Abstract:
A device for providing fluid to an organ within a living body comprises an elongate member including a distal portion configured for insertion to a target location within a living body. The elongate member includes a withdrawal lumen extending from an outlet in a proximal end thereof to an inlet at a distal end of the elongate member, the inlet opening into a target organ when the distal portion of the elongate member is in the target location. The elongate member further includes an infusion lumen extending from an inlet in the proximal end thereof to an outlet which, when the distal portion of the elongate member is in the target location, opens into the target organ. A first portion of a wall separating the withdrawal lumen from the infusion lumen is configured to move between an expanded configuration and a collapsed configuration in which the cross-sectional area of a first portion of the infusion lumen adjacent to the first portion of the wall is reduced as compared to the expanded configuration so that a cross-sectional area of a first portion of the withdrawal lumen adjacent to the first portion of the wall is greater when the first portion of the wall is in the collapsed configuration than when the first portion of the wall is in the expanded configuration.

Description:
PRIORITY CLAIM 
       [0001]    The present application claims priority to U.S. Provisional Application Ser. No. 61/291,515 entitled “Collapsible Irrigation Channel for Procedures Involving Fluid Circulation” filed on Dec. 31, 2009 to Isaac Ostrovsky, Jozef Slanda and Ashley Seehusen, the entire disclosure of which is incorporated herewith by reference. 
     
    
     BACKGROUND 
       [0002]    One technique for the treatment of menorrhagia involves the ablation of the uterine lining by supplying heated fluid to the uterus. This heated ablation fluid is supplied via a supply lumen in a device inserted into the uterus via the cervix and withdrawn therefrom via a return lumen in the device. To protect the patient, such systems must closely monitor the volume of fluids flowing into and out of the uterus to ensure that fluids are not being absorbed into the body and/or escaping from the uterus (e.g., through a tear in the uterine wall). This also helps these systems maintain desired levels of efficiency and effectiveness. Such systems generally employ concentric lumens extending through a hysteroscope with a first one of the lumens configured to infuse fluid into the body and a second one of the lumens configured to withdraw the fluids from the body. However, dislodged tissue can be aspirated into the return lumen and circulated through the hysteroscope, jamming one or both of the lumens, restricting flow therethrough and/or interfering with the insertion of instruments through the hysteroscope. Obstruction of the circulation can cause burning or other damage to the uterus and reduce the efficacy of the treatment. Furthermore, the rigid structure of the first and second lumens extending through the hysteroscope prevents the insertion of additional instrumentation therethrough. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention is directed to a device for providing fluid to an organ within a living body comprising an elongate member including a distal portion configured for insertion to a target location within a living body. The elongate member includes a withdrawal lumen extending from an outlet in a proximal end thereof to an inlet at a distal end of the elongate member, the inlet opening into a target organ when the distal portion of the elongate member is in the target location. The elongate member further includes an infusion lumen extending from an inlet in the proximal end thereof to an outlet which, when the distal portion of the elongate member is in the target location, opens into the target organ. A first portion of a wall separating the withdrawal lumen from the infusion lumen is configured to move between an expanded configuration and a collapsed configuration in which the cross-sectional area of a first portion of the infusion lumen adjacent to the first portion of the wall is reduced as compared to the expanded configuration so that a cross-sectional area of a first portion of the withdrawal lumen adjacent to the first portion of the wall is greater when the first portion of the wall is in the collapsed configuration than when the first portion of the wall is in the expanded configuration. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
           [0005]      FIG. 1  shows a perspective partial zoom view of a system according to a first exemplary embodiment of the present invention in a first operative configuration; and 
           [0006]      FIG. 2  shows a perspective view of the system of  FIG. 1  in a second operative configuration. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]    The present invention may be further understood with reference to the following description. The present invention relates to a system and method for regulating ablative fluid flow into a living body to maintain a desired fluid flow into and out of the body (e.g., by preventing tissue dislodged from an inner surface of a hollow organ from jamming flow paths). In particular, the present invention relates to a collapsible infusion channel which is capable of changing its shape and/or position within a hydrothermal ablation (“HTA”) device under forces applied thereto by dislodged tissue, fluid flow, instruments inserted through the device, etc. The exemplary system and method of the present invention are described with respect to devices for ablating the endometrium. However, those skilled in the art will understand that the present invention, and/or components thereof, may be utilized in conjunction with devices for prostate treatment (microwave or cyroablation), irrigation systems or other devices for procedures which infuse fluids to the body. 
         [0008]    HTA systems generally utilize one or more resistive heating elements to warm a circulating fluid (e.g., saline) to a predetermined, substantially constant temperature. For example, such a thermal ablation system may heat the ablation fluid within a disposable cassette portion removably coupled to a reusable console. The heated ablation fluid may then be circulated through a hollow organ to ablate the lining thereof and subsequently returned to the system either for recirculation or disposal. One such system is described in a U.S. Provisional Patent Application entitled “Thermal Ablation System”, naming as inventors Robert J. Bouthillier, Michael P. Fusaro, Joseph M. Gordon, Stephen S. Keaney, Brian MacLean, Andrew W. Marsella, David Robson and Boris Shapeton filed on Nov. 14, 2007 and assigned Ser. No. 60/987,913. The entire disclosure of this application is hereby expressly incorporated by reference herein. The fluid follows a path passing a heating element which elevates the fluid temperature to the desired level. The fluid is then circulated through the hollow organ after which it is filtered and returned to the heating element for recirculation to the organ in a closed loop. A disruption of flow may interrupt circulation of the fluid, thus potentially causing a buildup of fluid in the body and/or overheating the fluid by extending the time during which fluid remains in a fluid reservoir exposed to the heater. 
         [0009]      FIGS. 1-2  depict an ablation device  100  according to an exemplary embodiment of the present invention. The device  100  is an HTA ablation probe comprising a handle  102  and an elongated cannula  104  extending distally therefrom. The cannula  104  comprises a lumen  106  extending therethrough from a proximal opening (not shown) to a distal opening  110  permitting engagement with a reduced diameter cannula  112  extending distally therefrom. Specifically, the cannula  112  may be attached to a distal end of the cannula  104  or, in another embodiment, may extend through the cannula  104 . The cannula  112 , which is configured for insertion into a target organ within a living body (e.g., via a body lumen accessed via a naturally occurring body orifice) comprises a seal  118  at a distal end thereof which is configured to extend around and seal an opening of the uterus or another body cavity to prevent heated fluids injected thereinto from leaking out of the uterus. The seal  118  is configured so that an outer wall thereof engages the inner diameter of the cervix to prevent fluid leakage from the uterus. Those skilled in the art will understand that the accordion shape and flexibility of the fins of the seal  118  increase a frictional engagement between the device  100  and the wall of the cervix to ensure secure engagement therewith. Furthermore, as the device  100  is inserted into the cervix, the fins of the seal  118  flex proximally, facilitating the insertion. A user may insert the device  100  into the uterus to a depth sufficient to pass all of the fins beyond the distal end of the cervix and then withdraw the device  100  proximally to seat the fins against the cervical os to fully seal the cervix and prevent heated fluid from passing thereinto and injuring non-targeted tissue. The seal  118  is attached to a distal section  120  having different material properties than the cannula  112 . Specifically, the distal section  120  may be more or less flexible than the cannula  112  and/or may have a different diameter than the cannula  112 . The distal section  120  comprises a lumen  122  extending therethrough. A proximal end of the lumen  122  is aligned with and open to a distal end of the lumen  106  of the cannula  112 . Furthermore, it is noted that the distal section  120  may be formed of any desired length without deviating from the scope of the present invention. 
         [0010]    A conduit  124  extending through the cannula  112  and the distal section  120  has a length at least as long as the combined length of the cannula  112  and the distal section  120 . The conduit  124  is formed with a collapsible, thin wall having a stiffness selected so that, when subject to the forces to which the conduit  124  will be exposed in use (e.g., the bending forces to which such flexible medical instruments are subject intralumenally as well as fluid pressures within and external to the conduit  124 ), at least a portion of the conduit  124  collapses, moves and/or flexes to adapt to different conditions such as a blockage (e.g., due to detached tissue) or the need to insert an instrument through the device  100  and into the uterus. That is, when a pressure outside the conduit  124  exceeds the pressure therewithin by a differential greater than a threshold level at any point along the length of the conduit  124 , that portion of the conduit  124  collapses to a reduced area configuration in which a wall of the conduit  124  is moved radially inward reducing a cross-sectional area thereof. When the differential between the pressure external to the conduit  124  and the pressure therewithin is less than the threshold level, the wall of the conduit  124  is moved radially outward to an expanded configuration in which a cross-sectional area thereof is greater than it is in the collapsed configuration. The wall of the conduit  124  is configured so that a certain level of internal pressure (e.g., 1-3 mm Hg) is required to maintain the conduit  124  in the expanded configuration. For example, a force applied by an endoscope or other medical instrument inserted through the cannula  112  may collapse one or more parts of the conduit  124  depending, for example, on the curvature of the cannula  112  along its length, inward pressure due to contact with body structures, etc. Those skilled in the art will recognize that the conduit  124  may be used as an inlet passage to supply fluids to the target body organ. Thus, if for any reason it is desired to move the conduit  124  to the collapsed configuration, fluid supply to this lumen may be reduced or halted to reduce the pressure therein. For example, if dislodged tissue from the body becomes clogged in a portion of the lumen  122 , the fluid supply through the conduit  124  may be reduced or halted to cause the conduit to collapse and increase the dimensions of a clearance space  125  located therearound. The increased clearance space  125  permits the dislodged tissue to move through the lumen  112  and out of a withdrawal port  140  located on the handle  102 . 
         [0011]    In another embodiment, a force applied to an outer wall of the conduit  124  by the dislodged tissue flowing through the cannula  112  may cause at least a partial collapse of the conduit  124 , temporarily expanding that portion of the cannula  112  and permitting the dislodged tissue to move therepast to the withdrawal port  140  on the handle  102 , as will be described in greater detail later on. In yet another embodiment, negative pressure may be applied to the cannula  112  externally of the conduit  124  to cause the conduit  124  to collapse, especially in the absence of a positive fluid flow through the conduit  124 . It is noted that the collapse of the conduit  124  may be facilitated by any other means without deviating from the spirit and scope of the present invention. The conduit  124  may also be configured with behavioral properties that vary along its length. Specifically, predetermined sections of the conduit  124  may be configured to be more easily collapsed to permit inflation of these areas when an excessive pressure is reached within the conduit. Thus, a physician or other user may collapse the conduit  124  to prevent a further buildup of pressure or bursting of the conduit  124 . 
         [0012]    The conduit  124  is formed of a layer of Teflon®, polyethylene or any other substantially resilient and/or elastic polymer material having a thickness of approximately 0.0127 mm.-0.254 mm. An outer diameter of the conduit  124  may be selected based on the inner diameter of the cannula  112  and the distal section  120 —i.e., to provide any desired clearance space  125  between the outer surface of the conduit  124  and an inner surface of the cannula  112 . In one embodiment, the cannula  112  may have an outer diameter of approximately 6 mm. Although conventional hydrothermal ablation devices have generally included a rigid lumen concentrically placed within an outer channel, the conduit  124  of the present invention is configured to warp and change a diameter and cross-sectional shape thereof to accommodate changes in fluid flow through the cannula  112  and/or to facilitate the insertion of instruments therethrough. Specifically, the conduit  124  may warp to change a cross-sectional shape thereof as an instrument is inserted therethrough or as a fluid clearance space  125  within the cannula  112  changes. The conduit  124 , which provides inlet flow of fluid to the uterus, is formed of a material having a flexibility sufficient to permit the conduit  124  to fold in on itself to a collapsed configuration when not pressurized. In this collapsed configuration, the conduit  124  provides a clearance  125  of approximately 3 mm. for the insertion of an instrument through the cannula  112  and the distal section  120 . The material of the conduit  124  is preferably be selected so that a pressure provided by a fluid flowing therethrough is sufficient (e.g., 200-350 ml/min when uterine pressure is 65 mmHg.) to maintain the conduit  124  in a non-collapsed, substantially cylindrical configuration. The thin walls of the conduit  124  permit the conduit  124  to assume a cross-sectional shape matching a cross-sectional shape of its boundaries, wherein the possible shapes include, but are not limited to elliptical and oblong. If no outer boundaries are present, the cross-sectional shape of the conduit  124  may be substantially cylindrical. The conduit  124  is also sized so that when an endoscope eyepiece  126  is inserted through the device  100 , the clearance space  125  is provided with predetermined dimensions to permit fluid to be withdrawn from the body, as those skilled in the art will understand. The endoscope  126  may be inserted into the lumen  106  and through the lumen  122  at the same time that an instrument  10  is inserted through the instrument port  108  located on the handle  102 . When the conduit  124  is pressurized, the clearance space  125  provided for the endoscope may be reduced to approximately 2 mm. Thus, when there is a need to insert another instrument (e.g., a sterilization coil, etc.) through the lumens  106 ,  122 , the conduit  124  may be moved to the collapsed configuration as shown in  FIG. 2  or may assume the partially warped configuration shown in  FIG. 1 . 
         [0013]    The conduit  124  is configured to warp an outer diameter thereof to a plurality of cross-sectional shapes without affecting a flow volume and flow rate of fluid passing therethrough. In the non-pressurized configuration, the conduit  124  assumes an oblong shape having a substantially arced cross-sectional shape so that the conduit  124  may be seated against a side wall of the lumen  122  to maximize the size of the clearance space  125 . It is noted however, that the material of the conduit  124  may be pre-formed to hold any shape within the lumens  106 ,  122  as would be understood by those skilled in the art. In one example, pressure applied to the walls of the conduit  124  by the instrument  10  causes the conduit  124  to assume a different shape to accommodate movement of the instrument  10  within the lumens  106 ,  122 . Accordingly, depending on the size of the instrument to be inserted through the lumen  122 , a flow through the conduit  124  may remain unchanged, be reduced to a lower flow rate to permit a partial collapse of outer walls thereof or may be terminated, as shown in  FIG. 1 , wherein the exemplary flow rate may be selected to maintain the patient organ or cavity in an open configuration for visualization while still preventing overpressurization thereof. The lumens  122 ,  106  are open to the fluid withdrawal port  140  located on the handle while the conduit  124  is open to a fluid supply port  142  on the handle to permit the introduction of heated fluid to a target organ in the living body. 
         [0014]      FIG. 2  depicts another embodiment of the present invention, wherein the endoscope  126  may be removed to further increase the size of the clearance space  125  within the distal section  120  and the cannula  112 . Specifically, in this embodiment, the distal face  132  of this apparatus includes a camera  128  and light fibers  130  which from this distal face  132  to the proximal end of the device at which they may be coupled to a source of light to illuminate a field of view of the camera  128  thereby eliminating the need for an endoscope  126  as described in the previous embodiment. Specifically, the light fibers  130  may extend within an outer wall of the device  100 ′ to a proximal end thereof to a connection with a light source. The camera  128  transmits an image signal via a signal cable  134  extending through the outer wall of the device  100 ′ on the handle  102  for connection to a processor or other computing device which may be housed within the device or external thereto. In this configuration, a greater clearance space  125  is provided in the lumen  122  for the insertion of other instruments therethrough. Thus, if desired, the conduit  124  may made larger than the conduit  124  of  FIG. 1  or, in another embodiment, the distal section  120  and cannula  112  may be made smaller to, for example, facilitate insertion of the device to locations inaccessible to larger instruments. Furthermore, since the light fibers  130  are substantially flexible, the device  100 ′ permits the insertion of non-planar tools therethrough such as, for example, a sterilization coil delivery tool including a probe tip which may be articulated to a predetermined orientation prior to advancing the delivery tool through the device  100 ′. 
         [0015]    Those skilled in the art will understand that the described exemplary embodiments of the present invention may be altered without departing from the spirit or scope of the invention. Thus, it is to be understood that these embodiments have been described in an exemplary manner and are not intended to limit the scope of the invention which is intended to cover all modifications and variations of this invention that come within the scope of the appended claims and their equivalents.