US20150174367A1 - Material removal catheter and method - Google Patents

Abstract

A catheter device and methods useable to extract material from a body conduit, e.g., a blood vessel, are provided. The catheter comprises a flexible catheter advanceable into the body conduit, an opening in a wall of the catheter in fluid communication with a material collection chamber, and a controllably arcuate segment near the distal tip of the catheter and the opening. The catheter may include a sliding member, located within a lumen of the catheter, used to move the material entering the catheter through the arcuate segment opening, into the material collection chamber and away from said opening. The catheter may include a single mechanism utilized to both generate a vacuum to cause material to enter the catheter at the arcuate segment opening and also cause the sliding member to travel, inside the catheter, moving material away from the opening and into the material collection chamber.

Description

CROSS REFERENCE TO RELATED APPLICATION
• This application is a continuation application of U.S. patent application Ser. No. 13/369,969, filed Feb. 9, 2012, which is a continuation of U.S. patent application Ser. No. 12/246,995, filed Oct. 7, 2008, now U.S. Pat. No. 8,133,214, issued Mar. 13, 2012, which is a continuation of U.S. patent application Ser. No. 10/615,122, filed Jul. 8, 2003, now U.S. Pat. No. 7,449,010, issued Nov. 11, 2008, which relies for priority upon U.S. Provisional Patent Application Ser. No. 60/396,042, filed Jul. 15, 2002, now expired, entitled MATERIAL REMOVAL CATHETER AND METHOD.
FIELD OF THE INVENTION
• The present invention relates generally to medical devices, systems and methods and more particularly to a material removal catheter and methods that are useable to remove thrombus and other undesired material from the vasculature or other internal conduit of a patient, the apparatus being particularly well suited for saphenous vein grafts, coronary arteries and the peripheral vasculature.
BACKGROUND OF THE INVENTION
• Human blood vessels often become partly or fully occluded by various undesired materials including plaque, thrombi or other substances that restrict the flow of blood within the vessel. Depending on the location of the occlusion, serious injury or even death can occur. When diagnosed, it is often advantageous to remove the occlusive material in a safe and effective manner. Coronary heart disease is an extremely common form of this occlusive disease, and is the leading cause of death in the United States.
• Arteriosclerosis is a chronic disease characterized by abnormal thickening and hardening of the arterial walls. As the coronary arteries are first narrowed by plaque, at locations known as stenoses, further constriction may be caused by the formation of blood clots, or thrombi, on the rough surface of the plaque. A severe complication of arteriosclerosis is a myocardial infarction, or MI. An MI is the death of a section of heart muscle when its blood supply is cut off, usually by a blood clot in a coronary artery narrowed by arteriosclerosis. An MI can occur spontaneously due to severely narrowed vasculature or due to an embolus, such as a thrombus released from an upstream stenosis. An embolus can even be caused in a medical procedure intended to reduce or remove a stenosis.
• Various types of interventional techniques have been developed that can be utilized to reduce or remove a blockage in a blood vessel. One technique, known as balloon angioplasty, involves using a special catheter that includes a balloon near its distal tip, advancing the balloon into the constricted area, and inflating the balloon to expand the constriction. Other therapeutic options include atherectomy, deployment of stents, infusion of therapeutic medications and heart bypass surgery. All of these therapeutic options involve the risk of dislodging a portion of the occlusive material, causing embolus to move downstream thus causing further complications.
• Heart bypass surgery is an extremely invasive and traumatic form of therapy to treat coronary occlusive disease. In one form of bypass, a portion of vein taken from the patient's leg, the saphenous vein, is connected between the aorta and a portion of the blocked artery distal to the blockage, supplying oxygenated blood to the portions of heart muscle supplied by the artery prior to its being occluded. These saphenous vein grafts often used in heart bypass procedures are also susceptible to occlusive disease, and over time may become restricted by plaque and thrombus. Atherosclerotic plaque in saphenous vein grafts tends to be softer and more friable than their arterial counterparts and thus more prone to embolizing during treatment.
• Chemical thrombolytic drugs are available to treat saphenous vein grafts but require the patient to be non-ambulatory throughout their use and have numerous risks and complications. Balloon angioplasty of saphenous vein grafts is associated with a higher rate of embolus generation, potentially migrating downstream to block a portion of the coronary artery to which it is attached and causing a myocardial infarction. Directional Coronary Atherectomy, or DCA catheters include cutting blades that can damage the vessel wall and the systems have a propensity to become clogged and generate embolus similar to balloon angioplasty. Adjunctive devices are available to reduce the complications of embolization by trapping the released emboli downstream. These devices are expensive, and complicated to use. Vacuum extraction catheters have been developed to treat saphenous vein grafts, however they tend to be large and bulky and have had sub optimal results and numerous complications.
• Clearly, therefore, there is a need for improved devices, systems and methods for removal of undesired material from an internal body conduit such as a saphenous vein graft or coronary artery that improve the efficiency of material removal and reduce the risks to the patient.
SUMMARY OF THE INVENTION
• The present invention is directed to a device and method that simply and effectively removes undesired material from the wall of a conduit, such as a blood vessel. The device is a catheter with an elongate catheter shaft having a proximal end and a distal end. The distal end of the catheter shaft has a diameter less than the conduit containing the undesired material, said catheter shaft including a controllably arcuate portion or segment which can be directed toward and make contact with the undesired material prior to extraction. The controllably arcuate segment includes one or more openings into which the material is drawn by applying a negative pressure, or suction from the inside of the opening. The controllably arcuate segment can be transformed into both a relatively straight and a relatively bowed geometry with operator controls contained on the proximal end of the catheter device.
• The catheter device of the present invention may be inserted into various body conduits including but not limited to blood vessels such as coronary vessels, peripheral vessels, coronary bypass grafts and arteriovenous fistulas. The device may be used for diagnostic applications, such as taking a material sample, or therapeutic applications such as reducing an occlusion within a saphenous vein graft. The device can be used in various hospital and outpatient settings, and can be guided using fluoroscopy and other imaging technologies. The device may include various markers or other visualization elements, such as radiopaque fillings or bands, ultrasound crystals or ultrasonic markers, or other markers or indicators to aid in positioning and use of the device. Such markers may include rotational orientation markers to indicate the position of one or more openings in the controllably arcuate segment. In addition or alternatively, the catheter device may include an arcuate condition indicator providing visual or other feedback to the operator as to the relatively straight or relatively bowed geometric conditions of the controllably arcuate segment. In a preferred embodiment, an audio signal is provided, such as when the controllably arcuate segment is in the relatively bowed geometry, to prevent the clinician from inadvertently advancing or otherwise moving the catheter shaft when the controllably arcuate segment should be in a relatively straight geometry. In another preferred embodiment, the catheter device includes a lumen, included along a minority or a majority of the length of the catheter shaft, through which a guidewire can be inserted for practice of over the wire interventional techniques.
• The openings in the controllably arcuate segment of the device are in fluid communication with one or more ports or chambers in the proximal, external portion of the device via one or more lumens. Within or at the end of the lumens may exist one or more valves oriented to permit flow of material in one direction only. Located in a distal portion of the catheter, near to and in fluid communication with the openings is a material collection chamber. The material collection chamber is proximal or distal to the openings, and is in fluid communication with the proximal, aspirating portion of the device via a connecting lumen. In a preferred embodiment, the material collection chamber is the connecting lumen itself. Suction applied to the aspiration portion is communicated to the openings in the controllably arcuate segment via the material collection chamber.
• In a preferred embodiment, the aspiration chamber may be connected to a waste exit, such as by a one-way valve such that when positive pressure is applied, material collected in the aspiration chamber from the openings in the controllably arcuate segment is evacuated from the aspiration chamber.
• In a preferred embodiment, within a lumen of the catheter shaft is a sliding member that is connected to a mechanical linkage extending through the catheter shaft to the proximal portion of the device. The linkage is connected to sliding or other controls on the handle of the catheter device for advancement and retraction of the sliding member. In a preferred embodiment, the sliding member and mechanical linkage include a lumen permitting a guidewire to be placed through each. The linkage system may include one or more mechanical stops that limit the advancement or retraction. In the fully advanced position, the tip of the sliding member, which preferably is tapered, extends beyond the distal end of the catheter. The tip of the sliding member may extend beyond the end of the catheter in the fully retracted position as well. The sliding member can be used to change the geometry of the controllably arcuate segment. In a preferred embodiment, the controllably arcuate segment is normally bowed, and placing the sliding member within the lumen of the controllably arcuate segment changes the segment into a relatively straight geometry. To facilitate the change in shape of the controllably arcuate segment, the sliding member is constructed to be less flexible than the controllably arcuate segment. The sliding member, which may have a sharpened end that is oriented toward the opening, is advanced or retracted to move toward the opening thereby cutting and or pushing material away from the opening and into the material collection chamber. The one or more openings can have different cross sectional profiles, such as round or oval perimeters, or various angles of tapers, and may change geometry based on the geometry of the controllably arcuate segment and or the position of the sliding member. The material collection chamber may be located proximal or distal to the opening of the controllably arcuate segment, whereby the sliding member is retracted or advanced respectively to move the material received through the opening into the material collection chamber. In order to draw material from the outside of the catheter shaft through the opening in the controllably arcuate segment, a negative pressure or suction is applied at an opening on the proximal end of the catheter device. Aspiration or negative pressure may be maintained during the period of time that the sliding member is advanced or retracted. The present invention includes various means of providing the suction including connections to attach to syringes or sophisticated vacuum and material collection generators as well as integrated aspiration systems. The present invention may include one or more valves to prevent blood leakage, avoid over pressurization, allow one way flow of fluid and other material into or out of various chambers or other locations and other purposes.
• In another preferred embodiment, the controllably arcuate segment has a normally bowed bias which is converted to a relatively straight geometric shape by integral straightening means. The normally bowed bias can be created during manufacturing with catheter shaping processes known to those of skill in the art, or with embedded curved stiffeners. The sliding member can function as the integral straightening means, as is described above, or an embedded element can change the controllably arcuate segment from a relatively bowed to a relatively straight geometry, on command, via controls located on the proximal portion of the device. In another preferred embodiment, the controllably arcuate segment has a normally straight bias which is converted to a relatively bowed geometric shape by integral curving means. Various curving means are described including mechanical pull wires or embedded curving elements that are attached, such as via electrical wires, to control means located on the handle on the proximal end of the device. An embedded battery and a switch located on the handle are used to connect the curving elements to a power source driving the shape change of the curving element. Multiple states, or transitional geometric shapes may be formed in the controllably arcuate segment in addition to a maximally straight and a maximally bowed geometry. Curving elements may be constructed of shaped memory components, such as shaped memory alloys or shaped memory polymers, piezo material, or electromagnet assemblies. Curving elements may have a filament shape, a tubular shape or a non-uniform shape. Curving elements may consist of single or multiple components that cause the controllably arcuate segment of the catheter shaft to transform to the proper bowed geometry, thus positioning the controllably arcuate segment's opening up against the wall of the body conduit into which the catheter device of the present invention is inserted. Curving or straightening elements may work in combination with a sliding member to change the geometry of the controllably arcuate segment. Changing curvature of the controllably arcuate segment can cause the openings in the segment to change shape including changing from a fluidly closed to a fluidly open state.
• In a preferred embodiment, the proximal end of the catheter device includes a handle with an integrated plunger assembly. Retraction of a grasper moves a syringe like shaft and plunger to create a negative pressure at the opening in the controllably arcuate segment. In addition, continued retraction continues the aspirating pressures causing material to be drawn through one or more lumens in the catheter device to a chamber in the handle. Advancement of the grasper causes material to evacuate the chamber through a waste exit. In this particular embodiment, the grasper may also advance or withdraw a mechanical linkage connected to a sliding member which is used to sever or otherwise move material away from the opening in the controllably arcuate segment.
• In a preferred embodiment, the catheter device includes a thru lumen from the proximal handle to the distal tip, such that material, such as thrombus, can be aspirated from the handle through the catheter shaft and removed from a location where the distal end of the catheter resides. Alternatively, a core assembly, such as an assembly including the mechanical linkage and sliding member, is removable wherein removal of the core creates the lumen that can be used to aspirate material from the distal end of the catheter. In another preferred embodiment, the catheter device includes a lumen for injecting fluids, such as radiopaque dye or blood thinning agents, wherein the lumen is attached to an input port on the handle of a the device and an exit located at or near the distal end of the catheter device. The lumen can also be used to extract material from the distal end of the catheter.
• In another preferred embodiment, the catheter device includes an elongate catheter body with a proximal end and a distal end, an aspiration chamber located near the proximal end, a controllably arcuate segment including at least one opening, and an aspiration lumen in fluid communication with the aspiration chamber and one or more openings in the controllably arcuate segment. The device may include a sliding member to move material drawn through the opening under pressure, away from the opening. The device may have a normally bowed or a normally straight bias. The device may further include one or more curving elements, controllable from the proximal end of the catheter device, for transforming the controllably arcuate segment from one geometric shape to another.
• A preferred method of using any of the catheter embodiments of the present invention is also disclosed. The method for removing material from a biological conduit includes providing a catheter device having an elongate catheter shaft having a proximal end and a distal end, a controllably arcuate segment including at least one opening in fluid communication with the proximal end and a sliding member that moves material received through the arcuate segment opening away from said opening. The device is percutaneously or surgically advanced into a biological conduit, preferably with the controllably arcuate segment in a relatively straight geometry, after which suction is applied to cause negative pressure at the one or more openings. The sliding member is then retracted to move material away from the opening. The controllably arcuate segment is changed to a relatively straight geometry prior to advancing, retracting or rotating the catheter device. In another preferred method, after the catheter device is used to first extract material, it is rotated and additional material is removed, each rotation accompanied by a predecessor step of changing to a relatively straight geometry, and each extraction step accompanied by a predecessor step of changing to a relatively bowed geometry.
• Another preferred method is disclosed for removing material from a biological conduit comprising the steps of providing a catheter device having an elongate catheter shaft having a proximal end and a distal end, a controllably arcuate segment including at least one opening in fluid communication with the proximal end, percutaneously or surgically inserting and transluminally advancing the catheter into the biological conduit, applying suction to the at least one opening in the controllably arcuate segment and changing the shape of the controllably arcuate segment from a relatively bowed geometry to a relatively straight geometry. Additional steps may include changing from a relatively bowed to a relatively straight geometry prior to insertion of the catheter device. The device may be changed from a relatively straight geometry to a relatively bowed geometry prior to applying suction. Additional steps may include use of radiopaque markers to position the device within the body conduit.
• The present invention, therefore, provides a catheter device for removing undesirable material, such as thrombus, from a body conduit, such as a saphenous vein graft or other blood vessel, including a controllably arcuate segment which further includes an opening that can be brought in contact with the undesired material with sufficient force such than under suction, the material is drawn through the opening into an lumen, cavity or chamber within the catheter device. The use of the device is simple and straightforward, and does not require bulky or expensive equipment not otherwise included in the various hospital settings in which it will be used.
• These aspects of the invention together with additional features and advantages thereof may best be understood by reference to the following detailed descriptions and examples taken in connection with the accompanying illustrated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1A is a side view of a first exemplary embodiment of a catheter device constructed in accordance with the present invention showing a controllably arcuate segment in a relatively straight geometry.
• FIG. 1B is a side view of the device ofFIG. 1A showing the controllably arcuate segment in a relatively bowed geometry.
• FIG. 2 is a cross-sectional view of the device ofFIGS. 1A and 1B showing the opening in the controllably arcuate segment positioned at a site in a biological conduit prior to removal of occlusive material.
• FIG. 3 is a cross-sectional view of a preferred embodiment of a catheter device constructed in accordance with the present invention.
• FIG. 3A is an enlarged sectional view of the proximal end of the catheter device contained incircle3A ofFIG. 3.
• FIG. 3B is an enlarged sectional view of a distal end of the catheter device contained incircle3B ofFIG. 3.
• FIG. 4 is a cross-sectional view of the catheter device ofFIG. 3 shown with a grasper of the handle assembly in a retracted position.
• FIG. 4A is an enlarged sectional view of the proximal end of the catheter device contained incircle4A ofFIG. 4.
• FIG. 4B is an enlarged sectional view of the distal end of the catheter device contained incircle4B ofFIG. 4.
• FIG. 5 is a cross-sectional view of another preferred embodiment of a catheter device constructed in accordance with the present invention.
• FIG. 5A is an enlarged sectional view of the proximal end of the catheter device ofFIG. 5 shown with the grasper of the handle assembly shown in a fully advanced position.
• FIG. 5B is an enlarged sectional view of the proximal end of the catheter device ofFIG. 5 shown with the grasper of the handle assembly shown in a partially retracted position.
• FIG. 5C is an enlarged sectional view of the distal end of the catheter device ofFIG. 5 shown with the sliding member in the partially retracted position corresponding to the grasper position ofFIG. 5B.
• FIG. 5D is an enlarged sectional view of the proximal end of the catheter device ofFIG. 5 shown with the grasper of the handle assembly shown in a fully retracted position.
• FIG. 5E is an enlarged sectional view of the distal end of the catheter device ofFIG. 5 shown with the sliding member in the fully retracted position corresponding to the grasper position ofFIG. 5D.
• FIG. 5F is an enlarged sectional view of the proximal end of the catheter device ofFIG. 5 shown with the grasper of the handle assembly shown in a partially advanced position.
• FIG. 5G is an enlarged sectional view of the distal end of the catheter device ofFIG. 5 shown with the sliding member in the a partially advanced position corresponding to the grasper position ofFIG. 5F.
• FIG. 6 is a cross-sectional view of another preferred embodiment of a catheter device constructed in accordance with the present invention.
• FIG. 6A is an enlarged sectional view of the distal end of the catheter device ofFIG. 6 shown with the controllably arcuate segment in a relatively straight geometric shape.
• FIG. 6B is an enlarged sectional view of the distal end of the catheter device ofFIG. 6 shown with the controllably arcuate segment in a relatively bowed geometric shape.
• FIG. 7 is an enlarged sectional view of the distal end of another preferred embodiment of the catheter device of the present invention.
• FIG. 8 is an enlarged sectional view taken along line A-A ofFIG. 7 showing a preferred configuration of a curving element.
• FIG. 9 is an enlarged sectional view taken along line A-A ofFIG. 7 showing another preferred configuration of a curving element.
• FIG. 10 is an enlarged sectional view taken along line A-A ofFIG. 7 showing yet another preferred configuration of a curving element.
• Like reference characters designate identical or corresponding components and units throughout the several views.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
• Referring first toFIGS. 1A and 1B, there is illustrated an exemplary embodiment of acatheter device10 constructed in accordance with the present invention. Thecatheter device10 includes acatheter shaft20 constructed of materials that are biocompatible and also permit flexibility of the device required to allow insertion into and advancement through the vasculature of a patient.Catheter shaft20 contains one or more hollow lumens within its structure that allow flow of material such as blood or thrombus, as well as permit controlling shafts, mechanical linkages or flexible tubes or wires to slide back and forth. Fixedly attached to the proximal end ofcatheter shaft20 is a handle, handle70, which allows the user to advance and maintain the position of the distal end ofcatheter device10, as well as rotate thecatheter shaft20.
• Handle20 includesaspiration port75 that is in fluid communication with an internal lumen ofcatheter shaft20.Aspiration port75 can be connected to various means of creating a vacuum or suction, such as a vacuum generator or simple syringe.Aspiration port75 may include standardized threads, such as standard luer threads, or other mechanical connection means to facilitate connection to thesuction device77.Aspiration port75 is in fluid communication with a hollow lumen ofcatheter shaft20 via a similar lumen, opening or cavity withinhandle70, all not shown, but described in detail in subsequent figures. Exitinghandle70 is a mechanical linkage,linkage30 which terminates at its proximal end with a separate handle for the user to grasp,grasper60. Advancement and retraction ofgrasper60 causes similar linear motion oflinkage30 that is slidingly received through thehandle70 and intocatheter shaft20.
• Attached to the distal end oflinkage30 is a cylindrical element, slidingmember100. Preferably, bothlinkage30 and slidingmember100 contain a thru lumen such that a standard interventional guidewire can be inserted therethrough, andcatheter device10 advanced and retracted over the guidewire using standard interventional over the wire techniques. The combined lengths oflinkage30 and slidingmember100 are preferably chosen such that whengrasper60 is in both a fully advanced and a fully retracted position, the distal tip of slidingmember100 exits the distal end ofcatheter shaft20. Preferably, the distal end of slidingmember100 is tapered to allow atraumatic advancement ofcatheter device10 through the vasculature or other body conduits.
• Near the distal end ofcatheter shaft20 is controllablyarcuate segment40, a finite length ofshaft20, proximal to the tip ofcatheter device10, that can be controlled by the user to transform on command from a relatively straight geometry or shape, to a relatively bowed, or arcuate geometry. Included at or near the mid-portion of controllablyarcuate segment40 is a hole, opening50, which traverses from the outer surface ofshaft20 to an internal cavity contained withinshaft20. Referring specifically toFIG. 1A,grasper60 and slidingmember100 are shown in a retracted position, and the controllablyarcuate segment40 is shown in a relatively straight geometry. Referring now toFIG. 1B,grasper60 and slidingmember100 are shown in a fully advanced position, and the controllablyarcuate segment40 is shown in a relatively bowed geometry. There are various means of achieving control of the shape of controllablyarcuate segment40 including embodiments in which the controllablyarcuate segment40 is normally bowed and means are provided for transforming to a relatively straight geometry, as well as embodiments in which the controllablyarcuate segment40 is normally straight, and means are provided for transforming to a relatively bowed geometry. Numerous means of controlling the shape of controllablyarcuate segment40 forFIGS. 1A and 1B as well as additional figures are described in detail herebelow.
• FIGS. 1A and 1B depict a preferred embodiment in which a controllablyarcuate segment40 is simply a portion ofcatheter shaft20 that has been formed or shaped in its manufacturing process to have a relatively bowed geometry. A common process for catheter shaping includes inserting a pre-shaped metal mandrel in the catheter during manufacture, and heating the device with the mandrel in place. The mandrel length and shape geometry would be designed to cause the proper bow at the proper location along thecatheter shaft20. After a cooling time, the mandrel is removed and the catheter assumes the desired shape. This process is often used to form complex catheter tip shapes common to various cardiovascular guide catheters, and is an effective way of shaping an elastomeric tube with one or more internal lumens. InFIGS. 1A and 1B, the slidingmember100 acts as the means of transforming the normally bowed controllablyarcuate segment40 from its manufactured bowed geometry to a relatively straight geometry. When the slidingmember100 is advanced beyond the length of the controllablyarcuate segment40, controllablyarcuate segment40 assumes its bowed configuration established during the manufacturing process. The material selection, thickness and other geometric parameters of slidingmember100 are chosen such that whengrasper60 is retracted,linkage30 retracts slidingmember100 accordingly, causing a significant length of slidingmember100 to reside within the internal lumen of controllablyarcuate segment40, further causing controllablyarcuate segment40 to transform into a relatively straight geometry. When thegrasper60 and attachedlinkage30 are advanced, the majority of length of slidingmember100 slides out of the internal lumen of controllablyarcuate segment40, allowing it to reassume its bowed geometry. Subsequent advancement and retraction ofgrasper60, correspondingly advances and retractslinkage30 and slidingmember100 such that controllablyarcuate segment40 transforms to a relatively bowed geometry to a relatively straight geometry respectively.
• Referring again toFIGS. 1A and 1B, there is included near the midpoint of controllablyarcuate segment40 an hole, opening50, which extends from the outer surface ofcatheter shaft20 to an inner lumen. As described above,aspiration port75 is in fluid communication with an internal lumen ofcatheter shaft20, this particular lumen also in fluid communication withopening50 such that when a vacuum is applied toaspiration port75 by way of a syringe or other means, suction is applied at opening50 causing material in close proximity to opening50 to be drawn into the lumen ofshaft20 viaopening50. Controllablyarcuate segment40 construction materials and geometry and the geometry of opening50 may be chosen such that when controllablyarcuate segment40 is in its relatively bowed geometry, opening50 is relatively open, however when controllablyarcuate segment40 is in its relatively straight geometry, opening50 is relatively closed.
• Referring now toFIG. 2, a preferred method of utilizingcatheter device10 is depicted. Thecatheter device10 of the present invention can be placed percutaneously or intraoperatively, and advanced through a body conduit such as the vascular system. In a preferred embodiment,catheter device10 is inserted percutaneously into the vasculature to treat a blood vessel, such as a coronary vessel or saphenous vein graft placed during coronary artery bypass graft surgery. Typically a guide catheter, not shown, is placed at a convenient vascular access point such as a femoral artery, and advanced to a point proximal to a stenotic location such as the ostium of an occluded saphenous vein graft. Typically a guidewire, such as an 0.014 inch guidewire, guidewire300, is advanced through the guide catheter and into the lumen of the vessel to be treated to a location past the stenosis.
• Next thecatheter device10 of the present invention is percutaneously inserted and transluminally advanced through the guide catheter and overguidewire300 into the vessel to be treated,blood vessel200, positioning theopening50 of the controllablyarcuate segment40 near the area of occlusive material to be removed,occlusive material210. Each time thecatheter device10 is inserted with the controllablyarcuate segment40 in the relatively straight geometric condition, shown inFIG. 2 at a later step with the controllablyarcuate segment40 in the relatively bowed geometry. The operator would assure and or change to that relatively straight geometry condition not only prior to insertion, but each time the device is transluminally advanced, withdrawn or rotated. In this particular embodiment, the catheter device ofFIGS. 1A and 1B, the operator would simply retractgrasper60 to cause the controllablyarcuate segment40 to be in the relatively straight geometric shape. Other means for changing the shape of controllablyarcuate segment40 are described with the subsequent figures below.Catheter shaft20 has a length appropriately chosen such that a small portion of the proximal end ofcatheter shaft20 extends out of the guide catheter, placinghandle70 in close proximity to the insertion site, when opening50 is properly positioned at the location of theocclusive material210.
• The axial position of the guide catheter, guidewire300 and various components ofcatheter device10 are known within the vessel utilizing conventional techniques and equipment which may include, for example, fluoroscopy, ultrasound, nuclear magnetic resonance imaging (NMR), and other visualization techniques and equipment commonly found in hospital operating rooms, catheterization laboratories and other therapeutic and diagnostic environments. In a preferred embodiment,catheter shaft20 can be visualized with visualization equipment such as fluoroscopy, orcatheter shaft20 has been modified to be visualized. Insertion of radiopaque agents, such as barium sulfate, in small amounts, allows relatively thin catheter shafts to be visualized with x-ray equipment such as fluoroscopy. Various surface modification or air bubble impregnation techniques can be employed to make the implantable materials be visualized with ultrasound and other modifications can be accomplished to be compatible with other visualization technologies.Catheter shaft20 and controllablyarcuate segment40 shall be modified such that the user can differentiate when the controllablyarcuate segment40 is in its relatively straight geometry versus its relatively bowed geometry. In a preferred embodiment, a visualization marker,marker51, preferably a radiopaque band, is also included near or surroundingopening50 such that during rotation ofcatheter shaft20, the angular orientation as well as the longitudinal positioning ofopening50 can be visualized. Additionally, thecatheter device10 may include an internal lumen or pathway, not shown, that allows angiographic dye to be injected into it, exiting at a point at or near the distal tip ofcatheter shaft20, such as through the guidewire lumen, around the guidewire lumen, or throughopening50.
• Referring still toFIG. 2, thecatheter device10 has been transluminally advanced overguidewire300 such thatopening50 has been positioned near theocclusive material210. Note that at this point in the procedure, controllablyarcuate segment40 remains in the relatively straight geometry, not depicted inFIG. 2, that it has maintained through the entire insertion process thus far. At this time, the operator transforms the controllablyarcuate segment40 from the relatively straight geometry to the relatively bowed geometry depicted inFIG. 2. With the particular embodiment ofFIGS. 1A and 1B, the operator would simply advance thegrasper60 to its fully advanced position. The outside diameter ofcatheter shaft20 is chosen to be somewhat less than the inner diameter of the vessels it is advanced through, including the vessel diameter at the stenosis. The radius of curvature and length of controllablyarcuate segment40 in its maximally bowed geometric shape is chosen such thatopening50 is pushed against the occlusive material with some amount of force.Catheter device10 will be manufactured with not only various lengths and diameter profiles, but numerous radii of curvature and segment lengths for controllablyarcuate segment40, to accommodate a range of body conduits to be treated, specifically blood vessels such as saphenous vein grafts. Catheter diameters, lengths and other geometric criteria are chosen based on the path from the percutaneous entry site to the treatment site, as well as the size and geometry of the vessel to be treated and the size and geometry of the occlusive material to be removed. In its maximally bowed geometry depicted inFIG. 2, theopening50 of controllablyarcuate segment40 is positioned such that as suction is applied viaaspiration port75,occlusive material210 is drawn into an internal cavity ofcatheter shaft20. In a preferred embodiment, controllablyarcuate segment40 at the general area of opening50 would place a small amount of force against the occlusive material when the controllablyarcuate segment40 is in its relatively bowed geometric shape.
• A next step for the operator is to retractgrasper60 causinglinkage30 and thus slidingmember100 to also retract. As slidingmember100 retracts, its proximal end pushes, potentially cutting, material projecting through opening50 to a location away from the opening, more proximal to theaspiration port75. Vacuum or suction may be maintained during the retraction of slidingmember100. Optionally,grasper60 can be advanced again, advancinglinkage30 and slidingmember100 causing controllablyarcuate segment40 to change from a relatively straight geometry to a relatively bowed geometry andpositioning opening50 again against any remainingocclusive material210. Suction can be reapplied, andgrasper60 again retracted, once again moving any material protruding throughopening50 away from opening50, as well as causing controllablyarcuate segment40 to change from a relatively bowed geometry to a relatively straight geometry.
• When the controllablyarcuate segment40 has been placed in its relatively straight geometry, thecatheter device10 can be removed by retracting it back overguidewire300 and out through the guidecatheter leaving guidewire300 and the guide catheter in place. Alternatively, also when the controllablyarcuate segment40 has been placed in its relatively straight geometry, thehandle70 can be rotated causingcatheter shaft20 to also rotate. When opening50 is rotated to its desired angular position, as may be determined using fluoroscopy andmarker51,grasper60 can be advanced, again causing controllablyarcuate segment40 to change to its relatively bowed condition and simultaneously positioningopening50 with a minimal level of force against additional occlusive material. Suction can again be applied, causing additional material to be drawn throughopening50, andgrasper60 can then be retracted, causinglinkage30 and thus slidingmember100 to simultaneously retract similarly pushing the additional material protruding throughopening50 away from opening50 as well as causing controllablyarcuate segment40 to change from a relatively bowed geometry to a relatively straight geometry.
• A preferred method includes the steps of 1) changing controllablyarcuate segment40 to its relatively bowed shape; 2) applying suction; 3) retractinggrasper60 and thus also retracting slidingmember100; 4) advancinggrasper60 and thus also advancing slidingmember100 simultaneously causing controllablyarcuate segment40 to change back to a relatively straight geometry and 5) rotatinghandle70 and thuscatheter shaft20. These steps can be repeated through a 360 degree rotation or more to remove undesired material present along the luminal walls of a body conduit. In addition to the above steps, longitudinal positioning, forward or back, may also be performed, again only with the controllablyarcuate segment40 in its relatively straight geometric condition. It should be noted that it might not be necessary to change the controllablyarcuate segment40 from a bowed condition to a maximally straight geometry for some forms of repositioning such as rotation or transluminal advancement or retraction. Partial straightening may suffice. Also, the above description include two distinct shapes for controllablyarcuate segment40, it should be noted that modifications to the controlling means, such asgrasper60,linkage30 and slidingmember100 described hereabove, can be made to allow the operator to place controllablyarcuate segment40 in multiple transitional shapes from a maximally bowed geometry to a maximally straight geometry.
• Although this system was described specifically for a saphenous vein graft, it is readily applicable to any stenosis of a vessel or other applicable tubular conduit in the body. For example, thecatheter device10 could be used to open stenoses in the other coronary vessels, a carotid artery, dialysis fistulas, peripheral vasculature, etc. Although the present invention has only been described for the removal of plaque or thrombus, thecatheter device10 could also be used to remove other stenotic or occluding material or tissue from ducts such as the ureters or the fallopian tubes. Mammalian patients would include both humans and other animal patients.
• FIGS. 3,3A and3B show another preferred embodiment ofcatheter device10 which is similar to the catheter device ofFIGS. 1A and 1B withgrasper60,linkage30 and slidingmember100 all in a fully advanced position and controllablyarcuate segment40 in its maximally bowed geometry. Accordingly, elements of this embodiment which are similar to elements ofcatheter device10 ofFIGS. 1A and 1B are referenced with the same reference numerals. Referring specifically toFIG. 3,catheter device10 includes anaspiration chamber72 included inhandle70.Catheter shaft20 is fixedly attached to handle70 while creating a fluid path fromaspiration port75, intoaspiration chamber72 and continuing throughaspiration lumen21 tomaterial collection chamber90.Material collection chamber90 is in fluid communication with opening50 of controllablyarcuate segment40. As shown inFIG. 3,material collection chamber90 may be a simple continuation ofaspiration lumen21, ormaterial collection chamber90 may have a specific geometry or cavity-like structure while still in fluid communication withaspiration lumen21.
• Present within an internal lumen ofcatheter shaft20 is a flexible shaft,linkage30, which is preferably a hollow tube permitting a guidewire to be inserted through its internal lumen,linkage lumen31.Linkage30 may be constructed of a flexible metal, such as a flexible steel hypotube, or a superelastic material such as Nitinol, a nickel titanium alloy in its superelastic state. Alternatively,linkage30 may be constructed of a flexible plastic tube. As shown inFIGS. 3 and 3A, an opening aroundlinkage30 provides fluid communication betweenaspiration chamber72 andaspiration lumen21. At its proximal end,linkage30 is fixed to grasper60 that controls the advancement and retraction oflinkage30 and its connected components.Linkage30 is fixed at its distal end to slidingmember100. Thegrasper60,linkage30 and slidingmember100 are shown in the fully advanced position and the controllablyarcuate segment40 is shown in a maximally bowed geometry.
• Referring additionally toFIG. 3A,grasper60 surrounds and is fixedly attached tolinkage30. The proximal end oflinkage30 includes guidewire opening32 into which a guidewire can be placed and from which a guidewire can exit.Linkage lumen31 may include a valve, not shown, in its path to prevent leakage of blood once inserted. Alternatively, the diameter oflinkage lumen31 is chosen to be as small as possible, slightly larger than the outside diameter of the guidewire it is to be placed over.Linkage30 enters handle70 such that a relatively fluid tight seal is created. In order to prevent fluid leakage, a sealing element,linkage seal71, is included that preferably consists of an elastomeric o-ring which seals betweenhandle70 andlinkage30 yet allowslinkage30 to slide back and forth asgrasper60 is advanced and retracted.Linkage30 may include a mechanical stop, such aslinkage stop35, included on the outer diameter oflinkage30 to limit the maximum retraction distance ofgrasper60.Linkage stop35 is positioned along the outer diameter oflinkage30 such that whengrasper60 is retracted,linkage stop35 makes contact with the inside surface ofaspiration chamber72 andlinkage seal71 limiting further retraction. At this maximally retracted state, shown inFIGS. 4,4A and4B, slidingmember100 is positioned within controllablyarcuate segment40.
• As shown inFIG. 3A,aspiration port75 may include a valve,connector valve76, such that when the attachable vacuum source, such as a vacuum generator or syringe, is not attached, fluid will not leak out ofaspiration chamber72.Aspiration lumen21 is in fluid communication withaspiration chamber72 through a clearance aroundlinkage30 and an opening in the distal end ofhandle70 inside of the attachment point forcatheter shaft20.
• Referring additionally toFIG. 3B, Slidingmember100 includes a thru lumen continuing the guidewire clearance lumen provided bylinkage30. At the distal end of slidingmember100 isguidewire exit33, which allows the guidewire to be inserted into or exit from the device during over the wire procedures.FIGS. 3,3A and3B showgrasper60 in its fully advanced position, andFIG. 3bdepicts the corresponding location of slidingmember100 in its fully forward or advanced position with controllablyarcuate segment40 shown in its maximally bowed geometry. Located at the midpoint of controllablyarcuate segment40 is opening50 that creates a fluid path from the outer portion of controllablyarcuate segment40 tomaterial collection chamber90.Opening50 is sized to allow collection of occlusive material, such as thrombus, utilizing various applicable vacuum pressures.Opening50 may be a single hole or multiple holes, the holes may be round, oval or other shape. The holes may be of uniform geometry from inside to outside, or the holes may be tapered or transform in shape as they pass through the wall of controllablyarcuate segment40. Furthermore, opening50 may be designed such that an open fluid path is created only when controllablyarcuate segment40 is in a relatively bowed geometry and the fluid path through opening50 is closed or near closed when controllablyarcuate segment40 is in a relatively straight geometry.
• In a preferred embodiment, controllablyarcuate segment40 is normally bowed and is transformed to a relatively straight geometry when slidingmember100 is retracted to reside within the lumen of controllablyarcuate segment40. Controllablyarcuate segment40 can be normally bowed by a treatment, such as a heat treatment, in the manufacturing process as has been described hereabove, via embedded curving elements in or near the controllablyarcuate segment40 or via other curving means. Various designs for curving elements can be provided such as internal curving or bending members, the details of which are described in subsequent embodiments in detail herebelow.
• FIGS. 4,4A and4B show thecatheter device10 ofFIGS. 3,3A and3B withgrasper60,linkage30 and slidingmember100 all in a fully retracted position and controllablyarcuate segment40 in its maximally straight geometry. Accordingly, elements of this embodiment which are similar to elements ofcatheter device10 ofFIGS. 3,3A and3B are referenced with the same reference numerals. Referring specifically toFIG. 4,grasper60 has been pulled back from its advanced position a distance equal to retraction distance RD. Accordingly,linkage30 and slidingmember100 have also traveled in a direction toward the proximal end and away from the distal end ofcatheter device10 an equivalent distance equal to retraction distance RD. Referring additionally toFIG. 4A, the amount of retraction distance is limited by a radial projection,linkage stop35, which is fixedly attached tolinkage30 and stops further retraction when linkage stop35contacts linkage seal71 and or the proximal end ofaspiration chamber72. Referring additionally toFIG. 4B, slidingmember100, in its fully retracted position, has its proximal portion fully contained within an internal lumen of controllablyarcuate segment40 causing controllablyarcuate segment40, which is naturally biased to be in a relatively bowed geometry, to be transformed into a relatively straight geometry. Slidingmember100 may be made from a material more rigid than the material ofcatheter shaft20, such as a metal or a more rigid plastic or elastomer, and or its geometric construction chosen such that controllablyarcuate segment40 is straightened by the straight slidingmember100 in its fully retracted position. Slidingmember100 preferably includes a thru lumen with an exit,guidewire exit33, that is coaxial with alinkage lumen31 which is a thru lumen oflinkage30.
• Asgrasper60 is withdrawn from its fully advanced position, as shown inFIGS. 3,3A and3B, to its fully retracted position, as shown inFIGS. 4,4A and4B, the proximal end, cuttingend101 of slidingmember100 retracts toward and reaches opening50 of controllablyarcuate segment40. With suction applied ataspiration port75 and communicated to opening50 viaaspiration lumen21 andmaterial collection chamber90, loose material near the outside surface ofcatheter shaft20 in the region of opening50 will be pulled through opening50 to the inside ofcatheter shaft20. Asgrasper60 is continually retracted, and slidingmember100 continues to retractpast opening50, the material pulled throughopening50 by the suction is cut and or pushed by slidingmember100 away from opening50 further intomaterial collection chamber90. Simultaneous with the retraction of slidingmember100 is the transformation of controllablyarcuate segment40 from a relatively bowed geometry to a relatively straight geometry.FIGS. 3 and 3B andFIGS. 4 and 4B show a controllablyarcuate segment40 with a symmetrical geometry, specifically whereinopening50 is at the midpoint of the semicircle of controllablyarcuate segment40 and the two arcs on either side of opening50 have the same radius of curvature and length. It should be appreciated, and considered within the scope of this application, that various other non-symmetrical geometries are applicable, and may be preferred, such as a geometry wherein the controllablyarcuate segment40 has been minimally straightened when slidingmember100 reaches opening50 and the majority of straightening of controllablyarcuate segment40 occurs when slidingmember100 is further retracted to the maximum retraction ofgrasper60.
• Opening50 is covered and may be sealed by slidingmember100 whengrasper60,linkage30 and slidingmember100 are in their fully retracted position as is limited bylinkage stop35 and slidingmember100 has its proximal portion contained within controllablyarcuate segment40. Continued application of vacuum or aspiration ataspiration port75 for the purpose of evacuating the material severed by cuttingend101 of slidingmember100 and contained inmaterial collection chamber90 may best be accomplished with inclusion of an additional thru lumen, not shown, toaspiration lumen21 such that a circulatory path is provided to properly flush out the material fromcollection chamber90 throughaspiration lumen21 and intoaspiration chamber72 where it can then be evacuated into the vacuum source connected toaspiration port75. Note that inFIGS. 3,3A,3B,4,4A and4B aspiration lumen21 andmaterial collection chamber90 are a continuous cross-section lumen withmaterial collection chamber90 simply the part of that lumen closest to opening50 of controllablyarcuate segment40. It should be understood, and it may be desirable, formaterial collection chamber90 to have a larger cross sectional area thanaspiration lumen71, or to have other alternative shapes to facilitate the collection of body material that is pushed intomaterial collection chamber90 each time 1) vacuum is applied toaspiration port75 with opening50 positioned at a target stenotic location of a vessel; 2) controllablyarcuate segment40 is in a relatively bowed geometry; and 3) slidingmember100 is retracted.
• FIGS. 5 and 5A thru5G show another preferred embodiment of the catheter device of the present invention which is similar to thecatheter device10 ofFIGS. 1A and 1B further comprising an integral aspiration or vacuum assembly and a connected waste receptacle. Accordingly, elements of this embodiment which are similar to elements ofcatheter device10 ofFIGS. 1A and 1B are referenced with the same reference numerals. Referring specifically toFIG. 5,catheter device10A includes acatheter shaft20 which is fixedly attached to handle70 and includes one or more lumens extending from the proximal end to a point at or near the distal end, and may additionally include enclosed cavities or chambers which may be used to store collected occlusive material. A chamber withinhandle70,aspiration chamber72 includes a syringe-like piston and plunger,plunger assembly65. A flexible linkage,linkage30, exits the proximal end ofhandle70 and continues through an internal lumen ofcatheter shaft20 and is connected at its distal end to slidingmember100, shown inFIG. 5 in its fully advanced position.Linkage30 contains a lumen therethrough,linkage lumen31, which is sized to fit over a standard guidewire, such as an0.014 guidewire.Linkage lumen31 includes an opening at its proximal end,guidewire opening32.
• Controllablyarcuate segment40, shown in its maximally bowed geometry, is again showed with a normally curved bias which can be caused by numerous means such as those described in detail hereabove and herebelow. Alternatively, controllablyarcuate segment40 may have a normally straight bias, with shape control means changing controllablyarcuate segment40 to a bowed bias as is shown and described in detail in subsequent figures and their detailed descriptions provided herebelow. Controllablyarcuate segment40 has, near its midsection, anopening50 which traverses from the outside surface of controllablyarcuate segment40 to an internal lumen in fluid communication with a chamber,material collection chamber90, used to store previously occlusive material, such as thrombus, which has been drawn via suction throughopening50 when the controllablyarcuate segment40 is in a relatively bowed geometry.Material collection chamber90 is shown in fluid communication with a lumen ofcatheter shaft20,aspiration lumen21, which is in fluid communication withaspiration chamber72.
• Alternatively, not shown,material collection chamber90 may be a captured cavity, in fluid communication withopening50 only, sized to store an appropriate amount of extracted occlusive material. In this particular embodiment,aspiration lumen21 would be fluidly connected to opening50 to permit aspiration, or an applied vacuum, to opening50 to draw the occlusive material throughopening50, and may include a valve, such as a flap valve, also not shown, to isolateaspiration lumen21 from opening50 and ormaterial collection chamber90 when a suction is not applied viaaspiration lumen21. Such a valve would prevent collected material from being drawn into theaspiration lumen21 from thematerial collection chamber90 when suction is applied toaspiration lumen21. Similar to previous embodiments, when slidingmember100 is withdrawn, the protruding occlusive material would be pushed into the closed cavitymaterial collection chamber90.
• Still referring toFIG. 5,aspiration chamber72 has an attached evacuation chamber,waste chamber80, connected toaspiration chamber72 viawaste exit81. Referring additionally toFIG. 5A,plunger assembly65 includes a longitudinal shaft,plunger shaft61 which is fixedly connected on its proximal end to grasper60 and includes on its distal end a flexible covering,plunger66, which forms a seal with the inner walls ofaspiration chamber72. Preferably,aspiration chamber72 has a circular cross section, however other cross sections are viable including oval, rectangular as well as asymmetrical cross sections. The cross section ofaspiration chamber72 is uniform along, at a minimum, the length of travel ofplunger assembly65 in which plunger66 contacts the inner walls ofaspiration chamber72.Plunger shaft61 is made from a rigid material such as a rigid plastic commonly used in standard syringes, and the distal end ofplunger shaft61 has a shape approximating the shape of the cross-section ofaspiration chamber72.Plunger66 covers the distal end ofplunger shaft61 and is preferably made of a flexible material such as rubber or other material with properties to facilitate a fluid seal between theplunger assembly65 and the walls ofaspiration chamber72.Plunger66 is shown as a covering for a disk-like projecting end ofplunger shaft61 but it should be understood that various other geometries could be utilized to form the desired seal including a simple notch along the outer diameter ofplunger shaft61 whereinplunger66 is a standard0-ring.
• As shown specifically inFIG. 5A,catheter shaft20, preferably of circular cross section, is mechanically attached to handle70.Aspiration lumen21 is in fluid communication with an internal cavity ofhandle70,aspiration chamber72 viahandle aspiration lumen78. Handleaspiration lumen78 may include a one way valve, such as a duck-bill valve,aspiration valve79 shown.Aspiration valve79 allows fluid and material to pass frommaterial collection chamber90 andaspiration lumen21 intoaspiration chamber72 when negative pressure or suction is applied withinaspiration chamber72 however prevents material from enteringaspiration lumen21 when positive pressure is applied withinaspiration chamber72. Negative pressure is created whenplunger assembly65 is retracted by the operator, and positive pressure is created whenplunger assembly65 is advanced. When positive pressure is created, liquid and material collected inaspiration chamber72 exits to wastechamber80 viawaste exit81.Waste chamber80 may be a rigid or preferably flexible container such as a flexible bag or pouch.Waste exit81 may be a piece of tubing, attached to handle70 to cause a fluid path toaspiration chamber72.Waste exit81 may include an integrated one way valve,waste valve82, such as a duck-bill valve similar in construction and performance toaspiration valve79. Whenplunger assembly65 is advanced by advancinggrasper60, the positive pressure created drives the liquid and other material fromaspiration chamber72 intowaste exit81 and eventually wastechamber80.Waste chamber80 may include a vent, not shown.
• Plunger shaft61 includes a lumen therethrough, which provides some clearance aroundlinkage30.Plunger shaft61 further includes a projection,shaft projection62, extending radially inward fromplunger shaft61 while making minimal or no contact with the outer surface oflinkage30.Linkage30 includes a projection,linkage projection36 extending radially outward fromlinkage30 while making minimal or no contact with the inner surface ofplunger shaft61. The projections,linkage projection36 andshaft projection62 are positioned to cause a specific series of coordinated and timed linear movements oflinkage30 and slidingmember100 asgrasper60 and connectedplunger assembly65 are advanced and retracted by the operator. The linear movements are described in detail herebelow with reference toFIGS. 5A thru5G. As shown inFIGS. 5 and 5A,grasper60 andplunger assembly65 is shown in its maximally advanced positioned, advanced position P1.Linkage30 and slidingmember100 are also in their maximally advanced position as caused byshaft projection62 forcinglinkage projection36 forward.Plunger66 has a surface,proximal edge67, which faceslinkage projection36 and whenplunger assembly65 is in advanced position P1,proximal edge67 is offset fromlinkage projection36.Grasper60 is maximally advanced when it makes contact withhandle70.Linkage30 may include another projection, linkage stop35A, to limit advancement oflinkage30. Linkage stop35A also extends radially outward and positioned alonglinkage30 to limit forward travel by making contact with the distal end ofaspiration chamber72. Each of the projections,linkage stop35A,linkage projection36 andshaft projection62 may have a ring-like structure fully surrounding their appropriate shafts or may be one or more rectangular projections.
• Referring now toFIG. 5B and 5C,Grasper60 has been partially retracting causing partial retraction ofplunger assembly65 to intermediate position P2. During retraction, negative pressure is created inaspiration chamber72 and this suction is communicated fromaspiration chamber72 throughhandle aspiration lumen78 and its internal valve,aspiration valve79, intoaspiration lumen21, throughmaterial collection chamber90 toopening50. Fluid communication, in other words the effect of the negative pressure, is cut off fromwaste exit81 by the action ofwaste valve82 oriented to prevent flow fromwaste exit81 intoaspiration chamber72. Sinceproximal edge67 has just made contact withlinkage projection36, movement ofplunger assembly65 from advanced position P1 to intermediate position P2 has not caused any retraction oflinkage30, therefore slidingmember100 has not moved, and controllablyarcuate segment40 remains in its bowed geometry. When appropriately placed in a blood vessel for material extraction, relatively loose material, such as thrombus, in the general proximity to opening50 would be drawn throughopening50. It should be appreciated and understood that configurations in whichaspiration lumen21 communicates directly with opening50 not by way ofmaterial collection chamber90, configurations not shown, could be used and is another preferred embodiment of this application.
• Referring now toFIGS. 5D and 5E,Grasper60 has been fully retracting causing full retraction ofplunger assembly65 to retracted position P3. During retraction, negative pressure continued to be created inaspiration chamber72 and this suction is communicated fromaspiration chamber72 throughhandle aspiration lumen78 and its internal valve,aspiration valve79, intoaspiration lumen21, throughmaterial collection chamber90 to opening50, similar to the suction created asplunger assembly65 retracts from advanced position P1 to intermediate position P2. Fluid communication, in other words the effect of the negative pressure, remains to be cut off fromwaste exit81 by the action ofwaste valve82 oriented to prevent flow fromwaste exit81 intoaspiration chamber72. Movement ofplunger assembly65 from intermediate position P2 to retracted position P3 has now causedlinkage30 to also retract, caused by an urging force generated byproximal edge67 ofplunger66 pushing onlinkage projection36 oflinkage30, simultaneously causing slidingmember100, fixedly attached to the end oflinkage30, to also retract. The retraction of slidingmember100 is such that the proximal longitudinal portion of slidingmember100 resides within controllablyarcuate segment40 and slidingmember100 is of sufficient rigidity to cause controllablyarcuate segment40 to transition from its normally biased curved geometry to the relatively straight geometry of slidingmember100. The material that was previously drawn via suction throughopening50 is pushed away from opening50 intomaterial collection chamber90 as the slidingmember100 is retracted byplunger assembly65 moving from intermediate position P2 to retracted position P3.
• Withgrasper60 in the fully retracted position, as represented inFIGS. 5D and 5E,plunger assembly65 as well as slidingmember100 are also retracted and controllablyarcuate segment40 is in a relatively straight geometry. In this state, thecatheter device10A could be removed from patient's body and the procedure completed. Alternatively, additional steps of an alternative procedure may be performed wherein additional one or more cycles of changing controllablyarcuate segment40 from straight to bowed geometries and back, appropriately applying suction and retraction of slidingmember100 moving material away from opening50. Performance of various components and assemblies ofcatheter device10A for such additional steps are described immediately herebelow.
• Referring now toFIGS. 5F and 5G,grasper60 has been advanced, causingplunger assembly65 to advance from retracted position P3 to second intermediate position P4.Proximal edge67 ofplunger66 has moved away fromlinkage projection36 oflinkage30 andshaft projection62 has reached and come in contact withlinkage projection36 such that further advancement ofplunger assembly65 will causelinkage30 to advance.Linkage30 did not yet advance asplunger assembly65 advanced from retracted position P3 to intermediate position P4 therefore slidingmember100 remains in its fully retracted position wherein the proximal portion of slidingmember100 is contained within a lumen of controllablyarcuate segment40 such that controllablyarcuate segment40 is in a relatively straight geometry.
• Advancement ofplunger assembly65 causes positive pressure to be generated inaspiration chamber72 causing fluid and other material to be evacuated fromaspiration chamber72 thruwaste valve82 andwaste exit81 and intowaste chamber80. One way valve,aspiration valve79 prevents the fluid and other material contained inaspiration chamber72 from enteringaspiration lumen21.
• Further advancement ofplunger assembly65 from second intermediate position P4 to advanced position P1, shown inFIGS. 5 and 5A, continue the generation of positive pressure to further evacuate the equivalent volume of fluid and material fromaspiration chamber72 intowaste chamber80. In addition to the positive pressure and material evacuation,linkage30 is advanced. Because of the initial contact betweenshaft projection62 andlinkage projection36 that occurs whenplunger assembly65 reaches second intermediate position P4, continued advancement to advanced position P1 causeslinkage30 to advance due to an urging force placed uponlinkage projection36 byshaft projection62. Referring back toFIGS. 5 and 5A, whengrasper60 is fully advanced, its proximal end making contact with the distal end ofhandle70,linkage30 is fully advanced causing slidingmember100 to be fully advanced. As sliding member is advanced, the proximal portion moves out of controllablyarcuate segment40 allowing controllablyarcuate segment40 to transition from a relatively straight geometry to a relatively arcuate or bowed geometric shape.
• FIG. 6 depicts another preferred embodiment of catheter device of the present invention which is similar to thecatheter device10 ofFIGS. 1A and 1B withgrasper60,linkage30 and slidingmember100 all in a fully advanced position. Accordingly, elements of this embodiment which are similar to elements ofcatheter device10 ofFIGS. 1A and 1B are referenced with the same reference numerals. Referring specifically toFIG. 6,catheter device10B is shown with controllablyarcuate segment40 in its maximally straight geometry, and in this particular also preferred embodiment, controllablyarcuate segment40 is naturally biased to be in a maximally straight geometry as opposed to the normally curved bias ofFIGS. 1A and 1b.Catheter device10B includes anaspiration chamber72 included inhandle70.Catheter shaft20 is fixedly attached to handle70 while creating a fluid path fromaspiration port75, intoaspiration chamber72 and continuing throughaspiration lumen21 tomaterial collection chamber90.Material collection chamber90 is in fluid communication with opening50 of controllablyarcuate segment40 and located proximal toopening50. As shown inFIG. 6,material collection chamber90 may be a simple continuation ofaspiration lumen21, ormaterial collection chamber90 may have a specific geometry or cavity-like structure while still in fluid communication withaspiration lumen21. Material collection chamber may alternatively be fluidly isolated fromaspiration lumen21 such as by way of an integrated valve that allowsaspiration lumen21 to be in fluid communication withopening50 when vacuum or suction is applied by way ofaspiration port75.
• Present within an internal lumen ofcatheter shaft20 is a flexible shaft,linkage30, which is preferably a hollow tube permitting a guidewire to be inserted through its internal lumen,linkage lumen31.Linkage30 may be constructed of a flexible metal, such as a flexible steel hypotube, or a superelastic material such as Nitinol, a nickel titanium alloy in its superelastic state. Alternatively,linkage30 may be constructed of a flexible plastic tube. As shown inFIG. 6, an opening aroundlinkage30 provides fluid communication betweenaspiration chamber72 andaspiration lumen21. At its proximal end,linkage30 is fixed to grasper60 which controls the advancement and retraction oflinkage30 and its connected components.Linkage30 is fixed at its distal end to slidingmember100. Thegrasper60,linkage30 and slidingmember100 are shown in the fully advanced position and the controllablyarcuate segment40 is shown in a maximally bowed geometry. Slidingmember100 has a beveled, sharpened or otherwise tapered end, tapered cuttingend102 which facesopening50 such that when slidingmember100 is retracted, material protruding throughopening50 can be severed from attached material located within opening50 to prevent jamming of slidingmember100. In alternative embodiments, whereinopening50 is distal to slidingmember100, tapered cuttingend102 would be located on the opposite end of slidingmember100, the distal end, such that when slidingmember100 is advanced, material protruding throughopening50 is similarly severed.
• Grasper60 surrounds and is fixedly attached tolinkage30. The proximal end oflinkage30 includes guidewire opening32 into which a guidewire can be placed and from which a guidewire can exit if inserted from the other end.Linkage lumen31 may include a valve, not shown, in its path to prevent leakage of blood or other fluid oncecatheter device10B is inserted into the body. Alternatively, the diameter oflinkage lumen31 is chosen to be as small as possible, slightly larger than the outside diameter of the guidewire it is to be placed over.Linkage30 enters handle70 such that a relatively fluid tight seal is created, such as that created with an elastomeric o-ring which seals betweenhandle70 andlinkage30 yet allowslinkage30 to slide back and forth asgrasper60 is advanced and retracted as was described in reference toFIGS. 3 and 3a.Linkage30 may include a mechanical stop, such aslinkage stop35, included on the outer diameter oflinkage30 to limit the maximum retraction distance ofgrasper60.Linkage stop35 is positioned along the outer diameter oflinkage30 such that whengrasper60 is retracted tilllinkage stop35 is in contact with the inside surface ofaspiration chamber72, slidingmember100 is properly positioned within controllablyarcuate segment40, the advanced position shown in and described withFIGS. 6,6A and6B. In this preferred embodiment, the distal end of slidingmember100 extends beyond the distal end ofcatheter device10 throughout the fully advanced and fully retracted travel ofgrasper60 andlinkage30.
• As mentioned previously, thecatheter device10B ofFIG. 6 is constructed such that the normal bias of controllablyarcuate segment40 is a straight geometry, generally along the longitudinal axis ofcatheter shaft20. It should be noted that in this and all other embodiments of this application, controllablyarcuate segment40 while naturally biased to be bowed or straight, is relatively flexible, i.e. flexible enough relative to its length to allow insertion ofcatheter device10B through the body, such as through the vascular system, without disrupting or otherwise damaging the inner walls of conduits such as blood vessels. This flexibility may or may not be compromised when slidingmember100 is retracted to reside within a lumen of controllablyarcuate segment40. Thecatheter device10B ofFIG. 6 further includes means to change controllablyarcuate segment40 from its naturally straight geometry to a relatively bowed or curved geometry. Various curving means are described in accordance with theFIGS. 6,6A,6B and7 through10 however it should be understood and considered within the scope of this application, that numerous alternatives are possible to cause, based on controls that can be activated from the proximal end ofcatheter device10, such as those on ornear handle70, shape transformation of controllablyarcuate segment40.
• Again, referring specifically toFIG. 6 and additionally toFIGS. 6A and 6B, contained or embedded within the walls of controllablyarcuate segment40 is curvingelement110 which can on command convert controllablyarcuate segment40 from a relatively straight geometry to a relatively bowed geometry. The curvingelement110 is preferably an electrically activatable component such as a piezo element, an electromagnetic assembly or a shaped memory component, such as a shaped memory alloy or shaped memory polymer. When connected to an energy source applying a voltage and or a driving current, curvingelement110 changes its shape thus causing controllablyarcuate segment40 to also change shape. Curvingelement110 is attached to controls inhandle70 byarcuate control wires113, preferably flexible electrical conductors, such as wires, embedded in or on the inside diameter ofshaft20. At the proximal end ofarcuate control wires113 is an energy source,power source112, which is preferably an integrated battery or battery assembly. Completing the electrical circuit is a switch,arcuate control switch111, which when depressed by the user, fully connectspower source112 to curvingelement110 thus causing both curvingelement110 and controllablyarcuate segment40 to change geometry such as changing from a relatively straight geometry to a relatively curved geometry. It should be noted, however, that a similar configuration of curvingelement110 can be used to change controllablyarcuate segment40 from a relatively bowed geometry to a relatively straight geometry when power is applied to curvingelement110.FIG. 6A depicts curvingelement110 without power attached, i.e. arcuatecontrol switch111 not depressed, and controllablyarcuate segment40 in a relatively straight geometry.FIG. 6B depicts curvingelement110 with power attached, i.e. arcuatecontrol switch111 depressed by the operator, and controllablyarcuate segment40 in a relatively bowed geometry. It may be desirable to add an indicator, not shown, to indicate the geometric shape of controllablyarcuate segment40 when the catheter device of the present invention is inserted into the patient, i.e. when the controllablyarcuate segment40 cannot be directly visualized. The shape indicating means, all not shown, may include a visual indicator, such as an indicator light located on the handle of the device, and or an audio indicator such as an electronic buzzer which generate feedback to the user to indicate the geometric shape of controllablyarcuate segment40. For example, since the catheter device of the present invention is generally not to be advanced or retracted unless controllablyarcuate segment40 is in a relatively straight geometric shape, an audio indicator may be included which creates a buzzing sound whenever the controllablyarcuate segment40 is not in a relatively straight geometric shape.
• Still referring toFIG. 6, slidingmember100 is shown in its fully advanced position, sincegrasper60 is fully advanced causinglinkage30 to also be fully advanced. Controllablyarcuate segment40 has a normally straight geometric bias, and is converted to a relatively bowed geometry by activation of curvingelement110 as well as being converted back to a relatively straight geometry by deactivation of curvingelement110. Unlike thecatheter device10 ofFIG. 1, slidingmember100 does not have to be used to change the shape of a pre-curved controllablyarcuate segment40. Slidingmember100 inFIG. 6 still however provides the function of moving material away from opening50 when retracted, aided by a sharpened leading edge, tapered cuttingend102. Since slidingmember100 ofcatheter device10B ofFIG. 6 does not provide the function of changing the shape of controllablyarcuate segment40, slidingmember100 can be made of very flexible materials which do not impact the shape of controllablyarcuate segment40 when slidingmember100 enters and exits the lumen of controllablyarcuate segment40. When controllablyarcuate segment40 is in its maximally bowed geometry as caused by curvingelement110, and vacuum is applied at opening50 thus drawing material throughopening50, slidingmember100 can be retracted pushing material away from opening50 without altering the shape of controllablyarcuate segment40.
• Referring specifically toFIGS. 6A and 6B,catheter shaft20 has a diameter, catheter diameter D, near its distal end. When controllablyarcuate segment40 has a relatively curved geometry, the maximum offset from the outside diameter ofcatheter shaft20 is defined as axial offset AO. In cardiovascular applications, catheter diameter D will typically between 1.5 and 4 millimeters. Curvingelement40 has a length and radius of curvature of both its proximal and distal arc that are chosen to create a group of products that provide a wide range of values for axial offset AO. Typically catheter diameter D is chosen to be applicable to navigate the tortuosity of the vasculature to reach the target lesion to be treated, and axial offset AO is chosen to cause theopening50 to be in contact, with sufficient force, to the target lesion when controllablyarcuate segment40 is in its maximally bowed geometry. Some applications, such as interventional neurological procedures, may require much smaller diameters and axial offsets, while other applications may permit or require larger diameters and offsets.
• FIG. 7 depicts another preferred embodiment of catheter device of the present invention which is similar to the catheter device ofFIG. 6 with an integral means for curving controllablyarcuate segment40, curving means110 embedded within the walls of controllablyarcuate segment40. As described previously, curving means110 can be of various shape altering forms, such as shaped memory components, piezo components, electromagnetic assemblies and other electrically and non electrically activated shape changing components known to those of skill in the art, and all considered within the scope of this application. Curving means110 is attached to electrical controlling wires,arcuate control wires113 which connect to power and switching means contained in the proximal handle. Controllablyarcuate segment40 also includes one or more holes, opening50 which are in fluid communication with a chamber,material collection chamber90, into which material received throughopening50 is pushed by tapered cuttingend102 of slidingmember100.Linkage30 and slidingmember100 are shown in their fully advanced position.FIG. 7 defines a cross-sectional view A-A directed toward the distal end ofcatheter shaft20.
• FIG. 8 shows a preferred embodiment of thecurving element110 located near the distal end ofcatheter shaft20 shown at the cross-sectional view A-A ofFIG. 7. The curvingelement110 ofFIG. 8 has a tubular construction, with a circular cross section contained within the walls ofcatheter shaft20 in the region of controllablyarcuate segment40. Alternatively but not shown, curvingelement110 may be outside of the walls within the lumen ofcatheter shaft20. Curvingelement110 would include a thru-hole or opening, curving element opening115 which is aligned with opening50 to allow material to pass through opening50 and curving element opening115 from the outside ofcatheter shaft50 to an inner lumen ofcatheter shaft20 when suction is applied. Curvingelement110 is controlled from the proximal end ofcatheter device10, such as has been described hereabove, and its tubular structure changes shape to cause controllablyarcuate segment40 to change from a relatively straight geometry to a relatively bowed geometry or causes controllablyarcuate segment40 to change from a relatively bowed geometry to a relatively straight geometry. Curvingelement110 may be attached to electrical wires connected to a switch and power supply as described inFIGS. 6,6A and6B or other activation means controllable from the proximal end ofcatheter device10.
• FIG. 9 shows another preferred embodiment of thecurving element110 located near the distal end ofcatheter shaft20 shown at the cross-sectional view A-A ofFIG. 7. The curvingelement110 ofFIG. 8 has a filament-like construction, with a chord-like cross section contained within the walls ofcatheter shaft20 in the region of controllablyarcuate segment40. Alternatively but not shown, curvingelement110 may be outside of the walls within the lumen ofcatheter shaft20. Curvingelement110 would be placed away from opening50 such that material will pass through opening50 from the outside ofcatheter shaft20 to an inner lumen ofcatheter shaft20 when suction is applied. Curvingelement110 is controlled from the proximal end ofcatheter device10, such as has been described hereabove, and its filament-like structure changes shape to cause controllablyarcuate segment40 to change from a relatively straight geometry to a relatively bowed geometry or cause controllablyarcuate segment40 to change from a relatively bowed geometry to a relatively straight geometry. Curvingelement110 may be attached to electrical wires connected to a switch and power supply as described inFIGS. 6,6A and6B or other activation means controllable from the proximal end ofcatheter device10.
• FIG. 10 shows yet another preferred embodiment of thecurving element110 located near the distal end ofcatheter shaft20 shown at the cross-sectional view A-A ofFIG. 7. The curving element ofFIG. 10 consists of two curving elements, first curvingelement110A and secondcurving element110B both of which have a filament-like construction, with a chord-like cross section contained within the walls ofcatheter shaft20 in the region of controllablyarcuate segment40. First curvingelement110A and secondcurving element110B may have different lengths and or cross-sectional geometries, and they may be controlled together or independently. Alternatively but not shown, first curvingelement110A and or secondcurving element110B may be outside of the walls within the lumen ofcatheter shaft20. Both firstcurving element110A and secondcurving element110B would be placed away from opening50 such that material will pass through opening50 from the outside ofcatheter shaft50 to an inner lumen ofcatheter shaft20 when suction is applied. Both firstcurving element110A and secondcurving element110B is controlled from the proximal end ofcatheter device10, such as has been described hereabove, and the filament-like structures change shape to cause controllablyarcuate segment40 to change from a relatively straight geometry to a relatively bowed geometry or cause controllablyarcuate segment40 to change from a relatively bowed geometry to a relatively straight geometry. Independent control of firstcurving element110A and secondcurving element110B can be used to create multiple states of curvature for controllablyarcuate segment40 such as to cause different axial offsets as has been described hereabove. Both firstcurving element110A and secondcurving element110B may be attached to electrical wires connected to a switch and power supply as described inFIGS. 6,6A and6B or other activation means controllable from the proximal end ofcatheter device10.
• Referring collectively to all of the figures and their descriptions included hereabove, the catheter devices of the present invention are intended to enter the body of a mammalian patient, such as via percutaneous or surgical means, to perform a therapeutic or diagnostic procedure. To properly accomplish these types of procedures, the devices would be provided in a sterile condition, with appropriate packaging to maintain sterility up until use. In addition, the catheter device may be part of a kit, with numerous other components applicable to the procedure, such as a guide catheter and guidewire, included in the sterile packaging or in separate sterile packaging included in the same purchased kit. The catheter device of the present invention may be inserted into the body over a standard interventional guidewire to assist in advancing the device to the intended location. The various figures and included text have described configurations wherein the device has a guidewire that enters and exits the catheter at or near the distal and proximal ends. Devices with this configuration utilize guidewires which are approximately twice the length of the over the wire device to allow placement of the device with a pre-placed guidewire and withdrawal of the device leaving the guidewire in place. In an alternative catheter design, also considered within the scope of this application, near the distal end of the catheter device is included a small length of material attached to the catheter shaft, similar to a sidecar, which consists of a single lumen and its surrounding walls. In this configuration, a smaller length guidewire can be inserted through the lumen of the sidecar only, not through the entire length of the catheter device, and the catheter device advanced and retracted over this shorter guidewire.
• The catheter of this invention may be a precursor to other material removal or treatment procedures such as balloon angioplasty, stenting or other procedures. Although this system was described specifically for a saphenous vein graft, it is readily applicable to any stenosis of a vessel or other applicable tubular body conduit in the body. For example, the catheter device of the present invention could be used to open stenoses in the carotid artery, dialysis fistulas, peripheral vasculature, etc. Although the present invention has only described the removal of plaque or thrombus from human vessels, the catheter device of the present invention could also be used to remove other stenotic or occluding tissue from ducts such as the ureters or the fallopian tubes. Mammalian patients would include both humans and other animals. Also, although percutaneous procedures have been described, catheter devices of the present invention, particularly those with larger diameters or where the intended site is a body conduit that is not a blood vessel, could be used intraoperatively by surgical incision into an access point appropriate for the intended site.
• In order to draw material throughopening50, a negative pressure is applied to the inner side of opening50 which is communicated through a lumen withincatheter shaft20. Various means of causing this negative pressure, also referred to synonymously throughout this application as vacuum, suction or aspiration, can be used. Vacuum generators can be integral to catheter device such as has been described in reference toFIGS. 5 and 5A through5G, or external vacuum generators can be attached including a simple syringe to more complex aspiration and material collection devices. The various embodiments described hereabove show a fluid communication betweenaspiration lumen21 andopening50 that is connected viamaterial collection chamber90. It should be understood and considered within the scope of this application thataspiration lumen21 can be connected directly to opening50 andmaterial collection chamber90 isolated from the negative pressure by way of a valve or other means. This particular configuration is another preferred embodiment and may be useful in avoiding clogging or otherwise obstructingaspiration lumen21 from being able to apply the appropriate amount of suction at opening50.Opening50 may include one or more holes with various cross-sectional geometries and tapers.Opening50 may be designed to be fluidly closed when controllablyarcuate segment40 is in a relatively straight geometry and open as controllablyarcuate segment40 transforms to a bowed geometry, or opening50 may be fluidly open at all times.
• Also, it is intended for opening50 to be brought in close proximity to the material to be removed, and apply a finite amount of force to the wall of the body conduit or on the material to be removed by the portion ofcatheter shaft20 immediately surrounding the opening, each feature intended to enhance the ability of the vacuum to draw material throughopening50. This proximity is achieved when controllablyarcuate segment40 is changed from a relatively straight geometry to a relatively bowed geometry. The various embodiments described hereabove show various configurations of relatively bowed geometries, however it should be understood and considered within the scope of this application that any geometry that causes an axial offset of opening50 from the outer surface of the majority ofcatheter shaft20 would function to bringopening50 towards the wall of the biological conduit into which it is inserted. It also should be understood that controllablyarcuate segment40 may be able to assume multiple geometries with multiple axial offsets or other geometric configurations that provide specific advantages for the various anatomies and disease states and locations being treated. It is preferred that a portion ofcatheter shaft20 extend beyond controllablyarcuate segment40 such that a portion of non shape altering catheter shaft exists between the distal tip ofcatheter shaft20 and controllablyarcuate segment40.
• In the various procedures described hereabove, it may be desirable to remove material such as thrombus that may be present at the end ofcatheter shaft20. To facilitate this function, a lumen may be provided to support simple suction removal from the end of thecatheter shaft20, or an internal mechanism or a removable core, such aslinkage30 and slidingmember100 may be removable to create a lumen to which suction can be applied to remove material from the distal end of the catheter.
• In another preferred embodiment of the present invention, a catheter device includes an elongate catheter body or shaft having a proximal end and a distal end, a controllably arcuate segment, an aspiration chamber located near the proximal end of the catheter shaft, a controllably arcuate segment including at least one opening and an aspiration lumen in fluid communication with the aspiration chamber and one or more of the openings in the controllably arcuate segment. This particular catheter device may include a separate lumen to allow over the wire insertion and a lumen to allow aspiration from the distal tip of the catheter.
• The various embodiments described hereabove, such as those described in reference toFIGS. 5 and 5A through5G, have described acatheter device10A wherein retraction ofgrasper60 causeslinkage30 and thus slidingmember100 to also retract to accomplish one or more functions including moving material away from opening50 in a proximal direction and intomaterial collection chamber90 which is proximal toopening50. It should be appreciated and considered within the scope of this application whereinmaterial collection chamber90 is distal to opening50, and advancement ofgrasper60 causes advancement oflinkage30 and thus slidingmember100 such that material is moved away from opening50 in a distal direction intomaterial collection chamber90. In this particular configuration, slidingmember100 would not exit the distal end ofcatheter shaft20 but would remain within a lumen ofcatheter shaft20 in both its fully advanced and fully retracted positions. Similar to other embodiments, material is drawn through opening50 via suction from the proximal end ofcatheter device10, such as viaaspiration port75 andaspiration lumen71.
• It is to be understood and appreciated that the invention has been described herein with reference to certain presently preferred embodiments and examples only, and no effort has been made to exhaustively describe all possible embodiments and examples of the invention. Indeed, as those killed in the art will appreciate, various additions, deletions, modifications and variations may be made to the particular embodiments and examples described hereabove without departing from the intended spirit and scope of the invention. In addition, wherever steps of a method have been described, there is no intent for a required order unless specifically described. Accordingly, it is intended that all such additions, deletions, modifications and variations be included within the scope of the following claims.

Claims (20)

1. A transluminal method for removing material from a biological conduit, said method comprising the steps of:

providing a catheter device that comprises:

an elongated catheter shaft having a proximal end and a distal end;

a controllably arcuate segment configured to selectively transition between a relatively straight configuration and a relatively curved configuration having an axial offset with respect to the catheter shaft, the controllably arcuate segment defining at least one opening in fluid communication with the proximal end; and

a mechanism at the proximal end of the catheter shaft configured to selectively transition the controllably arcuate segment between the relatively straight and relatively curved configurations in response to manipulation of the mechanism;

percutaneously or surgically inserting and transluminally advancing the controllably arcuate segment into the biological conduit;

subsequently manipulating the mechanism to change the controllably arcuate segment from the relatively straight configuration to the relatively curved configuration; and

subsequently applying suction to the at least one opening in the controllably arcuate segment.

2. A transluminal method for removing material from a biological conduit, said method comprising the steps of:

providing a catheter device that comprises:

an elongated catheter shaft having a proximal end, a distal portion and a distal end; and

a controllably arcuate segment positioned in the distal portion of the catheter shaft, proximal to the catheter shaft distal end, the controllably arcuate segment configured to selectively transition between a relatively straight shape and a relatively curved shape, the relatively curved shape having an axial offset with respect to the catheter shaft, the controllably arcuate segment including at least one opening in fluid communication with the proximal end of the catheter shaft; and

a control configured to engage the controllably arcuate segment to selectively effect the transition between the relatively straight and relatively curved shapes in response to activation of the control;

percutaneously or surgically inserting the catheter distal portion into the biological conduit and transluminally advancing the controllably arcuate segment through the biological conduit to a location proximate a material to be removed;

activating the control to change the controllably arcuate segment from a relatively straight shape to a relatively curved shape; and

removing the material from the biological conduit via the at least one opening of the controllably arcuate segment having the relatively curved shape.

3. The method ofclaim 2, further comprising applying suction to the at least one opening in the controllably arcuate segment to remove the material from the biologically conduit.

4. The method ofclaim 3, wherein the catheter device further comprises a suction device configured to apply the suction to the at least one opening in the controllably arcuate segment.

5. The method ofclaim 3, wherein the catheter device further comprises a plunger assembly, and wherein the control comprises a grasper operably attached to the plunger assembly such that movement of the grasper applies the suction to the at least one opening.

6. The method ofclaim 2, wherein the catheter device further comprises a sliding member movable within the elongated catheter shaft and controllably arcuate segment, and wherein the method further comprises:

retracting the sliding member to move the material away from the at least one opening and toward the proximal end of the elongated catheter shaft.

7. The catheter ofclaim 2, wherein the catheter device further comprises a sliding member movable within the elongated catheter shaft and controllably arcuate segment, wherein the controllably arcuate segment has a normally curved bias, and wherein the method further comprises:

positioning the sliding member within the controllably arcuate segment to cause the arcuate segment to take the relatively straight shape.

8. The method ofclaim 2, wherein the relatively curved shape of the controllably arcuate segment is formed by arcing the controllably arcuate segment in a first direction to create external convex and concave surfaces of the controllably arcuate segment in the first direction where the proximal and distal ends of the catheter shaft remain aligned along a longitudinal axis of the catheter.

9. The method ofclaim 8, wherein the at least one opening is located at the convex portion of the controllably arcuate segment when the arcuate segment takes the relatively curved shape.

10. The method ofclaim 2, further comprising, when the controllably arcuate segment takes the relatively curved shape, maintaining substantially straight portions of the elongated catheter shaft on both sides of the controllably arcuate segment that are co-axial with a longitudinal axis of the catheter.

11. The method ofclaim 2, wherein the material to be removed is disposed on a wall of the biological conduit.

12. The method ofclaim 2, wherein the controllably arcuate segment comprises a normally curved bias.

13. The method ofclaim 2, wherein the catheter device further comprises a flexible linkage and a sliding member attached to the flexible linkage, and wherein the control comprises a grasper operably attached to the flexible linkage, and wherein the method further comprises:

moving the grasper to move the sliding member relative to the controllably arcuate segment.

14. The method ofclaim 13, wherein movement of the grasper causes the controllably arcuate segment to transition between the relatively straight shape and the relatively curved shape.

15. The method ofclaim 13, wherein movement of the grasper causes the controllably arcuate segment to selectively traverse the at least one opening to move the material away from the at least one opening.

16. The method ofclaim 2, wherein the catheter device further comprises an electrically activatable component positioned within the controllably arcuate segment and attached to at least one electrical wire, and wherein the control comprises a switch attached to the at least one electrical wire, and wherein the method further comprises:

activating the switch to cause the controllably arcuate segment to transition between the relatively straight shape and the relatively curved shape.

17. The method ofclaim 16, wherein the electrically activatable component comprises a component selected from the group consisting of piezo element; electromagnetic assembly; shaped memory component; shaped memory alloy; shaped memory polymer; and combinations of at least two thereof

18. The method ofclaim 16, wherein the catheter device further comprises a power source configured to provide power to the electrically activatable component.

19. The method ofclaim 2, wherein the catheter device further comprises a visualization marker configured to indicate the angular orientation of the at least one opening, and wherein the method further comprises:

rotating the catheter shaft and controllably arcuate segment based on the positioned of the visualization marker.

20. The method ofclaim 19, wherein the visualization marker is located on a portion of the controllably arcuate segment.

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