunum.

24. The method of claim 1 wherein controlling the delivery of radiofrequency energy across the tissue surface within the target area and into the depth of tissue within the target area allows achievement of a partial ablation in tissue layers of the gastrointestinal tract.

25. The method of claim 24 wherein the target area is in the epithelial layer of the gastric antrum.

26. The method of claim 24 wherein the target area is in epithelial layer of the any of the duodenum or jejunum.

27. The method of claim 24 wherein partial ablation in the epithelial layer slows the rate of nutrient absorption through the epithelial layer.

28. The method of claim 24 wherein the target area includes the muscularis of the gastric antrum causing a slowing of gastric emptying.

29. The method of claim 24 wherein the target area includes the muscularis of the pyloris causing a slowing of gastric emptying.

30. The method of claim 24 wherein the target area includes the muscularis of the duodenum causing a slowing of gastric emptying.

31. The method of claim 1 wherein the ablation has a permanent effect on the function of the target area.

32. The method of claim 1 wherein the ablation has a transient effect on the function of the target area.

33. The method of claim 32 wherein the transient effect has duration that ranges from a period of about one day to about one year.

34. The method of claim 32 wherein during the time when the function of the target region is transiently affected, the method further includes evaluating the patient for a beneficial therapeutic effect of the ablation.

35. The method of claim 34 wherein in the event of a beneficial therapeutic effect, the method further includes repeating the ablation of the target region.

36. The method of claim 35 wherein the repeated ablation is a transient ablation.

37. The method of claim 35 wherein the repeated ablation is a permanent ablation.

38. The method of claim 1 wherein the electrode pattern is configured circumferentially through 360 degrees around the ablation structure.

39. The method of claim 38 wherein transmitting energy from the ablation structure includes transmitting energy asymmetrically through the 360 degree circumference such that ablation is focused within an arc of less that 360 degrees.

40. The method of claim 1 wherein the electrode pattern is configured circumferentially through an arc of less than 360 degrees around the ablation structure.

41. The method of claim 1 further comprising evaluating the target area at a point in time after the delivering energy step to determine the status of the area.

42. The method of claim 41 wherein the evaluating step occurs in close time proximity after the delivery of energy, to evaluate the immediate post-treatment status of the site.

43. The method of claim 41 wherein the evaluating step occurs at least one day after the delivery of energy.

44. The method of claim 1 wherein the delivering energy step is performed more than once.

45. The method of claim 1 further compromising deriving energy for transmitting from an energy source that is controlled by a control system.

46. The method of claim 45 wherein the energy source is a generator

47. The method of claim 45 further comprising feedback controlling the energy transmission so as to provide any of a specific power, power density, energy, energy density, circuit impedance, or tissue temperature.

48. The method of claim 1 further comprising:

advancing an ablation structure into the alimentary canal, the non-penetrating electrode pattern on the structure, the structure supported on an instrument;

positioning the ablation structure adjacent to the target area; and

moving the ablation structure toward the surface of the target area to make therapeutic contact on the target area prior to delivering energy.

49. The method of claim 48 wherein the moving step includes inflating a balloon member.

50. The method of claim 48 wherein the moving step includes expanding a deflection member.

51. The method of claim 48 wherein the moving step includes moving a deflection member.

52. The method of claim 48 wherein the moving step includes expanding an expandable member.

53. The method of claim 46 further including a position-locking step following the moving step.

54. The method of claim 53 the position-locking step includes developing suction between the structure and the ablation site.

55. The method of claim 48 further comprising evaluating the target area prior to the positioning step, the evaluating step to determine the status of the target area.

56. The method of claim 48 wherein multiple target areas are being treated, the method comprising the positioning, moving, and transmitting energy steps to a first target area, and further comprises the positioning, moving, and transmitting energy steps to another target area without removing the ablation structure from the patient.

57. An ablation system for treating a target area in a gastrointestinal tract comprising:

an electrode pattern including a plurality of electrodes;

a longitudinal support member supporting the electrode pattern;

a generator coupled to the plurality of electrodes;

a computer controller in communication with the generator, the controller having programming to direct the generator to deliver energy to the plurality of electrodes, the programming including the ability to direct delivery of energy to a subset of the electrodes, the electrodes of the pattern configured such that, when receiving energy from the generator and in therapeutic contact with a tissue target area, the electrodes ablate a portion of tissue in the target area and leave a portion of tissue in the target area non-ablated.

58. The ablation system of claim 57 wherein the electrode pattern, having a longitudinal axis, forms a fully circumferential surface orthogonal to its longitudinal axis, the pattern sized for contacting tissue in a target area within the gastrointestinal tract.

59. The ablation system of claim 57 wherein the electrode pattern forms a partially circumferential surface orthogonal to its longitudinal axis, the pattern sized for contacting tissue in a target area within the gastrointestinal tract.

60. The ablation system of claim 59 wherein the electrode pattern forms an arc of about 180 degrees.

61. The ablation system of claim 59 wherein the electrode pattern forms an arc of about 90 degrees.

62. The ablation system of claim 57 wherein the electrode elements are distributed into a pattern such that when the programming directs the generator to deliver energy to all the electrodes, the electrode pattern, when therapeutically contacted to a target tissue area, ablates a portion of tissue within the target area and does not ablate another portion of tissue within the target area.

63. The ablation system of claim 57 wherein the programming directs the generator to deliver energy to a subset of electrode elements that form a pattern which, when therapeutically contacted to a target tissue area, ablates a portion of tissue within the target area and does not ablate another portion of tissue within the target area.

64. The ablation system of claim 63 wherein the portion of tissue which is ablated is rendered at least partially dysfunctional, and wherein the portion of the tissue which is not ablated retains its functionality.

65. The ablation system of claim 64 wherein nutrient-absorbing epithelial cells are included in the target area, and nutrient-absorbing cells that are ablated are compromised in their ability to absorb nutrients, and the nutrient-absorbing cells that are not ablated retain their nutrient-absorbing functionality.

66. The ablation system of claim 64 wherein endocrine cells are included in the target area, and endocrine cells that are ablated are compromised in their ability to secrete hormones, and the endocrine cells that are not ablated retain their secrete hormone.

67. The ablation system of claim 64 wherein nerve cells are included in the target area, and nerve cells that are ablated are compromised in their in synaptic functionality, and the nerve cells that are not ablated retain their synaptic functionality.

68. An ablation system for treating a target area in a gastrointestinal tract comprising:

an ablation structure supported by an instrument,

a non-penetrating electrode pattern on the ablation support structure, the electrode pattern configured to control the delivery of energy to a target tissue such that a portion of the surface of the target area receives sufficient radiofrequency energy to achieve ablation and another portion of the surface of the target receives insufficient energy to achieve ablation;

means supported by the instrument by which to bring the ablation structure to make therapeutic contact with tissue at the target area.