Title:  Method and devices for creating a trap for confining therapeutic drugs and/or genes in the myocardium

United States Patent:  6,224,566

Assignee:  Cardiodyne, Inc. (Irvine, CA)

Filed:  May 4, 1999

Devices and methods for effective administration of therapeutic drugs or gene therapy to the myocardium is achieved by creating a trap or pocket within the myocardium for confining the injected therapeutic. The pocket can be created using mechanical and light energy, or other means.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a device and procedure for utilizing mechanical energy to create a passageway through the epicardium or endocardium, as the case may be, which seals more quickly and dependably than a laser created channel, and delivering sufficient laser energy only into the myocardium, to form a receptacle, i.e., a cavity, chamber, pocket, or the like, in the heart muscle which can hold therapeutic agents.

The contemplated therapeutic agents suitable for use with the invention include, but are not limited to, drugs, purified or recombinant human proteins, naked DNA genes, gene expression/therapy vectors, anti-sense nucleic acids or other such therapeutics known in the art, whether administered alone or in combinations with other agents in solution, or packaged within suitable carriers such as liposomes, microcapsules, transformed cells, viral vectors, and the like. Such suitable therapeutic agents, whether chemical or molecular biological in nature, can be useful for treating a patient's heart to induce angiogenesis, which are or can produce clot inhibiting or dissolving enzymes, that are or can produce useful enzymes, to reduce inflammation, to treat infection, or to reduce pain, among other uses.

A device suitable for the administration of a predetermined amount of the aforementioned therapeutic agent includes a catheter, which terminates at its distal end in a hollow, open-ended puncturing tip, and encases an optical fiber, operably associated with a laser energy source when in use. The puncturing tip is in fluid flow communication with the catheter and defines a fluid channel for dispensing the therapeutic agent, The optical fiber is situated within the catheter so that the distal end of the optical fiber extends into the puncturing tip. The optical fiber together with the catheter define a confined flow passageway which is in communication with the fluid channel in the puncturing tip. In this manner, a therapeutic agent is introduced into the myocardium as the therapeutic agent exits the fluid channel defined by the tip.

The device embodying the present invention is especially suitable for use in medical applications for delivering laser energy to a selected tissue site at a controlled rate in a uniform manner, so the depth of the coagulation zone surrounding the pocket and size of the pocket formed can be controlled as desired. Furthermore, the present device allows formation of uniformly or otherwise desirably shaped pockets between heartbeats in a periodically moving structure such as a human heart, from either the outside of the heart (epicardium) or from the inside of the heart chamber (endocardium).

A preferred surgical device embodying the present invention includes a source of laser energy, an optical fiber optically coupled to the source of laser energy, a hollow needle surrounding at least a portion of the distal end of the optical fiber, and a catheter surrounding at least a portion of the optical fiber communicating with the space between the needle and the optical fiber. These components can also be movably disposed within an outer catheter terminating in a handpiece, for easy handling, from which a metal cannula may extend distally. An actuator rod may be optionally provided to actuate the transmission of laser energy, when it is depressed a selected distance by contact with the heart's surface. The actuator rod can also actuate a mechanism to extend the needle, and the optical fiber contained therewithin, from the cannula into the tissue at the site where the pocket is to be formed. The pocket is formed by energizing, after the needle containing the optical fiber has penetrated a first desired distance into the tissue, a suitable laser source and passing a laser beam from the source through the optical fiber emitting laser energy as the fiber/needle moves a second, additional desired distance into the tissue and, after ceasing the emission of laser energy, injecting a therapeutic agent into the pocket created by the laser energy through the space between the needle and the optical fiber as the fiber/needle combination is being withdrawn from the pocket, after which the fiber needle withdraws the first desired distance from the tissue. The fiber/needle may be beveled and/or pointed, as in traditional syringe needles, or may be blunt but of sufficiently narrow diameter to act as a fine puncture device, where such a blunted device may also incorporate a trocar shape or beveled circumference. The tip assembly of the invention will be called, in various embodiments a fiber/tip, needle/tip, fiber/needle, or other such combination of terms, which emphasize the scope of elements which can be combined to create the tip apparatus embodied by the invention.

The pocket in the myocardium may also be similarly formed by mechanical energy, such as a rotating burr, or by delivering radio-frequency electrical energy, high intensity ultrasound energy or microwave energy at a controlled rate in a uniform manner directly onto a selected tissue site within the heart wall for creating a pocket into which a therapeutic agent can be injected and confined.

A mechanical rotating burr device embodying the present invention includes a cannula, a flexible drive cable with a distal burr such that the rotation of the drive cable translates into the rotation of the burr.

A radio-frequency electro-surgical device embodying the present invention includes a cannula, and an electrically conductive lead with a distal end/electrode within an insulated sleeve, which is received within a bore that passes through the cannula. An actuator may optionally be operably coupled to a source of energy and/or a mechanism for advancing the sleeve and lead assembly into the tissue. The lead is energized by a suitable energy source to form a desirably sized pocket within the tissue, into which the therapeutic agent is injected through the space between the lead and the sleeve as the sleeve and lead are withdrawn from the pocket. Optionally, the lead may be located within a separate channel within the cannula.

Claim 1 of 22 Claims

I claim:

1. A device suitable for administering a predetermined amount of a therapeutic agent into a mammalian heart myocardium comprising:

a catheter defining a fluid flow channel and having a distal end;

a hollow open ended puncturing tip in the form of a hollow needle at the distal end of the catheter and defining at least one fluid channel exiting the tip;

an optical fiber within the catheter and having a distal end extending into the fluid channel of the tip, the optical fiber together with the catheter defining a confined flow passageway in communication with the fluid channel in the puncturing tip, such that a therapeutic agent introduced via the confined flow passageway exists through the fluid channel of the tip, and

wherein the needle contains protrusions within the bore of the needle which run substantially parallel with the length of the needle, or spirally along the length of the needle, and define channels which maintain fluid communication through the length of the needle when an optical fiber is fixed within the bore of the needle.

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