1. Field of the Invention.
The present invention relates generally to medical apparatus. More particularly, the present invention relates to apparatus for treating ureters and other body lumens.
It is common for kidney stones to pass from the kidney through the ureter to the urinary bladder. While muscular peristalsis of the ureter will often pass the stones into the bladder without complication, in some instances large and/or irregularly shaped stones may become lodged within the ureter causing discomfort and potential damage to the ureter and upper collective system.
A number of ways have been proposed for dislodging such kidney stones. For example, extracorporeal shock wave lithotripsy (ESWL) can be used to break up the kidney stones but is often ineffective when the stones are present in the ureter. Moreover, ESWL can produce irregularly-shaped fragments which, while smaller than the original stone, may have sharp edges that will prevent spontaneous passage of the particles through the ureter. As an alternative to ESWL in the case of a stone or fragment impacted in the ureter, it is common practice to attempt capture, using a wire stone basket. The basket is introduced through a ureteroscope which itself is typically introduced retrograde through the urinary tract. In many cases, further lithotripsy through the scope is performed (ISWL).
It is often difficult to advance such stone baskets past the obstructing material. Attempts to pass wire baskets or other grasping apparatus past a stone lodged in the ureter also presents risk of damage to the ureter. Abrasion, stretching, or perforation of the ureter at the impaction site can cause local urine leakage or edema even if the stone or resulting debris is successfully captured; and removal of the basket with the stone may be quite difficult. In some instances, baskets containing captured stones or fragments cannot themselves be removed, and it is difficult if not impossible to release the captured stone material back into the lumen of the ureter. In those cases, the basket must often be retrieved surgically or fragmented using an endoscopic laser with the fragments removed separately. Finally, if and/or when ISWL is performed, it would be useful to have some means of stabilizing stone fragments at the treatment site, rather than letting them escape up the ureter in a retrograde direction.
As an improvement over lithotripsy and the use of baskets for collecting kidney stones and debris, it has recently been proposed to use a compacted length of material, such as a polymeric film, to form a compacted occluding structure within a ureter. The compacted length of material can be used to directly draw and remove the kidney stone from the ureter into the bladder. Alternatively, the compacted length of material can be used to contain fragments which are produced in an energy-based lithotripsy procedure. As described in prior copending applications Ser. Nos. 10/866,866; 11/777,522; and 12/041,241, the length of material can be an everting tubular member, a flat membrane which folds as an accordion structure, can or take a variety of other configurations.
While each of these approaches can be effective, if the simpler approaches such as sweeping with a compacted structure fail, then it is often necessary to start over with a more invasive or traumatic procedure, such as conventional lithotripsy. The need to successively deploy different and often single-use devices is both costly and potentially damaging to the patient. For these reasons it would be desirable to provide apparatus, methods, and systems which allow for increasing level of intervention depending on the difficulty of stone removal. In particular, it would be desirable if the systems could first utilize a simple sweeping device for drawing a stone from the ureter into the bladder. If the simple sweeping device proves ineffective, the systems should allow for removal enhancements without the need to withdraw or exchange the simple sweeping device. Such stone removal systems and protocols should allow use of the minimum level of intervention necessary for stone removal in an individual patient. Moreover, the systems and protocols should be efficient and economic as the more costly interventions, such as lithotripsy, are reserved for those patients requiring them. At least some of these objectives will be met by the inventions described below.
2. Description of the Background Art.
U.S. Pat. No. 4,295,464 describes a pair of axially spaced-apart balloons that can be used to dislodge stones from a ureter. The use of an everting sleeve composed of thin, tensilized polytetrafluoroethylene for introducing catheters to body lumens is described in U.S. Pat. Nos. 5,531,717; 5,676,688; 5,711,841; 5,897,535; 6,007,488; 6,240,968; and EP605427B1. A wire coil for preventing stone fragment movement through a body lumen during lithotripsy procedure is available under the Stone Cone tradename from Boston Scientific Corporation. See Published U.S. Application No. 2003/0120281. Copending application Ser. No. 10/794,337, filed on Mar. 5, 2004, the full disclosure of which is incorporated herein by reference, describes a sheet delivery system that could be used in performing some of the methods described herein. Various stone removal baskets and capture devices are described in U.S. Pat. Nos. 4,046,149; 4,706,671; 5,192,286; and 5,989,264. Laser lithotripsy is described in U.S. Pat. No. 5,135,534.
The present invention provides apparatus, systems, and methods for removing urinary or kidney stones from a ureter. The invention allows a progressive or sequenced treatment protocol where an initial attempt is made to remove the stone using a sweeping structure deployed on a kidney side of the stone. The sweeping structure will typically be a compacted, conformable length of material, as described in more detail below, but could also be other mechanically expandable structures. Should removal of the stone using the sweeping structure prove ineffective, the present invention provides for enhanced stone removal using a dilating structure which is introduced from a bladder side of the stone, typically being introduced over a shaft of the sweeping structure. The dilating structure is deployed to dilate the tract immediately below the stone and dislodge the stone, where the dislodged stone may then be drawn down through the ureter using the previously deployed sweeping structure. Should sweeping of the dislodged stone prove ineffective, protocols of the present invention allow for further intervention using a lithotripsy device introduced into the ureter while the sweeping structure remains deployed. Usually, the dilation structure will also remain deployed in order to expand the working space below the stone, but in some instances it may be desirable to remove said dilating structure prior to lithotripsy. The lithotripsy device will be used to direct energy, such as laser energy or ultrasonic energy, into the stone, typically deployed through the dilating structure which has an open scaffold or other open structure which effects the desired dilation. After the stone has been fragmented, the sweeping structure can be used to remove the stone fragments, again by drawing down the sweeping structure toward the bladder. These methods and protocols are particularly beneficial since only those patients who require the more costly and intrusive lithotripsy protocols will receive them.
In a first aspect, methods of the present invention for removing urinary stones from a ureter comprise deploying a sweeping structure on a kidney side of a urinary stone in the ureter. An open scaffold is expanded to dilate the ureter on the bladder side of the stone to dislodge or mobilize the stone. The deployed sweeping structure is then drawn to engage and sweep the stone toward the bladder. The stone may be thus withdrawn in a single sweep where both the sweeping structure and open scaffold are drawn together, typically in tandem, with the stone captured therebetween. Alternatively, the ureter may be repeatedly dilated by expanding the scaffold at different positions in the ureter as the stone is drawn sequentially toward the bladder by the sweeping structure. Typically, the expanding and drawing steps will be alternated.
While in some instances the sweeping structure may comprise balloons, cages, or other structures, it will be preferred to use a compacted length of material which provides a number of advantages. The length of material will generally be relatively flexible or soft and will be atraumatic when it is compacted within the ureter. The compacted length of material will also conform to non-circular ureter geometries as well as to the irregular shape of the kidney stone prior to disruption. Additionally, the length of material can typically be drawn to a very thin profile, thus facilitating introduction of the length of material past the kidney stone prior to compaction and enlargement. The ability to stretch and draw down the width of the material is also advantageous if it is desired to withdraw the occluding structure from the ureter and/or to release the stone or stone fragments which may have been captured in the compacted material. Such release is very difficult with a wire basket or similar structure.
Initially, the length of material will usually be positioned in the body lumen in a generally elongate or unfurled configuration. The length of material is subsequently pulled, furled, or drawn back on itself so that the material compresses or compacts into the desired occluding structure, typically forming a layered structure. The material typically comprises a polymer film, a woven fabric, a non-woven fabric, and composites and laminates thereof. Exemplary polymer materials include polytetrafluoroethylene (PTFE), polyethylene (PE), perfluoroalkoxy (PFA), polyurethane (PU), perfluoromethylvinylether (PMFA), and perfluoropropylvinylether (PPVE). Other exemplary materials include films, fabrics woven of any supple material such as nylon, polyester, silk, etc., lamination of these materials, and the like. The materials will generally be chosen so that they compress or compact into a relatively soft, non-traumatic mass of material. The compaction may be by folding, twisting, spiraling, or otherwise collapsing so that the length of the material becomes shorter and the width becomes slightly greater than the uncompacted flat film, where length is a dimension generally aligned with the axis of the body lumen and width is the dimension generally transverse to the axis when the material is in the body lumen. In the exemplary embodiments, the length of material prior to compaction is in the range from 1 cm to 10 cm, usually from 2 cm to 6 cm, and most typically from 3 cm to 5 cm. The original length will be foreshortened so that the resulting compacted mass has a width that approximates the internal diameter of the lumen in the range from 1 mm to 20 mm, usually from 2 mm to 12 mm, and preferably from 7 mm to 10 mm.
If the kidney stone resists removal using the sweeping structure alone, the open scaffold or other dilating member can then be expanded or deployed on the bladder side of the stone to dislodge or mobilize the stone. Typically, the open scaffold or other dilating structure will be positioned within a region extending 20 mm on the bladder side of the stone. The open scaffold is typically expanded by foreshortening an elongate element, such as wire, usually by mechanically drawing ends of the element together, heating the element to induce a conformational change, passing current through the element to induce a conformational change, removing a constraint from around a self-expanding structure, or the like. In the exemplary embodiments, a linear wire is foreshortened to form a radial loop, coil, cage, or the like. A radial loop which is in the form of an open tapered helix may be particularly useful for traversing the expanded dilator axially through the ureter. Alternatively, a tubular braid may be foreshortened to form an expanded braid having an open structure.
In a second aspect of the present invention, a method for urinary stone removal comprises deploying a sweeping structure on a kidney side of a urinary stone in a ureter. The sweeping structure is then drawn in an antegrade direction to pull the urinary stone from the end of the ureter and into the bladder. If the urinary stone resists being pulled by the sweeping structure, the treating physician may then introduce a dilating structure, typically coaxially over the shaft of the sweeping structure, so that it lies on the bladder side of the kidney stone. The dilating structure is then expanded to open the ureter and dislodge the stone. The sweeping structure may then be drawn to pull the dislodged urinary stone with or without the dilating structure into the bladder. Should dislodgement of the stone using the dilating structure prove insufficient, the user may then introduce a lithotripsy device into the ureter while the sweeping catheter remains in place. Energy from the lithotripsy device may then be directed into the urinary stone to fragment the stone. The sweeping structure may then be drawn to pull the fragmented stone into the bladder. Typically, the dilating structure will be left in place during use of the lithotripsy device. The open scaffold or other structure of the dilating structure allows the device to be introduced through the structure to contact the stone. Alternatively, energy from the device could be directed at the stone after removal of the open dilating structure, the prior dilation providing improved access. The use of the open dilating structure in particular, is further advantageous as it permits viewing of the stone using an endoscope or other means during removal or fragmentation.
In a third aspect of the present invention, a system for urinary stone management comprises a sweeping device including a shaft and a compactable structure at a distal end of the shaft. The system further comprises a dilation device including a body having an expandable open scaffold at a distal end of a catheter or hollow shaft. The dilation device is adapted to be advanced over the shaft of the sweeping device when the expandable structure on the sweeping device is expanded on a kidney side of a stone in the ureter. The compactable structure on the sweeping device is typically a conformal structure, but can be any of the structures described above. The scaffold structure on the dilating device may comprise any open system which permits viewing and the introduction of a catheter or other device axially therethrough. Usually, the scaffold structure will comprise a loop, coil, cage, or malecot, although in other cases it could comprise an expandable braid, typically a metal braid, and in still other cases a self-expanding cone. The open scaffold is typically expanded by foreshortening, heating, or by passing electrical current therethrough. In the exemplary embodiments, the open scaffold of the dilating device comprises a linear wire that can be foreshortened to form a loop, coil, or cage.
Referring now to
As illustrated in
While a useful embodiment of the sweeping structure has been illustrated in
The dilating structure 14 is preferably configured in
The dilating structure 14 will typically comprise a hollow shaft 40 having a distal end 42 and a proximal end 44. The shaft 40 will have a central passage or lumen extending its entire length in order to slidably receive a hollow rod 46. The rod 46 extends distally of the distal end 42 and proximally of the proximal end 44 of the shaft so that a user may hold the shaft 40 and axially advance and retract the hollow rod 46 or conversely axially advance and retract the hollow shaft 40 over the hollow rod 46 using two hands. A wire element 50 is attached at a distal end 52 to a distal end 54 of the hollow rod 46 and at a proximal end 56 to the distal end 42 of the shaft 40. In this way, the hollow rod 46 may be advanced distally relative to the shaft 40 to reduce the diameter of the wire 50, as shown in
While the coiled loop embodiment of the dilating structure 14 is particularly useful, the dilating structure could comprise a variety of other expandable scaffolds or structures which can be opened or closed within the ureter or other body lumen. As shown in
As a further alternative, the dilating structure could comprise a wire braid structure 70, as illustrated in
As shown in
Referring now to
In the event that the kidney stone KS cannot be removed using the sweeping structure 12 alone, the methods of the present invention will further comprise dilating the lumen L of the ureter U on the bladder side of the kidney stone, as illustrated in
In some instances, however, even dilation of the lumen L of the ureter U with the dilating structure 14 will not be sufficient to dislodge the stone KS. In such instances, the kidney stone KS can be further treated using a lithotripsy device 80 or other supplemental treatment, as illustrated in
Referring to
While the above is a complete description of the preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. Therefore, the above description should not be taken as limiting the scope of the invention which is defined by the appended claims.
The present application claims the benefit of U.S. provisional patent application No. 61/053,742 (Attorney Docket No. 021807-004100US) filed on May 16, 2008, and the benefit of U.S. Provisional Patent Application No. 61/118,802 (Attorney Docket No. 021807-004200US), filed on Dec. 1, 2008, the full disclosures of which are incorporated herein by reference. The present application is related to, but does not claim the benefit of, the following commonly-owned U.S. patent application Ser. No. 12/041,241 (Attorney Docket No. 021807-004010US) filed on Mar. 3, 2008; Ser. No. 11/777,522 (Attorney Docket No. 02807-004000US), filed on Jul. 13, 2007; Ser. No. 10/886,886 (Attorney Docket No. 021807-000800US), filed on Jul. 7, 2004; and Ser. No. 11/777,515 (Attorney Docket No. 021807-000830US), filed on Jul. 13, 2007, the full disclosures of which are incorporated herein by reference.
Number | Date | Country | |
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61118802 | Dec 2008 | US | |
61053742 | May 2008 | US |