Methods and apparatus for testing disruption of a vagal nerve

• US 20050240231A1
• Filed: 02/24/2005
• Published: 10/27/2005
• Est. Priority Date: 03/14/2003
• Status: Active Grant

• Current Assignee: EndoVx, Inc.
• Original Assignee: EndoVx, Inc.
• Inventors: Aldrich, William N., Miller, David
• Granted Patent: US 7,430,449 B2
• Time in Patent Office: Days
• US Class Current: 607/3
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 18/1477 Needle-like probes
• CPC Class Codes: A61B 2018/00482 Digestive system
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/4233 oesophagus
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

Method and apparatus for disrupting a gastric vagal nerve in the gastroesophageal region and testing the function and disruption of the vagal nerve. In one example embodiment, a treatment device applies ultrasound at a high energy level, such as high intensity focused ultrasound, to a vagal nerve to disrupt it and then ultrasound at a lower energy level to another portion of the vagal nerve, preferably further from the stomach, so as to stimulate the vagal nerve. Alternative ways to test the function or disruption of the vagal nerve involve using PCP-GABA, a pancreatic polypeptide, pressure changes inside the stomach, the gastric mucusol pH, a dye agent in the stomach, and other tests.

Claims

1. A method for testing the function of a gastric vagal nerve of a patient, the method comprising:

positioning an energy delivery device within the esophagus adjacent a vagal nerve, the vagal nerve being located outside the esophagus wall;

delivering a high level energy from the energy delivery device sufficient to disrupt the vagal nerve; and

determining whether the vagal nerve has been disrupted.

2. The method of claim 1 further comprising;

moving the energy delivery device away from the location; and

delivering a lower level energy from the energy delivery device to another portion of the vagal nerve to stimulate the vagal nerve.

3. The method of claim 2 further comprising determining whether the vagal nerve is completely disrupted.

4. The method of claim 3 further comprising measuring the pressure in the stomach after delivering the lower level energy to the vagal nerve.

5. The method of claim 4 further comprising

measuring the pressure in the stomach before delivering the lower level energy to the vagal nerve;

and

comparing the pressure in the stomach before delivery of the lower level energy to the pressure in the stomach after delivery of the lower level energy.

6. The method of claim 3 wherein the determining step includes comparing the pressure in the stomach before delivery of the lower level energy to the pressure in the stomach after delivery of the lower level energy.

7. The method of claim 1 further comprising

applying a dye agent into the stomach;

and

measuring a time for the dye to change color.

8. The method of claim 7 wherein the dye agent includes Congo Red.

9. The method of claim 8 wherein the measuring step includes measuring the time for the Congo Red dye to change from a red color to a black color.

10. The method of claim 1 further comprising:

applying an electrical stimulus to the vagal nerve after delivery of the energy sufficient to disrupt the vagal nerve; and

monitoring the stomach.

11. The method of claim 10 further comprising measuring the pressure in the stomach after applying the electrical stimulus to the vagal nerve.

12. The method of claim 2 further comprising measuring the pressure in the stomach after applying the lower energy level to the vagal nerve.

13. The method of claim 11 further comprising

measuring the pressure in the stomach before applying the electrical stimulus to the vagal nerve;

and

comparing the pressure in the stomach before applying the electrical stimulus to the vagal nerve to the pressure in the stomach after applying the electrical stimulus to the vagal nerve.

14. The method of claim 5 further comprising determining that the vagal nerve is completely disrupted if the pressure in the stomach does not change.

15. The method of claim 11 further comprising determining that the vagal nerve is completely disrupted if the pressure in the stomach before applying the electrical stimulus to the vagal nerve is substantially the same as the pressure in the stomach after applying the electrical stimulus to the vagal nerve.

16. The method of claim 1 wherein the step of determining whether the vagal nerve is disrupted includes measuring a gastric mucosal pH of the stomach.

17. The method of claim 16 wherein the step of determining whether the vagal nerve is disrupted includes introducing PCP-GABA before measuring the gastric mucosal pH of the stomach.

18. The method of claim 2 wherein moving step includes retracting the energy delivery device further away from the stomach.

19. The method of claim 1 wherein the energy is ultrasound.

20. The method of claim 1 wherein the energy sufficient to disrupt the vagal nerve is high intensity ultrasound.

21. The method of claim 1 wherein the energy sufficient to disrupt the vagal nerve is high intensity focused ultrasound.

22. The method of claim 1 wherein the energy is radio frequency energy.

23. The method of claim 2 wherein the lower energy level is delivered by electrodes which are passed through the wall of the esophagus.

24. The method of claim 2 further comprising using electrodes to locate a vagal nerve branch.

25. The method of claim 1 wherein the energy delivery device is introduced into the esophagus through the mouth.

26. The method of claim 1 wherein the energy delivery device is delivered to the esophagus through the nose.

27. The method of claim 2 wherein the lower energy level falls within the range of 500 mW/cm² and 5 W/cm².

28. The method of claim 1 wherein the high energy level falls within the range of 300 and 3000 W/cm².

29. The method of claim 27 wherein the high energy level falls within the range of 300 and 3000 W/cm².

30. The method of claim 1 further comprising measuring the pancreatic polypeptide response to a sham feeding or a phamacological stimulation.

31. The method of claim 1 further comprising using the Burge test to apply an electrical voltage to the vagal nerve and determining whether gastric pressure in the stomach changes in response to the electrical voltage.

32. The method of claim 1 further comprising using the Burge test with an inflatable balloon and measuring a distension of the stomach.

33. The method of claim 1 further comprising introducing histamine into the patient and checking the pH of the mucosa of the stomach.

34. The method of claim 1 further comprising introducing PCP-GABA into the patient.

35. The method of claim 1 further comprising introducing insulin into the patient.

36. The method of claim 1 further comprising introducing 2-deoxy-glucose into the patient.

37. The method of claim 1 further comprising introducing a neurotransmitter amino acid into the patient.

38. A system for testing the function of a gastric vagal nerve comprising:

an elongate device adapted to be inserted into an esophagus; and

an energy delivery device located on the elongate device, the energy delivery device being adapted to deliver energy from within the esophagus to a vagal nerve branch.

39. The system of claim 38 further comprising a pressure transducer adapted to be inserted into the stomach, the pressure transducer also adapted to measure the pressure in the stomach.

40. The system of claim 38 wherein the energy delivery device is adapted to deliver energy at two or more energy levels including a high energy level sufficient to disrupt the vagal nerve branch and a low energy level sufficient to stimulate the vagal nerve branch without disrupting the vagal nerve branch.

41. The system of claim 40 further comprising:

a pressure transducer adapted to be inserted into the stomach and to measure the pressure in the stomach; and

a processor adapted to compare the pressure measured by the pressure transducer in the stomach before the energy delivery device delivers the low energy level to the vagal nerve branch with the pressure measured by the pressure transducer in the stomach after the energy delivery device delivers the low energy level to the vagal nerve branch.

42. The system of claim 40 further comprising:

a pressure transducer adapted to be inserted into the stomach and to measure the pressure in the stomach; and

a processor adapted to compare the pressure measured by the pressure transducer in the stomach before the energy delivery device delivers the low energy level to another portion of the vagal nerve branch with the pressure measured by the pressure transducer in the stomach after the energy delivery device delivers the low energy level to the another portion of the vagal nerve branch.

43. The system of claim 38 further comprising a dye agent for introduction into the stomach, the dye agent adapted to change its color at a rate proportional to the amount of acid in to the stomach.

44. The system of claim 43 wherein the dye agent includes Congo Red.

45. The system of claim 43 further comprising a processor that measures a time for the dye agent to change color inside the stomach.

46. The system of claim 38 further comprising an electrical stimulator adapted to apply an electrical stimulus to the vagal nerve.

47. The system of claim 46 further comprising a pressure transducer adapted to be inserted into the stomach and to measure the pressure in the stomach.

48. The system of claim 46 further comprising:

a pressure transducer adapted to be inserted into the stomach and to measure the pressure in the stomach; and

a processor adapted to compare the pressure measured by the pressure transducer in the stomach before the electrical stimulator delivers the electrical stimulus to another portion of the vagal nerve branch with the pressure measured by the pressure transducer in the stomach after the electrical stimulator delivers the electrical stimulus to the another portion of the vagal nerve branch.

49. The system of claim 38 further comprising a pH detector adapted to measure a pH of the stomach mucosa.

50. The system of claim 49 further comprising an agent adapted to stimulate the stomach into producing acid.

51. The system of claim 49 further comprising PCP-GABA.

52. The system of claim 38 further comprising a retractor adapted to retract the energy delivery device further away from the stomach.

53. The system of claim 38 wherein the energy delivery device is an ultrasound transducer.

54. The system of claim 53 wherein the transducer is a high intensity ultrasound transducer.

55. The system of claim 54 wherein the transducer is a high intensity focused ultrasound transducer.

56. The system of claim 38 wherein the energy delivery device is a radio frequency electrode.

57. The system of claim 38 further comprising an inflatable balloon on the elongate device and a strain gauge.