Abstract:
The present invention provides devices, systems, methods and kits for the percutaneous removal of unwanted tissue or obstructive matter from body cavities or lumens, particularly from the vasculature. Blood vessels, including the coronary, peripheral and neurovascular circulation, which are narrowed or blocked by atheromatous material or plaque are often treated with traditional endarterectomy procedures. The present invention allows the benefits of such a procedure with an intraluminal approach, particularly a percutaneous approach. Generally, the present invention provides a set of catheters or tools which are percutaneously introduceable to the site of the blockage or occlusion. The tools dissect or cut through the innermost tissue layer of the lumen to an underlying tissue layer. The innermost tissue layer is then stripped away from the underlying layer with the occlusive material thereattached. The detached tissue layer and occlusive material is then removed from the lumen; this may include additional cutting, maceration and removal through mechanical aspiration. In any case, the resulting lumen is free of obstruction.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   This application claims the benefit and priority of U.S. Provisional Patent Application No. 60/195,653, filed Apr. 7, 2000, and U.S. Provisional Patent Application No. 60/274104, filed Mar. 7, 2001, the full disclosures of which is hereby incorporated by reference for all purposes. 

   BACKGROUND OF THE INVENTION 
   The present invention relates generally to medical apparatus and methods, and more particularly, to devices and methods for percutaneous removal of unwanted tissue such as thrombus, atheroma, fluid, polyps, cysts or other obstructive matter from body lumens, such as blood vessels, ureters, bile ducts or fallopian tubes. More specifically, the present invention relates to the excision of the thickened atheromatous tunica intima of an artery, a procedure known as an endarterectomy. 
   An endarterectomy is a surgical procedure that removes material involved in a narrowing or blockage of an artery. Typically, such a procedure is performed on the carotid arteries where atheromatous material or plaque has narrowed or occluded the carotid arteries reducing the supply of blood flow to the brain. Untreated, this may lead to neurological deficits and stroke. Deficits can occur due to a decrease in oxygen-rich blood to the brain causing destruction of brain tissue. Strokes can occur due to uncontrolled blood pressure or bursting of weakened blood vessels in the brain. The risk of both of these conditions can be reduced by carotid endarterectomy. 
   A typical endarterectomy procedure is illustrated in  FIGS. 1A-1C .  FIG. 1A  is a cross-sectional view of a blood vessel BV prior to treatment. As shown, the wall of the blood vessel BV is comprised of two layers, an intimal layer INT or inner-most layer of the lumen which is in contact with the blood and an adventitial layer ADV or outer layer which is covered by the intimal layer INT. In this case, the blood vessel BV is narrowed or partially blocked by occlusive material or an occlusion OC. Blood flowing through the vessel is restricted through the area of the occlusion OC as illustrated by arrows. It should be noted that the term occlusion OC might refer to any substance or anatomic morphology that acts to severely occlude a body conduit such that it is difficult to pass a wire from proximal end of the occlusion to the distal end. Depending on the type of material occluding the body conduit (soft plaque, calcified plaque, thrombus, fibrin, clot, fatty tissue etc.) some occlusions may be more severe than others but all are included in the scope of the present invention when there may be some difficulty passing a guidewire therethrough. 
   Referring to  FIG. 1B , an endarterectomy procedure may involve removing the occlusion OC along with the intimal layer INT in the region of the occlusion. Here, the intimal layer INT is cut, split or cleaved to access the adventitial layer ADV. The intimal layer INT is then pulled away, stripped or delaminated from the adventitial layer ADV along the length of the occlusion OC. Referring to  FIG. 1C , the intimal layer INT is also cleaved on the opposite side of the occlusion OC to remove the delaminated intimal layer INT containing the occlusion OC from the vessel wall. The excised material may then be removed from the blood vessel BV. It may be appreciated that the above described procedure may be readily adapted for use in any body lumen or body cavity wherein unwanted material may be removed in a similar fashion. 
   Currently, there are many clinical approaches to removing unwanted material, many of which are performed surgically, wherein the treatment site is accessed directly through a surgical incision. An example of this surgical procedure utilizes a set of surgical tools, like The MollRing Cutter™, which enable the surgeon to cleave a plane of an occluded vessel and strip the atheromatous intimal layer, such as described in U.S. Pat. Nos. 5,843,102 and 5,954,713. 
   In recent years, a variety of catheter devices have been developed for use in intraluminal and intravascular procedures for fragmentation and removal of blood clots, or thrombus, from blood vessels. More recently, devices that can be inserted percutaneously through a puncture in the skin have been developed to make the procedures less invasive. For example, a catheter device is inserted into a blood vessel at some distance away from the intended treatment site, and is then advanced through the vessel lumen until the selected location is reached. In many cases the vessel to be treated is totally blocked by an occlusive lesion usually comprising, thrombus, soft plaque, and calcified plaque. 
   Several techniques have been introduced to fragment the unwanted plaque or tissue from blood vessels such as rotating baskets or impellers as described in U.S. Pat. Nos. 5,766,191 and 5,569,275, cutters U.S. Pat. No. 5,501,694, or high pressure fluid infusion to create a Venturi effect as described in U.S. Pat. No. 5,795,322. Other devices, such as atherectomy cutters, may also be employed such as those described in U.S. Pat. Nos. 5,904,968, 5,224,945, 5,312,425 and 5,330,484. 
   In many instances, these techniques further include aspirating the unwanted occlusive materials through a lumen of the treatment device or using a secondary catheter hooked up to a source of vacuum/suction. Critical to the success of an improved procedure is having a device that can rapidly aspirate the occlusive material from the body lumen. One such device is described in U.S. patent application Ser. No. 09/454,517 and in U.S. Provisional Application No. 60/154,752. 
   Although these techniques provide many benefits, it is also desired to provide some of the benefits of traditional endarterectomy in intraluminal and intravascular procedures. In particular, it would be desired to percutaneously treat a total occlusion using a set of tools that perform similar functions to those performed in traditional surgical endarterectomy procedures. These tools would first provide a cleavage plane circumferentially or longitudinally of the lesion, dissect the cylindrical core, macerate the core, and aspirate the material. Thus, it would be desirable to provides devices, systems, methods and kits to this end. At least some of these objectives will be met by the aspects of the present invention. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides devices, systems, methods and kits for the percutaneous removal of unwanted tissue or obstructive matter from body cavities or lumens, particularly from the vasculature. Blood vessels, including the coronary, peripheral and neurovascular circulation, which are narrowed or blocked by atheromatous material or plaque are often treated with traditional endarterectomy procedures. The present invention allows the benefits of such a procedure with an intraluminal approach, particularly a percutaneous approach. Generally, the present invention provides a set of catheters or tools which are percutaneously introduceable to the site of the blockage or occlusion. The tools dissect or cut through the innermost tissue layer of the lumen to an underlying tissue layer. The innermost tissue layer is then stripped away from the underlying layer with the occlusive material thereattached. The detached tissue layer and occlusive material is then removed from the lumen; this may include additional cutting, maceration and removal through mechanical aspiration. In any case, the resulting lumen is free of obstruction. 
   In a first aspect of the methods and devices of the present invention, the intimal layer or innermost layer of the wall of the lumen or cavity is dissected, cleaved or cut to access and expose a portion of the underlying adventitial layer or outer layer. This is accomplished with a dissection tool which is part of or disposed near the distal end of a catheter. A number of embodiments of such dissection tools are described and illustrated herein. Many of these comprise a radially expansive element configured to contact the vessel wall when in an expanded position. This feature of expansion allows the element to be introduced percutaneously in a low profile to the treatment or target site and then to expand radially to perform the treatment steps. Such expansion may be achieved by action of an inflatable member or similarly functioning device, or the element may be self-expanding. 
   In some cases, the expansive element comprises a cutting surface configured to cut through the intimal layer of the vessel wall to expose a portion of the underlying adventitial layer after contact with the vessel wall in the expanded position. Similarly, the expansive element may comprise an abrasive surface which is designed to abrade through the intimal layer to the underlying adventitial layer. With either surface, the surface may be rotated to aid in the dissection. Alternatively, the expansive element may have an adhesive surface adapted to adhere to an intimal layer of the vessel wall upon contact. In this case, the adhered portions of the intimal layer and attached occlusive material are peeled away from the adventitial layer when the element is removed. Such adhesion may be achieved with the use of a variety of adhesives, vacuum suction or setting the adhesive surface to various temperatures. 
   In other embodiments of the dissection tool, the tool comprises a radially extensible element configured to contact the vessel wall in an extended position. Typically, the element comprises a pointed instrument which is designed to cut through the intimal layer upon contact and/or by rotation of the element. In addition, an exemplary embodiment of a system of devices comprises a dissection tool and end cutter such as described in patent WO 9511633A1 and U.S. Pat. No. 5,843,102, incorporated herein by reference. 
   In a second aspect of the methods and devices of the present invention, the intimal layer or innermost layer of the wall of the lumen or cavity is stripped or delaminated from the underlying adventitial layer or outer layer, thereby removing the unwanted tissue. This is achieved with a stripping tool which is part of or disposed near the distal end of a catheter. Alternatively, the stripping tool is incorporated into or receivable by the catheter having the dissection tool or the dissection tool may further function as a stripping tool. A number of embodiments of such stripping tools are described and illustrated herein. The stripping tools are adapted to contact the exposed portion of the adventitial layer and advance along the exposed portion to delaminate the intimal layer from the adventitial layer along a segment of the blood vessel. The stripping tool comprises a stripping component. In some embodiments, the stripping component comprises a radially expansible ring which is positionable between the intimal and adventitial layers so that the intimal layer passes through the inside of the ring during advancement. Optionally, the delaminated material may be macerated and removed by an aspiration pump as it is stripped from the vessel. In some cases, the stripping component further comprises a funnel shaped dissection propagator which is connected to the ring to guide the delaminated material into the macerator and/or aspiration pump. Exemplary examples of maceration devices are described in related U.S. patent application Ser. No. 09/454,517, incorporated herein by reference, as well as in U.S. Provisional Application No. 06/193,539 and U.S. Provisional Application No. 60/195,653, both incorporated herein by reference. Examples of aspiration devices are described in U.S. patent application Ser. No. 09/590,915, U.S. Provisional Application No. 60/260,170, and U.S. patent application Ser. No. 09/388294, all incorporated herein by reference. 
   In one embodiment, the stripping component comprises a radially expansible coil positionable between the intimal and adventitial layers os that the intimal layer and attached atheroma passes through the inside of the coil during advancement. The coil may have an oblique angle formed leading edge which assists in removing material as the coil is advanced by rotation. Removed material may then be macerated and aspirated as described above. 
   In another embodiment, the stripping component comprises a rod having an atraumatic distal tip. The rod is angularly extendable from the catheter body and the tip is configured to be positionable between the intimal and adventitial layers. The rod is then advanced and optionally rotated to delaminate the intimal layer from the underlying adventitial layer. 
   In a further embodiment, the stripping component comprises an inflatable member. Here, the inflatable member is inflated in the area of dissection, previously made by a dissection tool, so that it is in contact with the exposed adventitial layer. The inflatable member is then advanced along the blood vessel, pushing and stripping the intimal layer from the adventitial layer as it progresses. To assist in providing adequate force, an anchoring component may be positioned near the area of dissection or the exposed portion of the adventitial layer and remain fixed in place during advancement of the stripping component. Fixation or anchoring of the anchoring component may be achieved by expanding the component to the extent that it overexpands the blood vessel. This will provide adequate tension for applying stripping force to the intimal layer. 
   In an additional embodiment, the stripping tool comprises a shaft having a proximal end and a distal end, wherein the stripping component is disposed therebetween. Further, a proximal occlusion member and a distal occlusion member are mounted on the shaft on opposite sides of the stripping component. In this way, a section of the vessel may be isolated between the occlusion members. The isolated section is fillable with saline or other solution to aide visualization by an angioscope and light source disposed between the occlusion members. Thus, the delamination process may be visualized during advancement of the stripping component. 
   In still a further embodiment, the stripping tool comprises a stripping component which is configured to be inserted between the intimal and adventitial layers and to be rotated around a longitudinal axis of the catheter body to delaminate the intimal layer from the adventitial layer along a segment of the blood vessel. In this case, the stripping component typically comprises a wire or stripping element which is longitudinally extended. In addition to rotation, the component may be in tension and/or a linear movement may be applied to the component to enhance separation of the internal and external vessel layers. Examples of this linear movement would be translational, vibrational, or ultrasonic motion. The stripping wire may alternatively be in tension using two percutaneous sticks that may be created by a device described in U.S. patent application Ser. No. 09/388,294, incorporated herein by reference. In tension the stripping wire may be manually pulled to remove the core, or assisted using motion to enhance separation of internal and external vessel layers, such as using sawing motion or subsonic or ultrasonic vibration as mentioned. In any case, once the component has been rotated 360 degrees, the intimal layer and associated occlusional material should be completely delaminated. The stripped material then is removed using a mechanical aspiration catheter or with a thrombectomy catheter. 
   In a third aspect of the present invention, dissection and stripping may be achieved simultaneously. Although both of these functions may be achieved with either a dissection tool or a stripping tool, these functions may also be achieved with combination tools. In one embodiment of a combination tool, a treatment catheter comprises a proximal occlusion member and a distal occlusion member mounted on one or more shafts so that the members may be slidably separated. Optionally, between the occlusion members may be disposed a maceration device. The catheter is inserted within a blood vessel so that the occlusion members straddle an area to be dissected and/or stripped. With the occlusion members firmly contacting the vessel walls, the occlusion members are separated to create a tension zone between them. Since the adventitial layer is more flexible than the intimal layer, the intimal layer and occlusive material will separate from the adventitial layer, wherein in may then be removed. 
   In a fourth aspect of the present invention, delaminated material may require cutting from the intact material for successful removal. Such cutting may be achieved with a variety of cutting tools. In a preferred embodiment, the cutting tool is comprised of a ring which slides between the intimal and adventitial layers which have been previously separated. The ring comprises a support tube and a cutting wire wherein the support tube is retractable to expose the cutting wire. The cutting wire is configured to cut through the intimal tissue when tensioned to release the delaminated intimal tissue from the vessel wall. The delaminated material may then be removed from the lumen by any suitable means. 
   Following any of the above described treatments, the remaining debris can be removed by activating the macerating and aspirating function of the device of the present invention as specifically described in U.S. patent application Ser. No. 09/454,517 and U.S. patent application Ser. No. 09/590,915, which claims the benefit of U.S. Provisional Application No. 60/154,752, all applications of which are incorporated herein by reference. Once the material has been removed, the dissection or stripping tools can be used to remove any remaining flaps in order to ensure complete removal within the inner diameter of the treated vessel. In addition, adjunctive procedures and devices may be performed upon the treated lesion to ensure vessel patency such as, placements of stents, stent-grafts, grafts, anti-stenotic and anti-thrombotic material, percutaneous transluminal angioplasty, radiation, and the like. Most often a stent or stent-graft will be placed to ensure that any flaps created through the dissection procedure would be tacked down. 
   Other objects and advantages of the present invention will become apparent from the detailed description to follow, together with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1A-1C  prior art) illustrate a typical endarterectomy procedure. 
       FIGS. 2A-2C  illustrate an embodiment of a dissection tool comprising a radially extensible pointed instrument and its method of use. 
       FIGS. 3A-3B  illustrate a dissection tool comprising a radially expansive element and its method of cutting through an intimal layer of a blood vessel. 
       FIG. 4  illustrates a dissection tool comprising a radially expansive element which is expanded by an expandable member and its method of abrading through an intimal layer of the blood vessel. 
       FIG. 5  illustrates a dissection tool comprising a radially expansive element which is self-expanding and its method of abrading through an intimal layer of the blood vessel. 
       FIGS. 6A-6B  depict a dissection tool comprising a radially expandable element which comprises an inflatable member having an adhesive surface and its methods of use. 
       FIGS. 7A-7B  illustrate a dissection tool its methods of use wherein an adhesive surface is provided by an adhesive element. 
       FIGS. 8A-8B  depict an embodiment of a stripping tool comprising a funnel-shaped dissection propagator or stripping component and its method of use. 
       FIGS. 9A-9B  illustrates an embodiment of a stripping tool comprising a radially expansible ring and its method of use. 
       FIGS. 10A-10B  illustrate an embodiment of a stripping tool comprising radially expandable arms which are positionable between the intimal and adventitial layers and its method of use. 
       FIG. 11  depicts an embodiment of a stripping tool comprising a rod having an atraumatic tip and its method of use. 
       FIG. 12  illustrates the stripping tool of  FIG. 11  further including occlusion members to create a visualization zone. 
       FIG. 13  illustrates an embodiment of a stripping tool that utilizes mechanical advantage. 
       FIG. 14  depicts a stripping tool comprising a radially expansible coil. 
       FIGS. 15A-15B  illustrate an embodiment of a stripping tool comprising a stripping component and an anchoring component, wherein the stripping component comprises an inflatable member, and its method of use. 
       FIGS. 16A-16C  illustrate an embodiment of a stripping tool comprising a wire or stripping element and its method of use which includes rotating the element circumferentially to separate the intimal layer from the adventitial layer. 
       FIGS. 17A-17C  depict an embodiment and method of use of a combination tool. 
       FIG. 18  illustrates an embodiment of a cutting tool. 
       FIGS. 19A-19E  illustrate the methods of using the cutting tool of  FIG. 20 . 
       FIGS. 20A-20B  depict the location of layers in a body lumen or cavity which may be treated by the methods of the present invention. 
       FIG. 21  illustrates a kit constructed in accordance with the principles of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Devices, systems and methods of the present invention generally relate to three basic features of an endarterectomy or similar procedure. These features include: 1) dissecting, cleaving or cutting the intimal layer or innermost layer of the wall of the lumen or cavity to access the adventitial layer or outer layer, 2) stripping or delaminating the innermost layer from the outer layer, and 3) removing the delaminated material from the lumen which may include maceration. All of these features are not essential to the present invention nor are they intended to limit the scope of the invention. However, embodiments of the present invention will be described according to these general features for clarity. Typically devices for each feature of the procedure are independent and may be used in any combination. However, some devices may be designed for specific use in combination with other devices. 
   I. Dissection Tools 
   An embodiment of a dissection tool constructed in accordance with the present invention and its method of use is illustrated in  FIGS. 2A-2C . Referring to  FIG. 2A , the dissection tool  10  is inserted within the lumen of the blood vessel BV to a position near the occlusion OC. As shown, the blood vessel BV has an adventitial layer ADV and an intimal layer INT to which the occlusion OC is adhered. The dissection tool  10  is part of a catheter  20  having a catheter shaft  13  with a distal tip  14 . The shaft  13  has at least two lumens, one of which is a guidewire lumen  15  adapted for passage of a guidewire GW (not shown). Referring to  FIG. 2B , another lumen is adapted for passage of a sharp or blunt point instrument  11  which is radially extensible such that its tip protrudes radially outward from the shaft  13 . Alternatively, the instrument may be fixedly attached to the shaft  13  in this position. The instrument  11  is used to pierce, dissect, cleave or cut through the intimal layer INT to the adventitial layer ADV as shown. To assist in accessing the adventitial layer ADV, the tool  10  may additionally comprise a balloon  16  which may be inflated to force the instrument  11  against and or through the intimal layer INT. The intimal layer INT may be cut along the circumference of the lumen by rotating the shaft  13  around its axis as in the direction of the arrow. Referring now to  FIG. 2C , the result is a dissection D of the intimal layer INT revealing the adventitial layer ADV underneath. As shown, the instrument  11  may be retracted and the catheter  20  withdrawn from the blood vessel BV. 
   Additional embodiments of the dissection tool comprise a radially expansive element configured to contact the vessel wall in an expanded position. Upon such contact, the element cuts or cleaves through the intimal layer INT to create the dissection.  FIGS. 3A-3B  illustrate such a treatment catheter  100  having a dissection tool and its method of use. As shown, the catheter  100  comprises a catheter shaft  106  (optionally including a mechanical aspiration pump  103 ), a guidewire lumen  102 , an expandable member  104  mounted near its distal end  101  and a radially expansive element, in this case a cutting element  105 . In use, a guidewire GW is advanced to the occlusion OC or treatment area within the blood vessel BV as shown in  FIG. 3A . Once the guidewire GW is in place, the catheter  100  is advanced over the guidewire GW so that the cutting element  105  is positioned proximal to the occlusion OC at the point in which a dissection is desired. The expandable member  104  is then inflated which in turn expands the cutting element  105 . The cutting element  105  has a cutting surface  108  which is pushed into the intimal layer INT as a result of the action of the expandable member  104 , thereby creating a dissection. In addition, the cutting surface  108  may be configured to cut through the intimal layer INT by rotation of the radially expansive element or cutting element  105  as illustrated by the arrow. As shown in  FIG. 3B , either such action creates a dissection D and exposes a portion of the adventitial layer ADV after the cutting surface  108  contacts the vessel wall in the expanded position. 
     FIG. 4  illustrates a similar embodiment of a treatment catheter  100  and dissection tool. Again, the catheter  100  comprises a catheter shaft  106  (optionally including a mechanical aspiration pump  103 ), a guidewire lumen  102 , an expandable member  104  mounted near its distal end  101  and a radially expansive element, in this case a cutting element  105 . Once the guidewire GW is in place, the catheter  100  is advanced over the guidewire GW so that the cutting element  105  is positioned proximal to the occlusion OC at the point in which a dissection is desired. The expandable member  104  is then inflated which in turn expands the cutting element  105 . In this case, the cutting element  105  has an abrasive surface  115  which is configured to abrade through the intimal layer INT to expose a portion of the adventitial layer ADV. Typically, such abrasion is achieved by rotation of the radially expansive cutting element  105  as indicated by the arrow. 
   In any of the above embodiments, the radially expansive element may be self-expanding such that an expandable member  104 , such as a balloon, is not required to expand the element. In these cases, the radially expansive element may be constructed of a self-expanding material, such as shape-memory alloy or nickel titanium. Expansion may be activated by release of any restriction holding the element a collapsed form.  FIG. 5  illustrates a dissection tool or treatment catheter  100  having a radially expansive element  117  which is self-expanding. Again, the catheter  100  comprises a catheter shaft  106 , a guidewire lumen  102 , and the radially expansive element  117  disposed near its distal end  101 . Once the guidewire GW is in place, the catheter  100  is advanced over the guidewire GW so that the element  117  is positioned proximal to the occlusion OC at the point in which a dissection is desired. The element  117  is then expanded, as shown, so that it contacts the walls of the blood vessel BV. In this case, the element  117  has an abrasive surface  115  which is configured to abrade through the intimal layer INT create a dissection D and expose a portion of the adventitial layer ADV. Typically, such abrasion is achieved by rotation of the radially expansive cutting element  105  as indicated by the arrow. 
   In additional embodiments of the dissection tool, the radially expandable element has an adhesive surface adapted to adhere to an intimal layer of the vessel wall upon contact with the vessel wall in the expanded position. In one such embodiment, shown in  FIG. 6A , the radially expandable element comprises an inflatable member  700  having an adhesive surface  702 . The adhesive surface  702  may comprise cyanoacrylate, UV curable adhesive, epoxy, bioadhesives, collagen based adhesive for biological applications and other adhesive materials. Further, the adhesive surface  702  may comprise a material having a temperature in the range of approximately −100° C. to 0° C. This may be achieved by inflating the member  700  with a liquid having a temperature in a similar range. Alternatively, the adhesive may comprise a material having a temperature in the range of approximately 42° C. to 100° C. Again, this may be achieved by inflating the member  700  with a liquid having a temperature in a similar range. The inflatable member  700  is mounted on the distal end of a shaft  720  through which a guidewire GW may be placed. Once the tool  10  is positioned within the blood vessel BV in a desired location, the member  700  is inflated so that the adhesive surface  702  contacts the intimal layer INT or material to be removed from the lumen. As shown in  FIG. 6B , once the adhesive surface  702  has adhered to the intimal layer INT or material, the member  700  is deflated. Upon deflation, the member  700  removes the adhered portions from the vessel wall to create a dissection D and expose portions of the adventitial layer ADV. The tool  10  may then be withdrawn as indicated by arrows. 
   It may be appreciated that such an adhesive surface may be used with previously described embodiments of the expansive element. For example, an adhesive surface may replace the cutting surface in  FIGS. 3A-3B  or the abrasive surface in  FIGS. 4-5  and function in a manner similar to that described above. Further, as shown in  FIGS. 7A-7B , an adhesive surface  800  may be provided by an adhesive element  802  which is part of a dissection tool  10 . Here, the adhesive element  802  is disposed on the distal end of a shaft  804 . To create a dissection, the adhesive element  802  is positioned so that the adhesive surface  800  contacts the vessel wall and adheres to the intimal layer INT of the blood vessel BV. Upon withdrawal of the adhesive element  802 , shown in  FIG. 7B , the adhered portions of the intimal layer INT are removed to expose portions of the adventitial layer ADV. In this and other cases mentioned above, the adhesive surface  702  may comprise vacuum suction, any of the adhesive materials described above, or any suitable material. 
   Angioscopy and IVUS can be used with any of the dissection tools  10  to visualize the dissection. 
   II. Stripping Tools 
   The next feature of the present invention involves stripping or delaminating the innermost layer or intimal layer from the outer layer or adventitial layer. Generally, once a dissection of the intimal layer has been made to expose a portion of the adventitial layer, the intimal layer may be delaminated from the adventitial layer with the use of a variety of stripping tools. 
   In one embodiment, shown in  FIG. 8A , the stripping tool  20  comprises a shaft  24  and a funnel-shaped dissection propagator or stripping component  22 . The component  22  is configured to contact the exposed portion of the adventitial layer ADV in the area of the dissection D. Alternatively, the component  22  may be attached to a ring  25  which contacts the adventitial layer ADV in the same manner. The ring  25  is typically a radially expansible ring which expands to fit any sized lumen. As shown in  FIG. 8B , the component  22  is advanced toward the occlusion OC so that the dissected intimal layer INT is delaminated from the adventitial layer ADV and drawn into the funnel-shaped component  22 . Such action may be assisted by a mechanical aspiration pump  17  within the shaft  24 . In addition, a rotating macerator  18  may be incorporated in the aspiration pump  17  to facilitate maceration and removal of the occlusive material OC and delaminate intimal layer INT. The aspiration pump  17  and macerator  18  are rotated using a variable speed motor drive unit. The motor drive unit may also be put in reverse to change the direction of the pump  17  and macerator  18 . When such a pump  17  and macerator  18  are present during the initial creation of the dissection, these devices may be utilized during the dissection step to ensure complete aspiration of the occlusive material and potential emboli. In addition, a separate pump and macerator may also be positioned on the distal side of the occlusion OC for added protection against loose material becoming embolic. 
   In a similar embodiment, illustrated in  FIGS. 9A-9B , the stripping tool  20  may comprise a radially expansible ring  110  which is also positionable between the intimal layer INT and adventitial layer ADV of the blood vessel BV. Here, the ring  110  is mounted on a shaft  111  which may be extensible from a treatment catheter (not shown) or may be independently insertable into the blood vessel BV. As shown in  FIG. 9A , an expansion member  112  may be inserted through the ring  110  to provide a number of functions. The expansion member  112  may first be used to expand a cutting element  105 , as previously shown and described in  FIGS. 3A-3B . As described, the cutting element  105  has a cutting surface  108  which is pushed into the intimal layer INT as a result of the action of the expandable member  104 /expansion member  112 , thereby creating a dissection D and exposing a portion of the adventitial layer ADV. Referring now to  FIG. 9A , the expansion member  112  may then be used to expand the ring  110  from a reduced dimension (shown in dashed line) to an expanded dimension. The expansion member  112  may also be used as a guide for directing the ring  110  into the dissection D and between the intimal layer INT and adventitial layer ADV, as shown. Referring to  FIG. 9B , the ring  110  is advanced, or retracted depending on the direction of its insertion, along the adventitial layer ADV of the blood vessel BV so that the intimal layer INT and associated occlusive material OC are delaminated and pass through the inside of the ring  110 . The delaminated material may be drawn into a mechanical aspiration catheter  120  which houses an aspiration pump  103  and optionally a macerator, therein described by U.S. Provisional Application No. 60/260,170, U.S. patent application Ser. No. 09/454,517, and U.S. patent application Ser. No. 09/590,915 which claims the benefit of U.S. Provisional Application No. 60/154,752. 
   It may be appreciated that although the radially expansible ring  110  has been described as a separate tool, a stripping tool, from the cutting element  105 , a dissection tool, the ring  110  may serve both purposes. The ring  110  may have a cutting surface  108  or any other type of surface suitable for dissection wherein the ring  10  is used for dissection. The ring  110  may then be used in a manner described above for stripping or delaminating the intimal layer INT from the adventitial layer ADV. 
     FIGS. 10A-10B  illustrate an additional embodiment of a stripping tool and its methods of use. Referring to  FIG. 10A , the stripping tool  700  comprises a shaft  740  having a distal end  742  whereupon at least one but typically two or more radially expandable arms  706  are mounted. The arms  706  are expandable so that blunt-end tips  744  of the arms  706  are positionable between the intimal layer INT and adventitial layer ADV in the area of dissection D. Referring to  FIG. 10B , the stripping tool  700  is then retracted or moved axially so that the tips  744  slide along the exposed adventitial layer ADV creating a dissection plane or delamination of the intimal layer INT from the adventitial layer ADV. As shown, the delaminated intimal layer TNT collects within the arms  706  along with associated thrombus, atheroma or occlusive material OC. The removed material may be directed towards a mechanical cutting or aspiration system  714  where it is cut and removed. The system  714  may be disposed in a catheter shaft  703  of a treatment catheter  701  or it may be disposed in a separate catheter or device. 
   Referring to  FIG. 11 , an additional embodiment of a stripping tool and its methods of use is shown. Here, the stripping tool  20  includes a shaft  510  having a guidewire lumen  505  therethrough and a stripping component  500  comprising a rod  502  having an atraumatic distal tip  504 . Once the stripping tool  20  is positioned in the blood vessel BV near the dissection area D, by advancement over the guidewire GW, the rod  502  is angularly extended from the shaft  510  so that the tip  504  is positioned in the dissection area D between the intimal layer INT and the adventitial layer ADV, as shown. The rod  502  may be adjusted angularly or extendably to accommodate blood vessels of various sizes. By advancing the tool  20  so that the rod  502  moves along the exposed adventitial layer ADV, the intimal layer INT is delaminated and a cleavage plane is created. In addition, the rod  502  may be rotated around a longitudinal axis  508  of the shaft  510 , as indicated by the arrow, to assist in the cleaving process. 
   Referring to  FIG. 12 , the above described embodiment of the stripping tool  20  may optionally include devices for visualization of the cleaving process. Here, a light source and angioscope  520  are disposed on the shaft  510  near the stripping component  500 . A proximal occlusion member  512  is shown mounted on the shaft  510  and a distal occlusion member  514  is shown mounted on a separate shaft  516  which is introduced through a lumen in the shaft  510 . However, it may be appreciated that the distal occlusion member  514  may be mounted on shaft  510  in other embodiments. Once the blood vessel BV is occluded by the occlusion members  512 ,  514 , the portion of the blood vessel therebetween may be filled with saline SA or other suitable fluid to form a zone for visualization. Since the stripping component  500  is located in this zone, the stripping or cleaving process can be monitored through visualization. Such monitoring may be achieved continuously throughout the cleaving process or at discrete intervals. 
   Another embodiment of a stripping tool is shown in  FIG. 13 . Here, the stripping tool  400 , comprising a shaft  402 , having distal end  404 , a proximal end and a threaded surface  406  along at least a portion of its length, may be inserted into the blood vessel BV. In this embodiment, a stripping component  408  is mounted on the shaft  402  in a locked position. The stripping component  408  is then positioned against the exposed portion of the adventitial layer ADV. The shaft  402  may then be rotated which advances the stripping component  408  between the intimal layer INT and adventitial layer ADV to create a cleavage plane CP. It may be appreciated that the component  408  may be retracted by reverse rotation of the shaft  402 . In any case, rotation may be provided by a torque provider which may attach to the proximal end of the shaft  402 . In addition, the stripping tool  400  may also include means for locking the stripping component  408  to the shaft  408 , typically by interlocking the threaded surface  406  with threads on the stripping component  408 . This may terminate the stripping after a specified distance. 
   Yet another embodiment of a stripping tool is depicted in  FIG. 14 . As shown, the stripping tool  450  comprises a shaft  451 , allowing the passage of a guidewire GW therethrough, and stripping component  452 , comprising a radially expansible coil  454 . The coil  454  may have an oblique angle formed leading edge  456 , as shown. When the stripping component  452  is positioned near the dissection area D, the coil  454  may be expanded so that the leading edge  456  is in contact with an exposed portion of the adventitial layer ADV. Such positioning will allow the edge  456  to move between the intimal layer INT and adventitial layer ADV when the tool  450  is advanced. Advancement of the tool  450  is achieved by rotation, as indicated by arrows, of the coil  454  by a drive unit or other means. As the intimal layer INT is delaminated, a cleavage plane is created and the stripped material, including associated thrombus and occlusive material OC, is passed through the inside of the coil  454 . The stripped material is then removed, typically by maceration and aspiration. 
     FIGS. 15A-15B  illustrate an additional embodiment of a stripping tool  601  and its methods of use. As shown in  FIG. 15A , the stripping tool  601  comprises an anchoring component  606  mounted on a shaft  605  and a stripping component  600  mounted on a separate shaft  607 . The shafts  605 ,  607  are coaxially arranged so that shaft  605  is slidably disposed within shaft  607 . The stripping tool  601  is positioned within the blood vessel BV so that the anchoring component  606  is positioned near the previously created dissection D where a portion of the adventitial layer ADV is exposed. The anchoring component  606  is then expanded so that it firmly contacts the vessel wall. Here the component  606  is inflatable so the component  606  may be overinflated, as shown, expanding the blood vessel BV to ensure anchoring ability. The stripping component  600  is positioned within the area of dissection D. Here the component  600  comprises an inflatable member  602  which is inflated so that it contacts a portion of the exposed adventitial layer ADV. Referring to  FIG. 15B , the inflatable member  602  is then advanced along the blood vessel, or in this case retracted toward the proximal end of the tool  601 , to create a cleavage plane. Optionally, the inflatable member  602  may house an angioscope  604  for visualization of the cleaving process. As the member  602  moves along the exposed adventitial layer ADV, the intimal layer INT is delaminated and pushed along by the member  602 . Since such pushing may require significant force, the anchoring component  606  will assist in creating tension. The stripping component  600  may also include surface features to enhance removal of the intimal layer INT such as those previously described in relation to  FIGS. 6A-6B  and  FIGS. 7A-7B . The delaminated material and associated occlusive material OC is then removed, typically by maceration and aspiration. 
     FIGS. 16A-16C  illustrate an additional embodiment of a stripping tool for use in longitudinal vessel stripping. In this concept a wire or stripping element  201  is used to delaminate the intimal layer INT from the adventitial layer ADV of a blood vessel BV. Generally, a portion of the adventitial layer ADV is first exposed by any suitable dissection method. As shown in a cross-sectional view in  FIG. 16A , the distal end  202  of the stripping element  201  is then inserted into the dissection D and wedged between the intimal layer INT and adventitial layer ADV. The element  201  is then advanced longitudinally along the blood vessel BV between the two layers INT, ADV. Such advancement is illustrated in  FIG. 16B  where one portion of the illustration is a cross-sectional view and another is a perspective view to illustrate the positioning of the element  201 . Referring to  FIG. 16C , the stripping element  201  is then rotated around the vessel circumferential plane, in the direction of the arrows, to loosen and delaminate the intimal layer INT from the adventitial layer ADV. The intimal layer INT is shown separated the from the adventitial layer ADV. The stripping element  201  may be in tension and/or a linear movement may be applied to the element  201  to enhance separation of the internal and external vessel layers. Examples of this linear movement would be translational, vibrational, or ultrasonic motion. Once the element  201  has been rotated 360 degrees, the intimal layer INT should be completely delaminated. 
   III. Combination Tools 
   Although each of the above described dissection tools and stripping tools may be used with each other, some tools may provide both dissection and stripping functions. This was previously mentioned above in relation to the radially expansible ring  110  in  FIGS. 9A-9B . An additional example of an embodiment providing a combination of functions is illustrated in  FIGS. 17A-17C  along with its method of use. 
     FIG. 17A  illustrates a treatment catheter  651  comprising a proximal occlusion member  650  mounted on a shaft  653  and a distal occlusion member  652  mounted on a separate shaft  658 . The shafts are coaxially arranged so that shaft  658  is slidably disposed within shaft  653 . In addition, a maceration device  660  may be disposed between the members  650 ,  652  as shown. The catheter  651  is inserted within a blood vessel BV and positioned so that the occlusion members  650 ,  652  are disposed on opposite sides of an area which is desired to be dissected and/or stripped. Such positioning may be achieved with the use of a guidewire GW, as shown. In this example, the occlusion members  650 ,  652  are positioned on opposite sides of an occlusion OC and inflated so that they firmly contact the intimal layer INT. Referring to  FIG. 17B , the catheter shaft  658  is then elongated between the occlusion members  650 ,  652 , by slidably advancing the shaft  658  out from the coaxial shaft  653 , which moves the occlusion members  650 ,  652  apart. Thus, a tension zone is created between the members  650 ,  652 . Since the adventitial layer ADV is more flexible than the intimal layer INT, the intimal layer TNT and any associated occlusive material OC will separate from the adventitial layer ADV. A cleavage plane CP is shown where the intimal layer INT has delaminated from the adventitial layer ADV. In addition, the intimal layer INT may split or crack exposing the adventitial layer ADV and creating fragments of loose tissue and occlusion material, as depicted in  FIG. 17C . The delaminated material may then be macerated by the maceration device  660 , shown positioned between the occlusion members  650 ,  652 , or any other suitable device. 
   It may be appreciated that the above described embodiment may be used for dissection and stripping of an area, as described, or it may be used to simply create a dissection. In the latter case, the occlusion members  650 ,  652  may be positioned relatively close together on opposite sides of an area in which a dissection is desired to be made. Separation of the members  650 ,  652  may simply split open the intimal layer INT between the members  650 ,  652  creating dissection. The catheter  651  may then be removed and an area may be stripped using the dissection as an entry point by any desired method. In addition, the occlusion members  650 ,  652  may both be mounted on the same shaft wherein the members are separated by extension of the shaft. 
   IV. Cutting Tools 
   The last of the three basic features mentioned of an endarterectomy or similar procedure includes removing the delaminated material from the lumen. Removal may occur during or after the stripping process. For example, the material may be gradually aspirated and/or macerated as it is delaminated to remove it from the body lumen. Or, the material may first be delaminated and then separately removed. In some cases, the delaminated material is present in discrete chunks or sections which are easily removed by aspiration and/or maceration. In other cases, it is necessary to cut the delaminated material from the intact material within the blood vessel to allow removal. Cutting may be achieved with a variety of cutting tools. In addition, cutting may also be achieved with any of the previously described dissection tools. 
   An embodiment of a cutting tool is illustrated in  FIG. 18  and its method of use is depicted in  FIGS. 19A-19E . As depicted in  FIG. 18 , the cutting tool  300  is comprised of a support tube  301 , a cutting wire  302 , a shaft  303 , a distal end  304 , a handle  307 , a lever  306  to control the cutting wire  302 , and a lever  305  to retract the support tube  301 . The support tube  301  may be comprised of any suitable material, such as nitinol or spring steel hypotube, and forms a loop near the distal end  304  as shown. Within the tube  301  resides the cutting wire  302  shown in dashed line; the wire  302  may be comprised of any suitable material such as nitinol or spring steel wire. The tool  300  is illustrated in use in  FIGS. 19A-19E . Referring to  FIG. 19A , the cutting tool  300  is inserted within a blood vessel BV wherein a portion the intimal layer INT has been delaminated from the adventitial layer ADV creating a core C and a cleavage plane CP therebetween. The tube  301  is retracted within the shaft  303  as shown. Referring to  FIG. 19B , support tube  301  and cutting wire  302  loop is then placed over the core C so the core C passes through the loop. As depicted in  FIG. 19C , the support tube  301  and cutting wire  302  loop is then advanced through the cleavage plane CP to a desired position wherein the core C will be cut. As shown in  FIG. 19D , the support tube  301  is retracted by manipulating lever  305  to expose the cutting wire  302 . The support tube  301  is pulled back into the shaft  303  so the cutting wire  302  remains surrounding the core C. Referring to  FIG. 19E , the cutting wire  302  is then pulled/tensioned to cut through the intimal layers INT and the core C by manipulating lever  306 . This releases the delaminated material from the intact material within the blood vessel BV. The delaminated material may then be removed from the lumen by any suitable means. 
   Contrast may be injected through the cutting tool in order to facilitate visualization. 
   V. Adjunctive Therapies 
   Depending on the occlusion to be treated, a distal protection device, such as a balloon fixed to a guidewire, or a filter device, may be employed distal of the occlusion and expanded to minimize any embolization of clot or other material. In addition an occlusion balloon may be deployed distally of the occlusion and one proximal of the occlusion to isolate the lesion and allow the treatment device to infuse: 
   Thrombolytic Agents (Enzymatic action breaks down fibrin clot matrix.) 
   
       
       
         
           Alteplase, tPA, Activase®, Genentech, Inc. 
           Anistrpelase, a-SK, Eminase®, Roberts Pharmaceuticals 
           Reteplase, r-PA, Retavase®, Centocor, Inc. 
           Streptokinase, SK, Streptase®, AstraZeneca, Inc. 
           Tenecteplase, TNK, TNKase®, Genentec, Inc. 
           Abbokinase®, Abbott, Inc. (not currently marketed)
 
GP IIb/IIIa Inhibitors (Inhibit fibrinogen binding site of platelet membrane.)
 
           Abciximab, ReoPro®, Centecor, Inc. 
           Tirofiban, Aggrastat®, Merck, Inc. 
           Eptifibatide, Integrelin®, Cor Therapeutics, Inc. 
           Other IIb/IIIa Inhibitors: Bitistatin, Kistrin 
           Other anti-platelet agents: Aspirin
 
Anti-Thrombin Agents and Agents Directed toward Prevention of Restenosis
 
           Heparin (LMW contains most anticoagulant activity, also inhibits smooth muscle Proliferation and migration, examples include enoxaparine (Lovenox®), dalteparin (Fragmin®) and ardeparin (Normoflo®)) 
           Other anti-thrombin agents: Hirudin, Argatronban, PPACK (inhibit thrombin induced platelet activation and platelet secretion of PDGF which is responsible for smooth muscle proliferation and migration.) 
           Radioactive agents (vascular brachytherapy, inhibits smooth muscle proliferation) 
           Locally delivered nitrate (nitric oxide, prevents reflex vasoconstriction at site of injury and inhibits activation of circulating platelets in order to decrease late luminal narrowing) 
           HA11077 (Inhibits action of cellular protein kinases and sequestration of cellular calcium, acts as vasodilator. Shown to inhibit smooth muscle proliferation.) 
           Other anti-restenosis agents: calcium antagonists, angiotensin converting enzyme inhibitor, anti-inflammatory agents, steroidal agents, anti-mitotic agents, HMG CoA reductase inhibitors, colchicine, angiopeptin, cytoclasin B
 
Gene Therapeutic Agents
 
           Agents are currently under development in hopes of preventing restenosis and promoting angiogenesis. Agents may be delivered via plasmid vectors or by viral vectors. Examples include genes relating to: VEGF, C-myb, FGF, transforming growth factor b, endothelial growth factor, protooncogenes such as C-myc, C-myg, CDC- 2 , PCNA.
 
Chemotherapeutic Agents
 
           Agents designed to treat malignancies. Examples might include adriamycin (Doxorubicin®).
 
Imaging Media
 
           Contrast media, radioactively labeled agents.
 
Other Potential Agents
 
           Plasminogen additive as an adjunct to thrombolytic therapy, immunosuppressive agents. 
         
       
     
  
   In addition, saline, pharmacologic agents such as tPA, ReoPro, platelet aggregation inhibitors and the like, or chemical ablation agents or acid solutions such as those described in PCT Application No. PCT/US99/15918 (WO 00/03651) may be used. 
   VI. In General 
   It may be appreciated that the above described devices and methods may be adapted for use in other body lumens and cavities, such as the esophagus, stomach, lungs, kidneys, intestines, rectum and uterus, to name a few. In these and other cases, a first layer may be dissected and stripped from a second layer of the lumen or cavity wall.  FIG. 20A  illustrates the location of a first layer or inner layer  900  and a second layer or outer layer  902  of a body lumen  904 . As shown, the inner layer  900  substantially covers the outer layer  902  in the lumen.  FIG. 20B  illustrates the location of a first layer or inner layer  900  and a second layer or outer layer  902  of a body cavity  906 . Again, the inner layer  900  substantially covers the outer layer  902  in the lumen. In either case, the inner layer  900  may not cover the outer layer  902  throughout the lumen  904  or cavity  906 , but may only cover the outer layer  902  in the target location or specific area to be treated. Although illustrated separately, in many embodiments the terms lumen and cavity may be used synonymously. In addition to the inner layer, various tissues, tumors or other material may be removed in a similar fashion. The above described devices and methods may also be used in the vascular system for procedures other than endarterectomies and may be used to create cleavage planes between tissues, layers and other materials other than the intimal and adventitial layers of the vessel wall. 
   Referring now to  FIG. 21 , kits  1000  according to the present invention comprise any of the above described devices related to percutaneous endarterectomy or similar procedures and instructions for use IFU. For example, kits  1000  may include a dissection tool  1010  and instructions for using the dissection tool according to the methods of the present invention. Typically the dissection tool  1010  is disposed near the distal end of a percutaneous catheter  1012 . Alternatively or in addition, the kits  1000  may include a stripping tool  1014  and/or a cutting tool  1016  and instructions for use. Optionally, the kits may further include any of the other components described above, such as a guidewire GW, aspiration pump  1018 , macerator  1020 , various percutaneous treatment catheters and other components. Further, the kits  1000  may include an adhesive material  1030  for application to an adhesive surface which is typically located on a dissection tool  1010 . All kit components will usually be packaged together in a pouch  1032  or other conventional medical device packaging. Usually, those kit components which will be used in performing the procedure on the patient will be sterilized and maintained within the kit. Optionally, separate pouches, bags, trays or other packaging may be provided within a larger package, where the smaller packs may be opened separately to separately maintain the components in a sterile fashion. 
   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 present invention.