Surgical instrument and method

A method of injecting a drug into prostate tissue comprising

• a. positioning a distal end of a surgical instrument adjacent a region of prostate tissue into which it is desired to inject the drug;
• and
• b. emitting a high pressure stream of the drug from a aperture in the distal end of the surgical instrument using needle-less injection.

A method of visualizing ethanol injection into a prostate comprising;

• a. transurethrally inserting a surgical instrument to inject ethanol into a prostate;
• and
• b. delivering both an echogenic agent and ethanol as the medium delivered to the prostate by the surgical instrument.

A method of visualizing ethanol injection into a prostate comprising:

• a. providing an ultrasonically visible marker near the tip of a delivery cannula for delivering ethanol to the prostate;
• and
• b. observing the marker using ultrasound to position the cannula for delivery of ethanol to a desired location with respect to the prostate.

A method of extending a needle from a surgical instrument for injecting a liquid drug into a prostate, the method comprising:

• a. providing a link assembly at a distal end of the surgical instrument with the link assembly connected to a needle and to a housing carrying the needle;
• and
• b extending the needle generally transversely to the housing using a pusher moving longitudinally in the housing acting through the link assembly.

A kit for injecting a liquid drug into a prostate, the kit comprising:

• a. a cystoscope and scope sheath;
• and
• b. a surgical instrument having a main body, a needle deployment port, a needle, first and second handles, and a lockout release mechanism to limit the distance the needle is extendable beyond the needle deployment port.

A method of visualizing placement of a therapeutically effective substance that is substantially invisible to ultrasound in the treatment of prostate tissue comprising adding an echogenic substance to the therapeutically effective substance to enable visualization during the procedure to assess penetration depth.

Apparatus for visualizing a polymer injection head which is formed of a clear polymer in the treatment of prostate tissue comprising a visually perceptible marker located on the head to indicate its position.

A selective coupling apparatus for a surgical instrument of the type having an remotely controllable extendable and retractable needle, the selective coupling apparatus comprising a mechanism for selectively engaging and releasing first and second members from moving with respect to each other wherein the mechanism provides a mechanical connection between the first and second members when in an operating condition and the mechanism provides clearance between the first and second members when in a de-coupled condition.