System and method for endometrial ablation

1. An endometrial ablation method, comprising:

creating a negative pressure in a fluid tight interior chamber of an ablation structure configured for endometrial ablation;

introducing transcervically the ablation structure into a patient's uterine cavity wherein the negative pressure maintains the ablation structure in a collapsed condition as the ablation structure is introduced into the patient's uterine cavity; and

creating a positive pressure in the fluid tight interior chamber after the ablation structure has been introduced into the patient's uterine cavity, thereby maintaining the ablation structure in an expanded condition in contact with tissue of the patient's uterine cavity.

2. The method of claim 1 wherein the creating of the negative pressure collapses a frame in the interior chamber.

3. The method of claim 2 wherein expanding the ablation structure includes at least in part expanding a frame.

4. The method of claim 2 wherein expanding the ablation structure includes at least in part introducing an inflation medium into the structure.

5. The method of claim 1 wherein the creating of the negative pressure provides a bullet-shaped distal nose on the structure for facilitating transcervical introduction.

6. The method of claim 1 wherein the creating of the negative pressure draws opposing frame tips into close proximity.

7. The method of claim 1 wherein the creating of the negative pressure flexes first and second distal frame tips toward one another.

8. The method of claim 1 wherein the negative pressure is at lower than −1 psi, lower than −2 psi, lower than −4 psi, lower than −6 psi or lower than −8 psi.

9. The method of claim 1 wherein the negative pressure is controlled by a controller and pressurizing source configured to alter the pressure in the interior chamber between lower than −2 psi and higher that +0.5 psi.

10. The method of claim 1 further comprising relieving the negative pressure, expanding the ablation structure, and delivering energy from the structure to ablate endometrial tissue.

11. An endometrial ablation device, comprising:

an expandable ablation surface extending along a longitudinal axis; and

a flexible frame supporting the ablation surface, the frame having first and second distal frame tips and being actuatable between a linear frame-collapsed shape about the axis and a triangular frame-expanded shape with a first distal apex and a second distal apex spaced away from the axis;

wherein the first and second distal frame tips, when the flexible frame is in the frame-collapsed shape, are angled inward toward the axis; and

a pressurization source capable of providing a negative pressure in an interior chamber of the expandable ablation surface, wherein the negative pressure provided is configured to maintain the flexible frame in the frame-collapsed shape.

12. The endometrial ablation device of claim 11 wherein the angled-inward tips in the frame-collapsed shape are angled relative to the axis between 5° and 60°.

13. The endometrial ablation device of claim 11 wherein the angled-inward tips have a length ranging from 5 mm to 30 mm.

14. The endometrial ablation device of claim 11 further comprising an RF source operatively coupled to at least one electrode carried by the ablation surface.

15. The endometrial ablation device of claim 14 further comprising an RF source operatively coupled to at least one electrode exposed to the interior chamber.

16. The endometrial ablation device of claim 11 wherein the pressurization source is capable of providing a positive pressure in the interior chamber of the expandable ablation surface, wherein the positive pressure provided is configured to maintain the flexible frame in the frame-expanded shape.