Abstract:
A cryosurgical instrument that is selectively positioned in a patient tissue by rotation. The instrument includes: a manipulation section that permits a user to rotate the instrument; a cryogen supply portion; and a positioning section having a sharp tip at an end and a helical configuration, the positioning section configured to receive cryogen and to permit the received cryogen to cool the positioning section. The positioning section urges the cryosurgical instrument deeper into the patient when the instrument is rotated in a first direction, via the manipulation section, and urges the cryosurgical instrument outward when the instrument is rotated in a second direction that is opposite the first, via the manipulation section.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. provisional patent application No. 61/382,953, filed on Sep. 15, 2010. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    Embodiments of the present invention relate generally to cryosurgical instruments such as cryoprobes and, more particularly, to cryosurgical instruments suitable for the ablation of a large volume of tissue. 
         [0004]    2. Description of Related Art 
         [0005]    Cryosurgical ablation of a large volume of tissue typically involves placement of several (i.e., multiple) cryosurgical instruments within a defined volume to cause continuous ablation of the tissue in that volume. 
         [0006]    Two principles are used to assist the physician to obtain the desired relationship between the cryosurgical instruments: some type of guide, such as an external template, or guiding sleeves; and clustering the cryosurgical instruments for insertion to the defined volume, typically simultaneously. The cryosurgical instrument penetrates the tissue along its main axes. The templates or the guiding sleeves can bend the flexible cryosurgical instrument and direct it in relationship to the other inserted cryosurgical instruments. However, the instrument may only be bent at a narrow angle, in order to maintain the integrity of the instrument. 
         [0007]    The proper positioning of the cryosurgical instruments in relation to each other depends on the flexibility of the cryosurgical instruments, the diameter of the guide (and hence the degree of “play” or potential inaccuracy in guiding the instruments), and the skill of the physician. An instrument with greater flexibility may be more easily bent within the template or the sleeve, but once it is outside this guide, the instrument may bend further and so may not maintain the desired position. The diameter of the guiding element is always larger than the diameter of the cryosurgical instrument and therefore, further introduces error. Finally it is the judgment of the physician through the information received by the imaging tool, such as ultrasound imaging, CT or MRI, to determine whether the position of the cryosurgical instruments is adequate in three-dimensional space. Since the cryoablation volume induced by a single individual instrument is small in size, the relationship between the cryosurgical instruments is crucial to the success of the treatment. As a result, a physician may frequently insert more cryosurgical instruments than necessary to treat the required volume. 
         [0008]    An additional challenge in the placement of several cryosurgical instruments in the selected tissue is caused by the deformability of human tissue, and the need for fixation of the organ within the body. To solve this problem two approaches are used: (1) cooling the first instrument to a temperature that effectively sticks the instrument to the tissue (creating contact surface of −20° C. or lower); or (2) holding the organ in place, using a mechanical anchor such as cork-screw element, while inserting several cryosurgical instruments into it. 
         [0009]    The use of corkscrew (i.e., helical) type elements as mechanical anchors for various cryosurgical purposes is known (see, e.g., U.S. Pat. and Patent Publication Nos. 6,343,605, 6,004,269, 7,567,838, 2006/0253080, 2009/0292279 and 2010/0015196) or as a grasper (see. e.g., U.S. Patent Publication No. 2008/0294179). 
         [0010]    The use corkscrew type elements to attach other components to each other is also known (see, e.g. , U.S. Pat. Nos. 4,917,106 and 5,195,540 and U.S. Patent Publication No. 2006/0259050). Similarly, a thermocouple has been attached to the cork screw element as a sensor during surgery (see, e.g., U.S. Pat. Nos. 5,800,432, 5,688,266, 5,688,267, 6,053,912, and 5,735,846. 
         [0011]    A corkscrew type element has been also used to transmit electrical signals (see, e.g., U.S. Pat. No. 5,6269,272 and U.S. Patent Publication No. 2005/0101984), and as a RF electrode (see, e.g., U.S. Patent Publication 2004/0147917). 
         [0012]    A corkscrew element has also been used as a biopsy tissue sampler (see, e.g., U.S. Pat. Nos. 4,682,606 and 6,142,957 and U.S. Patent Publication No. 2004/0147917) and as a lesion marker (U.S. Pat. No. 5,195,540) or as a vertebral support (U.S. Patent Publication No. 2008/0140203). 
       BRIEF SUMMARY 
       [0013]    The background art does not provide, however, a helical element, introduced by rotation, suitable for cryosurgical applications, in which the element transmits cryogens and ablates a large volume of tissue without the placement of several (i.e., multiple) cryosurgical instruments within a defined volume to cause continuous ablation of the tissue in that volume. 
         [0014]    One aspect of the present invention provides a cryosurgical instrument that is selectively positioned in a patient by rotation, including: a manipulation section that permits a user to rotate the instrument; a cryogen supply portion; and a positioning section having a sharp tip at an end thereof and a helical configuration, the positioning section configured to receive cryogen from the cryogen supply portion and to permit the received cryogen to cool the positioning section. 
         [0015]    A further aspect of the present invention provides a cryosurgical instrument having a substantially smooth, temperature conducting outer surface with an inner side, including: a sharp tip at an end to facilitate penetration into tissue; one or more cryogen supply lines that supply cryogen to the instrument; a manipulation section for positioning the instrument, at least a portion of the manipulation section extending along and defining a longitudinal axis of the instrument, the manipulating section having insulation along at least a portion of a length thereof, and a return fluid sleeve to permit exhaust of expanded fluid from the instrument; a cooling section connected to the manipulation section, extending from the manipulation section to the tip, and having a helical configuration spiraling around the longitudinal axis, and a heat exchanger in fluid communication with the one or more cryogen supply lines, surrounding the one or more cryogen supply lines in the cooling section, and delivering received cryogen to a port at a distal end thereof proximal to the tip, the heat exchanger including a plurality of channels that are circumferentially disposed along the inner side of the outer surface and that interconnect the one or more supply lines to the a return gas sleeve, the heat exchanger permitting cryogen from the one or more supply lines to cool the cooling section; and an expanded fluid return pathway surrounding the one or more cryogen supply lines and bounded by the one or more cryogen supply lines and the inner side of the outer surface of the instrument so that gas in the pathway is in thermal communication with the inner side. 
         [0016]    Another aspect of the present invention provides a cryosurgical instrument having a substantially smooth, temperature conducting outer surface with an inner side, including: a sharp tip at an end to facilitate penetration into tissue; a manipulation section for positioning the instrument, at least a portion of the manipulation section extending along and defining a longitudinal axis of the instrument, the manipulating section having insulation along at least a portion of its length; a cooling section connected to the manipulation section, extending from the manipulation section to the tip, and having a helical configuration spiraling around the longitudinal axis; one or more cryogen supply lines that supply cryogen to the instrument, each supply line delivering cryogen to one or more ports along a portion of a length thereof in the cooling section, at least one of the supply lines having a port at a distal end thereof proximal to the tip; and a return fluid sleeve to permit exhaust of expanded gas from the instrument, the sleeve surrounding the one or more cryogen supply lines and bounded by the one or more cryogen supply lines and the inner side of the outer surface of the instrument so that fluid in the sleeve is in thermal communication with the inner side, the sleeve permitting cryogen from the one or more supply lines to cool the cooling section. 
         [0017]    Still another aspect of the present invention provides a cryosurgical instrument having a substantially smooth, temperature conducting outer surface with an inner side, including: a sharp tip at an end to facilitate penetration into tissue; a cryogen supply line that delivers cryogen to a port at an end proximal to the tip; a manipulation section for positioning the instrument, at least a portion of the manipulation section extending along and defining a longitudinal axis of the instrument, the manipulating section having insulation along at least a portion of a length thereof, and a return fluid sleeve to permit exhaust of expanded gas from the instrument; a cooling section connected to the manipulation section, extending from the manipulation section to the tip, and having a helical configuration spiraling around the longitudinal axis, and a barrier that is disposed only in the cooling section and spirals about the cryogen supply line, the barrier yielding a spiraling channel that is circumferentially disposed along the inner side of the outer surface, that is bounded by the cryogen supply line and the inner side of the outer surface of the instrument, and that interconnects the supply line to the a return gas sleeve, the barrier permitting cryogen exiting the port to cool the cooling section. 
         [0018]    Yet another aspect of the present invention provides a cryosurgical instrument having a substantially smooth, temperature conducting outer surface with an inner side, including: a sharp tip at an end to facilitate penetration into tissue; a cryogen supply line that delivers cryogen to a port at an end proximal to the tip; a manipulation section for positioning the instrument, at least a portion of the manipulation section extending along and defining a longitudinal axis of the instrument, the manipulating section having insulation along at least a portion of a length thereof, and a return fluid sleeve to permit exhaust of expanded gas from the instrument; a cooling section connected to the manipulation section, extending from the manipulation section to the tip, and having a helical configuration spiraling around the longitudinal axis, and a core that is disposed only in the cooling section and that extends from the manipulating section to substantially near the tip. The cryogen supply line spirals around the core. The spiraling of the cryogen supply line yields a spiraling channel that is circumferentially disposed along the inner side of the outer surface, that is bounded by the cryogen supply line and the inner side of the outer surface of the instrument, and that interconnects the supply line to the a return fluid sleeve, the spiraling channel permitting cryogen exiting the port to cool the cooling section. 
         [0019]    Optionally, the cryosurgical instrument features a single tip and in operation, is used singly to ablate the large volume of tissue, without requiring the insertion of multiple cryosurgical instruments. 
         [0020]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is neither intended to identify key features or essential features of the claimed subject matter, nor should it be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantage noted in any part of this application. 
         [0021]    These, additional, and/or other aspects and/or advantages of the present invention are: set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The present invention will be more readily understood from the detailed description of embodiments thereof made in conjunction with the accompanying drawings of which: 
           [0023]      FIG. 1   a  is a partial cut-away view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0024]      FIG. 1   b  is a cross-sectional view of the cryosurgical instrument of  FIG. 1   a  taken along line A-A of  FIG. 1   a;    
           [0025]      FIG. 2   a  is a partial cut-away view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0026]      FIG. 2   b  is a cross-sectional view of the cryosurgical instrument of  FIG. 1   a  taken along line A-A of  FIG. 1   a;    
           [0027]      FIG. 3  is a side view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0028]      FIG. 4  is a side view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0029]      FIG. 5   a  is a partial cut-away, side view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0030]      FIG. 5   b  is a perspective view of a heat exchanger of the cryosurgical instrument of  FIG. 5   a;    
           [0031]      FIG. 5   c  is a cross-sectional view of the cryosurgical instrument of  FIG. 5   a  taken along line A-A of  FIG. 5   a;    
           [0032]      FIG. 6   a  is a partial cut-away, side view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0033]      FIG. 6   b  is a cross-sectional view of the cryosurgical instrument of  FIG. 6   a  taken along line A-A of  FIG. 6   a;    
           [0034]      FIG. 7  is a partial cut-away, side view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0035]      FIG. 8  is a partial cut-away, side view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0036]      FIG. 9  is a partial cut-away, side view of a cryosurgical instrument that is consistent with an embodiment of the present invention; 
           [0037]      FIGS. 10   a  and  10   b  respectively illustrate a system that is consistent with an embodiment of the present invention in a retracted and a protracted state; and 
           [0038]      FIG. 11  is a side view of a cryosurgical instrument that is consistent with an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0039]    Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures. 
         [0040]    Although the following text sets forth a detailed description of at least one embodiment or implementation, it is to be understood that the legal scope of protection of this application is defined by the words of the claims set forth at the end of this disclosure. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments and/or implementations are both contemplated and possible, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims. 
         [0041]    It is to be understood that, unless a term is expressly defined in this application using the sentence “As used herein, the term’ ‘is hereby defined to mean . . . ” or a similar sentence, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term is limited, by implication or otherwise, to that single meaning. Finally, unless a claim element is defined by reciting the word “means” and a function without the recital of any structure, it is not intended that the scope of any claim element be interpreted based on the application of 35 U.S.C. §112, sixth paragraph. 
         [0042]    As used herein, “large volume of tissue” means a volume that is greater than that which may be ablated with a standard straight cryosurgical instrument, as is currently known in the art. As used herein, “standard cryosurgical instrument” means a (i.e., conventional) cryoprobe with a single cooling zone, inserted either along its main axis or approximately in that direction. One example of such a conventional cryprobe is a cryoneedle. 
         [0043]    Turning now to the drawings,  FIGS. 1   a  and  1   b  illustrate a cryosurgical instrument  100  that is consistent with an embodiment of the present invention.  FIG. 1   a  shows a partial cut-away of cryosurgical instrument  100 , while  FIG. 1   b  shows a cross-section thereof taken along line A-A of  FIG. 1   a.    
         [0044]    The cryosurgical instrument  100  comprises a manipulation section  110  distal to a tip  103  of the cryosurgical device and a cooling section  105  extending from the manipulating section  110  to the tip  103 . 
         [0045]    The manipulating section  110  extends along and partially defines a longitudinal axis (not shown) of the cryosurgical instrument  100 . The manipulating section  110  includes insulation  108  along at least a portion of its length and a return gas sleeve  107  in gaseous communication with channels  109  to permit the exhaust of expanded/returning cryogen, as explained in detail below. 
         [0046]    The cryosurgical instrument  100  features a helical portion  104 , with surface  101  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  104  includes one or more spirals  111 , as illustrated, and terminates in a tip  103  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  111  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  104  may be constant as illustrated or may vary in pitch and/or diameter. 
         [0047]    The helical portion  104  may be disposed entirely within a cooling section  105  of the cryosurgical instrument  100 , as shown. Alternatively, the helical portion  104  may be disposed partially beyond the cooling section  105 . 
         [0048]    Cryogen (liquid, compressed gas or mixtures of gases) enters the cryosurgical instrument  100  through one or more feeding lines  102  and travels, via a heat exchanger  106 , through the cryosurgical device toward the tip  103 . 
         [0049]    Heat exchanger  106  receives the cryogen from the one or more feeding tubes  102  and delivers the cryogen to the tip  103  via port  113 , which is located proximal to the tip  103 . In more detail, the cryogen flows through the heat exchanger  106 , thereby cooling the heat exchanger  106 . And, since the heat exchanger  106  is in thermal communication with the outer surface  101 , the outer surface is, in turn, cooled. In this process, the cryogen either expands or evaporates and cools, through the Joules-Thompson effect or simple evaporation. The cryogen is emitted near tip  103  through a port  113 . Thereafter, the returning cryogen (cooled by the expansion, or evaporation) flows through the channels  109 , which is in contact with the inner surface of the cryosurgical instrument  100 , cooling the surface  101 . The cryogen is then exhausted in a return sleeve  107  that preferably runs within and through the inner diameter of the insulation  108 . 
         [0050]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  105  to encompass the tip  103 . Tip  103  may optionally comprise a reflective surface  112 , as shown. 
         [0051]    Referring specifically to  FIG. 1   b,  the arrangement of the one or more feeding lines  102 , the heat exchanger  106 , the channels  109  and the cooling surface  101  are illustrated. While six channels are illustrated, it is to be understood that other numbers are both possible and contemplated. 
         [0052]    The cooling surface  101  may optionally comprise one or more of metal, ceramic material, or plastic. The cooling section  105  is terminated at proximal end by insulation  108 . 
         [0053]    The use of the cryosurgical instrument  100  is discussed. The tip  103  of the cryosurgical instrument  100  is brought into contact with the tissue of a patient. Then sufficient force is applied to cause the tip  103  to pierce the skin of the patient. Contemporaneously or immediately thereafter, the cryosurgical instrument  100  is rotated in a manner akin to the insertion of a corkscrew into a cork so that the helical portion is embedded in the tissue. This rotational insertion causes the helical portion  104  to draw the instrument  101  toward/into the tissue to be ablated. Next, when the freezing portion  105  is positioned as desired, cryogen is supplied to cool the cooling section. 
         [0054]    As the aforementioned description implies, the helical configuration of the cooling section  105  serves as a positioning section. 
         [0055]    When the helical portion  104  is firmly embedded in the tissue of a patient, the spiral arrangement secures the cryosurgical instrument in the tissue. Also, when in the body, the instrument  100  can be positioned with far less forward or rearward pressure than conventional cryoprobes since the selective rotation of the helical portion  104  urges the instrument into the instrument into the body or urges the instrument out of the body. Further, the instrument  100  can be positioned with a majority of the force applied to the instrument applied to rotate the instrument. 
         [0056]      FIGS. 2   a  and  2 B illustrate another example of a cryosurgical instrument consistent with an embodiment of the present invention.  FIG. 2   a  shows a partial cut-away of cryosurgical instrument  200 , while  FIG. 2   b  shows a cross-section thereof taken along line A-A of  FIG. 2 . 
         [0057]    In a cryosurgical instrument  200 , the cryogen cools surface  201 , by either expansion or evaporation, with the assistance of a plurality of discrete heat exchange elements  206 , featuring grooves  209 . A plurality of grooved heat exchange elements  206  is disposed in multiple locations along the cooling section  205  of the length of the cryosurgical device  200 . Specific locations for the heat exchange elements depend on the desired volume of ablation. 
         [0058]    The cryosurgical instrument  200  features a helical portion  204 , with surface  201  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  204  includes one or more spirals  211 , as illustrated, and terminates in a tip  203  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  211  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  204  may be constant as illustrated or may vary. 
         [0059]    The helical portion  204  is disposed entirely within a cooling section  205  of the cryosurgical instrument  200 , as shown. Alternatively, the helical portion  204  may be disposed partially beyond the cooling section  205 . 
         [0060]    Cryogen (liquid, compressed gas or mixtures of gases) enters the cryosurgical instrument  200  through one or more feeding lines  202  and travels to port  213 , which is proximal to the tip  203 . 
         [0061]    The heat exchange elements  206  operate in a manner similar to the heat exchanger  106  of  FIG. 1   a,  where the grooves  209  allow the flow of the cryogen into the return gas sleeve  207 , thereby cooling the inner surface of cryosurgical instrument  200  at a plurality of locations as shown. Such cooling causes freezing of tissue that is in contact with the cooling surface  201 . The absorption of the heat from the tissue occurs throughout the cooling section  205  by either conduction through the cooled surfaces of the grooved heat exchange elements  206  or by flow of cryogen in contact with the inner surface of cryosurgical instrument  100 , up to the return fluid sleeve  207 , or both. Insulation  208  keeps the manipulation section  210  from being cooled by the cryogen. 
         [0062]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  205  to encompass the tip  203 . Tip  203  may optionally comprise a reflective surface  212 , as shown. 
         [0063]    Preferably the distribution of the grooved heat exchange elements is sufficient to yield a single, continuous ablations zone. However, the inventors also contemplate distributions that provide discrete ablations zones along segments of the length of the helical portion  204 . 
         [0064]      FIG. 3  shows another example of another cryosurgical instrument consistent with an embodiment of the present invention. 
         [0065]    The cryosurgical instrument  300  features a helical portion  304  that includes several spirals  311  such that the freezing portion spirals more than 360 degrees. Optionally any type of heat exchange element, such as the above-described grooves may be employed (not shown). The surface area in the cooling section  305  is therefore greater than the equivalent cooling surface of the systems of  FIGS. 1   a - 2   b.    
         [0066]      FIG. 4  shows another example of a cryosurgical instrument consistent with an embodiment of the present invention. In cryosurgical instrument  400 , the cryogen may optionally comprise any type of fluid and can be adapted for Joule-Thomson cooling. As is known in the art, Joule-Thomson cooling is based upon the Joule-Thomson effect, in which a compressed fluid is forced through a narrow opening, resulting in rapid expansion of the compressed fluid, and cooling of the fluid. 
         [0067]    The cryosurgical instrument  400  features a helical portion  404 , with surface  401  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  404  includes one or more spirals  411 , as illustrated, and terminates in a tip  403  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  411  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  404  may be constant as illustrated or may vary. 
         [0068]    The helical portion  404  is disposed entirely within a cooling section  405  of the cryosurgical instrument  400 . 
         [0069]    Cryogen (liquid, compressed gas or mixtures of gases) enters the cryosurgical instrument  400  through cryogen feed line  402  and travels toward the tip  103 . 
         [0070]    To support the Joule-Thomson effect, cryosurgical instrument  400  preferably features one or more adiabatic nozzles  413  to introduce the fluid cryogen into the inner area of cryosurgical instrument  400 . Upon expansion or evaporation of the cryogen, depending on the type of fluid, the surface  401  is cooled generating the cooling section  405 . Optionally, nozzle(s)  413  may be provided as ports or other openings (not shown). 
         [0071]    Alternatively, if one adiabatic expansion nozzle  413  is used, the adiabatic expansion nozzle  413  is preferably located at or near tip  403 . If a plurality of nozzles  413  is used, such adiabatic expansion nozzles  406  are preferably installed at multiple locations along the inlet feeding tube  402 , more preferably distributed more or less equally. Such one or more adiabatic expansion nozzles  413  let part, or all, of the pressurized cryogen flowing in the cryogen feed line  402 , to exit and expand. The cryogen feed line  402  delivers the cryogen, or portion of it if a plurality of nozzles  413  is present, to the tip  403 . 
         [0072]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  405  to encompass the tip  403 . Tip  403  may optionally comprise a reflective surface  412 , as shown. In addition, heat regenerating coils, not shown, may be added within the supply tube  402  and/or at each port  406 , to cool the compressed fluid before it is ejected from each port. 
         [0073]      FIGS. 5   a - 5   c  show an example of another cryosurgical instrument consistent with an embodiment of the present invention.  FIG. 5   a  shows a partial cut-away view of the cryosurgical instrument  500 .  FIG. 5   b  is a perspective view of the helical grooves  509  in relation to cryogen supply line  502 .  FIG. 5   c  is a cross-sectional view taken along line A-A of  FIG. 5   a.    
         [0074]    The cryosurgical instrument  500  features a helical portion  504 , with surface  501  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  504  includes one or more spirals  511 , as illustrated, and terminates in a tip  503  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  511  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  504  may be constant as illustrated or may vary. 
         [0075]    The helical portion  504  is disposed entirely within a cooling section  505  of the cryosurgical instrument  500 . 
         [0076]    Cryogen (liquid, compressed gas or mixtures of gases) enters the cryosurgical instrument  500  through cryogen feed line  502  and travels to the tip  503 . 
         [0077]    In cryosurgical instrument  500 , a plurality of discrete heat exchange elements  506  are disposed at various locations along a cryogen supply line  502  in a cooling zone  505 . Preferably each of the heat exchange elements  506  comprises a plurality of helical channels  509 . The cryogen supplied by input feeding line  502  then flows back to the return sleeve  507 , cooling the surface  501  by either direct contact of the cryogen flowing along the spaces created between the helical channels  509  and the outer surface of the instrument, or by conduction of heat via the contact surfaces of heat exchange elements  506  and the inner surface of cryosurgical instrument  500 , thereby cooling surface  501 . 
         [0078]    As shown in  FIG. 5   b , the channels  509  spiral about the cryogen supply line. 
         [0079]    Although only a single cryogen supply line  502  is shown, it is to be understood that multiple cryogen supply lines are both possible and contemplated. Also, when multiple cryogen supply lines  502  are present, each line may have multiple heat exchange elements  506 . 
         [0080]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  505  to encompass the tip  503 . Tip  503  may optionally comprise a reflective surface  512 , as shown. 
         [0081]      FIGS. 6   a  and  6   b  show another example of cryosurgical instrument consistent with an embodiment of the present invention.  FIG. 6   a  shows a partial cut-away view while  FIG. 6   b  shows a cross-sectional view along line A-A of  FIG. 6   a.    
         [0082]    The cryosurgical instrument  600  features a helical portion  604 , with surface  601  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  604  includes one or more spirals  611 , as illustrated, and terminates in a tip  603  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  611  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  604  may be constant as illustrated or may vary. 
         [0083]    The helical portion  604  is disposed entirely within a cooling section  605  of the cryosurgical instrument  600 . 
         [0084]    The cryosurgical instrument  600  includes a cryogen feeding input line  602  to feed cryogen to a single heat exchange element  606  having helical channels  609  that extend from a tip  603  to a return gas sleeve  607 . In operation, cryogen enters the cryosurgical instrument  600  via input line  602 , cools the heat exchanger  606 , is discharged through a port  613  proximal to the tip  603 , flows back through the helical channels  609  to the return fluid sleeve  607  thereby cooling the surface  601  by either: (1) direct contact of the cryogen flowing along the helical groove  609 ; or (2) conduction of heat via the contact surface of heat exchange element  606  and the inner surface of cryosurgical instrument  600  thereby cooling the surface  601 , throughout the cooling zone  605 . 
         [0085]    Referring to  FIG. 6   b , the relationship between the spiral grooves  609  and the feed line  602  are illustrated. 
         [0086]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  605  to encompass the tip  603 . Tip  603  may optionally comprise a reflective surface  612 , as shown. 
         [0087]      FIG. 7  shows another example of a cryosurgical instrument consistent with an embodiment of the present invention. The cryosurgical instrument  700  features insulation  708  disposed on the outer surface of the cryosurgical device in the manipulation zone  710 . In this example, a cryogen feeding input line  702  feeds cryogen to a single heat exchange element  706 , which delivers the cryogen to port  713  located proximal to the tip  703 . 
         [0088]    In more detail, the cryosurgical instrument  700  features a helical portion  704 , with surface  701  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  704  includes one or more spirals  711 , as illustrated, and terminates in a tip  103  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  711  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  704  may be constant as illustrated or may vary. 
         [0089]    The helical portion  704  is disposed entirely within a cooling section  705  of the cryosurgical instrument  700 . 
         [0090]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  705  to encompass the tip  703 . Tip  703  may optionally comprise a reflective surface  712 , as shown. 
         [0091]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  705  to encompass the tip  703 . Tip  703  may optionally comprise a reflective surface  712 , as shown. 
         [0092]      FIG. 8  shows an example of another cryosurgical instrument  800  consistent with an embodiment of the present invention. 
         [0093]    The cryosurgical instrument  800  features a helical portion  804 , with surface  801  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  804  includes one or more spirals  811 , as illustrated, and terminates in a tip  803  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  811  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  804  may be constant as illustrated or may vary. 
         [0094]    The helical portion  804  is disposed entirely within a cooling section  805  of the cryosurgical instrument  800 . 
         [0095]    In cryosurgical instrument  800 , a cryogen feeding input line  802  delivers cryogen to a tip  803 . The cryosurgical instrument  800  also includes a barrier  816  that urges the flow of returning cryogen toward outer surface  801  of the cryosurgical instrument  800  so as to cool surface  801 . Barrier  816  effectively forces the return fluid to flow in an open space  819  between the barrier  816  from tip  803  to the return gas sleeve  807 , creating the cooling zone  805 . The cooling zone  805  ends at insulation  808  that is located in manipulation zone  810 . 
         [0096]    The barrier  816  is illustrated as a coiled tube. However, it is to be understood that other configurations are both possible and contemplated. Indeed, the barrier  816  need not have the round cross-section as shown. Rather, any cross-section that urges the return flow towards the outer surface may be used. Also, the barrier may spiral with constant pitch as illustrated. Alternatively, the barrier  816  may spiral at a varied pitch. 
         [0097]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  805  to encompass the tip  803 . Tip  803  may optionally comprise a reflective surface  812 , as shown. 
         [0098]      FIG. 9  shows an example of a cryosurgical instrument  900  consistent with an embodiment of the present invention. 
         [0099]    The cryosurgical instrument  900  features a helical portion  904 , with surface  901  that, when inserted into a patient, is in contact with the tissue of the patient. The helical portion  904  includes one or more spirals  911 , as illustrated, and terminates in a tip  903  that is preferably sharp to ease penetration into the tissue. Although two spirals are illustrated, it is to be understood that other numbers of spirals are both possible and contemplated. In this regard, the inventors have determined that a plurality of spirals  911  can be optimal in many cryosurgical applications. Further, the spirals of the helical portion  904  may be constant as illustrated or may vary. 
         [0100]    The helical portion  904  is disposed entirely within a cooling section  905  of the cryosurgical instrument  800 . 
         [0101]    In cryosurgical instrument  900 , a cryogen feeding input line  902  is coiled around a solid core  915 , from the return fluid sleeve  907  to the tip  903 , ending with port  913  at which the cryogen is left to flow within the cooling surface  901 . In operation, cryogen flowing in the coiled line  902  cools the surface of the coiled tube  902 . This surface, in turn, cools the inner surface of the cryosurgical instrument  900 , which, in turn, is in thermal communication with and cools the cooling surface  901 . After the cryogen exits the supply line  902  at a port  913 , it flows back through the gap  919  created by the inlet tube  902  as a barrier next to the inner surface of cryosurgical instrument  900 . 
         [0102]    The cryogen supply line  902  may spiral at a constant rate as illustrated. Alternatively, the cryogen supply line  902  may spiral at a varied rate. 
         [0103]    The inventors have discovered that for many cryosurgical applications, it can be preferable to extend the cooling section  905  to encompass the tip  903 . The cooling zone  905  ends at insulation  908  that is located in a manipulation section (not shown). Tip  903  may optionally comprise a reflective surface  912 , as shown. 
         [0104]      FIGS. 10   a  and  10   b  show an example of a system that includes a cryosurgical instrument consistent with an embodiment of the present invention.  FIG. 10   a  illustrates a system  1000  with a flexible cryosurgical instrument  1001 . The instrument  1001  includes a helical section  1004  and a sharp tip  1003 . The instrument  1001  is selectively retractable into (i.e., drawn into) a sleeve  1020  of, for example a trocar, and selectively protractable from (i.e., extendable from) the sleeve  1020 . To facilitate this functionality, the instrument  1001  is flexible and compressible. Optionally, the cryosurgical instrument may be made of material with memory. 
         [0105]    Following the insertion of the cryosurgical instrument  1001  through the sleeve  1020 , the mechanical flexibility of the instrument  1001 , an applied pressure, and/or a temperature increase, causes the instrument to expand from the retracted condition shown in  FIG. 10   a  to the protracted condition as shown in  FIG. 10   b . Cryosurgical instrument  1001  may be any instrument consistent with any embodiment of the present invention. 
         [0106]      FIG. 11  shows an example of another cryosurgical instrument consistent with an embodiment of the present invention.  FIG. 11   a  shows a side view of cryosurgical instrument  1100 , while  FIG. 1   b  shows a cross-section thereof taken along line A-A of  FIG. 11   a.    
         [0107]    Cryosurgical instrument  1100  features a plurality of individual cryosurgical instruments  1101  arranged in a cluster, each with the same pitch and outside diameter. The plurality may include three instruments, as illustrated, although other numbers are both contemplated and possible. Also, all of the instruments may be the same instrument as illustrated, or a combination of different cryosurgical instruments. 
         [0108]    Each cryosurgical instrument  1101  may be any instrument consistent with any embodiment of the present invention. 
         [0109]    The cooling sections  1105  of each instrument  1101  may spiral about the longitudinal axis at a diameter and pitch that differs from those of the other cooling sections of the other instruments. Alternatively, the cooling sections  1105  of each instrument  1101  may spiral about the longitudinal axis at a diameter and pitch that is the same as those of the other cooling sections of the other instruments. 
         [0110]    The use of each of cryosurgical instruments  200 ,  300 ,  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000 , and  1101  is substantially similar to that of cryosurgical instrument  100 . 
         [0111]    As the foregoing shows, a specially shaped cryosurgical instrument has been devised that facilitates: placing several cryoprobes, or cryo-coolers, closely in relation to one another; positioning them in flexible unfixed organ; and eliminating the need for a guide. The novel cryosurgical instrument penetrates the tissue by rotation. The treatment of the large volume of tissue is achieved by either several cooling elements, prepositioned, or by cooling the whole surface of defined ablation zone. The prepositioned ablating elements eliminate the needed skill of the physician to place several small cryosurgical instruments in relation to one another to create continuous volume of ablation. Consequently, the need to penetrate the tissue in several places is avoided. In addition, because of its shape, the novel instrument is anchored in the tissue to retain it in its position during thawing part of the process without an additional holding force. 
         [0112]    An aspect of the present invention provides a cryosurgical instrument including a helical element that receives a cryogenic fluid and a tip that is cooled by the cryogenic fluid. The portion of the instrument that is cooled by the cryogenic fluid may optionally include an extended distal section of the instrument that, together with the tip, is a cooling zone. Upon insertion to a tissue the cooling zone is cooled and causes an ice ball to form, thereby causing cryoablation of the tissue volume defined by the ablation zone of the instrument. 
         [0113]    As the foregoing also shows, cryosurgical instruments according to at least some embodiments of the present invention overcome the above drawbacks of the background art, including but not limited to, the requirement to insert several cryosurgical instrument in a defined spatial volume and in relation to each other, to position such cryosurgical instruments in a flexible unfixed organ, and the need for a template or guiding element. 
         [0114]    Cryosurgical instruments according to at least some embodiments of the present invention, featuring at least one helical element, penetrate the tissue by rotation. By turning the instrument, the tip and the body of the instrument penetrate deep into the tissue. The treatment of the large volume of tissue is achieved by either several cooling elements, prepositioned within or attached to the cryosurgical instrument, or by cooling the whole surface of defined ablation zone. The prepositioned ablating elements eliminate the needed skill of the physician to place several small cryosurgical instruments in relation to one another to create a continuous volume of ablation. Another advantage is the creation of a single hole, rather than multiple holes as for the background art instruments. This instrument is also, inherently from its shape, anchored in the tissue and optionally no additional holding force is required to retain it in its position during thawing part of the process. 
         [0115]    As previously described, at least a portion of the cryosurgical instrument is in the shape of a spiral or corkscrew element, with a tip that is preferably a sharp penetrating tip. As the instrument enters the tissue to be ablated, rotation of the instrument causes the penetration thereof into the tissue. The depth of the penetration is determined by the size of the corkscrew element; however the freezing ablation zone volume is extended further out and forwards depending on the pitch and outside diameter of the spiral and the cooling capacity. The freezing element may either utilize the Joule-Thomson effect caused by expanded high-pressure gas, or evaporating liquefied gas. Heating the element to either thaw the frozen tissue or to release the instrument from the tissue, can be done by either supplying high pressure gas that heats upon expansion (Joule-Thomson method), supplying a heated gaseous form of the liquefied freezing cryogen, or supplying electrical power to specially placed heating elements. 
         [0116]    The use of various ones of the above-described examples is discussed. Generally, the shape of the cryosurgical instrument is a spiral type, with a sharp penetrating tip. As the instrument brought into contact with the desired ablated volume, the instrument is rotated, which causes the penetration of the tissue since the turning causes a forward motion like “cork screw”. The size of the penetration is the size of external tube; however the freezing ablation zone is extended further outward and forward depending on the pitch and outside diameter of the spiral and the cooling capacity. The freezing element may either utilize the Joule-Thomson effect caused by expanded high-pressure gas, or evaporating liquefied gas. Heating the element to either thaw the frozen tissue or to release the instrument from the tissue, can be done by either supplying high pressure gas which heats upon expansion (Joule-Thomson effect), supplying a heated gaseous form of the liquefied freezing cryogen, or supplying electrical power to specially placed heating elements. 
         [0117]    Examples of various features/aspects/components/operations have been provided to facilitate understanding of the disclosed embodiments of the present invention. In addition, various preferences have been discussed to facilitate understanding of the disclosed embodiments of the present invention. It is to be understood that all examples and preferences disclosed herein are intended to be non-limiting. 
         [0118]    Although selected embodiments of the present invention have been shown and described individually, it is to be understood that at least aspects of the described embodiments may be combined. 
         [0119]    Although selected embodiments of the present invention have been shown and described, it is to be understood the present invention is not limited to the described embodiments. Instead, it is to be appreciated that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and the equivalents thereof.