Method and apparatus for treating fluid build-up in a body cavity, including method and apparatus for treating ascites and pleural effusions

1. A method for treating pleural effusion in a patient, the method comprising:

providing a valve comprising:

a body having a distal end, a proximal end and a lumen extending therebetween;

an inlet disposed at the proximal end of the body, the inlet being fluidically connected to the lumen;

an outlet disposed at the distal end of the body, the outlet being fluidically connected to the lumen; and

at least one valve element disposed in the lumen of the body, the at least one valve element being a one-way valve element configured to permit the passage of fluid in a single direction through the lumen of the body; and

implanting the valve in the body of the patient such that the inlet of the valve is fluidically connected to the pleural cavity of the patient, and such that the outlet of the valve is fluidically connected to a second body cavity;

wherein the second body cavity comprises the abdominal cavity;

wherein the valve is implanted in the body of the patient by accessing the thoracic cavity and advancing the distal end of the body of the valve through the parietal pleura, through the diaphragm and into the abdominal cavity, such that once implanted in the patient, the proximal end of the body of the valve is disposed in the pleural cavity, the distal end of the body of the valve is disposed in the abdominal cavity and the body of the valve passes through the parietal pleura and the diaphragm of the patient.

2. A method according to claim 1 wherein the body of the valve comprises a stent body, and further wherein the stent body is configured to promote ingrowth of adjacent tissue into the stent body so as to anchor the stent body in position after the valve is implanted in the body of the patient.

3. A method according to claim 1 wherein the at least one valve element is formed out of the distal end of the lumen by flattening the distal end of the lumen of the valve so as to form the valve element.

4. A method according to claim 1 wherein the length of the body of the valve is at least equal to the thickness of the diaphragm plus the thickness of the parietal pleura plus the thickness of the interstitial tissue through which the valve is to extend.

5. A method according to claim 1 wherein the at least one valve element is configured to allow the passage of fluid therethrough when the pressure differential across the valve element is less than 10 mmHg in a selected direction.

6. A method according to claim 1 wherein the at least one valve element is configured to allow the passage of fluid therethrough when the pressure differential across the valve element is less than 5 mmHg.

7. A method according to claim 1 the valve element is configured to allow the passage of fluid therethrough when the pressure differential across the valve element is less than 2 mmHg.

8. A method according to claim 1 wherein the body of the valve comprises a circular cross-section.

9. A method according to claim 1 wherein the body of the valve is radially compressible.

10. A method according to claim 1 wherein the body of the valve comprises an expandable stent.

11. A method according to claim 10 wherein the expandable stent is a covered stent.