Abstract:
Devices and methods can be used to extract obstructions from medical drainage tubes. For example, this document provides catheter-based devices for insertion in a drainage tube to enable irrigation of obstructions, aspiration, and mechanical removal of obstructions. In some examples, medical drainage tube devices are used to provide an avenue for the body to expel the byproducts of an infection or inflammation. Medical drainage tubes can create a pathway from a location in the interior of a body to the surface of the body for withdrawal of fluids and discharges from a wound, sore, cavity, and the like.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/769,585, filed Feb. 26, 2013. The disclosure of the prior application is considered part of (and is incorporated by reference in) the disclosure of this application. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    This document relates to devices and methods for extracting obstructions from medical drainage tubes. For example, this document relates to catheter-based devices for insertion in a medical drainage tube to facilitate irrigation, aspiration, and mechanical removal of drainage tube obstructions. 
         [0004]    2. Background Information 
         [0005]    In some examples, medical drainage tube devices are used to provide an avenue for the body to expel the byproducts of an infection or inflammation. Medical drainage tubes can create a pathway from a location in the interior of a body to the surface of the body for withdrawal of fluids and discharges from a wound, sore, cavity, and the like. Closed drainage is a system of tubing and other apparatus attached to the body to remove fluid in an airtight circuit that prevents environmental contaminants from entering the wound or cavity. 
       SUMMARY 
       [0006]    This document provides devices and methods for extracting obstructions from medical drainage tubes. For example, this document provides catheter-based devices for insertion in a medical drainage tube to enable irrigation of obstructions, aspiration, and mechanical removal of obstructions. 
         [0007]    In general, one aspect of this document features a device for removing an obstruction from a medical drainage tube. The device comprises: a catheter with a proximal end and a tapered distal tip, the tapered distal tip including an aperture; an end cap fixedly coupled to the proximal end of the catheter, the end cap including a liquid sealing member; a wire with a first end and a second end, the wire being generally coaxial with the catheter and intersecting the liquid sealing member, wherein the first end is arranged to be manipulated by an operator of said device; and an expandable member at the second end of the wire, wherein the expandable member is arranged to expand from a low-profile configuration to an enlarged configuration. 
         [0008]    The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. The expandable member may be arranged to be in the low-profile configuration when the expandable member is located within the catheter, and the expandable member may be arranged to be in the enlarged configuration when the expandable member is outside of the catheter. The expandable member may be a brush having a plurality of flexible bristles. The device may further comprise a fitting attached to and in fluid communication with the catheter, wherein the fitting is configured to couple with an irrigation liquid source and to pass liquid into the catheter. 
         [0009]    In general, another aspect of this document features a method for removing an obstruction from a medical drainage tube. The method comprises: inserting a device into a lumen of the medical drainage tube; passing the distal tip through the obstruction; causing the expandable member to emerge out from inside the catheter and through the aperture, whereby the expandable member reconfigures from the low-profile configuration to the enlarged configuration; and retracting the device from the medical drainage tube such that the expandable member contacts the obstruction to move the obstruction out of the medical drainage tube. The device comprises: a catheter with a proximal end and a distal tip, the distal tip including an aperture; an end cap fixedly coupled to the proximal end of the catheter; a wire with a first end and a second end, the wire being generally coaxial with the catheter, wherein the first end is arranged to be manipulated by an operator of the device; and an expandable member at the second end of the wire, wherein the expandable member is arranged to expand from a low-profile configuration to an enlarged configuration. 
         [0010]    The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. The method may further comprise injecting an irrigation liquid into the catheter. In addition, the method may further comprise suctioning the irrigation liquid into an aspiration catheter. 
         [0011]    In another general aspect, this document features another device for removing an obstruction from a medical drainage tube. The device comprises: a catheter with a proximal end and a tapered distal tip, the tapered distal tip including an aperture; an end cap fixedly coupled to the proximal end of the catheter, the end cap including a liquid sealing member; an aspiration catheter with a first end portion and a second end portion; and an expandable member at the second end of the wire, wherein the expandable member is arranged to expand from a low-profile configuration to an enlarged configuration. In some embodiments, the aspiration catheter is generally coaxial with the catheter and intersecting the liquid sealing member. The first end portion of the aspiration catheter is arranged to be coupled to a suction source and manipulated by an operator of the device. 
         [0012]    In another general aspect, this document features another method for removing an obstruction from a medical drainage tube. The method comprises: inserting a device into a lumen of the medical drainage tube; passing the distal tip through the obstruction; causing the expandable member to emerge out from inside the catheter and through the aperture, whereby the expandable member reconfigures from the low-profile configuration to the enlarged configuration; and retracting the device from the medical drainage tube such that the expandable member contacts the obstruction to move the obstruction out of the medical drainage tube. The device comprises: a catheter with a proximal end and a distal tip, the distal tip including an aperture; an end cap fixedly coupled to the proximal end of the catheter; an aspiration catheter with a first end portion and a second end portion; and an expandable member at the second end of the wire, wherein the first end is arranged to be manipulated by an operator of the device; and an expandable member at the second end of the wire, wherein the expandable member is arranged to expand from a low-profile configuration to an enlarged configuration. In some embodiments, the aspiration catheter is generally coaxial with the catheter and intersecting the liquid sealing member. The first end portion of the aspiration catheter is arranged to be coupled to a suction source and manipulated by an operator of the device. 
         [0013]    In various implementations of the method, the method may further comprise injecting an irrigation liquid into the catheter. The method may also optionally include aspirating the irrigation liquid through one or more openings in the second end portion of the aspiration catheter. 
         [0014]    Particular embodiments of the subject matter described in this document can be implemented to realize one or more of the following advantages. In some embodiments, the devices and methods provided herein for removing obstructions from drainage tubes can reduce or prevent patient fluid accumulation that may otherwise progress to hematoma or abscess formation. In some embodiments, the devices and methods provided herein can reduce or eliminate the need for surgical replacement of a clogged drainage tube. In some embodiments, the devices and methods provided herein can reduce the potential for secondary illnesses, reduce patient discomfort, and lower healthcare costs by ensuring drainage tube patency using an easy-to-use device and low risk procedure. 
         [0015]    Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
         [0016]    The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description herein. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
         [0017]    DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a schematic diagram of a surgical drainage tube system with an obstruction in the tube. 
         [0019]      FIG. 2  is a longitudinal cross-sectional view of a drainage tube obstruction extractor device in accordance with some embodiments provided herein. 
         [0020]      FIGS. 3-5  are a series of illustrations depicting a drainage tube obstruction extractor device removing an obstruction from a drainage tube in accordance with some embodiments provided herein. 
         [0021]      FIG. 6  is a flowchart of an exemplary method of extracting an obstruction from a medical drainage tube. 
         [0022]      FIG. 7  is a longitudinal cross-sectional view of another drainage tube obstruction extractor device in accordance with some embodiments provided herein. 
     
    
       [0023]    Like reference numbers represent corresponding parts throughout. 
       DETAILED DESCRIPTION 
       [0024]    Medical drainage tubes can become obstructed with blood clots and other debris, despite adequate drainage tube care such as stripping the drainage tube and increasing suction. This document provides catheter-based devices and methods for extracting obstructions from medical drainage tubes, by enabling both irrigation of obstructions, aspiration, and mechanical removal of obstructions. Using the devices and methods provided herein, some drainage tube obstructions can be removed without requiring replacement of the drainage tube by re-operation or the use of radiological guidance. 
         [0025]    In some embodiments, the devices provided herein are catheters containing a wire that includes an expandable brush-like member at the distal end of the wire. The catheter can be inserted in a drainage tube, and the distal tip of the catheter can be passed through the drainage tube obstruction. In some embodiments, the distal tip of the catheter includes a tapered leading end to facilitate passage of the catheter&#39;s distal tip through the obstruction. In some instances, the obstruction can be softened using irrigation liquid injected through the devices provided herein. The irrigation liquid may loosen or dislodge the obstruction thereby facilitating its removal from the drainage tube. 
         [0026]    In some embodiments, when the distal tip of the catheter has passed through the obstruction, the catheter can be pulled-back in a proximal direction while maintaining the wire substantially stationary. The relative movement between the catheter and the wire can cause the distal end of the wire to protrude from the tip of the catheter. In some embodiments, the brush-like member on the distal end of the wire will emerge out of the catheter, and bristles of the brush-like member will expand. In some embodiments, the catheter and wire can then be retracted from the drainage tube, and the bristles of the brush-like member will mechanically force the obstruction out of the drainage tube. 
         [0027]    With reference to  FIG. 1 , a patient  100  is depicted as connected to a medical drainage tube  110  that transmits bodily fluids to a collection bag  120 . In the magnified view, an arrow  130  depicts the intended direction of flow of the bodily fluids through the tube  110 . 
         [0028]    An obstruction  140  is shown within tube  110 . In some instances, obstruction  140  may be a clot (e.g., a blood clot, or a clot of other bodily fluids). In some instances, obstruction  140  may be a collection of debris. In some instances, obstruction  140  may be another type of material. Obstruction has a proximal side  142  and a distal side  144 . 
         [0029]    Obstruction  140  may partially or fully block the flow of fluids through the drainage tube  110 . In such cases, fluids may not be expelled from patient  100  as desired, and patient&#39;s  100  health or healing rate may be negatively impacted. Therefore, removal of obstruction  140  from drainage tube  110  is desirable. 
         [0030]    With reference to  FIG. 2 , an exemplary drainage tube obstruction extractor  200  in accordance with some embodiments is illustrated. Extractor  200  is shown in a longitudinal cross-sectional view to promote good visualization and understanding of its components. Some components of example extractor  200  include a catheter  210 , a luer fitting connector  220 , an end cap  230 , and a wire  240 . 
         [0031]    In some embodiments, catheter  210  is a polymeric tube that is circular in cross-section. Catheter  210  has at least one lumen. In some embodiments, catheter  210  is an extruded tube made from plastic material such as vinyl, nylon, polyurethane, polyethylene terephthalate, or silicone to provide a few examples. In some embodiments, catheter  210  is wire-reinforced. In some embodiments, catheter  210  has a conically tapered distal tip  212 . In some embodiments, distal tip  212  is a thermo-formed end of catheter  210 . For example, heat or RF energy can be applied to the end of catheter  210 , and distal tip  212  can be formed in a die to attain the tapered shape. In some embodiments, distal tip  212  is a separate component that is attached to the end of catheter  210  during an assembly process. For example, distal tip  212  can be a separate molded part that is coupled onto the end of catheter  210 . 
         [0032]    Distal tip  212  includes an aperture  214 . In some embodiments, aperture  214  enables the distal end of wire  240  to emerge from catheter  210 . In some embodiments, aperture  214  is used to allow irrigation liquid to be emitted from catheter  210 . In some embodiments, aperture  214  enables both emergence of wire  240  and transmission of irrigation liquid. In some embodiments, more than one aperture  214  is included at distal tip  212 . For example, in some such embodiments, additional radial holes are included to provide additional irrigation liquid transmission ports. 
         [0033]    A proximal end  216  of catheter  210  is located opposite of distal tip  212 . Proximal end  216  can be attached to end cap  230 . In some embodiments, proximal end  216  is attached to end cap  230  by an adhesive, solvent bonding, a barbed connection, a compression clamp (or a combination of such methods) to provide a few examples. 
         [0034]    End cap  230  can be a polymeric or metallic fitting. For example, in some embodiments, end cap  230  is a molded plastic fitting. In some embodiments, end cap  230  is molded of polycarbonate, polystyrene, or polyvinyl chloride (PVC), for example. In some embodiments, end cap  230  includes flange  232 . Flange  232  can provide a convenient place for a clinician operator to grasp onto extractor  200 . End cap  230  can also include a gel lock  234 . In some embodiments, gel lock  234  is a sealing material that can allow wire  240  to pass through end cap  230  while maintaining a liquid seal. In some embodiments, gel lock  234  can be a urethane gel, silicone gel, polymer hydrogel, or other suitable flexible lubricous material or combination of materials. In some embodiments, gel lock  234  can also comprise a flexible fabric or membranous material, or such materials can be combined with the gel materials. 
         [0035]    Example drainage tube obstruction extractor  200  can include luer fitting connector  220 . Luer fitting connector  220  can be in fluid communication with catheter  210 . Luer fitting connector  220  can be used to inject irrigation liquid into catheter  210  as desired. In some embodiments, luer fitting connector  220  can be incorporated with end cap  230 , such that the two are a unitary component. In some embodiments, luer fitting connector  220  can be a separate component that is included in-line with catheter  210 . For example, luer fitting connector  220  can be a molded plastic component that is attached to catheter  220  by an adhesive, solvent bonding, a barbed connection, a compression clamp (or a combination of methods) to provide a few examples. Luer fitting connector  220  includes a cap  222  and a barrel  224 . To add irrigation liquid to catheter  210 , cap  222  can be removed and a compatible syringe or tube can be coupled to barrel  224 . In some embodiments, barrel  224  is a standard male or female luer lock fitting. In some embodiments, other types of connection features, such as a barbed fitting, can be included on barrel  224 . 
         [0036]    Wire  240  is generally coaxial with catheter  210 . Wire  240  intersects with and passes through gel lock  234 . Wire  240  can be made of metallic or polymeric materials, or a combination thereof. In some embodiments, wire  240  is made of aluminum, stainless steel, steel alloys, nitinol, titanium, titanium alloys, nylon, polyester, polyethylene, polypropylene, polystyrene, PTFE, carbon fiber, or PVC to name a few examples. In some embodiments, wire  240  is a single strand. In some embodiments, wire  240  has two or more strands that are twisted with each other or otherwise combined together to form a single elongate member. 
         [0037]    Example drainage tube obstruction extractor  200  includes a handle  246  at the proximal end of wire  240 . In some embodiments, no handle  246  is included. In some embodiments, other types of handles are included. 
         [0038]    A brush-like member  242  is at the distal end of wire  240 . In some embodiments, other types of devices are used at the distal end of wire  240 . For example, in some embodiments, rather than brush-like member  242  or in combination with brush-like member  242 , the distal end of wire  240  can include a corkscrew member, inflatable member, grasping device, cutting device, and the like. 
         [0039]    Brush-like member  242  includes bristles  244 . Bristles  244  can be compressed in a low-profile configuration inside catheter  210 . As described further herein, bristles  244  can expand when brush-like member  242  emerges from aperture  214  of catheter  210 . 
         [0040]    Bristles  244  can be made from a variety of materials including polymeric and metallic materials. In some embodiments, bristles  244  are made from dissolvable or biosorbable materials. In some embodiments, bristles  244  are nylon, polyester, polyethylene, polypropylene, polystyrene, PTFE, carbon fiber, or PVC to name a few polymeric examples. In some embodiments, bristles are aluminum, stainless steel, stainless steel alloys, titanium, titanium alloys, nitinol, or nitinol alloys to name a few metallic examples. In some embodiments, a combination of materials are used for bristles  244 . In some embodiments, all individual bristles  244  are substantially a uniform length. In some embodiments, brush-like member  242  includes individual bristles  244  that have a variety of lengths. 
         [0041]    In some embodiments, bristles  244  are attached to wire  240  by being compressed between wound wire filament strands that comprise wire  240 . In some embodiments, bristles  244  are flocked to wire  240 , using for example, an adhesive. In some embodiments, brush-like member  242  is a separate component that is attachable on the end of wire  240 , using a threaded coupling, welding, by adhesive, and/or other suitable methods. 
         [0042]    The length of example drainage tube obstruction extractor  200  can differ in various embodiments. For example, catheter  210  can range, in some embodiments, from about 20 cm to about 60 cm, about 50 cm to about 90 cm, about 80 cm to about 120 cm or longer. Wire  240  can range, in some embodiments, from about 30 cm to about 70 cm, about 60 cm to about 100 cm, about 90 cm to about 130 cm or longer. In general, wire  240  can be longer than catheter  210  so brush-like member  242  can be arranged to protrude from distal tip  212  of catheter  210 . 
         [0043]    With reference to  FIG. 3 , example drainage tube obstruction extractor  200  is shown inserted in medical drainage tube  110  to remove obstruction  140 . The illustration is a longitudinal cross-sectional view to enhance visualization and understanding of the devices and methods provided herein. In the illustrated configuration, collection bag  120  (refer to  FIG. 1 ) has been uncoupled from tube  110  to allow access to the interior of tube  110 . 
         [0044]    A clinician will insert extractor  200  in tube  110 , and advance extractor  200  so that distal tip  212  will approach obstruction  140 . In some instances, the tapered profile of distal tip  212  will enable the clinician to push distal tip  212  through obstruction  140  as depicted. In some instances, penetration of obstruction  140  by distal tip  212  may be difficult, and irrigation liquid can be delivered to soften, deteriorate, and/or dislodge obstruction  140 . For example, in some cases an irrigation liquid of sterile 0.9% normal saline, sterile water, or other suitable liquids can be used. 
         [0045]    To deliver irrigation liquid, the clinician can first position aperture  214  close to proximal side  142  of obstruction  140 . A source of irrigation liquid can be attached to luer fitting connector  220 . Irrigation liquid can be injected via luer fitting connector  220  into the interior of catheter  210 . Gel lock  234  will prevent irrigation liquid from flowing out end cap  230 —causing flow of irrigation liquid out of catheter  210  through aperture  214  at distal tip  212 . Irrigation liquid will thereby come into contact with obstruction  140  to soften, deteriorate, and/or dislodge obstruction  140 . Such softening of obstruction  140  can facilitate penetration of obstruction  140  by distal tip  212 , to attain the configuration shown where distal tip is located beyond the distal side  144  of obstruction  140 . At this stage, brush-like member  242  is located within catheter  210  in a low-profile configuration. 
         [0046]    With reference to  FIG. 4 , wire  240  has been pushed distally in relation to catheter  210  such that brush-like member  242  has emerged from distal tip  212 . Brush-like member  242  is positioned on the distal side of obstruction  140 . 
         [0047]    At this stage, bristles  244  have expanded towards their natural orientation in an enlarged configuration (whereas bristles  244  were previously constrained within catheter  210 ). In some embodiments, bristles  244  may expand to make contact with the inner wall of catheter  210 . In some embodiments, some individual bristles  244  may make contact with the inner wall of catheter  210  while other individual bristles  244  do not make contact. In some embodiments, no bristles  244  make contact with the inner wall of catheter  210 . 
         [0048]    In some implementations, rather than pushing wire  240  distally, a clinician may deploy brush-like member  242  by pulling back catheter  210  while maintaining the position of wire  240  substantially stationary. In some embodiments, a combination of techniques is used to deploy brush-like member  242 . In any case, brush-like member  242  is caused to emerge from aperture  214  of catheter  210  such that brush-like member  242  is positioned distally of obstruction  140 . 
         [0049]    In some cases, the clinician may choose to inject irrigation liquid at this stage. The addition of irrigation liquid may loosen obstruction  140  to facilitate removal of obstruction  140 . Irrigation liquid can be injected into catheter  210  via luer fitting connector  220  as described herein. 
         [0050]    With reference to  FIG. 5 , example drainage tube obstruction extractor  200  is shown being pulled proximally in relation to medical drainage tube  110  to remove obstruction  140 . Arrows  250  represent the relative direction of movement of extractor  200  in relation to tube  110 . 
         [0051]    As the clinician pulls extractor  200  proximally, bristles  244  contact obstruction  140 . As extractor  200  is pulled further proximally, bristles  244  push obstruction  140  proximally in relation to tube  110 . Irrigation liquid can be added as desired. In this manner, obstruction  140  can be pulled out of tube  110 . 
         [0052]    After removal of obstruction  140  from tube  110 , collection bag  120  can be re-coupled to tube  110 . At this stage, drainage tube  110  is free from obstruction  140  and the proper function of drainage tube  110  has been restored. 
         [0053]      FIG. 6  is a flowchart of an exemplary process  600  for removing an obstruction from a medical drainage tube using the catheter-based drainage tube obstruction extractor devices provided herein. As described herein, in general the obstruction extractor devices provided herein include a catheter with a distal tip, a wire within the catheter, and a brush-like member at the distal end of the wire. 
         [0054]    At operation  610 , the extractor device is inserted in a drainage tube that contains an obstruction. The extractor device is advanced within the drainage tube so that the distal tip approaches the obstruction. At operation  620 , irrigation liquid is optionally injected via the extractor device to soften the obstruction. The distal tip of the extractor device is advanced through the obstruction such that the distal tip of the extractor device is positioned beyond the distal side of the obstruction. 
         [0055]    At operation  630 , the extractor device&#39;s brush-like member is pushed out of the distal tip of the extractor device&#39;s catheter. The brush-like member has bristles that reconfigure from a low-profile arrangement (when in the catheter) to an expanded configuration as the brush-like member emerges from the catheter. At operation  640 , irrigation liquid can optionally be injected to soften/loosen the obstruction. 
         [0056]    At operation  650 , at least some of the irrigation liquid can be optionally aspirated by adding suction in the region near the obstruction using an aspiration catheter (e.g., refer to  FIG. 7 ). In addition, some material from the obstruction may be suctioned through the aspiration catheter. 
         [0057]    At operation  660 , the extractor device is retracted from within the drainage tube. The bristles of the brush-like member make contact with the obstruction. The bristles push the obstruction to move it within the drainage tube as the extractor device is retracted. The obstruction is removed from the drainage tube as the extractor device is fully removed from the drainage tube. 
         [0058]    Referring now to  FIG. 7 , another example embodiment of a drainage tube obstruction extractor  700  in accordance with some embodiments is illustrated. Extractor  700  is shown in a longitudinal cross-sectional view to promote good visualization and understanding of its components. Some components of example extractor  700  include a catheter  710 , a luer fitting connector  720 , an end cap  730 , and an aspiration catheter  740 . Aspiration catheter  740  is provided in this embodiment as a source of suction for removing irrigation fluid and materials from clots and other obstructions. 
         [0059]    In some embodiments, catheter  710  is a polymeric tube that is circular in cross-section. Catheter  710  has at least one lumen. In some embodiments, catheter  710  is an extruded tube made from plastic material such as vinyl, nylon, polyurethane, polyethylene terephthalate, or silicone to provide a few examples. In some embodiments, catheter  710  is wire-reinforced. In some embodiments, catheter  710  has a conically tapered distal tip  712 . In some embodiments, distal tip  712  is a thermo-formed end of catheter  710 . For example, thermo or RF energy can be applied to the end of catheter  710 , and distal tip  712  can be formed in a die to attain the tapered shape. In some embodiments, distal tip  712  is a separate component that is attached to the end of catheter  710  during an assembly process. For example, distal tip  712  can be a separate molded part that is coupled onto the end of catheter  710 . 
         [0060]    Distal tip  712  includes an aperture  714 . In some embodiments, aperture  714  enables the distal end of aspiration catheter  740  to emerge from catheter  710 . In some embodiments, aperture  714  is also used to allow irrigation liquid to be emitted from catheter  710 . In some embodiments, aperture  714  enables both emergence of wire  740  and transmission of irrigation liquid. In some embodiments, more than one aperture  714  is included at distal tip  712 . For example, in some such embodiments, additional radial holes are included to provide additional irrigation liquid transmission ports. 
         [0061]    A proximal end  716  of catheter  710  is located opposite of distal tip  712 . Proximal end  716  can be attached to end cap  730 . In some embodiments, proximal end  716  is attached to end cap  730  by an adhesive, solvent bonding, a barbed connection, a compression clamp (or a combination of such methods) to provide a few examples. 
         [0062]    End cap  730  can be a polymeric or metallic fitting. For example, in some embodiments, end cap  730  is a molded plastic fitting. In some embodiments, end cap  730  is molded of polycarbonate, polystyrene, or polyvinyl chloride (PVC), for example. In some embodiments, end cap  730  includes flange  732 . Flange  732  can provide a convenient place for a clinician operator to grasp onto extractor  700 . End cap  730  can also include a gel lock  734 . In some embodiments, gel lock  734  is a sealing material that can allow aspiration catheter  740  to pass through end cap  730  while maintaining a liquid seal. In some embodiments, gel lock  734  can be a urethane gel, silicone gel, polymer hydrogel, or other suitable flexible lubricous material or combination of materials. In some embodiments, gel lock  734  can also comprise a flexible fabric or membranous material, or such materials can be combined with the gel materials. 
         [0063]    Example drainage tube obstruction extractor  700  can include luer fitting connector  720 . Luer fitting connector  720  can be in fluid communication with catheter  710 . Luer fitting connector  720  can be used to inject irrigation liquid into catheter  710  as desired. In some embodiments, luer fitting connector  720  can be incorporated with end cap  730 , such that the two are a unitary component. In some embodiments, luer fitting connector  720  can be a separate component that is included in-line with catheter  710 . For example, luer fitting connector  720  can be a molded plastic component that is attached to catheter  720  by an adhesive, solvent bonding, a barbed connection, a compression clamp (or a combination of methods) to provide a few examples. 
         [0064]    Luer fitting connector  720  includes a cap  722  and a barrel  724 . To add irrigation liquid to catheter  710 , cap  722  can be removed and a compatible syringe or tube can be coupled to barrel  724 . In some embodiments, barrel  724  is a standard male or female luer lock fitting. In some embodiments, other types of connection features, such as a barbed fitting, can be included on barrel  724 . 
         [0065]    Aspiration catheter  740  is generally coaxial with catheter  710 . Aspiration catheter  740  intersects with and passes through gel lock  734 . Aspiration catheter  740  can be made of metallic or polymeric materials, or a combination thereof In some embodiments, aspiration catheter  740  is made of aluminum, stainless steel, steel alloys, nitinol, titanium, titanium alloys, nylon, polyester, polyethylene, polypropylene, polystyrene, PTFE, carbon fiber, or PVC to name a few examples. 
         [0066]    Aspiration catheter  740  defines at least one lumen, and in some embodiments, includes a proximal fitting  748 , a distal end opening  741 , and one or more distal end portion fenestrations  743 . Proximal fitting  748  is configured for coupling to a suction source. For example, in some embodiments, proximal fitting  748  is a barbed fitting that can be readily connected to a suction tube. 
         [0067]    When a suction source is connected to proximal fitting  748 , a suction force (vacuum) is conveyed through the lumen of aspiration catheter  740  to distal end opening  741  and distal end portion fenestrations  743 . Accordingly, liquids and other materials can be thereby drawn into the lumen of aspiration catheter  740  through distal end opening  741  and distal end portion fenestrations  743 . 
         [0068]    In some embodiments, aspiration catheter  740  includes a finger grip  746  at the proximal end portion of aspiration catheter  740 . In some embodiments, no finger grip  746  is included. In some embodiments, other types of gripping adapters are included. 
         [0069]    A brush-like member  742  is at the distal end of aspiration catheter  740 . In some embodiments, other types of devices are used at the distal end of aspiration catheter  740 . For example, in some embodiments, rather than brush-like member  742  or in combination with brush-like member  742 , the distal end of aspiration catheter  740  can include a corkscrew member, inflatable member, grasping device, cutting device, and the like. 
         [0070]    Brush-like member  742  includes bristles  744 . Bristles  744  can be compressed in a low-profile configuration inside catheter  710 . As described above in regard to bristles  244 , bristles  744  can expand when brush-like member  742  emerges from aperture  714  of catheter  710 . 
         [0071]    Bristles  744  can be made from a variety of materials including polymeric and metallic materials. In some embodiments, bristles  744  are made from dissolvable or biosorbable materials. In some embodiments, bristles  744  are nylon, polyester, polyethylene, polypropylene, polystyrene, PTFE, carbon fiber, or PVC to name a few polymeric examples. In some embodiments, bristles are aluminum, stainless steel, stainless steel alloys, titanium, titanium alloys, nitinol, or nitinol alloys to name a few metallic examples. In some embodiments, a combination of materials are used for bristles  744 . In some embodiments, all individual bristles  744  are substantially a uniform length. In some embodiments, brush-like member  742  includes individual bristles  744  that have a variety of lengths. 
         [0072]    In some embodiments, bristles  744  are attached to aspiration catheter  740  by being flocked to aspiration catheter  740 , using for example, an adhesive. In some embodiments, brush-like member  742  is a separate component that is attachable on the end of aspiration catheter  740 , using a threaded coupling, welding, by adhesive, and/or other suitable methods. 
         [0073]    The length of example drainage tube obstruction extractor  700  can differ in various embodiments. For example, catheter  710  can range, in some embodiments, from about 20 cm to about 60 cm, about 50 cm to about 90 cm, about 80 cm to about 120 cm or longer. Aspiration catheter  740  can range, in some embodiments, from about 30 cm to about 70 cm, about 60 cm to about 100 cm, about 90 cm to about 130 cm or longer. In general, aspiration catheter  740  can be longer than catheter  710  so brush-like member  742  can be arranged to protrude from distal tip  712  of catheter  710 . 
         [0074]    The technique for using example drainage tube obstruction extractor  700  can be substantially similar to the technique for using drainage tube obstruction extractor  200  as described above, except that drainage tube obstruction extractor  700  can also provide aspiration via aspiration catheter  740 . The capability of drainage tube obstruction extractor  700  to provide aspiration can be beneficial in some circumstances. For example, when brush-like member  742  is protruding from distal tip  712  of catheter  710  and irrigation fluid is flowing through catheter  710 , aspiration catheter  740  can suction up the irrigation fluid so as to allow for more irrigation to take place as compared to when no aspiration is being used. In another example, aspiration via distal end opening  741  and distal end portion fenestrations  743  can facilitate the removal of portions of an obstruction as the irrigation fluid breaks up the obstruction. Hence, aspiration can be used to improve the technique of clearing the obstruction out of drainage tubes. 
         [0075]    In some embodiments, an additional suction pressure release feature can be added to aspiration catheter  740 . This feature can enhance the ability of aspiration catheter  740  to provide suction even in the event that distal end opening  741  and/or distal end portion fenestrations  743  become occluded by materials. 
         [0076]    While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described herein as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. 
         [0077]    Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system modules and components in the embodiments described herein should not be understood as requiring such separation in all embodiments, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products. 
         [0078]    Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims.