Abstract:
A system and method to be used in ultrasonic or other types of lithotripsy of a stone in a ureter, the system including a catheter having a stone probe tip capable of transmitting stone reducing energy. The catheter can include an expandable funnel section adjacent to the probe tip, such that expansion of the expandable funnel section can dislodge a stone by pushing back on the ureter wall expanding it slightly. The funnel section also being capable of pooling some urine in the ureter to be used as an ultrasonic transmission media. The stone probe can be connected to a source of energy capable of driving the probe tip to deliver energy to break apart the stone.

Description:
[0001]     found in the lower ureter or stones impacted in the upper ureter for example. IL techniques, however, typically require use of general anesthetic, guidewires for getting a basket past the stone, stent placement, imaging equipment and the ability to respond to ureter perforations that may occur. For these reasons IL requires the use of a surgical suite to perform the procedure. One prior art approach to IL is transurethral lithotripsy. Transurethral lithotripsy involves using a fiber optic ureterscope to place an ultrasonic probe adjacent to a stone. The ureterscope is used to guide the placement of the probe through the bladder and up the ureter. Once placed against the stone an ultrasonic generator can drive the probe to produce U/S energy to destroy the stone. Another alternative is to use a laser to disintegrate the stone.  
         [0002]     A problem with prior art approaches to intracorporeal treatment of ureter stones is that the stone is not captured during treatment. The stone can be pushed up the ureter toward the kidney in response to the efforts to treat it. The stone can also move to the side of the catheter and wedge between the ureter wall and the end of the catheter. In some cases the stone may be difficult to image and a catheter containing fiber optic equipment might move the stone. In other cases a catheter containing the contact ultrasonic (U/S) probe might move the stone. Movement of the stone makes treatment difficult and increases the risk of injury to the interior of the ureter. This is one problem that leads to intracorporeal lithotripsy being a more expensive in-patient treatment requiring a surgical suite as opposed to an out patient treatment.  
         [0003]     Another problem caused by stone movement is that most treatment techniques are most effective when the stone location is precisely known and can be held. If the stone is moving in response to the treatment and in response to body changes then the lithotripsy treatment will be more difficult and time consuming to perform. Another factor worthy of consideration is the stone and prior art treatment device size. A too large stone and/or device requires a stent to be placed in the ureter to overcome strictures preventing urine flow.  
         [0004]     It can be seen that there is a need for an improved apparatus and method to treat stones in the ureter. In can be seen that there is a need for a treatment system and method where a stone will not move during treatment. It can also be seen there is a need for a stone treatment procedure that can be performed without getting behind the stone.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     The present invention relates to a system and method to be used in stone management within a ureter. The system can include a catheter having a probe tip capable of transmitting ultrasonic energy, an expandable device adjacent to the probe tip and a source of energy capable of driving the probe tip to deliver ultrasonic energy to break apart the stone.  
         [0006]     In another aspect of the invention, an inflatable balloon can cause pooling of urine fluid in the ureter such that the pooled urine fluid can act as a medium to transmit ultrasonic energy from the probe to the stone.  
         [0007]     In yet another aspect, the system includes a catheter having a probe tip capable of transmitting disintegration energy to a stone. The system can include an expandable portion adjacent to said probe tip, the expandable portion including fingers that can push outward against a wall of the ureter to release a stone lodged in the ureter. The system can also include a source of energy capable of driving the probe tip to break apart the stone.  
         [0008]     In a further aspect of the invention, a method of performing ultrasonic lithitripsy is disclosed including the steps of placing a catheter having an ultrasonic probe in the ureter adjacent to a stone. The method can include a step of expanding a device to pool urine fluid and to cause movement of the stone. The step can include expanding the device adjacent to the stone to hold back the wall of the ureter and allow a stone to dislodge from the ureter. Under pressure from the flow of urine, peristaltic pressure from the urine or gravity, the stone will move into the expanded funnel where it can be held in a known position for treatment and allows the use of an ultrasonic energy source to drive the probe to break apart the stone.  
         [0009]     In yet a further aspect of the invention, the device and method may be used to remove smaller stones by grasping them and pulling them out of the ureter without breaking them.  
         [0010]     The present invention is useful in open or endoscopic surgeries as well as robotic-assisted surgeries.  
         [0011]     Further features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0012]      FIG. 1  is a view of the components of the stone treatment catheter distal end;  
         [0013]      FIG. 2  is a cross-sectional view of the distal end of the device presented to a stone;  
         [0014]      FIG. 3  is an enlarged view of the distal end in accordance with the invention;  
         [0015]      FIGS. 4   a - e  illustrate the sequential method steps of use for one aspect of the invention;  
         [0016]      FIG. 5  is a partial sectional view of an alternate embodiment of the invention;  
         [0017]      FIG. 6  is a partial sectional view of the alternate embodiment shown in  FIG. 5  and with an expanded distal end; and  
         [0018]      FIG. 7  illustrates a cut-away view of one aspect of the invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     Before explaining the present invention in detail, it should be noted that the invention is not limited in its application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative embodiments of the invention may be implemented or incorporated in other embodiments, variations and modifications, and may be practiced or carried out in various ways. Furthermore, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative embodiments of the present invention for the convenience of the reader and are not for the purpose of limiting the invention.  
         [0020]     The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which  FIG. 1  shows a partial cross section of the catheter system  10 . The catheter system  10  includes a center section  12 , which can include a fiber optic  14  to view the treatment area and a second fiber  16  to carry light to an operation site.  
         [0021]     The catheter system  10  further comprises a funnel section  20 , a catheter sheath section  22  and a balloon section  24 . Each section  20 - 24  can be in the shape of a hollow cylinder. The fiber optic section  12  can be slid out of the funnel section  20  such that a stone treatment probe ( 26  in  FIG. 3 ) of about the same diameter can be inserted into the funnel section  20 .  
         [0022]      FIGS. 2 and 3  show the catheter system  10  and its distal tip  30  in operation. Inside the ureter U the balloon section  24  is expanded by air or other biocompatible fluids through channel  25 . The expansion of the balloon section  24  slightly expands the ureter U wall and dams the urine causing the stone S, which had been held by the ureter U, to loosen. Once the balloon section  24  expands, the funnel section  20  can be moved forward, the fingers  20   a  are exposed and radially expand towards a free state, shown in  FIG. 3 , further expanding the ureter wall to release the stone S.  
         [0023]     The fingers  20   a  are formed to normally, in a free state, have a funnel shape  40  (shown in  FIG. 3 ) the larger end of which can be larger than the inside diameter of the sheath  22 . The tips of fingers  20   a , have curves  21  that curve back into the center axis of the catheter system  10  to grip as can be seen in  FIGS. 2 and 3 . When the fingers  20   a  are in the sheath section  22 , the fingers  20   a  are collapsed to form a cylinder funnel section  20  as shown in  FIG. 1 . When the funnel section  20  is slid forward to expose the fingers  20   a , the fingers can flare out to the normal funnel shape  40  forming a gap  20   c  between fingers.  
         [0024]      FIG. 3  shows more details including all the fingers of the funnel section  20 . Four fingers  20   a  can be separated by four gaps  20   c . With the funnel section  20  pushed forward, the fingers  20   a  can assume their normal free state positions forming a funnel shape  40 . Flared out in the ureter U as shown in  FIG. 2 , the funnel shape  40  can hold the stone S in a steady, known position.  FIG. 3  shows that the center section  12 , containing fiber optics  14  and  16 , has been removed and has been replaced with an catheter stone treatment probe  26  that can be driven by a power supply (not shown) to reduce the size of stone S. The center section  12  is removed from the funnel section  20  by sliding it out and the catheter stone treatment probe  26  is slid into the funnel section  20  replacing the center section  12 . Pulling the center  12  section out can create a suction that will further pull the stone S into the fingers  20   a  if it is not fully held by the actions of the balloon  24  and finger section  20 .  
         [0025]     In operation, the catheter  10  is guided through a bladder and into the ureter U using fiber optics  14  and  16 . The tip  30  is positioned adjacent the stone S. The balloon  24  is expanded and the funnel section  20  is pushed forward exposing fingers  20   a . The expansion of the balloon  24  loosens the stone S, the release of the fingers  20   a  and pressure from urine dammed by the balloon  24  can release the stone S from the ureter and the stone S moves into the funnel shape  40 . With the balloon  24  expanded, the dammed urine adjacent the tip  30  can act as a medium to transmit ultrasonic energy to the stone S.  
         [0026]     With the stone S in place in the funnel shape  40 , the center section  12  containing fiber optics  14  and  16  can be slid out of the funnel section  20  and a catheter section (not shown) tipped by stone probe  26  can be inserted into the funnel section  20 . Ultrasonic energy or other means can be applied through the stone probe  26  to disintegrate the stone S. A representative ultrasonic transducer for use is disclosed in U.S. Pat. Nos. 6,049,159; 6,050,943; and 6,120,452; each of which is incorporated herein by reference. Alternatively, a small stone, gripped by fingers  20   a  may be moved to any desired location within the ureter or pulled out of the ureter without use of ultrasonic or other lithotripsy techniques.  
         [0027]      FIGS. 4   a - e  show a simplified view of the operation of the device  10 . The device  10  is presented to a stone S in  FIG. 4   a . In  FIG. 4   b , the balloon  24  is inflated and the finger section  20  is extended toward the stone S. The stone S is released from the wall of the ureter U (not shown here) and moves toward the device  10 . In  FIG. 4   c  the stone S is grasped within the fingers  20 . In  FIG. 4   d  the stone S can be pulled closer to the device by retracting the finger section  20 . The center section is removed and replaced by the stone treatment probe. In  FIG. 4   e  the stone S is broken apart. As mentioned for a small stone S,  FIG. 4   d  could be followed by an alternate step of simply pulling the stone S out. The stone S could be addressed by ultrasonic energy or by laser for example. As stone treatment proceeds, it is possible to re-introduce the center section  12  to view progress between applications of ultrasonic energy.  
         [0028]      FIG. 5  shows a cross sectional view of an alternate embodiment of the device. A catheter  110  can include a catheter inner funnel section  112  connected by hinge portion  114  to outer funnel section  116 . The arrangement includes an outer elastic band  120  surrounding fingers  122 . In this embodiment, the fingers  122  can include gripping teeth  124  that can improve the ability of the fingers  122  to grip a stone S. The outer funnel section  116  can include a stop ring  126 . A sheath portion  140  can include a cooperating stop ring  142 . The sheath portion  140  can include a ratcheted stop ring  144  and the inner funnel section  112  can include an annular detent  150 .  
         [0029]      FIG. 6  shows a cross sectional view of the embodiment of  FIG. 5  in an expanded position. Sheath portion  140  has been pulled down so that the stop rings  126  and  142  meet. As the operator pulls further, arrows  130  and  132  show lines of force that will be applied. An upward force  130  is placed on the inner funnel section  112  while a downward force  132  of equal magnitude is placed on the outer funnel section  116 . The result of the forces  130 , 132  is that the fingers  122  open up to form a funnel shape  240  indicated by dashed lines. The fingers  122  are separated by slits  123  that allow the relative forces  130 / 132  to deform the fingers  122 . The elastic band  120  is provided to prevent injury to the inner wall of the ureter U that might be pinched when the slits  123  closed if the band  120  were not present. Once the relative forces  130 , 132  are removed the fingers  122  can be returned to their original positions as shown in  FIG. 5 . During a procedure to reduce a stone S the forces  130 , 132  can be maintained by a clamp mechanism created by ratcheted stop ring  144  and detent  150 . As can be seen, the teeth of ratcheted stop ring  144  will maintain the inner  112  and outer  116  funnel sections in their biased relationship until an operator releases it. Ultrasound can transmit through inner funnel  112  and fingers  122 . Fingers  122  can serve to transmit sound energy to the stone. The ratcheted stop ring  144  can be progressively stepped further into the detent  150  to further open the fingers  122  and widen the funnel  240 .  
         [0030]      FIG. 7  illustrates the proximal end  180  opposite the distal tip  30  of the catheter  10 . The passage  25  provides air from a fitting  152  to the balloon  24 . A working space  156  allows for the placement and manipulation of sections such as the center section  12 . Fittings  160  and  162  allow for the locking of any section in place and for the establishment of location datum.  
         [0031]     In operation the embodiment of  FIGS. 5-7  is inserted through the bladder using a cystoscope (not shown) into the ureter U. Once in the ureter, the catheter  110  can be positioned near or adjacent to a stone as appropriate. Though not shown, fiber optic devices can be held in the inner diameter of the inner funnel section  112  and the fiber optics can be used to guide the catheter  110  through the ureter to a stone. Once presented to a stone, the inner funnel section  112  can be biased relative to the outer funnel section  116 . The relative forces, as demonstrated by arrows  130  and  132  in  FIG. 5 , will cause the flexible fingers  122  to flare outward where the fingers  122  can contact the wall of the ureter U and dislodge a stone as shown for the first embodiment in  FIG. 2 . The flared fingers  122  can form a funnel shape  240  that can capture and hold a stone using gripping teeth  124 . The ratcheted stop ring  144  can hold the fingers  122  in a desired position so that the operation can proceed.  
         [0032]     Similar to the first embodiment, once the catheter  110  is presented to a stone and the fingers  122  flared out, the stone can move in response to pressure from the flow of urine, peristaltic pressure or gravity to become lodged and held in the funnel shape  240 . Once the stone is positioned in the funnel  240 , the fiber optic portion of the catheter can be slid out and a stone treatment probe  26  ( FIG. 3 ) can be slid into the workspace  156  and inner funnel section  112 . The stone treatment probe  26  can then be used to break apart the stone. The band  120  can protect the wall of the ureter U during the procedure. Like the first embodiment, the expanded funnel  240  can be used to control the rate of flow of urine through the ureter so that a pool of urine fluid can be formed to act as a medium to transmit ultrasonic energy.  
         [0033]     Though the embodiment of  FIGS. 5 and 6  do not require a balloon as shown in  FIG. 7  it will be understood by those skilled in the art that a balloon could be used in cooperation with this embodiment to pool urine for example. Though not shown, it will be understood that irrigation fluid such as saline solution could be used to irrigate the stone as it is disintegrated and that irrigation or urine fluid could be drained away from the stone to carry away process byproducts. It will also be understood that the ureter stone treatment probe  26  could be of any conventional stone management type such as ultrasonic, laser, impact, or spark gap. Any method of intra-ureter stone treatment could be used. It will also be understood that while  4  fingers are shown forming the funnel shape in the disclosed embodiments, any number of fingers could be used. Further though shown as formed by fingers the funnel shape could be formed from a variety of shape memory or deformable elements that could be released to form a funnel shape. It will also be understood that the funnel could assume a variety of shapes similar to a cone and that a variety of shapes and materials could be used on the fingers to help them grip the stone.  
         [0034]     While the present invention has been illustrated by description of several embodiments, it is not the intention of the applicant to restrict or limit the spirit and scope of the appended claims to such detail. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the scope of the invention. Moreover, the structure of each element associated with the present invention can be alternatively described as a means for providing the function performed by the element. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.