Systems and methods for electrosurgical treatment of fasciitis

Abstract

Systems, apparatus, and methods are provided for promoting blood flow to a target tissue. In one aspect, the invention involves canalizing or boring channels, divots, trenches or holes through an avascular connective tissue, or through a tissue having sparse vascularity, such as a tendon or a meniscus, in order to increase blood flow within the tissue. In one method, an active electrode is positioned in close proximity to a target site on a tendon, and a high frequency voltage difference is applied between the active electrode and a return electrode to selectively ablate tendon tissue at the target site, thereby forming a channel or void in the tendon. The active electrode(s) may be moved relative to the tendon during, or after, the application of electrical energy to damage or sculpt a void within the tendon, such as a hole, channel, crater, or the like. In another aspect of the invention, an electrosurgical probe is used to elicit a wound healing response in a target tissue, such as an injured tendon, in order to stimulate vascularization of the target tissue. The present invention may also be used for vascularization of a torn or damaged tissue in conjunction with a surgical repair procedure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 10 / 372,591 filed Feb. 21, 2003, which is a divisional of U.S. patent application Ser. No. 09 / 845,034, now U.S. Pat. No. 6,805,130 which claims priority from U.S. Provisional Application No. 60 / 200,712, filed Apr. 27, 2000, now abandoned, and is a continuation-in-part of U.S. patent application Ser. No. 09 / 089,012, filed Jun. 2, 1998, now U.S. Pat. No. 6,102,046 which is a continuation-in-part of U.S. patent application Ser. No. 08 / 753,227, filed on Nov. 22, 1996, now U.S. Pat. No. 5,873,855, which is a continuation-in-part of U.S. patent application Ser. No. 08 / 562,331, filed on Nov. 22, 1995, now U.S. Pat. No. 5,683,366, the complete disclosures of which are incorporated herein by reference for all purposes. [0002] The present invention is related to commonly assigned co-pending U.S. patent application Ser. No. 08 / 990,374, filed Dec. 15, 1997 (Attorney Docket No. E-...

AI Technical Summary

Benefits of technology

[0017] One of the advantages of the present invention, particularly over previous methods involving lasers, is that the surgeon can more precisely control the location, depth, and diameter of the vascularizing channels formed in the tissue. The ability to precisely control the volumetric removal of tissue results in a field of tissue ablation or removal that is very defined, consistent, and predictable. This precise control of tissue treatment also helps to minimize, or completely eliminate, damage to healthy tissue structures, such as muscles, cartilage, bone, and / or nerves, which may be adjacent to the target tissue. In addition, any severed blood vessels at the target site may be simultaneously cauterized and sealed as the tissue is removed to continuously maintain hemostasis during the procedure. This increases the surgeon's field of view, and expedites the procedure. In one embodiment, the active electrode can remain in contact with the tendon tissue as the high frequency voltage ablates this tissue (or at least substantially close to the tissue, e.g., usually on the order of about 0.1 mm to 2.0 mm, and preferably about 0.1 mm to 1.0 mm). This preserves tactile sense and allows the surgeon to more accurately determine when to terminate cutting of a given channel so as to minimize damage to surrounding tissues and / or to minimize bleeding.

[0018] In open procedures, or in procedures in “dry” fields, the apparatus may further include a fluid delivery element for delivering electrically conductive fluid to the active electrode(s) and the target site. The fluid delivery element may be located on the probe, e.g., in the form of a fluid lumen or tube, or it may be part of a separate instrument. In arthroscopic procedures, however, the surgical area surrounding the tendon will typically be filled with electrically conductive fluid (e.g., isotonic saline) so that the apparatus need not have a fluid delivery element. In both embodiments, the electrically conductive fluid will preferably generate a current flow path between the active electrode(s) and one or more return electrode(s). In an exemplary embodiment, the return electrode is located on the probe and spaced a sufficient distance from the active electrode(s) to substantially avoid or minimize current shorting therebetween and to shield the return electrode from tissue at the target site.

Problems solved by technology

Coronary artery disease, the build up of atherosclerotic plaque on the inner walls of the coronary arteries, causes the narrowing or complete closure of these arteries resulting in insufficient blood flow to the heart.

However, some patients are too sick to successfully undergo bypass surgery.

For other patients, previous endovascular and / or bypass surgery attempts have failed to provide adequate revascularization of the heart muscle.

While recent techniques in LMR have been promising, they also suffer from a number of drawbacks inherent with laser technology.

One such drawback is that the laser energy must be sufficiently concentrated to form channels through the heart tissue, which reduces the diameter of the channels formed by LMR.

Otherwise, the laser beam will damage surrounding portions of the heart as the heart beats and thus moves relative to the laser beam.

Consequently, the surgeon must typically form the channel in less than about 0.08 seconds, which requires a relatively large amount of energy.

Thus, the relatively small diameter channels formed by existing LMR procedures (typically on the order of about 1 mm or less) may begin to close after a brief period of time, which reduces the blood flow to the heart tissue.

Another drawback with current LMR techniques is that it is difficult to precisely control the location and depth of the channels formed by lasers.

For example, the speed in which the revascularizing channels are formed often makes it difficult to determine when a given channel has pierced the opposite side of the heart wall.

In addition, the distance to which the laser beam extends into the heart tissue is difficult to control, which can lead to laser irradiation with heating or vaporization of blood or heart tissue within the ventricular cavity.

As a result, one or more blood thromboses or clots may be formed which can lead to vascular blockages elsewhere in the circulatory system.

Alternatively, when using the LMR technique in an endocardial approach (i.e., from the inside surface of the heart toward the outside surface), the laser beam may not only pierce the entire wall of the heart but may also irradiate and damage tissue surrounding the outer boundary of the heart.

Conditions such as rotator cuff tendinitis, patellar tendinitis, tennis elbow, and plantar fasciitis are extremely common, and yet have no well-defined minimally invasive treatment protocol.

In addition, with age, the meniscus begins to deteriorate, often developing degenerative tears.

Typically, when the meniscus is damaged, the torn pieces begins to move in an abnormal fashion inside the joint.

Because the space between the bones of the joint is very small, as the abnormally mobile piece of meniscal tissue (meniscal fragment) moves, it may become caught between the bones of the joint (femur and tibia).

When this happens, the knee becomes painful, swollen and difficult to move.

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