Needleless delivery systems

1. A method of treating a prostate condition, the method comprising the steps of:

preparing a needleless injector for insertion into a patient, the injector comprising:

a body at a proximal end;

a first shaft extending distally from the body and having a distal end;

an injection shaft extending from the body and comprising a distal end, the injection shaft being moveable along a length of the first shaft, wherein the distal end of the injection shaft is proximal to the distal end of the first shaft;

an injection orifice at the distal end of the injection shaft in fluid communication with a fluid chamber at the proximal end of the body, the injection orifice being positioned for fluid ejection in a lateral direction relative to a longitudinal axis of the injection shaft and located within the first shaft, wherein the injection orifice is axially moveable along the longitudinal axis;

a pressure source in communication with the fluid chamber;

and an extendable tissue tensioner located at the distal end of the injection shaft proximal to the injection orifice;

inserting the injection shaft into a urethra so the injection orifice is located within the prostatic urethra,

actuating the tissue tensioner to contact urethral tissue, and

injecting fluid from the injection orifice directly onto a prostate tissue surface.

2. The method of claim 1 , wherein the injector further comprises an injector head at the distal end of the injection shaft, the injector head comprising a flat surface that comprises the injection orifice and a vacuum orifice.

3. The method of claim 1 , wherein the tissue tensioner comprises a retractable tissue tensioner that retractably extends from the injection shaft away from the injection orifice.

4. A method of treating a prostate condition, the method comprising the steps of:

preparing a needleless injector for insertion into a patient, the injector comprising:

a body at a proximal end;

an injection shaft extending from the body to a distal end of the injection shaft;

a first shaft extending distally from the body and comprising a longitudinal slot and a distal end, wherein the injection shaft is axially moveable along a longitudinal axis of the first shaft and wherein the distal end of the injection shaft is proximal to the distal end of the first shaft;

an injection orifice at the distal end of the injection shaft in fluid communication with a fluid chamber at the proximal end, the injection orifice being positioned for fluid ejection in a lateral direction relative to a longitudinal axis of the injection shaft and located within the first shaft;

a pressure source in communication with the fluid chamber;

an extendable tissue tensioner located at the distal end of the injection shaft proximal to the injection orifice; and

inserting the injection shaft into a urethra so the injection orifice is located within the prostatic urethra,

actuating the tissue tensioner to contact urethral tissue, and injecting fluid from the injection orifice, through the longitudinal slot, and directly onto a prostate tissue surface;

wherein the injection shaft is located within the first shaft so that the injection orifice is moveable relative to the longitudinal slot.

5. The method of claim 1 , wherein the injection orifice is located on the injection shaft at a proximal location relative to a distal tip of the injection shaft.

6. The method of claim 1 , wherein the tissue tensioner is located at a length-wise position along the longitudinal axis of the injection shaft on the distal end that is the same as a length-wise position of the injection orifice such that when the distal end comprising the tissue tensioner and injection orifice is placed within a urethral lumen and the tissue tensioner is extended, tissue of the urethra is tensioned and the fluid is ejectable from the injection orifice to penetrate tissue under tension.

7. The method of claim 1 , wherein the injector comprises an injector head at the distal end of the injection shaft, the injector head comprising multiple injection orifices.

8. A method of treating a prostate condition, the method comprising the steps of:

preparing a needleless injector for insertion into a patient, the injector comprising:

a body at a proximal end;

an injection shaft extending from the body to a distal end of the injection shaft;

an injection orifice at the distal end of the injection shaft in fluid communication with a fluid chamber at the proximal end, the injection orifice being positioned for fluid ejection in a lateral direction relative to a longitudinal axis of the injection shaft;

a pressure source in communication with the fluid chamber;

an extendable tissue tensioner located at the distal end of the injection shaft proximal to the injection orifice; and

an injector head at the distal end of the injection shaft, the injector head comprising a flat surface, the flat surface comprising at least one injection orifice and at least one vacuum orifice, wherein the at least one injection orifice and the at least one vacuum orifice are in fluid communication with the fluid chamber at the proximal end through a plurality of lumens extending along a length of the injection shaft;

inserting the injection shaft into a urethra so the injection orifice is located within the prostatic urethra,

actuating the tissue tensioner to contact urethral tissue, and

injecting fluid from the injection orifice into the prostate.

9. The method of claim 1 , wherein the step of inserting the injection shaft into the urethra comprises inserting the injection shaft through the meatus and into the urethra.

10. The method of claim 1 , wherein the step of inserting the injection shaft into the urethra comprises preparing an external incision and a tissue path leading to the urethra.

11. The method of claim 1 , wherein the injector further comprises an optical device for viewing at a distal end of the device.

12. The method of claim 11 , wherein the optical device comprises an eyepiece at the proximal end and flexible optical fiber extending from the eyepiece to a location at the distal end of the injection shaft.

13. The method of claim 1 , further comprising the steps of axially moving the injection orifice to a secondary location within the prostatic urethra after the step of injecting fluid into the prostate, and then injecting fluid from the injection orifice into the secondary location of the prostatic urethra.

14. The method of claim 1 , wherein the step of injecting fluid from the injection orifice comprises injecting the fluid from a pressurized fluid source.

15. The method of claim 1 , wherein the step of injecting fluid from the injection orifice comprises ejecting fluid from the injection orifice as a fine, high-pressure stream.

16. The method of claim 1 , wherein the step of injecting fluid from the injection orifice comprises injecting the fluid into the prostate as a fine mist of tiny particles.

17. The method of claim 1 , wherein the injected fluid is distributed as a fine mist of tiny particles that enter and travel over a range of depths and directions into the prostate.