Abstract:
Catheters having laterally deployable elements (e.g., penetrators, needles, probes, electrodes, wires, etc.) and linear imaging arrays useable for imaging of such laterally deployable elements. These catheters are useable to perform or facilitate a wide variety of diagnostic and therapeutic functions, including but not limited to the delivery of drugs and other substances, accessing specific target locations within a subject&#39;s body, delivering diagnostic or therapeutic treatments to specific target locations within a subject&#39;s body, creating penetration tracts or passageways within a subject&#39;s body, etc.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to methods and apparatus for medical treatment and more particularly to catheters having laterally deployable elements (e.g., penetrators, needles, probes, electrodes, wires, etc.) and linear imaging arrays useable for imaging of such laterally deployable elements.  
       BACKGROUND  
       [0002]     Numerous types of medical catheters have laterally deployable elements that may be advanced or extended laterally from the body of the catheter and used to perform some intended therapeutic or diagnostic function. Such laterally deployable elements include penetrators (e.g., straight or curved needles), probes (e.g., cryogenic probes, heating probes, etc.), wires (e.g., guidewires) and electrodes.  
         [0003]     In many instances, it is desirable to image or visualize the laterally deployable element as it is advanced or extended from the catheter body. Moreover, the ability to image or visualize the laterally deployable element as well as nearby anatomical structures can be especially useful in situations where it is desired to advance or extend the laterally deployable element to a particular target anatomical structure and/or where is it desirable to avoid damaging or penetrating a particular anatomical structure.  
         [0004]     The prior art has included a number of catheters that have laterally deployable elements along with on-board imaging apparatus useable to view the advancement or extension of the laterally deployable element. For example, catheters having laterally deployable tissue penetrating members (e.g., needles) in combination with imaging apparatus useable to visualize the deployment of the tissue penetrator and/or to provide a pre-indication of the trajectory on which the tissue penetrator will advance include those described in U.S. Pat. Nos. U.S. Pat. No. 5,830,222 (Makower), U.S. Pat. No. 6,068,638 (Makower), U.S. Pat. No. 6,159,225 (Makower), U.S. Pat. No. 6,190,353 (Makower, et al.), U.S. Pat. No. 6,283,951 (Flaherty, et al.), U.S. Pat. No. 6,283,983 (Makower, et al.), U.S. Pat. No. 6,375,615 (Flaherty, et al.), U.S. Pat. No. 6,508,824 (Flaherty, et al.), U.S. Pat. No. 6,544,230 (Flaherty, et al.), U.S. Pat. No. 6,579,311 (Makower), U.S. Pat. No. 6,602,241 (Makower, et al.), U.S. Pat. No. 6,655,386 (Makower, et al.), U.S. Pat. No. 6,660,024 (Flaherty, et al.), U.S. Pat. No. 6,685,648 (Flaherty, et al.), U.S. Pat. No. 6,709,444 (Makower), U.S. Pat. No. 6,726,677 (Flaherty, et al.) and U.S. Pat. No. 6,746,464 (Makower), the entire disclosure of each such United States patent being expressly incorporated herein by reference.  
         [0005]     Also, U.S. Pat. No. 5,345,940 (Seward, et al.) describes a catheter that has an ultrasonic transducer proximate its distal end and a port from which a therapeutic device or the like may be deployed laterally from the catheter body under ultrasound visualization.  
         [0006]     Additionally, U.S. Pat. No. 6,544,230 (Ishihra, et al.) describes a laser beam irradiation apparatus having a laterally deployable laser beam irradiation probe and an ultrasonic transmitter/receiver for emitting ultrasonic waves toward the region to which the laser beam is applied by the probe, receiving reflected waves from the irradiated region, converting the reflected waves into an electrical signal, a measuring device for measuring the temperature of the irradiated region in accordance with the electrical signal from the ultrasonic transmitter/receiver, and an output adjuster for adjusting the output of the laser generating device in accordance with a temperature signal from the measuring device.  
         [0007]     There remains a need in the art for the development of new catheter deices having laterally deployable working elements and means for imaging the deployment of such working elements within the body of a human or animal subject.  
       SUMMARY OF THE INVENTION  
       [0008]     In accordance with the present invention there is provided a catheter device that comprises a catheter body, a laterally deployable working element that is advanceable or extendable from the catheter body and useable to perform a therapeutic or diagnostic function and a linear imaging array mounted longitudinally on or in the catheter body. The linear imaging array is useable to image the laterally deployable working element when it is advanced or extended from the catheter body. In some embodiments, the linear imaging array is also useable to image anatomical structures and may be used to locate an anatomical target site to which it is desired to advance or extend the working element. The linear imaging array may be any suitable type of imaging array, such as an ultrasound imaging array which displays an ultrasonic image on an extracorporeally located monitor or display screen. In some embodiments, indicia of the expected trajectory or path on which the working element will advance or extend may be superimposed or displayed on the image received from the linear imaging array. Additional imaging apparatus, such as a separate round imaging array may also be mounted on or in the catheter, along with the linear imaging array. The laterally deployable working element may comprise any suitable apparatus, device, energy form, composition or other element that is capable of performing or facilitating a diagnostic or therapeutic task, including but not limited to needles, curved needles, guidewires, catheters, cannulae, probes, cryogenic apparatus, cooling apparatus, heating apparatus, laser devices (e.g., laser wires), electrodes, electrosurgical probes, and antennae.  
         [0009]     Further in accordance with the present invention, there is provided a method for performing a diagnostic or therapeutic function at a target site located outside of a body lumen. Such method generally includes the steps of (a) providing a catheter device that comprises i) a catheter body having a distal end, ii) a laterally deployable working element that is advanceable or extendable from the catheter body and useable to perform the therapeutic or diagnostic function and iii) a linear imaging array mounted longitudinally on or in the catheter body, said linear imaging array being useable to image the laterally deployable working element when it is advanced or extended from the catheter body; (b) positioning the catheter body within the body lumen; (c) advancing or extending the laterally deployable working element; (d) using the linear imaging array to image the working element while in its advanced or extended position and (e) using the working element to perform the diagnostic or therapeutic function at the target location. In some embodiments, the catheter device provided in Step (a) may be the same as that summarized hereabove in the immediately preceding paragraph.  
         [0010]     Further aspects, details and embodiments of the present invention will be understood by those of skill in the art upon reading the following detailed description of the invention and the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a side view of one embodiment of a catheter device of the present invention having a laterally deployable element and a linear ultrasound array useable to visualize the advancement or extension of the laterally deployable element.  
         [0012]      FIG. 2  is an enlarged, cut-away view of a distal portion of the catheter device of  FIG. 1 .  
         [0013]      FIG. 3  is a rear perspective view of the catheter device of  FIG. 1  with the laterally deployable element in an extended position and the linear ultrasound array being used to image the laterally deployable element as well as nearby anatomical structures.  
         [0014]      FIG. 3A  is distal end view of the showing of  FIG. 3 .  
         [0015]      FIG. 3B  is a right side view of the showing of  FIG. 3 . 
     
    
       [0016]     The Figures are not necessarily to scale.  
       DETAILED DESCRIPTION  
       [0017]     The following detailed description, the accompanying drawings are intended to describe some, but not necessarily all, examples or embodiments of the invention. The contents of this detailed description and accompanying drawings do not limit the scope of the invention in any way.  
         [0018]      FIGS. 1-3B  show one example of a catheter device  10  of the present invention. This catheter device  10  comprises an elongate catheter body  12  having a distal end DE, laterally deployable working element  30  that advances laterally out of side port  32  formed in catheter body  12  and a linear imaging array  13  that is useable to image the working element  30  and the surrounding area as the working element  30  advances from the catheter body  12 . In the particular example depicted in the drawings, the laterally deployable working element comprises a hollow tissue penetrating member (e.g., a needle) having a lumen and an open distal tip. This tissue penetrating member may be formed of elastic or superelastic material (e.g., nickel-titanium alloy) and may be biased to a curved configuration, as shown. Those of skill in the art will appreciate that a substance, article or device may be delivered through the lumen of this hollow tissue penetrating member. For example, as seen in  FIG. 2 , additional working elements such as a delivery catheter  42  or guidewire  44  may be advanced through the lumen of this tissue penetrator. It should be understood that in the preferred embodiment delivery catheter  42  or guidewire  44 , but not both at the same time, may be advanced through the lumen of the tissue penetrator, although in the figures both are depicted simply to illustrate that either may be advanced. It should also be appreciated, however, that the laterally deployable working element  30  need not necessarily comprise a tissue penetrating member as seen in this example, but may additionally or alternatively comprise any other apparatus(es) or device(s) capable of performing diagnostic or therapeutic functions, including but not limited to guidewires, catheters, cannulae, probes, cryogenic apparatus, cooling apparatus, heating apparatus, laser devices (e.g., laser wires), electrodes, electrosurgical probes, and antennae.  
         [0019]     A handpiece  14  is provided on the proximal end of the catheter body  12 , as shown in  FIG. 1 . The laterally deployable working element  30  is longitudinally moveable between a retracted position where it is substantially retracted within the catheter body  12  and an extended position wherein it has been longitudinally advanced out of side port  32  such that it extends on a trajectory or path away from the catheter body  12 . The handpiece  14  comprises an advancement/retraction knob  15  which may be pushed in the distal direction to advance the working element  30  from its retracted position to its extended position and pulled in the proximal direction to retract the working element  30  from its extended position to its retracted position. An adjustable stop member  17  limits the extent of distal advancement of the advancement/retraction knob  15 , thereby controlling the length from the side port  32  to the distal tip of the working element  30  when the working element  30  is fully extended. It is to be appreciated, however, that longitudinal advancement and retraction of the working element  30  is only an example of the way in which the working element  30  may laterally deploy from the catheter body. Various other modes of advancement or extension of the working element  30  may be employed, for example the working element may telescope, fold or pivot instead of longitudinally advancing and retracting.  
         [0020]     In the particular embodiment shown in the drawings, a first proximal side arm  27  is connected to the proximal end of the lumen of the tissue penetrating member such that a substance, article or device may be delivered through the proximal side arm  27  and through that lumen. In the showing of  FIG. 2 , a guidewire  44  and a delivery catheter have been introduced through side arm  27  and advanced through the penetrator lumen such that they extend out of an beyond the distal end of the penetrator. In the preferred embodiment, the guidewire used is any suitable commercially available guidewire while the delivery catheter used may be the IntraLume™ Microcatheter (Medtronic, Inc. Minneapolis, Minn., USA) is used.  
         [0021]     A tapered distal tip member  36  having a lumen  38 (tip) is mounted on the distal end of the catheter body  12 . A through lumen  34  extends from a port  16  on the handpiece  14 , through the catheter body  12  and is continuous with the distal tip lumen  34 (tip) such that a continuous through lumen  38 ,  38 (tip) extends from proximal port  16  though the open distal end of distal tip member  36 . A guidewire may pass through this lumen  38 ,  38  (tip) for over-the-wire advancement of the catheter device  10 . It will be appreciated that, in some alternative embodiments, the lumen  38  may terminate proximally in a side opening in the catheter body  12 , thereby providing a rapid exchange type guidewire lumen. Also in the embodiment shown, an infusion port  18  is optionally formed on the handpiece  14  in communication with lumen  38  such that an infusion apparatus  20  (e.g., a syringe, intravenous tube, pump, injector, etc.) may be used to infuse fluid (e.g., saline solution, radiographic contrast medium, etc.) through lumen  38 ,  38 (tip) and out of the open distal end of the tip member  46 . A valve (e.g., a Tuohy-Borst valve) may be provided on proximal port  16  to secure a guidewire when desired and/or to form a fluid tight seat at proximal port  16  when fluid is being infused through infusion port  18 .  
         [0022]     The linear imaging array  13  may be mounted in or on the catheter body  12  in such a way as to provide an image from a limited field of view FV. This field of view FV may extend from one side of the catheter body and may encompass a substantial portion of the trajectory or path on which the working element  30  will advance or extend. Additionally, in at least some embodiments, the field of view FV may extend to a distance that is sufficient to image the intended target location to which the working element  30  is to be advanced or extended. In some embodiments, the field of view FV may constitute a defined radial area that extends from the catheter body in the same lateral direction in which the working element  30  will advance or extend. In such embodiments, the operator may rotate and longitudinally move the catheter body  12  within a body lumen (e.g., a blood vessel lumen) until the intended target site is located within (or centered within) the field of view FV as seen on a monitor which displays the image received by the linear imaging array  13 . This will allow the operator to use the image obtained from the linear imaging array to adjust the longitudinal position and/or rotational orientation of the catheter body  12  relating the intended target location prior to actual advancement or extension of the working element to ensure, or to at least increase the likelihood, that subsequent advancement or extension of the working element  30  will cause the working element  30  to enter the intended target site rather than some other location.  
         [0023]     Also, in some embodiments, an indicator of the expected trajectory or path on which the working element  30  will advance may be superimposed or otherwise shown on the image displayed by the imaging system  26  such that the operator may then adjust the longitudinal position and/or rotational orientation of the catheter body  12  until the indicator of the expected trajectory or path on which the working element  30  is within the target site seen on the image. For example, the expected trajectory (depicted as  30 - 1  in  FIG. 1 ) may be pre-programmed into the imaging system and, once the catheter is recognized by the system, said the expected trajectory would be superimposed on the display. This will ensure, or least increase the likelihood, that subsequent advancement or extension of the working element  30  will cause the working element  30  to enter the intended target site rather than some other location.  
         [0024]     In the example of  FIGS. 1-2A , connector wire(s)  40  extend from the linear imaging array  13 , through catheter body  12 , through proximal side arm  22  and are connected to an imaging system  26  which displays the image received by the linear imaging array  13 . However, in some other embodiments, the connector wires  40  may be replaced by wireless technology known in the art for sending and receiving signals between the linear imaging array  13  and the extracorporeally located imaging/display system  26 .  
         [0025]     The linear imaging array may comprise a linear ultrasound array consisting of a plurality of ultrasound emitters/receivers disposed in a substantially straight line and operating at a common frequency. For example, the linear array may consist of between  2  to  128  ultrasound emitters/receivers disposed in a substantially linear fashion along the catheter. The ultrasound emitters/receivers preferably operate at between  5  to 50 MHz. linear.  
         [0026]     It is to be appreciated that this catheter device  10  may be used for many different purposes wherein it is desired to advance or extend any laterally deployable working element  30  from a catheter to a desired location. In some instances, the target location may be within in the wall of a vessel in which the catheter body  12  is positioned. For example, the wall of a blood vessel is made up of several layers (e.g., tunica intima, tunica media and tunica adventitia or outer coat) and the working element  30  may be advanced from the lumen of the blood vessel to a location within the blood vessel wall (e.g., into the adventitia or outer coat of the blood vessel. This technique may facilitate advancement of a tubular working element  30  into the vessel wall such that a desired diagnostic or therapeutic substance can be injected directly into the vessel wall. For example, this technique may be used for injection of drugs into an artery wall to deter restenosis of the artery following an angioplasty procedure.  
         [0027]     In other instances, the target location may be outside of the wall of the luminal anatomical structure in which the catheter body  12  is positioned and the working element  30  may be advanced or extended all the way through the luminal wall to the desired target site. For example, the catheter body  12  may be positioned within the lumen of one blood vessel and a working element  30  comprising a tissue penetrator may be advanced to a target location within the lumen of another blood vessel. Such vessel-to-vessel penetration may be utilized to create, or to facilitate the creation of, a passageway or fistula between two blood vessels. Or, as a further example, the target location may be a natural or man made cavity or structure located adjacent to or a spaced distance away from the body lumen in which the catheter body  12  is positioned. Examples of such possible target locations include organs, tumors, body cavities, previously implanted devices such as substance reservoirs or drug eluting devices, etc. Examples of possible target locations, ancillary procedures and applications of the present invention include but are not limited to those described in U.S. Pat. Nos. U.S. Pat. No. 5,830,222 (Makower), U.S. Pat. No. 6,068,638 (Makower), U.S. Pat. No. 6,159,225 (Makower), U.S. Pat. No. 6,190,353 (Makower, et al.), U.S. Pat. No. 6,283,951 (Flaherty, et al.), U.S. Pat. No. 6,283,983 (Makower, et al.), U.S. Pat. No. 6,375,615 (Flaherty, et al.), U.S. Pat. No. 6,508,824 (Flaherty, et al.), U.S. Pat. No. 6,544,230 (Flaherty, et al.), U.S. Pat. No. 6,579,311 (Makower), U.S. Pat. No. 6,602,241 (Makower, et al.), U.S. Pat. No. 6,655,386 (Makower, et al.), U.S. Pat. No. 6,660,024 (Flaherty, et al.), U.S. Pat. No. 6,685,648 (Flaherty, et al.), U.S. Pat. No. 6,709,444 (Makower), U.S. Pat. No. 6,726,677 (Flaherty, et al.) and U.S. Pat. No. 6,746,464 (Makower).  
         [0028]     Also, in some instances, the catheter  12  may be inserted into a man made passage such as a guidewire tract or neo-lumen created in the wall of a blood vessel past an occlusive lesion (e.g., a chronic total occlusion) and a working element  30  comprising a penetrating member then be used to penetrate from the catheter body back into the true lumen of that blood vessel, at a location downstream of the obstruction. In such procedures, if the penetrating member has a lumen  32 , a guidewire may be advanced through the penetrator lumen and into the true lumen of the blood vessel downstream of the obstruction. Thereafter, the working element  30  may be retracted and the catheter device  10  removed, leaving the guidewire in place. A stent may then be delivered over that guidewire and used to stent the man made guidewire tract (e.g., “neo-lumen) thereby providing a bypass conduit for blood flow around the obstructive lesion.  
         [0029]     In applications of the invention where a flowable substance is to be delivered, the working element  30  may comprise a needle, catheter or other substance delivery device(s) that can advance or extend into a target site and used to deliver the desired substance to the target site. It will be appreciated that in some such embodiments, the working element  30  may comprise a hollow penetrator (e.g., a needle) having a lumen. The substance may in some cases be delivered directly though the lumen of that penetrator or, in other cases, a separate delivery catheter  42  may be advanced through the lumen of the penetrator as seen in  FIG. 2  and the substance may then be delivered through that delivery catheter  42 . In some of these cases, the delivery catheter  42  may be capable of penetrating through tissue and the working element  30  comprising a penetrator may be advanced to a first location some distance form the target site. The delivery catheter  42  may be advanced through the working element  30  and through any intervening tissue, from the first location to the target site. Examples of the types of substances that may be delivered include but are not limited to: contrast agents or other agents that provide an enhanced image of the target site, traceable substances that may be used to determine the rate at which the substance distributes away from or is otherwise inactivated at the target site or other pharmacokinetic or biodistributive parameters or variables, drugs, proteins, cells (e.g., stem cells, nerve cells, progenator cells, myoblasts, myocytes, secretory cells, pancreatic islet cells, dopamine secreting cells, endothelial cells, hepatocytes, cloned cells, cells grown in cell culture, genetically modified cells, and combinations thereof), angiogenic substances (e.g., vascular endothelial growth factor (VEGF), fibroblast growth factors (FGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), hepatocyte growth factor (HGF)or scatter factor, heparin combined with an adenosine receptor agonist, nerve cell growth factor (NGF), and combinations thereof), other agents that increase vascularity of an ischemic target site, myogenic substances, neurogenic substances, genes, gene therapy compositions, genetic material in combination vectors (e.g., viruses), stem cells of a type that will mature in situ into a type of cell that is currently deficient, substances that promote the growth of myocytes in tissue that is necrotic or characterized by a lack of living myocytes, secretory cells that secrete a substance (e.g., dopamine, insulin, a particular neurotransmitter) that is deficient, step F comprises insulin secreting cells, glial cell line-derived neurotropic factor (GDNF), nerve growth factor, neuro-immunophilin ligand, poly ADP-Ribose polymerase, and combinations thereof.  
         [0030]     In applications of the invention where an article is to be delivered to the target site, it will be appreciated that in some cases such article may be introduced directly through a lumen formed in the working element  30  or the desired article may be otherwise delivered though, over or released from the working element. Examples of the types of articles that may be delivered using catheter devices  10  of the present invention include but are not limited to; bulking agents, substance eluting implants, radioactive implants, embolic members, markers, and radiopaque markers.  
         [0031]     It is to be further appreciated that the invention has been described hereabove with reference to certain examples or embodiments of the invention but that various additions, deletions, alterations and modifications may be made to those examples and embodiments without departing from the intended spirit and scope of the invention. For example, any element or attribute of one embodiment or example may be incorporated into or used with another embodiment or example, unless to do so would render the embodiment or example unsuitable for its intended use. Also, where the steps of a method or process are described, listed or claimed in a particular order, such steps may be performed in any other order unless to do so would render the embodiment or example not novel, obvious to a person of ordinary skill in the relevant art or unsuitable for its intended use. All reasonable additions, deletions, modifications and alterations are to be considered equivalents of the described examples and embodiments and are to be included within the scope of the following claims.