US 20050004471 A1
Methods and apparatus are provided for improved administration of brachytherapy in the treatment of prostate disease. More particularly, a prostate visualization device is provided comprising a catheter coupled to at least one deployable member at the distal end of the catheter. The deployable member is preferably manufactured from a shape memory alloy having a petal-shaped configuration suitable for engaging and defining the proximal region of a patient's bladder. The deployable member may comprise tubing filled with air or other radiopaque agents to facilitate ultrasonic imaging of the deployable members near the bladder/prostate junction.
1. Apparatus for facilitating visualization of a patient's prostate/bladder junction, comprising:
a catheter having proximal and distal ends, a proximal deployment port at the proximal end, a first outlet port at the distal end, and a first lumen extending therebetween;
a plunger having proximal and distal ends, the distal end of the plunger configured to slidably pass through the proximal deployment port; and
at least one deployable member coupled to the distal end of the plunger, wherein the deployable member is expandable from a delivery configuration adapted for transurethral insertion, to a deployed configuration adapted for engagement of a proximal portion of the patient's bladder.
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26. A method of facilitating visualization of a patient's prostate/bladder junction, the method comprising:
providing apparatus comprising a catheter having proximal and distal ends, a proximal deployment port at the proximal end, a first outlet port at the distal end, a first lumen extending therebetween, a plunger having proximal and distal ends, and at least one deployable member affixed to the distal end of the plunger;
advancing the apparatus through the patient's urethra;
distally advancing the deployable member beyond the distal outlet port to deploy the deployable member to a predetermined configuration within the patient's bladder; and
proximally retracting the deployable member such that it engages a proximal portion of the patient's bladder.
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The present application is a continuation-in-part of U.S. patent application Ser. No. 09/648,319, filed Aug. 25, 2000, and claims the benefit of the filing date of U.S. provisional application Ser. No. 60/295,408, filed May 31, 2001, the disclosure of which is incorporated herein by reference in its entirety.
This invention relates to improved apparatus and methods for the treatment of prostate cancer. More particularly, the present invention provides a prostate visualization device having at least one deployable member suitable for imaging the bladder/prostate junction, and methods of use.
Excluding nonmelanoma skin cancers, prostate cancer is the most common cancer afflicting American men. The American Cancer Society estimates that over 180,00 new cases will be diagnosed in the U.S. in the year 2000 alone, and that nearly 32,000 people will die from the disease. Prostate cancer is second only to lung cancer as the leading cause of cancer death in men, accounting for roughly 11%.
Prostate cancer is defined as malignant tumor growth within the prostate gland. Its cause is unknown, although high dietary fat intake and increased testosterone levels are believed to be contributory factors. A letter scale (“A” through “D”), which accounts for the location of the cancer, is commonly used to classify the stage of disease. In Stage A, the tumor is not palpable but is detectable in microscopic biopsy. Stage B is characterized by a palpable tumor confined to the prostate. By Stage C, the tumor extends locally beyond the prostate with no distant metastasis. By Stage D, cancer has spread to the regional lymph nodes or has produced distant metastasis.
In the early stages, prostate cancer is most commonly treated by either prostate removal or by brachytherapy. More advanced cases are treated by hormonal manipulation or orchiectomy to reduce testosterone levels and curb spreading of the disease, by chemotherapy, or by external beam radiation therapy.
With regard to treatment of early stage prostate cancer, the state of the art has several drawbacks. Radical prostatectomy is often recommended for treatment of localized stage A and B prostate cancers. Under general or spinal anesthesia, an incision is made through a patient's abdomen or perineal area, and the diseased prostate is removed. The procedure is lengthy, especially if a lymph node dissection is simultaneously performed, and requires a hospital stay of 2-5 days. Possible complications include impotence and urinary incontinence.
Internal radiation therapy or brachytherapy has recently been developed and holds great promise for the treatment of early stage prostate cancer. Radioactive pellets or seeds of, for example, iodine-125, palladium-103, or iridium-192, are deposited directly into the prostate through needle placement. U.S. Pat. No. 5,928,130 to Schmidt provides a slightly modified example of such a needle device. Imaging techniques, such as transrectal ultrasound, CT scans, or MRI, are used to accurately guide placement of the radioactive material. Advantageously, radiation from the brachytherapy seeds is administered directly to the prostate with less damage to surrounding tissues, delivering a substantially higher radiation dosage to the prostate than to the surrounding tissues, as compared to external beam radiation therapy. The procedure need only be performed once, and impotence and urinary incontinence complications are significantly reduced, as compared to prostate removal procedures.
The seeds, which are permanently implanted, give off radiation for weeks or months. Their presence causes little discomfort, and they remain in the prostate after decay of the radioactivity. For several weeks following needle insertion, patients may experience pain in the perineal area, and urine may have a red-brown discoloration.
Although, when performed correctly, brachytherapy may provide several benefits when compared to prostate removal and other techniques, current apparatus and methods for delivering the seeds to target locations within the prostate are somewhat crude and are subject to practitioner error. The current method of identifying the depth of needle insertion is by ultrasound imaging. The junction of the base of the prostate and the bladder provides a common reference plane for needle insertion. Identifying this critical reference “base” plane is critical to proper needle and seed placement.
One previously known technique for imaging the base plane is to visualize the plane in either transverse or sagittal ultrasound imaging. Injection of contrast agent may facilitate imaging. A catheter, such as a standard Foley catheter, may be inserted into the patient's urethra proximal of the junction. Contrast agent comprising aerated K-Y jelly and water, may then be injected through an end port of the catheter. The agent moves distally towards the patient's bladder and is visible to an ultrasound probe, positioned in the patient's rectum, thereby facilitating imaging.
Attempts have been made to improve Foley catheters, as well as to facilitate improved imaging within a body lumen. For example, U.S. Pat. No. 5,715,825 to Crowley provides an acoustic imaging catheter with an inflatable dilation balloon and an ultrasound transducer. However, while Crowley may provide improved imaging, the device is mechanically and electrically complex, and is therefore costly. U.S. Pat. No. 5,916,153 to Rhea, Jr. provides a multifunction, modified Foley catheter. The device described in that patent, however, does not improve on current junction imaging techniques.
In view of the drawbacks associated with previously-known methods and apparatus for bladder/prostate junction imaging, it would be desirable to provide methods and apparatus that overcome such drawbacks.
It further would be desirable to provide methods and apparatus that provide reliable imaging of the bladder/prostate junction.
It still further would be desirable to provide methods and apparatus that may be used in conjunction with standard brachytherapy apparatus.
In view of the foregoing, it is an object of the present invention to provide methods and apparatus for bladder/prostate junction imaging that overcome drawbacks associated with previously-known methods and apparatus.
It is also an object of the present invention to provide methods and apparatus that provide reliable imaging of the bladder/prostate junction.
It still further is an object to provide methods and apparatus that may be used in conjunction with standard brachytherapy apparatus.
These and other objects of the present invention are accomplished by providing methods and apparatus for bladder/prostate junction imaging comprising a catheter having at least one distally deployable member that engages and defines the proximal region of the bladder. The deployable member is preferably constructed from a shape memory material that forms a petal-shaped configuration upon deployment. The deployable member is deployed within the patient's bladder, and may be retracted proximally to conform to the proximal wall of a patient's bladder. Gas pockets may be provided around the deployable member to enhance visibility with an ultrasound probe. Additionally, echo-contrast agent may be injected to the region to facilitate reliable imaging.
In a preferred embodiment, the deployable member comprises a plurality of petal-shaped Nitinol wires affixed to the distal end of a plunger that is coupled to a multi-lumen catheter. The catheter may include a deployment lumen, a bladder drainage lumen, a contrast injection lumen, and a prostatic therapy lumen. The catheter is advanced through a patient's urethra into the patient's bladder. The deployable member is deployed by advancing the plunger distally within the deployment lumen. Upon deployment within the bladder, the plunger is proximally retracted until the deployable member engages the proximal wall of the bladder. Echo-contrast agent then may be injected into a space near the bladder/prostate junction. Ultrasonic imaging may then proceed, often with an ultrasound probe positioned in the patient's rectum. Urine also may be emptied from the bladder via the bladder drainage lumen, and the patient's prostate may be accessed via the prostatic therapy lumen.
The deployment lumen may be used in combination with any of the drainage, contrast, and prostatic therapy lumens. In alternative embodiments, one or more catheter lumens may be configured to serve more than one function. For example, a single lumen catheter having only one distal outlet port may be provided whereby one or more proximal ports are in communication with the outlet port via the single lumen. In this embodiment, the single lumen of the catheter allows for passage of the deployable member, fluid injection, fluid drainage and delivery of prostatic therapy devices or therapeutic agents.
Additionally, tubing may cover the deployable member to form gas pockets around the deployable member such that the gas enhances ultrasonic imaging of the bladder/prostate junction. The tubing may comprise a variety of shapes and sizes to facilitate imaging of the deployable member.
Methods of using the present invention are also provided.
Additional objects and advantages of the invention will be apparent from the following description, the appended claims, and the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
The present invention provides methods and apparatus for improved administration of brachytherapy. More particularly, the present invention provides a prostate visualization device comprising at least one distally deployable member that engages and defines the proximal wall of a patient's bladder. The device is preferably coupled to a catheter to facilitate imaging of the patient's bladder/prostate junction.
With reference to
Ultrasonic imaging and location determination of base plane BP may be unreliable due to irregular ultrasonic images dependent on a density of the water/KY jelly combination at a given location, as well as flow conditions within the bladder and urethra. Thus, there exists a need for reliable apparatus and methods for bladder/prostate junction imaging.
Referring now to
Catheter 32 further comprises deployment lumen 33 and contrast lumen 35. A second contrast lumen 37 may be provided, and contrast lumens 35 and 37 may be separated by optional dividing wall 39 to enhance catheter stability during injection of the contrast agent.
Deployment lumen 33 extends between proximal deployment port 46 and distal deployment port 38. Proximal deployment port 46 is preferably a hemostatic port, e.g., a Touhy-Borst connector, that enables plunger 42 to slide longitudinally through the port while inhibiting fluid transfer. Contrast lumens 35 and 37 extend between proximal contrast port 34 and distal contrast port 40, which is located proximal of distal deployment port 38. Catheter 32, excluding plunger 42 and handle 36, preferably comprises a total length of 30-50 cm.
Deployable member 44 is expandable from a collapsed delivery configuration within deployment lumen 33, to an expanded deployed configuration, as shown in
Deployable member 44 preferably is provided in a concave configuration with respect to the bladder/prostate junction. The member is flexible such that it may automatically conform to the shape of the proximal wall of the bladder, without imposing excessive pressure on the prostate or bladder upon retraction of the member against the proximal wall of the bladder. In a preferred embodiment, deployable member 44 comprises twelve petal-shaped members, although greater or fewer numbers of petal-shaped members may be used. The petal-shaped members may either overlap circumferentially or be spaced apart circumferentially when deployed.
Referring now to
Catheter 32 then is retracted out of bladder B to a desired position within urethra U. Alternatively, catheter 32 first may be placed at the desired position within the urethra and plunger 42 then is advanced distally to push deployable member 44 through the remaining portion of the urethra and into the bladder. With deployable member 44 in the expanded configuration, plunger 42 is retracted proximally until deployable member 44 engages a proximal region of bladder B.
Echo-contrast agent then may be injected through proximal contrast port 34 so that it exits distal contrast port 40. Contrast lumens 35 and 37, and ports 34 and 40, are preferably dimensioned in a manner that accounts for the viscosity of the agent. Once the contrast agent has been injected, apparatus 30 facilitates reliable ultrasonic imaging with ultrasound probe 12 inserted through the patient's rectum R, as shown in
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Connector 50 may be affixed to deployable member 44 via adhesive 54. Alternatively, connector 50 may be omitted and plunger 42 may span the approximate length of catheter 32 such that it is directly affixed to deployable member 44. In this embodiment, plunger 42 may comprise a relatively rigid proximal section and a more elastic distal section that spans the majority of the length of catheter 32.
Referring now to
Biocompatible tubing 82 may be affixed to wire 80 by a biocompatible adhesive 84. The inner diameter of tubing 82 is sized to form gas pocket G around wire 80. Gas pocket G may comprise air, or any other radiopaque material, to enhance radiopaque imaging of deployable member 81 within the body.
Alternatively, tubing 92 may completely surround deployable member 91 and may extend toward the proximal end of catheter 32, as shown in
Referring now to
Urine and other fluids may be emptied from the patient's bladder B of
Prostatic therapy lumen 155 provides access to the patient's prostate P of
Referring now to
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Although particular embodiments of the present invention have been described above in detail, it will be understood that this description is merely for purposes of illustration. Specific features of the invention are shown in some drawings and not in others; this is for convenience only, and any feature may be combined with another in accordance with the invention. Further variations will be apparent to one skilled in the art in light of this disclosure and are intended to fall within the scope of the appended claims.