Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Arterial prosthesis – Stent structure
Reexamination Certificate
2001-11-13
2004-01-27
Snow, Bruce E (Department: 3738)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Arterial prosthesis
Stent structure
C604S101030, C604S103100
Reexamination Certificate
active
06682555
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods for treating the prostate and/or prostatic urethral stents configured for use after thermal ablation treatments.
BACKGROUND OF THE INVENTION
Conventionally, several types of thermal treatment systems have been proposed to treat certain pathologic conditions of the body by heating or thermally ablating targeted tissue. These thermal treatment systems have used various heating sources to generate the heat necessary to treat or ablate the targeted tissue. For example, laser, microwave, ultrasound, and radio-frequency (RF) energy sources have been proposed to produce the heat that is then directed to the targeted tissue in or around the selected body cavity. These types of thermal treatment systems have been used to thermally ablate the prostate (as well as other organs, body cavities, and/or natural lumens).
One particularly successful thermal ablation system thermally ablates the prostate by a thermocoagulation process. This thermal ablation system employs a closed loop liquid or water-induced thermotherapy (WIT) system which heats liquid, typically water, external to the body and then directs the circulating heated water into a treatment catheter which is inserted through the penile meatus and held in position in the subject undergoing treatment to expose localized tissue to ablation temperatures. The treatment catheter includes an upper end portion which, in operation, is anchored against the bladder neck and an inflatable treatment segment which is held relative to the anchored upper end portion such that it resides along the desired treatment region of the prostate. In operation, the treatment segment expands, in response to the captured circulating fluid traveling therethrough, to press against the localized or targeted tissue in the prostate to expose the tissue to increased temperatures associated with the circulating liquid, thereby thermally ablating the tissue at the treatment site. In addition, the pressurized contact can reduce the heat sink effect attributed to blood circulation in the body, thus enhancing the depth penetration of the heat introduced by the inflatable treatment segment into the prostatic tissue.
As an acceptable alternative to surgery (transurethral resection of the prostate (TURP)), the use of WIT has been shown to be particularly suitable for the treatment of BPH (benign prostatic hyperplasia). Generally stated, the term “BPH” refers to a condition wherein the prostate gland enlarges and the prostatic tissue increases in density which can, unfortunately, tend to close off the urinary drainage path. This condition typically occurs in men as they age due to the physiological changes of the prostatic tissue (and bladder muscles) over time. To enlarge the opening in the prostatic urethra (without requiring surgical incision and removal of tissue), the circulating hot water is directed through the treatment catheter, which is inserted into the penile meatus up through the penile urethra and into the prostate as described above. The treatment segment expands with the hot water held therein to press the inflated treatment segment against the prostate, which then conductively heats and thermally ablates the prostatic tissue. The circulating water is typically heated to a temperature of about 60-62° C. and the targeted tissue is thermally treated for a period of about 45 minutes to locally kill the tissue proximate the urinary drainage passage in the prostate and thereby enlarge the urinary passage through the prostate.
Subsequent to the delivery of the thermal ablation treatment, the treated tissue in the prostate undergoes a healing process. Initially, the ablated tissue can expand or swell due to inflammation or edema which can undesirably block or obstruct the prostatic urethra. Further, during the healing period, portions of the treated tissue can slough off and create an undesirable and unduly limited opening size. Thus, to facilitate proper healing and to enhance the efficacy of the ablation therapy, either the treatment catheter is left in the subject for a period of time and/or the treatment catheter is removed and a post-treatment catheter, such as a conventional Foley catheter, is reinserted and positioned in the subject. However, removal of the treatment catheter and reinsertion of another catheter or stent may cause the tissue along the insertion path and/or treatment region to experience additional irritation. In addition, the amount of time that the treatment or post-treatment catheter must reside in the subject can be from 2-14 days, or even longer. Therefore, it is desirable to configure the post-treatment stent in a minimally invasive manner to allow normal operation of the sphincter, remove the need for the use of an incontinence bag, and reduce the inconvenience or discomfort to the user.
Conventionally, Foley-type catheters with bladder anchoring balloons located on an upper end portion have been used as post-treatment catheters to allow the thermally ablated tissue to mold around the catheter perimeter during the initial healing phase. While these type catheters allow the post-treatment catheter to be securely positioned relative to the bladder neck of the subject, natural operation of the sphincter is inhibited, and the configuration is relatively cumbersome (in position it extends through the penile urethra) and can be considered unduly invasive by the user and may increase the risk of urinary tract infection (UTI) when in position in the subject (particularly, when used for extended periods of time). Other post-treatment catheter configurations (also known as “indwelling catheters” and “stents”) have also been proposed; however, some of the catheter types can inhibit the ability to flush out blood clots which may exist from the therapy, and others are undesirably invasive to the user and/or prevent or inhibit the natural operation of the sphincter. Still others are not able to be properly located within the prostatic cavity about the treatment region and/or are unable to retain their desired position in the prostate over time. Still others can, during prolonged use, promote muscle atrophy and/or localized tissue necrosis.
Examples of known post-treatment catheters or stents are described in U.S. Pat. No. 5,916,195 to Eshel et al., U.S. Pat. Nos. 5,876,417 and 5,766,209 to Devonec et al., and U.S. Pat. No. 3,811,450 to Lord. However, there remains a need to provide improved and/or minimally invasive stents and/or post-treatment catheters or stents that are cost effective and can be positioned in the body, such as in the prostate, proximate the treated tissue, to inhibit the restriction of the cavity or natural lumen. There remains a particular need to provide a prostatic stent that is suitable for use during a post thermal therapeutic treatment (such as ablation) healing process or cycle that can inhibit the closure of the urethra in a manner that reduces abrasion, trauma, or irritation that may be introduced to sensitive tissue along the urethra over conventional treatment procedures.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a biodegradable and/or biocompatible prostatic stent that that can be formed in situ via use of the treatment catheter and is suitable for inhibiting post thermal ablation therapy obstruction in the prostate.
It is another object of the present invention to provide methods to inhibit obstruction in an intermittent or periodic flow passage of natural cavities or lumens in the body to keep the flow passage sufficiently open such that the subject is able to discharge or intake fluids in a substantially normal manner.
It is another object of the present invention to deliver flowable stent material into the patient via the treatment catheter and then to form the stent to conform and be in intimate contact with the walls of the prostatic urethra in situ so as to inhibit obstruction in a lumen or cavity during a healing cycle.
These and other objects are satisfied by the present invention that pro
Cioanta Iulian
Klein Richard Barry
Ganz Bradley M.
Ganz Law PC
Snow Bruce E
WIT IP Corporation
Wolfe James L.
LandOfFree
Methods for treating the prostate and inhibiting obstruction... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods for treating the prostate and inhibiting obstruction..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for treating the prostate and inhibiting obstruction... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3227720