Patent Abstract:
Cross stream thrombectomy catheter and system for fragmentation and removal of thrombus or other material from blood vessels or other body cavities. High velocity saline jets emitted from a toroidal loop jet emanator or other jet emanator in a catheter distal end entrain fluid through inflow orifices, and with flow resistances create a back-pressure which drives cross stream streams through outflow orifices in a radial direction and thence radially and circumferentially to apply normal and drag forces on thrombotic deposits or lesions in the blood vessel or other body cavity, thereby breaking apart and transporting thrombus particles to be entrained through the inflow orifices, whereupon the high velocity jets macerate the thrombus particles which then transit an exhaust lumen or recirculate again via the outflow orifices.

Full Description:
CROSS REFERENCES TO CO-PENDING APPLICATIONS 
     This application is a division of application Ser. No. 09/417,395 filled Oct. 13, 1999; now U.S. Pat. No. 6,676,627 which is a CIP of Ser. No. 08/349,665 filed Dec. 5, 1994, now U.S. Pat. No. 6,558,366 which is a division of Ser. No. 08/006,076 filed Jan. 15, 1993, U.S. Pat. No. 5,370,609; which is a continuation of Ser. No. 07/563,313 filed Aug. 6, 1990, abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to apparatus for use in treatment of the human body. More particularly, the present invention relates to an elongated device which may be a single catheter assembly or a multiple component catheter assembly and which is suitable for use through percutaneous or other access, for endoscopic procedures, or for intraoperative use in either open or limited access surgical procedures. Still more particularly, the present invention relates to an elongated device in the form of a waterjet thrombectomy catheter, hereinafter termed cross stream thrombectomy catheter, for fragmentation and removal of thrombus or other unwanted material from blood vessels or body cavities that uses high velocity saline (or other suitable fluid) jets to macerate the thrombus or other unwanted material. The elongated device bears certain similarities to known waterjet thrombectomy catheter constructions but differs therefrom in several material respects, a major distinction being in the provision of means which produce cross stream jets to create a recirculation flow pattern optimized for clearing a large cross section of mural thrombus or other similar material, the name cross stream thrombectomy catheter deriving from this major distinction. Further, the present invention also relates to a system constituted either by the combination of the elongated device with both pressurized fluid source means and exhaust regulation means or by the combination of the elongated device with only pressurized fluid source means. 
     2. Description of the Prior Art 
     Waterjet thrombectomy catheters have been described in which a distal-to-proximal-directed waterjet (s) flow(s) past a window, orifice or gap at the distal end of the catheter, reentering the catheter and pushing flow through an evacuation lumen. When placed in a vessel containing thrombus and activated, the high velocity jet(s) will entrain surrounding fluid and thrombus into the window, orifice or gap region, where the high shear forces of the jet(s) will macerate the thrombus. The macerated particles will be removed from the body by the pressure generated on the distal end of the evacuation lumen by the impingement of the high velocity waterjet(s). 
     A limitation of these waterjet thrombectomy catheters has been the inability to remove organized, wall-adherent thrombus from large vessels. In accordance with the present invention, a cross stream thrombectomy catheter is described which overcomes this limitation by optimizing the recirculation pattern at the tip of the catheter to increase the drag force exerted on the mural thrombus to break it free from the vessel wall and allow it to be removed by the catheter. 
     SUMMARY OF THE INVENTION 
     The thrombectomy effect of waterjet thrombectomy catheters has been described as using the Venturi effect to create suction at the tip of the catheter to draw thrombus into the waterjets where it is then macerated and evacuated through an exhaust lumen. However, when operating in a relatively large blood vessel, the fluid velocities in the vessel decrease rapidly as the distance from the jet increases, so that at the wall of the vessel there is a minimal amount of pressure gradient to push the thrombus towards the low pressure area of the catheter. Thus, a different force is needed to remove mural thrombus, and that source is fluid drag. Drag on a surface is proportionate to the velocity gradient at that surface. Thus, in order to maximize the drag force, the velocity gradient at the surface must be maximized. 
     The catheter described herein is provided with outflow means and inflow means and is designed to optimize the drag force on the surface of the vessel by synergistically utilizing inflows and outflows at the catheter tip to create a recirculation pattern. Since the blood vessel can be considered as an open system, the geometric arrangement of the outflow means and inflow means is critical to the maximization of the drag force at the wall of the vessel. Since the catheter is designed to be easily advanced axially through a blood vessel, and axial flows are more likely to dissipate before contributing greatly to recirculation, the flow vectors in the recirculation most important for creating efficient thrombectomy are in the circumferential and radial direction. Radial high velocity flow vectors are created by maximizing the flow through one or more outflow orifices where the one or more outflow orifices are designed to aim the flow perpendicular to the axis of the catheter. Circumferential high velocity flow vectors are created by the demand for entrained fluid by one or more inflow orifices and are supplied substantially from the one or more outflow orifices, with change in fluid flow direction near the vessel wall to return to the catheter. 
     In the preferred embodiment of the catheter, there is provided inflow means in the form of one or more inflow orifices located in an exhaust tubular means adjacent and proximal to a jet emanator means in the form of a toroidal loop jet emanator located distally on a jet body. One or more high velocity saline (or other suitable fluid) jets emanate from the toroidal loop jet emanator; these high velocity jet(s) entrain fluid, drawing flow into the inflow orifices, and can macerate thrombus drawn near the jet(s). One or more of the high velocity jets can be oriented to aid in the exhaust of macerated thrombotic material through the exhaust tubular means. Multiple inflow orifices may be formed around the circumference of the exhaust tubular means in a single axial plane. An oval-shaped inflow orifice in which the major axis lies parallel to the axis of the catheter is preferred to offer an inflow orifice as large as possible without compromising the area for inflow and the structure of the exhaust tubular means. There is also provided outflow means in the form of one or more outflow orifices located in the exhaust tubular means near the one or more inflow orifices. Multiple outflow orifices may be formed around the circumference of the exhaust tubular means in a single axial plane. Preferably, the outflow orifice(s) are located proximal to the inflow orifice(s). The outflow orifice(s) are usually located but not are limited to being located in close proximity to the inflow orifice(s). The size and quantity of the outflow orifices are determined to maximize the momentum leaving the outflow orifices while not compromising the structural integrity of the exhaust tubular means. The high velocity jets and entrained fluid create an internal pressure near the tip of the catheter. This internal pressure is partially “vented” by the outflow orifice(s). Too small of an area of the outflow orifice(s) will minimize the outflow flow rate and risk plugging of the orifice(s) by macerated thrombotic material, whereas too large of an outflow area will weaken the radial flow vector of the outflow and may reduce the ability of the catheter to exhaust the macerated thrombotic material by allowing the internal pressure at the tip to be reduced to the point that there is no driving force for the exhaust. An alternative embodiment can be made in which outflow and inflow orifices are located in the same axial plane, where the direction of flow through the orifices is determined by fluid mechanical factors, e.g., non-symmetric distributions of jets near the orifices. While single inflow and outflow orifices (or a combination inflow/outflow orifice) can be used, having multiple inflow and outflow orifices helps to create effective recirculation on all sides of the catheter, avoiding the problem of having a single orifice blocked by the vessel wall or being oriented away from the deposit. 
     Though not required for most applications, isolation means can be utilized, either incorporated into the catheter, or as a separate device, to isolate the portion of the blood vessel near the catheter tip during use. Isolation means can include balloons, filters, baskets, membranes, blood pressure modification, fluid flow control, or other occlusion devices such as are known in the art. Isolation means can limit passage of debris in the blood vessel, limit the flow of blood in the area of the catheter, or confine the recirculation area near the catheter tip. 
     The preferred operation mode of the device is such that the exhaust is regulated to be equivalent to the flow rate of the high velocity saline supply. Another embodiment of the device can be one in which no exhaust is designed in the catheter, so that it becomes one that macerates the thrombus into particles small enough to pass through the distal vasculature without significant blockage. 
     The preferred embodiment of the catheter also uses a radio-opaque marker coil aligned in a tapered and flexible tip assembly welded or otherwise suitably attached to the toroidal loop jet emanator at the distal end of the jet body. The radio-opaque marker coil is imbedded in the wall of the tapered and flexible tip in alignment with an exhaust lumen in the exhaust tubular means to provide structural integrity to the device so that the orientation of the jet(s) with respect to the inflow orifice(s) remains constant as the device is advanced and torqued in the anatomy. This tapered flexible radio-opaque marker coil tip can also be used as a flexible base in which a preferentially shaped tip can be mechanically or adhesively affixed so as to produce an atraumatic tip which could also aid in tracking and insertion. 
     Alternative embodiments of the present invention include jet emanator means having jet orifice(s) in a formed tubular passage, but the tubular passage is not formed into a toroidal loop as in the preferred embodiment. The formed tubular passage can be a metal tube bent into a “J”, “L” or “U” shape, or a manifold or other chamber with at least one orifice through which fluid emanates as jet(s). The key features of inflow orifice(s) through which fluid passes as it is entrained by the jet(s), and the outflow orifice(s) through which some of this entrained fluid flows, provides non-axial flow for increased recirculation, and drag again provides enhanced thrombus removal. 
     One significant aspect and feature of the present invention is a thrombectomy catheter having cross stream from one or more outflow orifices for recirculating, creating normal and drag forces, and displacing the thrombus off the vessel wall and into one or more inflow orifices and having high velocity jets for macerating the thrombus. 
     Another significant aspect and feature of the present invention is the flow of the outflow jet(s) in a radial direction followed by circumferential flow whereupon which entrained thrombotic particles enter the inflow orifice(s) to be further macerated and exhausted through an exhaust lumen. 
     An optional feature of the present invention is a tapered and flexible tube assembly secured to a toroidal loop jet emanator at one end of a hypo-tube to maintain orientation of a jetted solution in an exhaust lumen and with respect to the inflow orifice(s) as the device is advanced and torqued in the anatomy. 
     Another significant aspect and feature of the present invention is the entrainment of fluid by the high velocity jet(s) through one or more inflow orifices providing a source of additional flow and a localized region of higher pressure for driving flow outward through one or more outflow orifices. This flow, and the associated recirculation and drag forces, provide a synergistic effect which greatly increases the effectiveness of the device over what would be expected without the flow recirculation. 
     Another significant aspect and feature of the present invention is that the aforementioned flow via the outflow orifice(s) provides the enhanced effectiveness without the need for complicated, expensive, or space consuming additional components, tubings or passageways. The enhanced effectiveness resulting from inflow and outflow orifices, improved recirculation, and vessel wall drag can extend the useful range of the device; the greatly enhanced ability to remove blood vessel deposits can allow lower source pressures to be used than otherwise would be required; and improved function provides for useful application in larger vessels or cavities than would otherwise be practical, even with a small, flexible catheter. 
     Another significant aspect and feature of the present invention is that recirculation via the inflow orifice(s) provides improved function without damage to the vessel wall which could be caused by a large opening adjacent the jet(s) allowing the vessel wall to be pulled into the large opening. The device offers enhanced effectiveness without significant trauma to the vessel wall, even when operated at high pressures, with 10,000 cm/s to 25,000 cm/s jet velocities, for example. 
     Having thus described embodiments of the present invention, it is the principal object of the present invention to provide a cross stream thrombectomy catheter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein: 
     FIG. 1A illustrates in block diagram form a cross stream thrombectomy catheter system according to one embodiment of the present invention showing the interrelation of the various functional means thereof; 
     FIG. 1B illustrates a side view of an elongated device in the from of a cross stream thrombectomy catheter with provision for exhaust; 
     FIG. 2 illustrates an exploded view in cross section of the distal end of the cross stream thrombectomy catheter; 
     FIG. 3 illustrates an assembled view in cross section of the distal end of the cross stream thrombectomy catheter; 
     FIG. 4 a  illustrates an isometric view of a toroidal loop jet emanator; 
     FIG. 4 b  illustrates an isometric view of a semi-toroidal loop jet emanator; 
     FIG. 4 c  illustrates an isometric view of an L-shaped jet emanator; 
     FIG. 4 d  illustrates an isometric view of a J-shaped jet emanator having jet orifices located on the J-shaped proximal facing surface; 
     FIG. 4 e  illustrates an isometric view of a J-shaped jet emanator having a jet orifice located at the jet emanator extreme end; 
     FIG. 4 f  illustrates an isometric view of a J-shaped jet emanator having a necked-down portion and co-located orifice; 
     FIG. 4 g  illustrates an isometric view of a J-shaped jet emanator having an inserted tubular orifice member; 
     FIG. 5 illustrates a mode of operation view of the cross stream thrombectomy catheter positioned in a blood vessel, artery or the like at the site of a thrombotic deposit or lesion; 
     FIG. 6 illustrates the cross stream of saline jets from the outflow orifice(s) to the inflow orifice(s); 
     FIG. 7, a first alternative embodiment, illustrates a side view showing the distal end of an exhaust tube having a single-opening dual-function orifice; 
     FIG. 8 illustrates a cross section view of the first alternative embodiment showing the distal end of the exhaust tube; 
     FIG. 9, a second alternative embodiment, illustrates a cross section view showing the distal end of an exhaust tube having a tip with a proximally facing planar surface and also showing a single-orifice U-shaped jet emanator aligned with an inflow orifice located at the end of the exhaust tube; 
     FIG. 10 illustrates an end view of the second alternative embodiment shown in FIG. 9; 
     FIG. 11 illustrates a view of the tip at the distal end of the exhaust tube along line  11 — 11  of FIG. 9; 
     FIG. 12, a third alternative embodiment, illustrates a cross section view showing the distal end of an exhaust tube having a tip with a proximally facing curved surface and also showing a single-orifice U-shaped jet emanator aligned with an inflow orifice located at the end of the exhaust tube; 
     FIG. 13 illustrates an end view of the third alternative embodiment shown in FIG. 12; 
     FIG. 14 illustrates a view of the tip at the distal end of the exhaust tube along line  14 — 14  of FIG. 12; 
     FIG. 15, a fourth alternative embodiment, illustrates a cross section view showing the distal end of an exhaust tube and showing a toroidal loop jet emanator aligned to an inflow orifice located at the end of the exhaust tube; 
     FIG. 16 illustrates an end view of the fourth alternative embodiment shown in FIG. 15; 
     FIG. 17 illustrates a view of the tip at the distal end of the exhaust tube along line  17 — 17  of FIG. 15; 
     FIG. 18, a fifth alternative embodiment, illustrates a side view of an elongated device in the form of another cross stream thrombectomy catheter similar to that of FIG. 1, but without exhaust provision; and, 
     FIG. 19 is a cross section view of the distal end of the cross stream thrombectomy catheter of FIG.  18 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1A illustrates in block diagram form a cross stream thrombectomy catheter system according to one embodiment of the present invention showing the interrelation of the various functional means thereof for use in removing thrombus or other unwanted material from a body vessel or cavity. 
     The major components of the system include an elongated device in the form of a cross stream thrombectomy catheter, a pressurized fluid source means, and, optionally, an exhaust regulation means connected to a collection system (not shown). 
     The elongated device includes first and second tubular means each having a proximal end and a distal end. The first tubular means is in the form of a high pressure tubular means having pressurized fluid connection means providing a fluid connection permanently or detachably coupled to its proximal end and jet emanator means at its distal end, the pressurized fluid connection means being connectible to the pressurized fluid source means. The second tubular means is in the form of either an exhaust tubular means, as shown, or other tubular means (not shown in FIG. 1A but described in detail in relation to FIGS. 18 and 19) which serves as an alternative to an exhaust tubular means in those instances when exhausting is not necessary or desired. When in the form of an exhaust tubular means, the second tubular means is usually associated with exhaust regulation means, although an exhaust regulation means is not essential. Whether in the form of an exhaust tubular means or other tubular means, the second tubular means includes outflow means and inflow means which in concert with high velocity jet(s) produced by the jet emanator means create cross stream jet(s) that establish a flow recirculation pattern. 
     The outflow means consists of one or more outflow orifices through which saline, blood or other fluid or a mixture thereof with macerated thrombus or other unwanted material debris flows from a region of higher pressure within the exhaust tubular means or other tubular means to outside the exhaust tubular means or other tubular means. The outflow orifices(s) are typically somewhat downstream from the high velocity region of the high velocity jet(s) where the velocities are lower and the mass flow rate is greater due to entrained fluid; and flow of fluid with or without macerated debris typically flows through the outflow orifice(s) with a component in the radial direction, creating cross stream jet(s). The outflow orifices may be round, elliptical, conical, slits, gaps between components, or other shape or design. 
     The inflow means consists of one or more inflow orifices through which the high velocity jet(s) draw in by fluid entrainment blood or other fluid from a body vessel or cavity, including thrombus or other unwanted material which may be present in the blood or other fluid. The inflow orifice(s) are typically near the high velocity region of the high velocity jet(s) where entrainment forces are great. The inflow orifices may be round, elliptical, conical, slits, gaps between components, or other shape or design. 
     The high pressure tubular means comprises an elongated structure having at least one passage or lumen along the length thereof suitable for passage of high pressure fluid. The elongated structure can be tubing with a circular or non-circular cross section and can be made of high strength polymeric material such as polyimide, metallic material such as stainless steel or titanium, or composite material such as fiber-reinforced material or a layered structure composed of layers of different materials. 
     The exhaust tubular means comprises an elongated structure having at least one passage or lumen along the length thereof suitable for passage of fluid and thrombus or other unwanted material debris. The elongated structure can be tubing with a circular or non-circular cross section and can be made of polymeric material such a polyethylene, polyester, polyurethane, or polyether block amide, high strength polymeric material such as polyimide, metallic material such as stainless steel or titanium, or composite material such as fiber-reinforced polymeric material or a layered structure composed of layers of different materials. Further, the elongated structure may have an attached structure near its distal end such as a chamber or manifold to accommodate the outflow means and the inflow means. 
     The other tubular means comprises an elongated structure having at least one passage or lumen along the length thereof suitable for passage of fluid. The elongated structure can be tubing with a circular or non-circular cross section or may resemble a shorter chamber such as a manifold, molded or constructed of multiple components. Suitable materials for the other tubular means are polymeric material such as polyethylene, polyester, or polyurethane, high strength polymeric material such as polyimide, metallic material such as stainless steel or titanium, or composite material such as fiber-reinforced polymeric material or a layered structure composed of layers of different materials. 
     If desired, isolation means (not shown) can be provided as part of the elongated device to isolate the region of the body vessel or cavity being treated, although this is not always required. Isolation means can include balloons, filters, baskets, membranes, blood pressure modification, fluid flow control, or other occlusion devices such as are known in the art. Isolation means can limit passage of debris in the blood vessel, limit the flow of blood in the area of the elongated device, or confine the recirculation area. Also if desired, additional tubular means can be provided for communication between the proximal end and the distal end of the elongated device, such as for passage of fluid or other material or for passage of devices such as guidewires, catheters, or imaging tools, or for actuation of isolation means, for inflation of a balloon, or for passage of medication or body fluids. The additional tubular means (not shown) comprises an elongated structure having at least one passage or lumen along the length thereof; for example, the elongated device can include a multiple-lumen tube, in which one lumen functions as the high pressure tubular means, a second lumen functions as the exhaust tubular means, and one or more additional lumens function as the additional tubular means which communicates between the proximal and distal ends of the elongated device. 
     The pressurized fluid source means includes fluid such as saline and one or more pumps or pressure intensifiers or pressurized fluid containers for delivering the fluid under pressure to the high pressure tubular means through the pressurized fluid connection means coupled to the proximal end thereof. The fluid can be provided at a single pressure or at multiple pressures, at variable or adjustable pressure, and at a steady flow or unsteady flow such as pulsatile flow. 
     The exhaust regulation means, when present, comprises structural components which increase, decrease, limit, or adjust the rate of flow of fluid and thrombus or other unwanted material debris along the exhaust tubular means and can be one or more pumps such as roller pumps or peristaltic pumps, clamps, restrictors, or other devices to influence the fluid flow rate. The exhaust regulation means can regulate exhaust at a predetermined or user-adjustable flow rate which can be correlated with or independent of the rate of flow of the pressurized fluid flowing along the high pressure tubular means. Further, the exhaust regulation means can have pressure measurement or flow rate measurement capabilities. The exhaust regulation means is connected to a suitable collection system (not shown). 
     The system is placed in operation by inserting the elongated device into a body vessel or cavity and advancing it to a site of thrombus or other unwanted material in the body vessel or cavity. Then the proximal end of the elongated device is connected to the pressurized fluid source means which provides pressurized saline (or other biologically compatible fluid) to the proximal end of the high pressure tubular means via the pressurized fluid connection means. At the distal end of the high pressure tubular means, pressurized saline (or other fluid) passes into the jet emanator means which produces high velocity saline (or other fluid) jet(s). The high velocity saline (or other fluid) jet(s) entrain blood or other fluid from the body vessel or cavity and draw it into the distal portion of the elongated device through the inflow means, carrying thrombus or other unwanted material from the body vessel or cavity along with the blood or other fluid. The high velocity saline (or other fluid) jet(s) together with the entrained blood or other fluid create a region of elevated pressure in the elongated device; this region of elevated pressure communicates with or is a part of the distal portion of the exhaust tubular means. The elevated pressure in the elevated pressure region drives fluid flow through the outflow means, creating cross stream jet(s) which have a radial component and may have circumferential and/or axial component(s) as well. The fluid in the elevated pressure region includes saline (or other fluid) from the high velocity jet(s) as well as the entrained blood or other fluid from the body vessel or cavity. The cross stream jet(s) impart normal and drag forces on thrombus or other unwanted material in the body vessel or cavity and greatly improve the effectiveness of the device in removing and breaking apart thrombus or other unwanted material which may be adhered to the body vessel or cavity, and form a recirculation pattern which further aids in drawing thrombus or other unwanted material towards the inflow means. The combination of outflow means, cross stream jet(s), recirculation pattern, inflow means, and high velocity jet(s) synergistically acts to provide for enhanced breakup and removal of thrombus or other unwanted material. The elevated pressure in the elevated pressure region can also aid in the transport of fluid and thrombus or other unwanted material debris through the exhaust tubular means. If desired, the rate of flow of fluid and thrombus or other unwanted material regulated by providing exhaust regulation means, although this is not always required. 
     FIG. 1B illustrates a side view of an elongated device in the form of a cross stream thrombectomy catheter with exhaust provision  10  useful for the removal of thrombus. Externally visible components, or portions of components, of the cross stream thrombectomy catheter  10  include a manifold  12 , a hemostasis unit  14  secured in the proximal end of the manifold  12 , pressurized fluid connection means in the form of a threaded high pressure connection  11  and a Luer fitting  16  located at the proximal end of an angled manifold branch  18  extending from the manifold  12  for coupling to the pressurized fluid source means, a Luer connection  20  for coupling to exhaust regulation means located at the proximal end of another angled manifold branch  22  extending from the manifold branch  18 , a Luer fitting  24  secured to the distal end of the manifold  12 , a strain relief  26  secured to the distal end of the manifold  12  by the Luer fitting  24 , exhaust tubular means in the form of an exhaust tube  28  having a proximal end  30  secured to the manifold  12  by the strain relief  26  and Luer fitting  24 , outflow means in the form of one or more distally located outflow orifices  32  at the distal end  38  of the exhaust tube  28 , inflow means in the form of one or more distally located inflow orifices  34  at the distal end  38  of the exhaust tube  28 , and a tapered and flexible tip assembly  36  located at and aligned to and attached, as later described and illustrated, to the distal end of a jet emanator means in the form of a toroidal loop jet emanator residing in as well as being attached to the distal end  38  of the exhaust tube  28 . 
     FIGS. 2 and 3 illustrate an exploded view and an assembled view in cross section of the distal end  38  and other distally located components of the cross stream thrombectomy catheter  10 , respectively, where all numerals mentioned before correspond to those elements previously described. The primary two components of the cross stream thrombectomy catheter  10  are first and second tubular means, the first being a high pressure tubular means made of metal or high tensile strength polymer or composite material and shown in the form of a hypo-tube  44  formed into a jet body  40 , and the second being in the form of an exhaust tubular means made of a flexible polymer and shown in the form of an exhaust tube  28  having a centrally located exhaust lumen  42 . The jet body  40  is formed from a small hypo-tube  44  with a size range of 0.010 to 0.030 inch outer diameter. The distal portion of the hypo-tube  44  may be reduced to a small diameter as shown by reduction  43  (FIG. 2) to make the catheter more flexible by drawing the hypo-tube  44  through a die. The distal end of the hypo-tube  44  is then welded shut and the end formed into a toroidal loop jet emanator  46  or a jet emanator of other shape which will provide a surface in which proximally directed jet orifices  60   a - 60   n  (FIG. 4 a ), ranging from 0.001 to 0.010 inch in diameter, may be formed that will direct jetted saline or other body-compatible solution including mixtures of saline and medications or mixtures of saline and a contrast medium in a flow at or close to a path parallel to and in the opposite direction of the fluid flow in the interior of the hypo-tube  44  of the jet body  40 . Alternatively, the jet body  40  may be of a short length and connected to a more flexible polymeric tube  45  (FIG. 3) in lieu of having a jet body  40  which extends proximally for the majority of the distance to the manifold  12 . A radio-opaque marker coil  48  in the form of a stainless steel or platinum alloy coil, for example, may be adhered to the end of the jet body  40  and other components, as later described in detail. 
     The jet body  40 , which has a smaller axial profile than that of the exhaust lumen  42 , is inserted through and located within the exhaust lumen  42 . The exhaust lumen  42  is central to the exhaust tube  28 , which could also have multiple lumens, which has an outer diameter ranging from 0.030 to 0.150 inch, and which is also flexible and similar to the hypo-tube  44  in that it may be reduced to a smaller diameter to make the catheter more flexible by drawing through a die. The tapered and flexible tip assembly  36  includes a flexible plastic tapered tube  37  which encapsulates and surrounds the radio-opaque marker coil  48 , which has a closely wound portion  54  and a loosely wound portion  56 . Alternatively, the radio-opaque marker coil  48  can have uniform wind spacing, or can be omitted in favor of a polymeric tip. 
     A mechanical bond can be made between the distal tip of the jet body  40  at the junction of the toroidal loop jet emanator  46  and the exhaust lumen  42 . For example, thermal and partial melting of the tapered distal tip  52  of the polymer exhaust tube  28  partially encapsulates the toroidal loop jet emanator  46  or other distal shape of the jet body  40 . Thermal melting can also be incorporated to join the interior wall  57  of the exhaust tube  28  to the proximal area  59  of the tapered tube  37  whereby further heat transfer and melting can also encapsulate and join the closely wound portion  54  and the loosely wound portion  56  of the radio-opaque marker coil  48  to the interior wall  58  of the tapered tube  37 . In the alternative, an adhesive can also be incorporated to join the toroidal loop jet emanator  46  to the interior of the exhaust tube  28  and to the proximal portion of the closely wound spring portion  54  and to the proximal area  59  of the tapered tube  37 . Multiple inflow and outflow orifices can be formed anywhere as desired along the length of exhaust tube  28 , either before or after the loading of the jet body  40 , preferably in the distal portion, which as described below includes inflow and outflow orifices  34  and  32 , respectively. Although the preferred embodiment of the catheter is made with multiple outflow and inflow orifices  32  and  34 , a substantially equivalent catheter could be designed such that the catheter has only one extended orifice, but separate regions in that one orifice provide inflow and outflow of fluid. Preferably, the inflow and outflow orifices  34  and  32  are oval or round in shape, but they can be of other suitable geometric configuration or shape. 
     FIGS. 4 a  through  4   g  illustrate jet emanator means which may be utilized at the end of and which are located at the distal end of the jet body  40 , each of which directs high velocity jet streams proximally along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . Each jet emanator means comprises a tubular structure through which pressurized fluid flows creating high velocity fluid jets which emanate from one or more orifices in the tubular structure. The tubular structure can be of straight, curved, L-shaped, J-shaped, U-shaped, helical, toroidal or semi-toroidal shape, or can be a chamber such as a manifold, and may be formed of a single component, such as a metal hypo-tube, or of multiple components, such as multiple hypo-tubes, welded manifold components, or molded manifold components. The tubular structure forming the jet emanator means may be formed as a unitary part of the high pressure tubular means such as by forming a metal hypo-tube into a toroidal shape, or one of the other shapes mentioned above, with a single orifice or multiple orifices produced by drilling or cutting. The orifices can be round, slits, or other shapes so that fluid flowing therethrough forms one or more discrete high velocity fluid jets or merges into combination jets. Alternatively, the tubular structure forming the jet emanator means may be a separate structure having any one of the aforementioned shapes and orifice constructions which is attached to the distal end of the high pressure tubular means. In either event, the tubular structure forming the jet emanator means is in fluid communication with the high pressure tubular means. In each figure, highly pressurized fluid(s) first passes through a lumen  41  enroute to the variously shaped and configured distally located jet emanator means located at the end of the jet body  40 . 
     FIG. 4 a  illustrates an isometric view of the toroidal loop jet emanator  46 , one jet emanator means of which may be utilized at the end of and which is located at the distal end of the jet body  40 , where all numerals mentioned before correspond to those elements previously described. Illustrated in particular are the plurality of proximally directed jet orifices  60   a - 60   n  located on the proximal surface of the toroidal loop jet emanator  46  which direct high velocity jet streams proximally, as shown by dashed lines, along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . The toroidal loop jet emanator  46  includes a circular space  50  along the inner circumference to provide for and to accommodate alignment of and for passage along a guidewire, such as the guidewire  51  shown partially in FIG.  5 . Multiple jet orifices  60   a - 60   n  located at points along the toroidal loop jet emanator  46  can advantageously direct high velocity jet streams on multiple sides of the guidewire  51  when it is positioned in the circular space  50  to avoid having guidewire  51  block inflow orifice(s)  34  or outflow orifice(s)  32  which could hamper the recirculation pattern, such as that shown in FIGS. 5 and 6. 
     FIG. 4 b  illustrates an isometric view of a semi-toroidal loop jet emanator  62 , another jet emanator means of which may be utilized at the end of and which is located at the distal end of the jet body  40 , where all numerals mentioned before correspond to those elements previously described. Illustrated in particular are the plurality of proximally directed jet orifices  64   a - 64   n  located on the proximal surface of the semi-toroidal loop jet emanator  62  which direct high velocity jet streams proximally, as shown by dashed lines, along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . The semi-toroidal loop jet emanator  62  includes a semi-circular space  66  along the inner circumference to provide for and to accommodate alignment of and for passage along a guidewire. 
     FIG. 4 c  illustrates an isometric view of an L-shaped jet emanator  68 , another jet emanator means of which may be utilized at the end of and which is located at the distal end of the jet body  40 , where all numerals mentioned before correspond to those elements previously described. Illustrated in particular is a proximally directed jet orifice  70  located on the proximal surface of the L-shaped jet emanator  68  which directs a high velocity jet stream proximally, as shown by a dashed line, along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . 
     FIG. 4 d  illustrates an isometric view of a J-shaped jet emanator  72  having jet orifices located on the J-shaped proximal facing curved surface, another jet emanator means of which may be utilized at the end of and which is located at the distal end of the jet body  40 , where all numerals mentioned before correspond to those elements previously described. The J-shaped jet emanator  72  and the jet body  40  and hypo-tube  44  align in a common plane. Illustrated in particular is a plurality of proximally directed jet orifices  74   a - 74   n  located on the proximal curved surface of the J-shaped jet emanator  72  which direct high velocity jet streams proximally, as shown by dashed lines, along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . 
     FIG. 4 e  illustrates an isometric view of a J-shaped jet emanator  75  having a jet orifice located at the emanator end, being another jet emanator means of which may be utilized at the end of and which is located at the distal end of the jet body  40 , where all numerals mentioned before correspond to those elements previously described. The J-shaped jet emanator  75  and the jet body  40  and hypo-tube  44  align in a common plane. Illustrated in particular is a proximally directed jet orifice  77  located at the extreme end  79  of the J-shaped jet emanator  75  which directs a high velocity jet stream proximally, as shown by a dashed line, along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . The extreme end  79  preferably is first welded shut to form a dome or other suitably shaped structure which is drilled or bored to form the appropriately sized jet orifice  77 . 
     FIG. 4 f  illustrates an isometric view of a J-shaped jet emanator  81  having a necked-down region and co-located orifice, another jet emanator means of which may be utilized at the end of and which is located at the distal end of the jet body  40 , where all numerals mentioned before correspond to those elements previously described. The J-shaped jet emanator  81  and the jet body  40  and hypo-tube  44  and a necked-down portion  89  align in a common plane. Illustrated in particular is a proximally directed jet orifice  83  located at the extreme end  87  of the necked-down portion  89  of the J-shaped jet emanator  81  which directs a high velocity jet stream proximally, as shown by a dashed line, along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . The necked-down portion  89  is appropriately drawn, formed and/or sized to produce an appropriately sized jet orifice  83 . 
     FIG. 4 g  illustrates an isometric view of a J-shaped jet emanator  91  having an inserted tubular orifice member, another jet emanator means of which may be utilized at the end of and which is located at the distal end of the jet body  40 , where all numerals mentioned before correspond to those elements previously described. The J-shaped jet emanator  91  and the jet body  40  and hypo-tube  44  align in a common plane. The J-shaped jet emanator  91  includes a housing  93  which is part of and which extends proximally from the curved region of the J-shaped jet emanator  91 . The housing  93  accommodates within an appropriately sized tubular orifice member  95  which directs a high velocity jet stream proximally, as shown by a dashed line, along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . 
     MODE OF OPERATION 
     FIG. 5 illustrates in cross section a mode of operation view of the cross stream thrombectomy catheter  10  with particular attention to the distal end  38  of the exhaust tube  28  positioned in a blood vessel  76 , artery or the like at the site of a thrombotic deposit or lesion  78 . High velocity jets  80  of saline (or other suitable fluid) are shown being emitted in a proximal direction from the toroidal loop jet emanator  46 . The semi-toroidal loop jet emanator  62  of FIG. 4 b , L-shaped jet emanator  68  of FIG. 4 c , the J-shaped jet emanator  72  of FIG. 4 d , the J-shaped jet emanator  75  of FIG. 4 e , the J-shaped jet emanator  81  of FIG. 4 f , or the J-shaped emanator  91  of FIG. 4 g  can be incorporated at the distal portion of the jet body  40 , as well as and as an alternative to the toroidal loop jet emanator  46  illustrated in this figure, to emanate or emit one or more high velocity jets  80  distally along or near the longitudinal axis of the jet body  40  and the exhaust tube  28 . The saline fluid of jet(s)  80  passes outwardly through the outflow orifice(s)  32  in a radial direction creating cross stream jet(s)  82  (lower velocity jet(s)) directed outwardly toward the wall of the blood vessel  76  and are influenced by the low pressure at the inflow orifice(s)  34  to cause the cross stream jet(s)  82  to flow circumferentially and distally to impinge on, provide drag forces on, and break up thrombotic deposits or lesions  78  and to, by entrainment, urge and carry along the particles of thrombotic deposits or lesions  78  through the inflow orifice(s)  34 , a relatively low pressure region, and into the exhaust lumen  42 . The entrainment through the inflow orifice(s)  34  is based on entrainment by the high velocity jet(s)  80 . The outflow is driven by internal pressure which is created by the high velocity jet(s)  80  and the fluid entrained through the inflow orifice(s)  34 . The enhanced clot removal is because of the recirculation pattern established between inflow and outflow orifices  34  and  32 , which creates a flow field that maximizes drag force on wall-adhered thrombus. 
     FIG. 6 illustrates in cross section the mode of operation view illustrating the cross stream jet(s)  82  (or stream(s)) and the recirculation pattern. For the purpose of clarity, the illustration shows the outflow orifice(s)  32  and the inflow orifice(s)  34  at the same station along the exhaust tube  28 . Shown in particular is the flow of the cross stream jet(s)  82  which flow outwardly in radial fashion from the outflow orifice(s)  32  to impinge thrombotic deposits or lesions  78  and to urge and carry macerated thrombotic deposits or lesion particles  78  to the inflow orifice(s)  34  where the particles of thrombotic deposits or lesions  78  are entrained by the high velocity jet(s)  80  (not shown) and carried away through the exhaust lumen  42 . Circumferential flow occurs along and substantially parallel to the inner boundary of the blood vessel  76  in a direction leading to the inflow orifice(s)  34 . 
     MODE OF OPERATION 
     A manifold is attached to the tubular assembly on the proximal end to allow connection of the hypo-tube  44  of the jet body  40  to a 10 to 200 cc/min supply of saline (or other suitable fluid) at a back pressure in the range of approximately 150 psi to 50,000 psi, and to allow connection of exhaust lumen  42  to tubing attached to a collection system, preferably with exhaust regulation means involved to control the level of the exhaust. Suitable specific pressure ranges for the supply fluid can be approximately 150-500 psi, approximately 500-2,500 psi, or approximately 2,500-50,500 psi, depending on the particular situation involved. 
     The catheter is operated by injection with the high pressure saline supply through the threaded high pressure connection  11 . The saline flows through the jet body  40  and into the jet emanator means wherein, depending on the supply pressure, it exists in pressure ranges of approximately 50-350 psi, 350-850 psi, or 850-35,000 psi. The saline exits the jet orifice(s)  60   a - 60   n  at a maximum instantaneous centerline velocity of approximately 2,000 to 30,000 cm/s, preferably 7,000 cm/s to 20,000 cm/s, and passes near at least one of the inflow orifice(s)  34  of the exhaust lumen  42 . Since the catheter is operated in liquid media within the body, the saline jet(s)  80  behave as submerged jet(s) in that their momentum is transferred to the surrounding fluid, a phenomena known as entrainment. Due to the geometry of the catheter, the entrained fluid is brought into the inflow orifice(s)  34  in flow rates of 1 to 20 times that of the high velocity saline exiting the jet orifices  60   a - 60   n.    
     Once entrained fluid has entered the inflow orifice(s)  34 , the fluid will take the path of least resistance to exit the catheter. If the catheter were made with no outflow orifice(s)  32  and the exhaust lumen had no hydrodynamic resistance, all the entrained fluid would be exhausted out of the body through the exhaust lumen  42  and into the collection system. However, if there is significant amount of hydrodynamic resistance, either through pipe flow resistance in the exhaust lumen  42  or an exhaust regulation means, not all of the entrained fluid can be exhausted from the catheter. If there were no outflow orifice(s)  32  in the catheter, at least a portion of the inflow orifice(s)  34  will have fluid transported out of the catheter in order to maintain a mass balance of fluid in the catheter (all components of the catheter are incompressible or inelastic so that there is no accumulation of mass in the catheter). 
     The incorporation of outflow orifice(s)  32  in the catheter allows maintenance of the mass balance at the tip of the catheter without a requirement that a portion of the inflow orifice(s)  34  will have fluid transported out of the catheter. The benefit of removing the two-directional flow through the inflow orifice(s)  34  is that friction between the entrained fluid and fluid that is being transported out of the catheter has been eliminated. Thus, both of these flows will be increased by having the outflow orifice(s)  32  incorporated into the catheter to act to greatly enhance the thrombectomy effect of the catheter on organized mural thrombus. 
     FIGS. 7 and 8 illustrate a side view and a cross section view, respectively, of a first alternative embodiment showing distal end  84  of the exhaust tube  28  which can be incorporated into use with the first embodiment of and for use with the majority of the components of the cross stream thrombectomy catheter previously described, where all numerals mentioned before correspond to those elements previously described. Although the preferred embodiment of the catheter includes multiple outflow and inflow orifices  32  and  34 , a substantially equivalent catheter having one or more single opening dual function orifices  85  can be provided, each orifice  85  having separate regions such that one single opening orifice provides for inflow and outflow of fluid. Preferably, the orifice  85  is an elongated shape, but can be of other suitable geometric configuration or shape. FIG. 7 illustrates an elongated and tapered orifice  85  having at one end a semi-circular distally located radiused inflow end  86  corresponding to the inflow orifice  34  and a semi-circular proximally located relatively smaller radiused outflow end  88  corresponding to the outflow orifice  32  opposing the radiused inflow end  86 . A cross stream thrombectomy catheter incorporating the distal end  84  of the exhaust tube  28  operates according to the teachings of the invention with the benefit of simpler and more easily accomplished construction which combines the inflow and outflow orifices into a single opening orifice. Although toroidal loop jet emanator  46  is shown in the embodiment, other jet emanators such the semi-toroidal loop jet emanator  62  of FIG. 4 b , the L-shaped jet emanator  68  of FIG. 4 c , the J-shaped jet emanator  72  of FIG. 4 d , the J-shaped jet emanator  75  of FIG. 4 e , the J-shaped jet emanator  81  of FIG. 4 f , or the J-shaped jet emanator  91  of FIG. 4 g , or other such suitable jet emanator or device can be incorporated into use with this embodiment of the present invention. Flow of the cross stream jet(s)  82  is illustrated in FIG.  7 . 
     FIGS. 9 through 17 illustrate second, third and fourth alternative embodiments of distal ends of the exhaust tube  28  where the inflow orifices are located at the extreme end of the exhaust lumen  42  of the exhaust tube  28  as an alternative to inflow orifice placement on the sidewall of the exhaust tube  28  as previously described, and where use of the tapered and flexible tip assembly  36  is not required. The distal ends are assigned different designator number references in allowance for differently located inflow or outflow orifices or other variances or combinations thereof at or near the distal ends. 
     FIGS. 9 and 10, illustrate a cross section view and an end view, respectively, of a second alternative embodiment showing distal end  90  of the exhaust tube  28  which can be incorporated into use with the manifold  12 , the jet body  40  and the exhaust tube  28  with the exception of the tapered and flexible tip assembly  36  of the first embodiment and is intended for use with the majority of the components of the cross stream thrombectomy catheter previously described, where all numerals mentioned before correspond to those elements previously described. A tip  92  is located at or near the distal end of the jet body  40  and at the distal end  90  of the exhaust tube  28 . The tip  92 , which can be of metallic, polymeric or other suitable material, aligns and suitably secures to the distal end  90  of the exhaust tube  28 . The tip  92  includes a bore  94  which supports the jet body  40 . The jet body  40  extends distally beyond the bore  94  of the tip  92  and forms a U-shaped jet emanator  96  having a single centrally located jet orifice  98 , which is the end of the lumen  41  of the extended jet body  40  making up the U-shaped jet emanator  96 . The jet orifice  98  of the U-shaped jet emanator  96  is directed at an inflow orifice  100  aligned longitudinally and located in the tip  92 . A high velocity jet  102  of saline is emitted in a proximal direction from the jet orifice  98  and through the inflow orifice  100 . Fluid is entrained by the high velocity jet  102  and is thereby drawn through the inflow orifice  100  and driven into the exhaust lumen  42  and mixes with saline from the high velocity jet  102 . Part of this entrained fluid mixed with the saline from the high velocity jet  102  passes outwardly through the outflow orifice  104  in a radial direction creating a cross stream jet  106  (lower velocity jet) directed outwardly toward the wall of a blood vessel and is influenced by the low pressure at the inflow orifice  100  to cause the cross stream jet  106  to flow circumferentially and distally to impinge on, provide drag forces on, and break up thrombotic deposits or lesions and to, by entrainment, urge and carry along the thrombotic deposits or lesions through the inflow orifice  100 , a relatively low pressure region, and into the exhaust lumen  42 . The flow of fluid and thrombotic deposits through the inflow orifice  100  is based on entrainment by the high velocity jet  102 . The outflow through outflow orifice  104  is driven by internal pressure which is created by the high velocity jet  102  and the fluid entrained through the inflow orifice  100 . The enhanced clot removal is because of the recirculation pattern established between inflow and outflow orifices  100  and  104 , which creates a flow field that maximizes drag force on wall-adhered thrombus. Although a U-shaped jet emanator  96  is shown in the embodiment, other jet emanators such as the semi-toroidal loop jet emanator  62  of FIG. 4 b , the L-shaped jet emanator  68  of FIG. 4 c , the J-shaped jet emanator  72  of FIG. 4 d , the J-shaped jet emanator  75  of FIG. 4 e , the J-shaped jet emanator  81  of FIG. 4 f , or the J-shaped jet emanator  91  of FIG. 4 g , or other such suitable jet emanator or device can be incorporated into use with this embodiment of the present invention. 
     FIG. 11 illustrates a view of the tip  92  along line  11 — 11  of FIG. 9, where all numerals correspond to those elements previously described. 
     FIGS. 12 and 13 illustrate a cross section view and an end view, respectively, of a third alternative embodiment which operates according to the teachings of the invention, and more specifically, according to the teachings of FIGS. 9,  10  and  11  and which incorporates many of the components shown in FIGS. 9,  10  and  11 . FIGS. 12 and 13 illustrate a tip  108  having similarities to tip  92  of FIG. 9, but including an inwardly or proximally facing curved surface  112 . The curved surface  112  assists and promotes alignment of a guidewire through an inflow orifice  110  of the tip  108 . The distal end  114  of the exhaust tube  28  including the tip  108  can be incorporated into use with the manifold  12 , the jet body  40  and the exhaust tube  28  with the exception of the tapered and flexible tip assembly  36  of the first embodiment and is intended for use with the majority of the components of the cross stream thrombectomy catheter previously described, where all numerals mentioned before correspond to those elements previously described. The tip  108  is located at or near the distal end of the jet body  40  and at the distal end  114  of the exhaust tube  28 . The tip  108 , which can be of metallic, polymeric or other suitable material, aligns and suitably secures to the distal end  114  of the exhaust tube  28 . The tip  108  includes a bore  115  which supports the jet body  40 . As previously described, the jet body  40  extends distally beyond the bore  115  of the tip  108  to form the U-shaped jet emanator  96  having a single centrally located jet orifice  98  which is the end of the lumen  41  of the extended jet body  40  making up the U-shaped jet emanator  96 . The jet orifice  98  of the U-shaped jet emanator  96  is directed at an inflow orifice  110  aligned longitudinally and located in the tip  108 . A high velocity jet  118  of saline is emitted in a proximal direction from the jet orifice  98  and through the inflow orifice  110  to operate in a manner and fashion such as described for FIGS. 9,  10  and  11 . Although U-shaped jet emanator  96  is shown in the embodiment, other jet emanators such as the toroidal loop jet emanator  46  of FIG. 4 a , the semi-toroidal loop jet emanator  62  of FIG. 4 b , the L-shaped jet emanator  68  of FIG. 4 c , the J-shaped jet emanator  72  of FIG. 4 d , the J-shaped jet emanator  75  of FIG. 4 e , the J-shaped jet emanator  81  of FIG. 4 f , the J-shaped jet emanator  91  of FIG. 4 g , or other such suitable jet emanator or device can be incorporated into use with this embodiment of the present invention. 
     FIG. 14 illustrates a view of the tip  108  along line  14 — 14  of FIG. 12, where all numerals correspond to those elements previously described. 
     FIGS. 15 and 16 illustrate a cross section view and an end view, respectively, of a fourth alternative embodiment showing distal end  122  of the exhaust tube  28  which can be incorporated into use with the manifold  12 , the jet body  40  and the exhaust tube  28  with the exception of the tapered and flexible tip assembly  36  of the first embodiment and is intended for use with the majority of the components of the cross stream thrombectomy catheter previously described, where all numerals mentioned before correspond to those elements previously described. A tip  124  is located at or near the distal end of the jet body  40  and at the distal end  122  of the exhaust tube  28 . The tip  124 , which can be of metallic, polymeric or other suitable material, aligns and suitably secures to the distal end  122  of the exhaust tube  28 . The tip  124  includes a bore  126  which supports the jet body  40 . The jet body  40  extends distally beyond the bore  126  of the tip  124  and forms a toroidal loop jet emanator  128  having a plurality of proximally directed jet orifices  130   a - 130   n . The jet orifices  130   a - 130   n  of the toroidal loop jet emanator  128  are directed at an inflow orifice  132  aligned longitudinally and located in the tip  124 . The high velocity jets  130   a - 134   n  of saline are emitted in a proximal direction from the jet orifices  130   a - 130   n  and through the inflow orifice  132 . Fluid, such as blood and thrombotic debris which may be near the tip  124 , is entrained by the high velocity jets  130   a - 134   n  and is thereby drawn through inflow orifice  132  and acts in a manner and fashion such as described for FIGS. 9,  10  and  11 , such that cross stream jets  106  and recirculation pattern between the outflow orifice  104  and the inflow orifice  132  synergistically enhances thrombus removal. 
     FIG. 17 illustrates a view of the tip  124  along line  17 — 17  of FIG. 15, where all numerals mentioned before correspond to those elements previously described. A circular space  136  along the inner circumference of the toroidal loop jet emanator  128  is provided to accommodate alignment and passage along a guidewire. 
     FIG. 18, a fifth alternative embodiment, illustrates a side view of a cross stream thrombectomy catheter  10 A which is similar to the cross stream thrombectomy catheter  10  of FIG. 1B but without exhaust provision, and therefore does not include the manifold branch  22  and Luer connection  20  which extend from manifold branch  18 . Also, in this fifth alternative embodiment the toroidal loop jet emanator of the FIG. 1B embodiment is not employed, and since no exhaust provision is present, the second tubular means characterized by the exhaust tubular means in the form of the exhaust tube  28  of the FIG. 1B embodiment is characterized by other tubular means in the form of a tube  137  which is similar to the exhaust tube  28  of the FIG. 1B embodiment but which has a distal end  138  of different construction from that of the distal end  38  of the embodiment of FIG.  1 B. Devices of the fifth alternative embodiment operate and function similarly to those of the FIG. 1B embodiment in that a recirculation pattern from outflow orifices  34  to inflow orifices  32  synergistically enhance clot breakup; however, this embodiment does not provide for removal of the thrombus debris through the catheter itself. If desired, thrombus debris can be removed from the body by separate means, such as a separate catheter or by chemical methods. In many cases, such thrombus debris removal would not be necessary since the enhanced clot breakup action of the device produces small debris which can be left in the body. 
     FIG. 19 depicts a cross section view of the distal end  138  of the tube  137 . All numerals appearing in FIGS. 18 and 19 which have been mentioned before correspond to those elements previously described. Preferably, hypo-tube  44  is formed into jet body  140  which directs a single high velocity jet  142  distally past inflow orifice  34 . Alternatively, jet body  140  may be of a short length and connected to a more flexible polymeric tube similar to polymeric tube  45  of FIG.  3 . Fluid, such as blood and thrombotic debris which may be near distal end  138 , is entrained by the high velocity jet  142  and is thereby drawn through inflow orifice  34 . The fluid mixes with saline from the high velocity jet  142 , and thrombus is broken apart and pulverized by the high velocity jet  142 . The fluid mixed with saline from high velocity jet  142  creates an internal pressure near outflow orifice  32 , which creates cross stream jet(s)  82  and a recirculation pattern, as indicated, from outflow orifice  32  to inflow orifice  34 . The recirculation pattern includes radial and circumferential flow vectors, and can include axial flow vectors as well. The recirculation pattern creates a flow field that maximizes force on wall-adhered thrombus or lesion. A guidewire  144  is shown passing through the tapered and flexible tip assembly  36  and through the tube lumen  143 . This fifth alternative embodiment of the present invention is similar in many respects to the other embodiments, but does not provide for thrombus debris removal out of the body through the catheter. In this embodiment, the key features of inflow/outflow orifices and recirculation allow thrombus to be pulled into the high velocity jet(s) and to be broken up sufficiently so that they can pass downstream in the blood vessel without significant embolic complications. The recirculation can provide for repeated passage of thrombus fragments into the high velocity jets(s) so that maceration of the thrombus can occur. This embodiment may be particularly useful in treating venous thrombus or arteriovenous graft thrombosis, as examples, where moderately small thrombus fragment embolization is less likely to be of concern. In other situations, isolation means can be incorporated to prevent significant embolization. This embodiment has certain advantages over others, in that jet body  140  is simpler to fabricate, smaller in overall diameter, and less expensive than the more complex configurations, and the manifold  12  of FIG. 18 is simpler and less expensive than that shown in FIG.  1 B. Also, since there is no requirement for removal of debris through the catheter, tube  137  of FIG. 18 can be a smaller diameter than exhaust tube  28  of FIG.  1 B. The resulting device can then be a smaller diameter and less stiff, which offers advantages in allowing a smaller access for inserting the catheter into a patient and advancing it to the location of the thrombus. While the simple, single-jet jet body  140  is preferred in the fifth alternative embodiment, multiple jets and multiple inflow and outflow orifices can be used. For example, a jet body configuration similar to the semi-toroidal loop jet emanator  62  of FIG. 4 b  could be used, provided that multiple jet orifices direct fluid jets distally past one or more inflow orifices. Multiple outflow orifices could be used as well, positioned farther from the jet(s) than the inflow orifice(s), or combination inflow/outflow orifice(s) similar to orifice(s)  85  of FIGS. 7 and 8 could be utilized. 
     Various modifications can be made to the present invention without departing from the apparent scope hereof.

Technology Classification (CPC): 0