Abstract:
A needleless injector including a body at a proximal end, a shaft extending distally from the body, at least one injection orifice at a distal end of the shaft in fluid communication with a fluid chamber at the proximal end, a pressure source in communication with the fluid chamber, and a tissue tensioner located at the distal end of the shaft proximal to the injection orifice, wherein the distal end including the tissue tensioner and injection orifice is positionable within a urethral lumen so that when the tissue tensioner is deployed, tissue of the urethra is tensioned at a location for injection of fluid from the injection orifice into the tissue of the urethra.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application of pending U.S. application Ser. No. 11/148,095, filed Jun. 8, 2005, which is a divisional application of U.S. application Ser. No. 10/269,405, now U.S. Pat. No. 6,905,475, which claims the benefit of U.S. provisional patent application No. 60/329,262, filed Oct. 12, 2001, entitled “Surgical Instrument and Method,” the entire disclosures of which are incorporated herein by reference for all purposes. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to surgical instruments and methods, particularly those for treating prostate tissue, and to surgical kits for use in such methods. 
         [0003]      FIG. 1  illustrates the anatomical position of the prostate  10  (including lateral lobes  15 ) and adjacent tissue including the seminal vesicles  11 , bladder neck  12 , and pelvic tissues including sphincter muscles  14 . 
         [0004]    Prostate disease is a significant health risk for males. Diseases of the prostate include prostatitis, benign prostatic hyperplasia or hypertrophy (BPH) and prostatic carcinoma. Benign prostatic hypertrophy is a very common disorder, affecting an estimated 12 million men in the United States alone. BPH is a chronic condition and is strongly age related; approximately 50% of men over 50, 75% of men over the age of 70 and 90% of men over the age of 80 have BPH. 
         [0005]    BPH is treated with a large number of therapeutic modalities. Transurethral resection of the prostate (TURP) is a preferred method of treating BPH. A typical TURP involves general anesthesia, and the placement of a resectoscope in the urethra to remove multiple small chips of hyperplastic prostatic tissue, thereby relieving the obstruction by removing the adenoma. Complications from TURP include bleeding, incontinence, retrograde ejaculation and impotence. 
         [0006]    Examples of surgical devices for prostate tissue treatment are disclosed in U.S. Pat. Nos. 4,461,283; 5,672,171 and 5,630,794 and PCT International Publication Nos. WO 92/10142 and WO 93/15664 (the entire contents of each of which are herein incorporated by reference). Examples of invasive techniques that surgically damage prostate tissue include laser treatments (including side firing, contact and interstitial laser procedures), and transurethral ethanol ablation of the prostate (TEAP) as described in DiTrolio, J. V.,  Transurethral Ablation of the Prostate , presented at the American Urological Association 94 th  Annual Meeting, March 1999; and DiTrolio, J. V.,  Chemoablation of the Prostate with Dehydrated Ethanol for Treatment of BPH,  5th International Consultation on BPH, June 2000 in Paris, France (the entire contents of each of which are herein incorporated by reference). Examples of devices and methods for surgically damaging prostate tissue are disclosed in U.S. Pat. Nos. 5,322,503; 5,562,703; 5,861,002; 6,231,591; and 6,461,296. 
       SUMMARY 
       [0007]    In accordance with an embodiment of the invention, a needleless injector of the invention is provided, which includes a body at a proximal end, a shaft extending distally from the body, at least one injection orifice at a distal end of the shaft in fluid communication with a fluid chamber at the proximal end, a pressure source in communication with the fluid chamber, and a tissue tensioner located at the distal end of the shaft proximal to the injection orifice. The distal end includes the tissue tensioner and injection orifice, which are positionable within a urethral lumen so that when the tissue tensioner is deployed, tissue of the urethra is tensioned at a location for injection of fluid from the injection orifice into the tissue of the urethra. In an exemplary embodiment, the tissue tensioner comprises a balloon, which may be at the distal end and positioned distally from the injection orifice relative to the proximal end. The fluid chamber may contain a volume of ethanol and/or an echogenic substance. In an exemplary embodiment, the fluid is ejectable from the at least one injection orifice in a direction that is generally parallel to a longitudinal axis of the at least one injection orifice. 
         [0008]    In accordance with another embodiment of the invention, a method of injecting a drug into urethral tissue is provided, which method first includes the step of positioning a distal end of a needleless injector adjacent a region of urethral tissue into which it is desired to inject the drug, the injector comprising at least one injection orifice at a distal end of a shaft and an expandable balloon operatively positioned relative to the at least one injection orifice. The balloon is then inflated until the at least one injection orifice is pressed against the urethral tissue and a desired amount of contact is achieved between the at least one injection orifice and the urethral tissue, and then a high pressure stream of the drug is ejected from the at least one injection orifice into the urethral tissue. The ejected drug may be a fluid, such as high-pressure ethanol, and the ejection step may further include ejecting echogenic bubbles with the drug. The method may further include deflating the balloon after a desired quantity of the drug is ejected into the urethral tissue. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic side view showing the anatomical location of prostate tissue. 
           [0010]      FIG. 2  is a side view of a disassembled surgical instrument for use in a preferred embodiment of the present invention. 
           [0011]      FIG. 3  is an enlarged side view of the surgical instrument of  FIG. 2  in an assembled condition, that uses arrows to show the motion of elements of the surgical instrument during deployment of a needle. 
           [0012]      FIG. 4  is a side view showing a surgical kit according to another aspect of the present invention. 
           [0013]      FIG. 5  is a view of another variation of the surgical instrument according to the present invention. 
           [0014]      FIG. 6  is a high pressure transurethral drug delivery embodiment of the present invention. 
           [0015]      FIG. 7  is another variation of the embodiment of  FIG. 6  to illustrate an additional surgical instrument and method according to the present invention. 
           [0016]      FIG. 8  is an enlarged view of a portion of  FIG. 7 . 
           [0017]      FIG. 9  is a view of an additional feature of the surgical instrument and method according to the present invention. 
           [0018]      FIG. 10  is a view of still another feature of the surgical instrument and method according to the present invention. 
           [0019]      FIG. 11  is a view of an arrangement to switch between ethanol and an echogenic agent useful in the practice of the present invention. 
           [0020]      FIG. 12   a  is a perspective view of an alternative embodiment of the surgical instrument and method of the present invention. 
           [0021]      FIG. 12   b  is an enlarged view of a portion of  FIG. 12   a.    
           [0022]      FIG. 13   a  is a view of an alternative embodiment of a surgical instrument in a first position according to the present invention. 
           [0023]      FIG. 13   b  is a view of the embodiment of  FIG. 13   a  in a second position. 
           [0024]      FIG. 13   c  is a perspective view corresponding to  FIG. 13   a.    
           [0025]      FIG. 13   d  is an exploded view of the embodiment of  FIG. 13   c.    
           [0026]      FIG. 14   a  is a view of an alternative embodiment of a surgical instrument in a first position according to the present invention. 
           [0027]      FIG. 14   b  is a view of the embodiment of  FIG. 14   a  in a second position. 
           [0028]      FIG. 15   a  is a view of an alternative embodiment of a surgical instrument in a first position according to the present invention. 
           [0029]      FIG. 15   b  is a view of the embodiment of  FIG. 15   a  in a second position. 
           [0030]      FIG. 16   a  is a view of a lockout arrangement according to an aspect of the present invention in a first, locked, position. 
           [0031]      FIG. 16   b  is a view of the lockout arrangement of  FIG. 16   a  in a second, unlocked, position. 
           [0032]      FIG. 17  is a fragmentary view of the surgical instrument showing an alternative embodiment of a locking mechanism useful in the practice of the present invention. 
           [0033]      FIG. 18   a  is fragmentary view of the surgical instrument showing an alternative embodiment of a locking mechanism useful in the practice of the present invention. 
           [0034]      FIG. 18   b  is a detailed section view of a portion of  FIG. 18   a.    
           [0035]      FIG. 19   a  is a fragmentary view of the surgical instrument showing a still further alternative embodiment of a locking mechanism useful in the practice of the present invention. 
           [0036]      FIG. 19   b  is a plan view of the locking mechanism of  FIG. 19   a.    
           [0037]      FIG. 20  is a fragmentary section view of an alternative embodiment of a de-coupling mechanism useful in the practice of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]      FIGS. 2 and 3  show an exemplary embodiment of surgical instrument  20  for use in treating prostate tissue by injecting an effective amount of an active ingredient (e.g. ethanol, acetic acid, phenol, Lidocaine, bulking agents, botox, oxybutenin, carboxylic acid).  FIG. 2  shows the device  20  in an unassembled condition and  FIG. 3  shows the device  20  in an assembled condition. 
         [0039]    The device  20  includes a scope sheath  22  with eye port  21 , a sheath  26  and a main body with a needle deployment port  24 , handle  30  and thumb ring  34 . The main body also includes an ethanol syringe port  32  that is designed to mate with a syringe  86 . Preferably the syringe  86  has a threaded connector of the type commercially available from Becton, Dickinson and Company under the trade designation “Luer-Lok”, as opposed to a bayonet syringe or a non-threaded connector. Detents  28  are provided for precise needle advancement through auditory, visual and tactile confirmation of needle-tip position in a lobe of the prostate. 
         [0040]    The surgical device  20  is preferably sized and shaped for transurethral entry under direct vision. Optionally, a conventional cystoscope  27  and sheath  26  for transurethral entry under direct vision may be utilized as a portion of a kit  40 . Alternatively, the device may be sized and shaped for transrectal use. It is to be understood that kit  40  preferably includes device  20 , syringe  86  and needle  76 , and optionally includes a reservoir  72  of ethanol or other therapeutically effective agent. 
         [0041]    The assembled device  20  is advanced into the prostatic urethra. The scope allows visual positioning of the needle port against the urethra adjacent to the lobe of the prostate to be treated. The needle is advanced (as shown in the arrows in  FIG. 3 ) one detent click at a time (e.g. 0.5 cm) to place the needle tip in the adenoma. A small volume (e.g. 3 to 5 ml) of an active ingredient such as anhydrous alcohol (ethanol) is slowly injected into the tissue. The urethral lumen may be continuously irrigated while the ethanol is being administered. 
         [0042]    The needle may then be withdrawn and the device  20  is removed from the sheath. The system may be rotated to target the next transurethral access point. An injection may be made to each lateral lobe of the prostate and in cases with median lobe enlargement, an injection may be made to the median lobe of the prostate. In cases of longer prostatic urethra, a second plane of injections may optional be administered. For example, a total amount of about 13 ml may be the average amount of ethanol injected per patient. 
         [0043]    The total dosage of ethanol will depend on a variety of factors including, but not limited to the size of the prostate, the shape of the prostate (e.g. length and width), the number of injection sites determined, and the nature and degree of prostate disease. The amount of ethanol could range from one or two mls to about 20 mls or more. 
         [0044]    Optionally, the method may include other steps commensurate with the physician&#39;s treatment strategy. Also optionally, other therapeutically effective agents may be used with the surgical devices according to the present invention, including the substances described in U.S. patent application Ser. No. 10/193,716, filed Jul. 9, 2002 with the title REGIMEN FOR TREATING PROSTATE TISSUE AND SURGICAL KIT FOR USE IN THE REGIMEN, the entire contents of which are hereby incorporated by reference. 
         [0045]    In another embodiment, the ethanol may be combined with another agent that enhances delivery and distribution of the ethanol within the prostate tissue. More preferably, the agent may more effectively disperse the ethanol in the vasculature of the prostate tissue. For example, the ethanol may be combined with GELFOAM® Sterile Powder, available from Pharmacia &amp; Upjohn of Kalamazoo, Mich. The GELFOAM powder is believed to enhance the retention of the ethanol within the prostate tissue and to more effectively deliver the ethanol to the capillaries associated with the prostate tissue. Alternatively, the ethanol may be combined with a means for enhancing visualization of the ethanol. For example, the agent may comprise a dye for enhancing visualization of the ethanol. Better visualization of the ethanol may assist some surgeons in more effectively delivering the ethanol to the prostate tissue and avoiding undesirable backflow. 
         [0046]    In a preferred embodiment, the needle deployment port  24  is designed to afford a complete view of the entire needle at all points of deployment. 
         [0047]    In another aspect, the present invention comprises the kit  40  for treating a human male. The kit  40  may comprise a surgical kit.  FIG. 4  illustrates one example of a surgical kit  40  according to the present invention. The kit  40  includes a surgical device for damaging, treating or therapeutically affecting prostate tissue according to the present invention. 
         [0048]    The kit  40  includes the surgical device  20  described in conjunction with  FIGS. 2 and 3 . The device  20  includes a cystoscope  27  having a scope sheath  22  with eye port  21 , a sheath  26  and a light cord connector  29 . Device  20  also includes main body  31  with a needle deployment port  24 , needle  25 , handle  30  and thumb ring  34 . The main body  31  also includes an ethanol syringe port  32  with a threaded Luer-Lok®feature. Detents  28  are also provided. 
         [0049]    Notably, the present invention is suitable for use in two piece assemblies in contrast to the three piece assembly shown in  FIG. 2 . For example, the function of the sheath  26  and main body  31  could be combined into a unitary piece that is designed to operate in conjunction with endoscope  27 . Also notably, the assembly may comprise a rigid assembly with, for example, a rigid sheath  26  and scope  27 . Alternatively, the present invention includes embodiments that include flexible assemblies, including, for example, flexible scopes  27  and flexible sheaths  26 . 
         [0050]    The kit  40  also includes a supply or reservoir  72  of a therapeutically effective substance such as ethanol or a bulking agent. Needle  76  and syringe  86  are provided to load the ethanol into syringe  86  from reservoir  72 . The syringe  86  may then be used to deliver ethanol  72  through the needle  25  during a surgical procedure. Preferably, the delivery is transurethrally. In operation, thumb ring  34  and handle  30  are manually grasped and drawn together in the direction indicated by arrow  37 , causing needle  25  to advance in the direction of arrow  39 . It is to be understood that the detents  28  may be used to stop advancement of needle  25  at predetermined distances set by the location of the individual elements of the detents  28 . Once the needle  25  is advanced to the desired position within the prostate  10 , syringe  86  is operated to deliver ethanol via needle  25  to the prostate  10 , as desired. When delivery of ethanol is complete, thumb ring  34  is manually fully retracted away from handle  30  in a direction opposite to arrow  37 , causing needle  25  to retract into the needle deployment port  24  in a direction opposite to arrow  39 . 
         [0051]    In another embodiment, the thumb ring  34  may be biased toward the position where the needle is fully retracted. 
         [0052]    The elements of the kit may be packaged and sterilized together, or they may be separately packaged and sterilized and assembled into a kit at a later date. 
         [0053]    Referring to  FIG. 5 , a lockout release  42  can be added to the surgical instrument of  FIGS. 2-4  to prevent premature deployment of the needle  25 . The lockout release  42  can be a button  44  which is spring loaded and will automatically re-lock when the needle is retracted. When button  44  is in the position shown in  FIG. 5 , button  44  will prevent advancement of the needle  25  via movement of a slide  45  because of interference with edge  46  of a frame  48  of the handle or finger grip  30  of a modified Prostaject device  50 . (Prostaject devices are available from American Medical Systems, Inc. of Minnetonka, Minn., U.S.A.) There are a number of possible ways to implement the concept, all involving the means to prevent or inhibit the relative motion between the handle/cystoscope and the slide/needle. The means to prevent or inhibit this movement can be removed by actuating a button when the physician is ready to advance the needle. The button will re-set when the needle is retracted. Because the force needed to insert the device transurethrally is in the same direction as the force needed to advance the needle  25 , there is a chance that the needle  25  can be prematurely deployed, causing a hazard to the patient. This device (the lockout release  42 ) will prevent this from happening. There are a variety of ways of implementing this concept, but all result in a structure that prevents or inhibits movement of the slide  45  relative to the front handle  30  and frame  48 . 
         [0054]    In another embodiment, a lockout assembly may be added to ethanol syringe port  32  that prevents or inhibits advancement of the needle (by advancing thumb ring  34 ) without a syringe  86  inserted in the syringe port  32 .  FIGS. 16   a  and  16   b  schematically illustrate a lockout release or assembly  42 ′ in both the locking and release positions. Although not shown in  FIGS. 16   a  and  16   b , it is to be understood that syringe  86  is a Luer-Lok® type syringe. In  FIG. 16   a , the lockout assembly  42 ′ is shown in a blocking position where a first lockout arm or member  52  is urged in the direction of arrow  54  by a spring  56  acting against slide  45 . A second lockout arm or member  58  is connected to the first lockout arm  52  at a pivot  60 . A distal end  62  of member  58  engages a blocking topology or notch  64  in an actuation member  66  which is operatively associated with the frame  48  and finger grip  30 . In  FIG. 16   a  it may be seen that slide  45  is blocked (i.e., in a blocking condition) from advancing in the direction of arrow  68  by the interengagement of end  62  and notch  64 . In  FIG. 16   b , a release position or condition may be seen in which the syringe  86  urges first member  52  in the direction of arrow  70  acting against spring  56  and causing member  58  to pivot against a fixed point or fulcrum  74  in slide  45 , moving in the direction of arrow  78  to move distal end  62  out of engagement with member  66 , allowing movement of slide  45  in the direction of arrow  68 . 
         [0055]    In another aspect, the present invention comprises a surgical instrument that includes a means to allow for visualization of a drug or the needle used to administer the drug that is injected into target tissue such as the prostate gland. The invention can be divided into categories of ways to make the needle more visible on ultrasound and ways to make the fluid delivered more visible. 
         [0056]    Another aspect of the present invention is shown in  FIGS. 6 through 8 . In this aspect, the present invention comprises a method with the step of injecting a drug into the prostate using a high-pressure needle-less injection system  80 . A novel device  82  forms an aspect of the present invention and can operate independently or with a cystoscope  27  for transurethral delivery of ethanol  84  into the prostate  10 . Advantages over a needle delivery system could include better depth of penetration control, containment within the prostate capsule, better volume delivery (minimize extravasation), faster procedure, less pain, and possible bubble formation or bubble injection for visualization in TRUS (transrectal ultrasound). As an alternative, an echogenic substance can be added to the ethanol to enable visualization during the procedure to assess penetration depth. 
         [0057]    In  FIG. 6 , ethanol  84  is injected into the prostate  10  by high pressure needle-less means  88 , preferably in the form of an aperture  90  delivering high pressure ethanol to a site adjacent the prostate transurethrally. This would have the advantages mentioned over a needle system and would be expected to further include better depth of ethanol penetration control. Optionally, a balloon may be used to press the means  88  against urethral tissue to ensure suitable contact between the means  88  and the urethral tissue. 
         [0058]      FIG. 7  shows a variation of this approach in which a clear plastic or polymer injection head  92  located adjacent a portion of the prostate  10 . A high pressure fluid delivery tube  94  is connected to head  92 . Borescope  22  is located within the cystoscope sheath  26  along with tube  94 . In operation, head  92  is positioned as desired using the borescope  22  for visual observation while manipulating the sheath  26 . A nozzle  100  delivers high pressure ethanol  84 , with echogenic bubbles  102 , if desired. Optionally, a visually perceptible marker may be placed on or in the head  92  to indicate its position. A urethral balloon may also be used with this embodiment of the present invention. 
         [0059]    Referring now also to  FIG. 8 , an enlarged view of the injection head  92  may be seen. In this view, it may be seen that the nozzle  100  has a first inlet  104  connected to tube  94  for delivering a chemical agent such as ethanol under high pressure. Nozzle  100  also has a second inlet  106  connected to a gas delivery tube  108  for introducing pressurized gas to form bubbles  102  as an echogenic agent in the prostate tissue  10 . 
         [0060]      FIGS. 9 and 10  illustrate other aspects of the present invention. These aspects of the surgical instrument  20  include means to either limit injection pressures to predetermined or desired levels during a transurethral ablation of the prostate (TEAP) procedure or features to indicate when unacceptably high pressures are reached. 
         [0061]      FIG. 9  is a pressure limiter  110  for ethanol injection. A Luer-Lok® type syringe  86  is connected to a housing  112  containing a pressure sensing diaphragm  114 , biased by a spring  116  to hold a shut-off valve  118  in an open position as shown. An (optional) adjustment screw  120  may be used to set the pressure at which valve  118  closes. The output  122  of the pressure limiter  110  is connected to the ethanol syringe port  32  of the Prostaject device  50 . The in-line pressure limiting valve can be used to prevent injection pressures from exceeding acceptable levels during TEAP procedures. If pressures become excessive at the injection site, extravasation can result or rapid flow can occur along tissue planes that allows the ethanol to miss the intended target. In operation, when the force resulting from pressure inside housing  112  in chamber  124  exerted on diaphragm  114  exceeds the force resulting from spring  116 , diaphragm  114  will move towards screw  120 , closing valve  118 . Valve  118  will remain closed for as long as sufficient pressure exists in chamber  126  to cause a force on valve  118  to remain closed against the force of spring  116 . Once the pressure in chamber  126  is reduced, the force from spring  116  will open valve  118 , and allow fluid to flow from chamber  126  to chamber  124  and outlet  122 . 
         [0062]    Referring now to  FIG. 10 , a pressure indicator  130  may be seen. Indicator assembly  130  preferably has an inlet fitting  132  for receiving a Luer Lok® syringe  86  and an outlet fitting  134  for coupling to the Luer Lok® compatible ethanol syringe port  32  on an Prostaject device  50 . It is to be understood that fittings  132  and  134  are shown in simplified form, without Luer Lok® details. Inlet and outlet fittings  132 ,  134  are preferably formed integrally with a housing  136  which defines a passage  137  connecting inlet  132  to outlet  134 . Housing  136  further includes a cylinder  138  carrying a piston  140  having an O-ring seal  142  sealing the piston  140  against the cylinder  138 . Piston  140  also has a rod or stem  144  carrying a visually perceptible indicator or flag  146  at a distal end thereof. Indicator housing  136  also contains a spring  148  urging piston  140  to a retracted position, shown in solid lines in  FIG. 10 , in which flag  146  is concealed within housing  136 . In operation, as pressures reach unacceptable levels (e.g., during a TEAP procedure), the moving rod  144  will extend, working against the preset force of spring  148 . The flag  146  will then extend beyond housing  134 , and indicate to the physician that pressures have exceeded acceptable levels. A groove  139  extends part way along the cylinder  138  in housing  136  to allow fluid to bleed past the piston and O-ring seal  142  in the event a predetermined maximum pressure level is reached. The groove  139  begins at a starting point  141  and extends a distance along the cylinder such that the liquid drug will leak past the piston  140  and O-ring seal  142  via the groove  139  when a predetermined maximum pressure level is reached within the passage  137  causing the piston  140  to move against the spring  148  a distance sufficient to move the piston past the starting point  141  of the groove  139 . 
         [0063]      FIGS. 11 ,  12   a  and  12   b  illustrate additional aspects of the surgical instrument and method according to the present invention. These aspects include means for making the needle more visible including the following. 1) The needle can be sandblasted to improve the ability to identify its location via ultrasound. 2) The needle can have a thin film conductor deposited over a dielectric for the purpose of operating a resistor for generating heat or a piezoelectric driver for generating ultrasonic vibration that could be detected via ultrasound imaging. The dielectric capacitance and length of strip create a L-C monopole or bipolar antenna emitting a frequency spectrum to be picked up by external receiver and/or alternatively by ultrasound probe. 3) Echogenic materials could be injected after the needle is inserted into the prostate to verify needle position via TRUS. The ethanol (or other drug) could then be injected. The echogenic materials could include microspheres in a fluid medium, gas bubbles or solid particles suspended in solutions. 4) The echogenic materials could be added to the drug and injected simultaneously either through mixing them before injection or using a double-barreled syringe and having them mix in the needle as seen in  FIG. 11 . 
         [0064]    Notably, the surgical device may optionally include an ultrasonic transducer (e.g. on or near the needle), to enhance the dispersion of the injected substance within the tissue. In another embodiment, the surgical needle may include a coating (e.g. on the needle) of Echo-Coat® material (available from STS Biopolymers Inc.) for better visualization and control. 
         [0065]      FIG. 11  shows a simplified view of an ethanol injection visualization  150  with a number of parts of the surgical instrument  20  omitted for simplicity. In this visualization, a cannula  152  is connected to a manual device or valve  154  for switching between an echogenic agent and the ethanol. One or more sand blasted surfaces in the form of bands  156 ,  158  are located at a distal end  160  of the cannula  152  in order to identify the needle tip and/or the location of injection of ethanol into the prostate  10 . Several means can be employed: 1) The drawing of  FIG. 11  shows a two-syringe system that could inject an agent visible on ultrasound first using the echogenic agent syringe  157 , then inject the ethanol using the ethanol syringe  86  after the position has been identified. The echogenic agent could include microspheres, solid particles in suspension, bubbles, fluids different in density from water, etc. 2) The needle itself can be modified to have better visualization on ultrasound. One way to accomplish this is to roughen the surface of the needle using sandblasting (as shown in  FIG. 11 ) or other means, as illustrated in  FIG. 12   b.    
         [0066]      FIGS. 12   a  and  12   b  show further ethanol injection visualizations  162 ,  164 .  FIG. 12   a  illustrates a means to inject a drug (ethanol) in combination with an echogenic marker or radio-opaque marker simultaneously using a Y-connection  166  where the fluids mix, coming from a first tube  168  having a lumen  170  carrying the ethanol and a second tube  172  having a lumen  174  carrying the echogenic agent, both of which are connected via the Y-connection  166  to the cannula  152 .  FIG. 12   b  illustrates an alternative embodiment of cannula  152  having first and second thin film conductors  176 ,  178  connected near the distal end  160  of cannula  152  to a resistor  180  or thin film/MEMS to produce a temperature signal or a piezo oscillator to produce an ultrasonic beacon. 
         [0067]      FIGS. 13   a  through  15   b  are views of additional embodiments of surgical instruments and methods according to the present invention. These embodiments have a mechanism for raising the needle  25  in a perpendicular or substantially perpendicular fashion relative to the sides of a needle deployment port. Optionally, an infrared or other light spot may be projected perpendicular to the sheath to the location in the body that would receive the needle. This feature would allow the surgeon to presight or target the specific tissue to be treated. 
         [0068]      FIGS. 13   a ,  13   b ,  13   c ,  13   d ,  14   a ,  14   b ,  15   a  and  15   b  show various embodiments of the present invention which have structure for raising the needle in perpendicular or substantially perpendicular direction to the longitudinal axis of the device. Moving the needle in this fashion is believed to provide better control over placement of the needle and thus, the injectable substance. Assemblies for raising a structure in a direction that is perpendicular or substantially perpendicular to the longitudinal axis of a surgical device are described in U.S. Pat. No. 5,306,284 to Agee et al., the contents of which are incorporated herein by reference. 
         [0069]      FIGS. 13   a  and  13   b  illustrate an embodiment having needle  182  operated by a pusher  184 , which moves in the direction of arrow  186  to raise the needle  182  along path  183  and in the general direction of arrow  185 .  FIG. 13   c  is a perspective view corresponding to  FIG. 13   a , and  FIG. 13   d  is an exploded view of this embodiment. It is to be understood that one or more trunnions  188  project out from needle  182  without blocking or providing a leak path with respect to the lumen  190  interior of needle  182 . In  FIGS. 13   c  and  13   d  it is to be understood that pivot pin  189  is secured to a housing  191  of the assembly. In  FIG. 13   c  the needle  182  is guided by a slot  187  to avoid urethral damage that might otherwise occur due to excessive needle displacement. Furthermore, such a slot guide is expected to reduce the potential for high backflow due to low resistance with an enlarged opening that could reduce the effectiveness of the treatment using the apparatus or method of the present invention.  FIGS. 14   a  and  14   b  illustrate another embodiment having needle  182  operated by pusher  184 , with at least two trunnions  188  on needle  182 . Pusher  184  is moved in the direction of arrow  186  to raise needle  182  generally in the direction of arrow  185 . 
         [0070]      FIGS. 15   a  and  15   b  illustrate still another embodiment having needle  182  operated by pusher  184  via trunnion  188  on needle  182 . Pusher  184  is pushed in the direction of arrow  186  to raise needle  182  generally in the direction of arrow  185 . In this embodiment, a plate  192  having a curved slot  194  is fastened to needle  182  by conventional means such as welding  196 . Slot  194  acts against a roller  196  secured to housing  198  to cause needle  182  to move in response to movement of pusher  184 . 
         [0071]    Referring now to  FIG. 17 , a still further variation of a lockout release  42  may be seen. In this variation, a loose pin  200  (preferably retained by a tether  202 ) is inserted manually into one of a plurality of pairs of through apertures  204  present for the detents  28  in the Prostaject device  50 . Placing the pin  200  in an aligned aperture pair  204  prevents advancement of the slide  45  associated with thumb ring  34  past a desired detent position with respect to frame  48  associated with handle  30 , and thus prevents over advancing needle  25  from the needle deployment port  24 . It is to be understood that  FIG. 17  shows pin  200  in both an installed position in aperture  204 , and in a free position, with the tether indicated by dashed line  206  in the free position. It is to be further understood that the apertures corresponding to predetermined distances the needle may be extended correspond to the various detent positions. In operation, the slide will be released to advance until an edge of the structure of the slide contacts the pin in one of the apertures  204 , limiting the movement of the slide with respect to the frame, as desired. A further variation of this approach is to provide an aperture which prevents any extension of the needle with the pin received in the aligned aperture pair, with one aperture in the slide and the other aperture in the frame. 
         [0072]      FIG. 18   a  is a fragmentary view and  FIG. 18   b  is a partial section view (along line  18   b - 18   b  of  FIG. 18   a ) of yet another variation of the lockout release  42 . In this variation, each detent  28  is surrounded by a generally spherical recess  208 . In this variation, a ball  210  of the detent  28  projects sufficiently far out of a recess  212  in slide  45  to block transverse movement of slide  45  with respect to frame  48 . When it is desired to permit transverse movement of slide  45  with respect to frame  48  (to advance or retract needle  25 ) ball  210  is manually depressed into recess  212  by engagement of an operator&#39;s finger in the spherical recess  208 . A spring  214  urges ball  210  away from recess  212 . It is to be understood that the frame  48  of the handle  30  of the Prostaject device  50  currently has the ball  210  that fit into the holes  204  to indicate position and act as detents  28  because the ball  210  only rests partially in one of holes  204 . This currently gives slight resistance to movement. If the ball  210  and hole diameter are sized to give a positive lock, that cannot be overcome by just the pressure on the thumb ring  34  pushing the slide  45  forward toward the handle  30 . in one form of this variation, only the back hole  216  can be made such that a finger of the operator&#39;s hand can push the ball  210  in and release the lock in the hole  216 , while the other holes  204  can be sized to give only slight interference. 
         [0073]    Referring now to  FIGS. 19   a  and  19   b , a stepped cam version of the lockout release  42  is shown. In this version a stepped cam  218  is located for rotational movement on the projection  220  that carries the ethanol syringe port  32 . The stepped cam  218  is in the form of a disk having steps  222 ,  224 ,  226 , and  228  with different radii and individual indices, represented by the letters “A” “B” “C” and “D.” It is to be understood that the projection  220  moves forward to the top finger support  230  where the cam  218  will hold the slide and frame apart by the distance set by the respective radius selected on cam  218  to be positioned between the projection  220  and finger support  230 . In operation, when the physician is ready to advance the needle  25  out from port  24 , he or she would rotate the disk  218  to a position that allows the needle  25  to be advanced to a predetermined distance. The physician would then advance the thumb ring  34  toward handle  30 , moving needle  25  forward until the selected step on disk  218  bottoms out against finger support  230 . It is to be understood that the indices associated with the steps preferably indicate the respective distances of advance for the needle  25 . 
         [0074]    Referring now to  FIG. 20 , a de-coupling mechanism useful in the practice of the present invention may be seen. In this version, a switch  242  provides for de-coupling a handle  240  from the needle  25  to prevent unwanted needle extension instead of blocking relative movement of the two members as described for the embodiment of, e.g.,  FIG. 5 . This allows the handle  240  to slide back and forth without movement of the needle until the switch or button  242  is pushed (or other actuation is used) that re-couples the handle  240  to the needle  25  and then allows the needle  25  to be advanced with the handle  240 . Specifically, in  FIG. 20 , the handle  240  (corresponding to thumb ring  34 ) is able to move relative to the needle  25  without button  242  being pushed. When button  242  is pushed, the handle  240  is mechanically connected to the needle  25  to advance and retract the needle, by movement of the handle  240  with respect to handle or finger grip  30 . It may thus be seen that the embodiment of  FIG. 20  provides selective coupling apparatus for a surgical instrument of the type having an remotely controllable extendable and retractable needle. The selective coupling apparatus includes a mechanism for selectively engaging and releasing first and second members (such as handles  240  and  30 ) from moving with respect to each other. The mechanism provides a mechanical connection between the first and second members when in an operating condition (when button  242  is pushed) and the mechanism provides clearance between the first and second members when in a de-coupled condition (when button  242  is released). 
         [0075]    In describing preferred embodiments of the invention, specific terminology is used for the sake of clarity. The invention, however, is not intended to be limited to the specific terms so selected, and it is to be understood that each term so selected includes all technical equivalents that operate similarly. 
         [0076]    These and other advantages of the invention are more fully shown and described in the drawings and detailed description of this invention, where like reference numerals are used to represent similar parts. It is to be understood, however, that the drawings and description are for the purposes of illustration only and should not be read in a manner that would unduly limit the scope of this invention. This invention may take on various modifications and alterations without departing from the spirit and scope thereof.