Abstract:
A thrombectomy catheter with a self-inflating proximal balloon having drug infusion capabilities is described. A self-inflating balloon is formed from an inflatable thin walled section of a flexible catheter tube. The self-inflating balloon includes a plurality of outflow orifices located about the peripheral circumference thereof and located proximal to an inflow gap interposed between a fluid jet emanator and the self-inflating balloon. The self-inflating balloon is inflated and expanded by internal operating pressures by proximal composite flow of fluid from the fluid jet emanator and entrained fluid from the inflow gap to uniformly space and position the outflow orifices of the self-inflating balloon in close proximity to the thrombus or vessel walls of a blood vessel. The thrombectomy catheter may be used for, among other things, thrombectomies, embolectomies, thrombus or vessel dilation, and for the delivery of drugs to a thrombus or vessel site.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application claims priority from the earlier filed U.S. Provisional Application No. 61/009,126 filed Dec. 26, 2007, and is hereby incorporated into this application by reference as if fully set forth herein. 
     This patent application is related to patent application Ser. No. 10/455,096 filed on Jun. 5, 2003, entitled “Thrombectomy Catheter Device Having a Self-Sealing Hemostasis Valve,” now U.S. Pat. No. 7,226,433. 
     This patent application is also related to patent application Ser. No. 11/294,006 filed on Dec. 5, 2005, entitled “Exhaust Pressure Operated Balloon Catheter System,” which is pending. 
     This patent application is also related to patent application Ser. No. 11/096,592 filed on Apr. 1, 2005, entitled “Rapid Exchange Fluid Jet Thrombectomy Device and Method,” which is pending. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure relates to a thrombectomy catheter, but more specifically relates to a rheolytic thrombectomy catheter with a self-inflating proximal balloon having drug infusion capabilities and, for purposes of brevity, is alternately referred to herein as a rheolytic thrombectomy catheter. The terms used herein are not intended to be limited to any particular narrow interpretation unless clearly stated otherwise in this document. 
     2. Description of the Prior Art 
     Prior art and its comparison to the devices of the present disclosure are partially set forth herein. Flow cessation of prior art devices to minimize hemolysis and for other reasons has been accomplished via a balloon on a proximally placed guide catheter or by way of proprietary occlusion guidewire technology, such as, but not limited to, the use of balloons on guidewires. With respect to thrombectomy performance, prior art cross stream jet catheter designs have been described in prior patents by the present inventors or assignees. Such prior art cross stream jet catheter designs use cross stream jets flowing between outflow orifices and inflow orifices located on an exhaust tube to impinge, macerate and carry thrombus debris away from a thrombus site and through the exhaust tube. In the present disclosure, as opposed to prior art thrombectomy catheters which place outflow orifices in the exhaust tube, outflow orifices are positioned on the periphery of a self-inflated balloon to provide significantly more effective thrombus removal. For example, a peripheral cross stream jet thrombectomy catheter exhaust tube may have the diameter of 2 mm (6 Fr) and may be treating an 8 mm blood vessel. Cross stream jets flowing outwardly from the side outflow orifices are used to liberate debris such that the thrombus may be evacuated by the inflow orifices. Ideally, these side exhaust jets would typically travel outwardly at an average of 3 mm to impinge and scrub thrombus deposits on a vessel wall. If the peripheral cross stream jet thrombectomy catheter exhaust tube is off center, which is the norm, the outwardly directed side outflow cross stream jets could travel up to 6 mm to impinge and scrub thrombus on a vessel wall. The side outflow orifices are typically less than 0.66 mm in diameter and as a result the cross stream jet may travel almost 10 diameters to impinge the vessel wall. As a cross stream jet travels, the surrounding fluid slows the cross stream jet, hence, the ability to remove debris is diminished. Compare the prior scenario to the devices of the present disclosure in which the outflow orifices are located on the periphery of a self-inflating balloon. The self-inflating balloon size and catheter are selected by the physician to match the treated vessel size in order that the balloon will always inflate to attempt to be in direct contact with the thrombus. Hence, the cross stream jets will travel a very short distance (i.e., less than 10 diameters) substantially unimpeded by surrounding fluids to impinge the thrombus with maximum velocity. Secondly, inflation of the self-inflating balloon ensures centering of the device so that the vessel is treated equally in all circumferential directions. This design enables a more effective and greater removal of tougher and more organized thrombus. Furthermore, it enables a greater and more uniform delivery of drugs into this tougher mural thrombus. 
     Vessel safety is improved and enhanced by use of devices of the present disclosure. In previous cross flow design thrombectomy catheters, vessel damage is primarily inflicted when the vessel wall is sucked in by the negative pressures at the inflow orifices to the point that the internal high velocity jet streams can damage the vessel wall. In fact, merely moving the catheter while the inflow orifices have been sucked onto the vessel wall is a likely mechanism for vessel damage from cross stream catheters. Vessel damage increases with the size of the inflow orifices and with the proximity of the high velocity fluid jet stream origin to the inlet orifice. In the case of devices of the present disclosure, an inlet gap (inlet orifice) is positionally located away from the vessel wall by the centering action of the self-inflating balloon. 
     SUMMARY OF THE DISCLOSURE 
     The general purpose of the present disclosure is to provide a rheolytic thrombectomy catheter sold under the trademark AngioJet®, to elegantly stop and/or impede blood flow in a vessel while simultaneously increasing the efficacy of thrombus removal. Flow cessation optimizes the effectiveness of thrombectomies, embolization containment, and procedures involving drug infusion, as well as minimizing hemolysis. Other issues addressed by the use of devices of the present disclosure relate to catheter centering, thrombus and/or vessel dilation or a modified embolectomy. 
     The main structure and feature of devices of the present disclosure involves the use of a proximally placed self-inflating balloon integral to and formed from a thin wall section of the exhaust tube of the rheolytic thrombectomy catheter which is inflatingly deployed using the back pressure created by the operation of the high velocity fluid jet streams used in a thrombectomy catheter, such as an AngioJet® catheter. The self-inflating balloon has a plurality of outflow orifices located about its peripheral circumference. Inflation of the balloon places the outflow orifices in close proximity to the thrombus buildup on a vessel wall. High velocity fluid jet streams emitted from an emanator exit these outflow orifices as uniformly distributed cross stream jets and return through an inflow gap, substantially a large inflow orifice, the function of which is closely related to that of multiple inflow orifices. 
     The device is a rheolytic enhanced thrombectomy catheter and can be used for removal of thrombus in coronary arteries, peripheral arteries or veins, neurological arteries or veins, or arterial venous conduits. By sizing the balloon for the intended vessel, the expanded balloon with peripheral circumference outflow orifices will be more efficacious in removing more organized clots. The blockage of blood flow by the inflated balloon also minimizes hemolysis. Hemolysis formed from a stagnant blood field is dramatically less than that of a flowing blood field. The self-inflating balloon of the present disclosure can also be used to dilate a vascular obstruction or narrowing. 
     The present disclosure describes the addition of a self-inflating balloon with outflow orifices or perforations to any of the AngioJet® catheter models. The self-inflating balloon is proximally located with respect to a high velocity fluid jet stream emanator. Although balloons attached to catheters proximally or distally have been suggested in the past, this concept goes one step further by creating a self-inflating balloon out of the distal exhaust tube (Pebax® material or polyurethane, etc.) while using the exhaust pressure of the high velocity fluid jet streams to fill and sustain the self-inflating balloon for purposes of proximal protection or occlusion (and in some cases when the rheolytic thrombectomy catheter is used in an anti-grade flow, distal protection). Furthermore, the self-inflating balloon includes a plurality of outflow orifices about its peripheral circumference so that when the self-inflating balloon is inflated, the fluid outflow in the form of cross stream jets is closely and intimately directed against the thrombus. In essence, the devices of the present disclosure provide a cross stream rheolytic thrombectomy catheter where the outflow orifices are in close or intimate proximity to the vessel wall and/or thrombus. This arrangement minimizes profile, minimizes the number of components and design complexity, minimizes manufacturing costs, and is very easy to use since the self-inflating balloon is deployed automatically when the rheolytic thrombectomy catheter is activated. 
     Since AngioJet® catheters remove debris more effectively in a stagnant flow, this device has several applications. It could be used with a filter to more effectively remove debris from within and around the filter. Furthermore, bench testing has shown that devices of the present disclosure are substantially more efficacious at clot removal than conventional AngioJet® catheters due to a cross stream jet configuration featuring a large inflow gap (inlet orifice). Cessation of flow and the large “pocket” the self-inflating balloon creates can ultimately increase the recirculated flow rate. Devices of the present disclosure can be used just to increase the amount of debris/thrombus removed from a particular vessel length. With this in mind, it should also minimize any distal or proximal embolization. It could also be used to deliver drugs more effectively in a stagnant field. The outflow orifices in the self-inflating balloon can drive the drugs deeper into the thrombus or even treat or lavage a vessel wall. The self-inflating balloon could also be used for centering or positioning the catheter in a vessel to minimize vessel damage as described above. Hence, the inlet orifice structure, herein referred to as an inflow gap, for the rheolytic thrombectomy catheter is enlarged to enable maceration of larger and tougher embolic debris. The self-inflating balloon could slightly dilate an occluded section, an obstruction, or a narrowed area due to the pressurized outwardly directed self-inflating balloon structure, thereby providing automatic angioplasty along with debris removal. Finally, the self-inflating balloon could be used to break up clots as it is moved through a blocked vessel, thereby performing a modified embolectomy. 
     According to one or more embodiments of the present disclosure, there is provided a rheolytic thrombectomy catheter including a manifold, a catheter tube connected to and extending distally from the manifold, a distally located tapered flexible tip spaced distally from the distal end of the catheter tube to form an inflow gap therebetween, a tubular shaped emanator secured at the proximal end of the tapered flexible tip by the use of a marker band, a distally located thin section of the catheter tube comprising a self-inflating balloon having a plurality of outflow orifices about the peripheral circumference thereof, marker bands secured over and about the catheter tube on each end of the self-inflating balloon, and a high pressure tube extending through portions of the manifold, through the catheter tube and self-inflating balloon, and through marker bands and extending further across the inflow gap to communicatingly terminate within the emanator. 
     Multiple significant aspects and features of a rheolytic thrombectomy catheter incorporate and exemplify many of the features and teachings and include enhancements thereof of a rheolytic thrombectomy catheter sold under the trademark AngioJet®. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with outflow orifices, which is created from the exhaust tube itself. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with outflow orifices, which balloon is deployed by the back pressure created during operation of devices of the present disclosure. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with outflow orifices, which balloon is fixed and positioned between two marker bands with an underlying stabilizing saddle or by another suitable means. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with outflow orifices, which balloon is used for the purpose of impeding fluid flow in a blood vessel or other conduit. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with orifices, which balloon is used for the purpose of cessation of fluid flow in a blood vessel or other conduit in order to maximize the effect of a thrombectomy catheter in terms of debris or tissue removal. 
     Another significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon which is used for the purpose of cessation of fluid flow in a blood vessel or other conduit in order to maximize the effect of a thrombectomy catheter in terms of debris or tissue removal from a distal protection filter wire or a balloon. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon used for the purpose of centering the catheter. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon used for the purpose of a modified embolectomy. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon used for the purpose of dilating a vessel or an occlusion. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon used for the purpose of minimizing hemolysis. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon used for the purpose of infusing drugs on a vessel wall or into a thrombus. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with outflow orifices used with an inflow gap for removing debris. 
     One significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with outflow orifices used with one or more inflow orifices for removing debris. 
     Another significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon with outflow orifices used with an inflow gap or one or more inflow orifices for removing debris and used with additional radially directed spray jets emanating from a jet body loop. 
     Still another significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon having a diameter which could range from 2-20 mm. 
     Still another significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon which could range from 2-200 mm in length. 
     Still another significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon which could be compliant, semi-compliant, or noncompliant in nature. 
     Still another significant aspect and feature of devices of the present disclosure is a self-inflating proximal balloon having an internal operating pressure up to 20 ATM. 
     Having thus briefly described one or more embodiments of the present disclosure and having mentioned some significant aspects and features of devices of the present disclosure, it is the principal object of the present disclosure to provide a rheolytic thrombectomy catheter with a self-inflating proximal balloon with drug infusion capabilities. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects of the present disclosure and many of the attendant advantages of the devices of the present disclosure 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. 1  is a plan view of the visible components of a rheolytic thrombectomy catheter with a self-inflating proximal balloon having drug infusion capabilities; 
         FIG. 2  is an isometric exploded and segmented view of  FIG. 1  showing the rheolytic thrombectomy catheter having an inflow gap; 
         FIG. 3  is an assembled view in partial cross section of the components of the manifold shown in  FIG. 2  and the closely associated components and features thereof including a guidewire; 
         FIG. 4  is a cross section view of the distal end of the rheolytic thrombectomy catheter; 
         FIG. 5  is an isometric view of a fluid jet emanator having rearwardly aligned jet orifices shown connected to and in communication with a high pressure tube; 
         FIG. 6  illustrates the rheolytic thrombectomy catheter connected to ancillary devices; 
         FIG. 7  is a side view in partial cross section of the distal portion of the rheolytic thrombectomy catheter; 
         FIG. 8  is a first alternative embodiment similar to  FIG. 2  illustrating a rheolytic thrombectomy catheter having a single inflow orifice; 
         FIG. 9  is an illustration similar to  FIG. 4  showing the distal end of the rheolytic thrombectomy catheter and the arrangement of the inflow orifice in relation to the self-inflating balloon; 
         FIG. 10  is a second alternative embodiment similar to  FIG. 8  illustrating a rheolytic thrombectomy catheter which can also emanate radially directed jets from the distal end thereof; 
         FIG. 11  is an illustration similar to  FIG. 5  showing a fluid jet emanator having rearwardly aligned and radially aligned jet orifices shown connected to and in communication with a high pressure tube; 
         FIG. 12  is an illustration similar to  FIG. 9  showing the distal end of a rheolytic thrombectomy catheter and the arrangement of the inflow orifices and the arrangement of the rearwardly and radially aligned jet orifices in relation to the self-inflating balloon; and, 
         FIG. 13  is an illustration similar to  FIG. 7  showing the performance of the method and use of the second alternative embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a plan view of the visible components of a rheolytic thrombectomy catheter  10 . The device includes a one-piece manifold  12  having multiple structures extending therefrom or attached thereto, and also includes a flexible catheter tube  14  and other components associated therewith as described herein. The visible portion of one-piece manifold  12  includes a central tubular body  16 , a threaded exhaust branch  18 , and a high pressure connection branch  20  extending angularly from central tubular body  16 , a partially shown cavity body  22  extending proximally from central tubular body  16  and a threaded connection port  24  extending distally from central tubular body  16 . The proximal end of catheter tube  14  is secured to manifold  12  by the use of a Luer fitting  26  accommodated by threaded connection port  24 . The proximal end of catheter tube  14  extends through a strain relief tube  28  and through Luer fitting  26  to communicate with manifold  12 . Also shown is a hemostasis nut  30  aligned with and threadingly engaged with the proximal region of cavity body  22 . A threaded high pressure connection port  32  is secured to high pressure connection branch  20  by a Luer connector  34 . An introducer  36  is also shown. 
     Catheter tube  14  extends distally to spacingly terminate a short distance from a tapered flexible tip  38  and a fluid jet emanator  52 , not shown in  FIG. 1  but shown in  FIGS. 4 and 5 , to provide an annular inflow gap  40 . A distal section of catheter tube  14  includes a self-inflating balloon  42  (shown inflated by dashed lines  42   a ) proximal to inflow gap  40 . A plurality of outflow orifices  44   a - 44   n  which can be arranged in various patterns is distributed about the central outer circumference of self-inflating balloon  42  for the disbursement of cross stream jets therefrom when the balloon is inflated. Catheter tube  14  functions as an exhaust tube for the evacuation of macerated effluence from the site of a thrombus or lesion. Preferably, catheter tube  14  includes a hydrophilic coating to enhance deliverability along the vasculature or other structure. Catheter tube  14  is made from a flexible plastic material or another suitable flexible material. 
       FIG. 2  is an isometric exploded and segmented view of rheolytic thrombectomy catheter  10  and  FIG. 3  is an assembled view, in partial cross section, of the components of manifold  12  and closely associated components and features thereof. 
     A collection of assembled components including a high pressure tube  50  and a fluid jet emanator  52  deliver a high pressure saline or other suitable fluid to the distal portion of catheter tube  14  for creation of high velocity jet streams which are directed proximally from fluid jet emanator  52  and which flow as exterior cross stream jets from the plurality of outflow orifices  44   a - 44   n  located at the peripheral circumference of self-inflating balloon  42  and return into inflow gap  40 , as later described in detail. High pressure tube  50 , preferably of flexible stainless steel or other suitable material, passes through and is generally distal to strain relief tube  28  and extends along a greater portion of and within a lumen of catheter tube  14  to terminate at fluid jet emanator  52 . The distal end of high pressure tube  50 , including fluid jet emanator  52 , is also shown in greater detail in  FIGS. 4 and 5 . 
     With reference to  FIGS. 2 and 3 , the devices of the present disclosure are further described. Manifold  12  includes connected and communicating passageways and cavities ( FIG. 3 ) including a high pressure connection branch passageway  54 , an exhaust branch passageway  56 , a tapered central passageway  58  extending from and through threaded connection port  24  and through central tubular body  16  to and communicating with a multiple radius cavity  60 , which preferably is cylindrical and located central to cavity body  22 . External threads  62  are located about the proximal portion of cavity body  22  at the proximal region of manifold  12  for accommodation of internal threads  64  of hemostasis nut  30 . 
     The devices of the present disclosure benefit from the use of a flexible self-sealing hemostasis valve  66 , and the use of a washer  68  which is located distal to self-sealing hemostasis valve  66 , the shapes and functions of which are described in the referenced U.S. Pat. No. 7,226,433. Self-sealing hemostasis valve  66  and washer  68  are aligned in and housed in the greater radius portion of multiple radius cavity  60  of cavity body  22 . Hemostasis nut  30  includes a centrally located cylindrical boss  70 . Washer  68  and self-sealing hemostasis valve  66  are captured within the greater radius portion of multiple radius cavity  60  by threaded engagement of hemostasis nut  30  to threads  62  at the proximal end of manifold  12 . Cylindrical boss  70  is brought to bear against the collective self-sealing hemostasis valve  66  and washer  68  to resultingly bring pressure to bear, as required, against self-sealing hemostasis valve  66 , which pressure culminates in a forcible sealing of self-sealing hemostasis valve  66  about guidewire  46 . Although one method of sealing against a guidewire is briefly shown and described, it is appreciated that other methods can be incorporated into this and other forms of the devices of the present disclosure such as those referenced in U.S. Pat. No. 7,226,433. 
     Also shown is a ferrule  76  which is aligned within a passageway  78  of threaded high pressure connection port  32 , the combination of which is partially aligned within an interior passageway  80  of Luer connector  34 . The proximal end of flexible high pressure tube  50 , shown in segmented form in  FIG. 2 , can be utilized for the delivery of high pressure ablation liquids or for the delivery of drugs or other liquids and is suitably secured in a central passageway of ferrule  76  to communicate with interior passageway  78  of threaded high pressure connection port  32 , as shown in  FIG. 3 . The proximal end of high pressure tube  50  also extends through high pressure connection branch passageway  54 , through part of tapered central passageway  58 , through strain relief tube  28  and Luer fitting  26 , and through a lumen  82  of catheter tube  14 . 
     High pressure tube  50  extends through support rings  84  and  86  and is suitably connected thereto, as shown in  FIG. 4 , to provide an anchoring and alignment structure for high pressure tube  50  in affixing the distal portion of high pressure tube  50  within the distal region of catheter tube  14 . In addition, high pressure tube  50  also extends through radiopaque marker bands  88  and  90 . High pressure tube  50  preferably is attached to support rings  84  and  86 , such as by welding or other suitable means, where support rings  84  and  86  function as co-located supports for catheter tube  14  in the region beneath radiopaque marker bands  88  and  90 . A short distal section of high pressure tube  50  extends across inflow gap  40  and terminates within an internal annular manifold (not shown) of fluid jet emanator  52 , which is suitably attached thereto where fluid jet emanator  52  communicates with the lumen of high pressure tube  50 , such as to a closely related fluid jet emanator described in the previously referenced patent application Ser. No. 11/096,592 or other applications or patents assigned to the assignee. Fluid jet emanator  52 , also shown in  FIG. 5  as an isometric view, includes an annular groove  94  which is in coordination use with a radiopaque marker band  92  to secure tapered flexible tip  38  about fluid jet emanator  52 . In  FIG. 2 , radiopaque marker bands  88  and  90  are shown displaced a short distance distal to support rings  84  and  86  and fluid jet emanator  52  is shown displaced proximally a short distance from radiopaque marker band  92  for the purpose of clarity and are shown in frictional engagement in their actual position along and with respect to the distal portion of catheter tube  14  in  FIG. 4 . 
     The relationships of radiopaque marker bands  88 ,  90  and  92 , support rings  84  and  86 , and fluid jet emanator  52 , respectively, to each other and to catheter tube  14  are shown best in  FIG. 4 . In  FIG. 4 , self-inflating balloon  42  is shown contiguous with catheter tube  14 , wherein self-inflating balloon  42  has a reduced wall thickness  14   a  when compared to the general wall thickness of catheter tube  14 . The reduced wall thickness  14   a  of self-inflating balloon  42  is of a suitable thickness in order to allow the inflation of self-inflating balloon  42  to thereby expand, meet and align against the wall of the vasculature or against the thrombus, whereby a thrombectomy procedure, drug delivery procedure or other procedure can take place. For the purpose of demonstration and illustration, self-inflating balloon  42  can range in length from 2 mm to 200 mm. When self-inflating balloon  42  is in the inflated state, as represented by inflated balloon  42   a , the central diameter of self-inflating balloon  42  can range from 2 mm to 20 mm. Inflated balloon  42   a  can be expanded, as desired, with an internal pressure up to 20 ATM. Radiopaque marker bands  88  and  90  and support rings  84  and  86  are shown forcibly contacting the full wall thickness of catheter tube  14  adjacent the ends of self-inflating balloon  42 , thereby allowing substantially the full length of reduced wall thickness  14   a  of self-inflating balloon  42  to be utilized for expansion. Expansion of self-inflating balloon  42  is shown in dashed lines by inflated balloon  42   a . Alternatively, reduced wall thickness  14   a  of self-inflating balloon  40  can be formed from other materials, as known in the art, and then bonded or extruded to catheter tube  14  to maintain a continuous structure throughout the length of catheter tube  14 . 
     In all embodiments of the present disclosure outflow orifices  44   a - n  can have any of a number of different configurations. For example, spiral or slotted cuts can be formed that extend from one end of the periphery of self-inflating balloon  42  to the other. Alternatively as few as two outflow orifices may be utilized to effectuate the delivery of fluid for thrombectomies or other procedures as described herein. Still other patterns and numbers of outflow orifices can also be utilized on all sections of the periphery of self-inflating balloon  42  without departing from the scope of the present disclosure. 
     Tapered flexible tip  38  is shown including a multiple radius inner passageway  96  for the accommodation of fluid jet emanator  52  and a guidewire  46  (not shown in  FIG. 4 ). The distally located radiopaque marker band  92  is forcibly applied around the external proximal portion of tapered flexible tip  38  to cause a frictional annular engagement of the proximal portion of tapered flexible tip  38  with all or part of an annular groove  94  of fluid jet emanator  52 . Such frictional engagement is sufficient to place the outer radial surface of radiopaque marker band  92  (also  88  and  90 ) in a position lesser than the general and greater outer radial surface of catheter tube  14 , thereby providing, in part, a catheter tube  14  having no elements protruding beyond the general outer radial surface thereof for an unimpeded and smooth distal or proximal transition of catheter tube  14  within a vein, artery or the like. A passageway  98  ( FIG. 5 ) is shown central to fluid jet emanator  52  to accommodate the passage of a guidewire. 
     Structure is provided to nurture and aid the introduction of and passage of the distal portion of catheter tube  14  through blood vessels, arteries and the like to the sites of thrombotic deposits or lesions. Tapered flexible tip  38 , as opposed to a rounded and nontapered flexible tip, can part and more easily penetrate thrombotic deposits or lesions during its insertional travel in a distal direction instead of advancing or pushing such thrombotic deposits or lesions distally. The decreasing diameter in a distal direction of tapered flexible tip  38  also allows for an increased flexibility in negotiating and passing through tortuous paths. 
     Exhaust tube support rings  84  and  86  in use with radiopaque marker bands  88  and  90  in the regions surrounding the opposed ends of self-inflating balloon  42  are examples of structures offering support or reinforcement along catheter tube  14  in the regions adjacent to the ends of self-inflating balloon  42 . Such support rings allow the use of a thinner wall thickness for catheter tube  14  in order to allow for a larger and more effective and efficiently sized lumen  82 , as well as contributing to a reduced sized outer diameter. Such support rings also contribute to supportively maintain the diameter and overall shape of catheter tube  14  when catheter tube  14  is pushed or advanced along a vein or vessel, as well as aiding in torsional support. 
       FIG. 5  is an isometric view of fluid jet emanator  52  shown connected to and in communication with high pressure tube  50 . Fluid jet emanator  52  includes a plurality of rearwardly aligned orifices  112   a - 112   n  paralleling the longitudinal axis of fluid jet emanator  52 , as well as including the previously described annular groove  94  and passageway  98 . Fluid jet emanator  52  delivers a high pressure saline or other suitable fluid to the distal portion of catheter tube  14  for the creation of high velocity jet streams  114  which are directed proximally from orifices  112   a - 112   n  of fluid jet emanator  52  and thence within the confines of self-inflating balloon  42  to contribute in the formation of inflated balloon  42   a  and to perform other functions as described herein. Although the use of the particular style of fluid jet emanator  52  is shown, other fluid jet emanators having other configurations, such as those disclosed in U.S. Pat. Nos. 5,370,609 and 6,676,637, both of which are incorporated herein by reference, can also be utilized with the devices of the present disclosure, along with other designs and securitization methods described in the literature by the assignee of the present disclosure. Each separate design of fluid jet emanator  52  works similarly in that they emanate high velocity jet streams  114  and can be used in lieu of the specific fluid jet emanator  52  herein disclosed; the use of other fluid jet emanators shall not be considered to be limiting to the scope of the present disclosure. 
     Mode of Operation 
     Generally, a normal guidewire is deployed in a vessel requiring treatment or, in the alternative, a filter guidewire or balloon occlusion guidewire could also be used. Distally located components of rheolytic thrombectomy catheter  10  consisting mainly of catheter tube  14 , high pressure tube  50 , fluid jet emanator  52 , and other components directly associated therewith, are advanced over and/or along a guidewire previously positioned in the vasculature for the purpose of debris/thrombus removal, drug infusion or other procedures and maneuvered into the appropriate position for treatment. A guide catheter or sheath can be incorporated as necessary to offer assistance in placing catheter tube  14  of rheolytic thrombectomy catheter  10  within the desired location of the vasculature. Rheolytic thrombectomy catheter  10  is then activated, wherein self-inflating balloon  42  is automatically and expandingly deployed reforming as an expanded balloon  42   a , and then thrombus, debris and the like are removed or drugs can be infused by a desired procedure. Self-inflating balloon  42  can be alternately pressurized and depressurized, wherein rheolytic thrombectomy catheter  10  may be moved proximally or distally during the procedure to maximize the effect of the system. When the procedure is complete, self-inflating balloon  42  is generally deflated sufficiently under normal arterial pressure to be removed safely, or deflation can be aided with a manual syringe attached to an effluent line, or deflation can be aided by means of a roller pump. Further interventions can be executed as normal over the remaining guidewire or guidewire device. 
     More specifically,  FIGS. 6 and 7  illustrate the mode of operation, where  FIG. 6  illustrates the embodiment connected to ancillary devices, and  FIG. 7  illustrates the distal portion of rheolytic thrombectomy catheter  10  in the performance of the method and use of devices of the present disclosure. The mode of operation is best understood by referring to  FIGS. 6 and 7 , along with the previously described figures. 
     In  FIG. 6 , rheolytic thrombectomy catheter  10  is shown engaged over and about a guidewire  46 , wherein guidewire  46  (previously inserted into a vein or artery) first slidably passes through passageway  96  of tapered flexible tip  38  followed by transiting passageway  98  of fluid jet emanator  52 , inflow gap  40 , the distal end of lumen  82  at the distal end of catheter tube  14 , self-inflating balloon  42 , lumen  82  of catheter tube  14  proximal to inflow gap  40 , strain relief tube  28 , tapered central passageway  58 , slidable within and in sealed engagement with hemostasis valve  66  and to finally exit from hemostasis nut  30 . A high pressure fluid source  100  and a high pressure fluid pump  102  are connected to the manifold  12  via the threaded high pressure connection port  32  and connector  104 . The fluid source may consist of saline, one or more drugs for attacking the thrombus, or a mixture of saline and one or more drugs and the fluid source can be changed dynamically while catheter tube  14  remains in the patient. An exhaust regulator  106 , such as a roller pump or other suitable device, and a collection chamber  108  are connected to the threaded exhaust branch  18  by a connector  110 , as shown. 
       FIG. 7  is a side view in partial cross section of rheolytic thrombectomy catheter  10  in the performance of the method and use thereof with particular attention given to the distal portion of catheter tube  14 , flexible tapered tip  38 , fluid jet emanator  52 , inflow gap  40 , inflated balloon  42   a , and other closely associated components positioned in a blood vessel  116  at a site of a thrombotic deposit or lesion  118 . Multiple high velocity fluid jet streams  114  of saline, for example, or other suitable fluid, are shown being emitted in a proximal direction from jet orifices  112   a - 112   n  of fluid jet emanator  52  in order to assist in the inflation of self-inflating balloon  42  for the purposes of, but not limited to, impeding fluid flow to effect a stagnate flow in the thrombectomy region, to provide centering of inflated balloon  42   a , and to ultimately accomplish thrombectomy or drug delivery functions as described herein. Use of devices of the present disclosure can also provide for the performance of a modified embolectomy by breaking up clots as inflated balloon  42   a  is moved through a blocked vessel, dilating a vessel or an occlusion with inflated balloon  42   a , infusing drugs on a vessel wall or into a thrombus by the use of inflated balloon  42   a  and outflow orifices  44   a - n  or to minimize any distal or proximal embolization. Self-inflating balloon  42  is pressurized by utilizing back pressure along catheter tube  14  in conjunction with the pressure of high velocity fluid jet streams  114  and is automatically and expandingly deployed reforming as an inflated balloon  42   a  by means of pressurized high velocity fluid jet streams  114 . Inflated balloon  42   a  can be compliant, semi-compliant, or noncompliant according to the procedure performed. Exhaust regulator  106  is used to influence the degree of inflation of expanded balloon  42   a , as well as to influence the outgoing fluidic macerated debris through catheter tube  14 . Fluid jet emanator  52  or other fluid jet emanators of appropriate size and/or configuration can be incorporated within the proximal section of tapered flexible tip  38  as an alternative to emanate or emit one or more high velocity fluid jet streams  114  proximally along or near the longitudinal axis of catheter tube  14 . 
     The positioning of the peripheral circumference of inflated balloon  42   a  aligns outflow orifices  44   a - 44   n  in close proximity to or against either the thrombotic deposit or lesion  118 , or as generally shown in  FIG. 7 , in close proximity to or against the wall of blood vessel  116  in order to effect fluid flow reduction or cessation. Inflated balloon  42   a  substantially provides uniform centering and positioning of outflow orifices  44   a - 44   n  with respect to the surrounding thrombotic deposit or lesion  118  and/or blood vessel  116 , thereby providing equally powered passage and distribution of high velocity fluid jet streams  114  outwardly from outflow orifices  44   a - 44   n  as cross stream jets  120 . High velocity fluid jet streams  114  of saline pass outwardly through outflow orifices  44   a - 44   n  creating cross stream jets  120  (lower velocity jets) directed outwardly toward and for immediate contact first with the thrombotic deposit or lesion  118 , if present, and thence with the wall of blood vessel  116 . Cross stream jets  120  are influenced by the low pressure at inflow gap  40  to cause cross stream jets  120  to flow circumferentially and distally to impinge on, provide drag forces on, and break up thrombotic deposits or lesions  118 , and to, by entrainment, urge and carry along one or more particles  118   a  of thrombotic deposits or lesions  118  through inflow gap  40 , a relatively low pressure region, into high velocity fluid jet streams  114  where thrombus particles  118   a  are further macerated into microscopic particles, and then urged along lumen  82  of catheter tube  14  by the action of high velocity fluid jet streams  114 . A certain portion of this macerated thrombus debris is mixed with the fresh saline high velocity fluid jet stream  114  and forcibly removed through lumen  82  of catheter tube  14  and a certain portion of this macerated thrombus flows back out outflow orifices  44   a - 44   n  and recirculates to break up more thrombus debris which is returned to inflow gap  40 . In this way, much more fluid flow circulates, or recirculates, through the system, than is injected through jet orifices  112   a - 112   n . For purposes of illustration and example, three to ten times more fluid flow circulates through the system than is delivered by jet orifices  112   a - 112   n . The entrainment of thrombus or debris through inflow gap  40  is based on entrainment by high velocity fluid jet streams  114 . The outflow of fluid and thrombus is driven proximally through catheter tube  14  by an internal pressure which is created by high velocity fluid jet streams  114  and the fluid entrained through inflow gap  40 . An enhanced clot removal is attainable because of the recirculation pattern established between outflow orifices  44   a - 44   n  and inflow gap  40 , which creates a flow field that maximizes a drag force on the wall-adhered thrombus. If catheter tube  14  is advanced far enough into the thrombetic deposits or lesions  118 , the flow may stop when self-inflating balloon  42  inflates thereby pushing outflow orifices  44   a - 44   n  directly against the thrombetic deposits or lesions  118 . When this occurs, high velocity fluid jet streams  114  drive deeply into thrombetic deposits or lesions  118  and gradually soften and then break apart the thrombetic deposits or lesions  118 . Once broken, the entrained thrombus is macerated into microscopic particles and re-entrained into inflow gap  40  at a high rate. Some of the macerated particles re-exit from outflow orifices  44   a - 44   n  along with high velocity fluid jet streams  114  but are not of sufficient size to significantly block circulation. In a no-flow situation, material can then be recirculated and rediluted until all particles are removed and all that remains is saline. Cessation of fluid flow in a blood or other conduit maximizes the effect of rheolytic thrombectomy catheter  10  in terms of debris or tissue removal. Also, cessation of fluid flow in a blood vessel or other internal conduit maximizes the effect of the rheolytic thrombectomy catheter  10  when incorporated into use with a distal protection filter wire or a balloon. 
       FIG. 8 , a first alternative embodiment, is an illustration similar to  FIG. 2  showing a rheolytic thrombectomy catheter  10   a  having a single inflow orifice  122  in lieu of inflow gap  40  of the first embodiment, where all numerals correspond to those elements previously described or as otherwise described herein. In the alternative, more than one inflow orifice could be utilized instead of single orifice  122 .  FIG. 9  is an illustration similar to  FIG. 4  showing the distal end of rheolytic thrombectomy catheter  10   a  and the arrangement of a single inflow orifice  122  in relation to self-inflating balloon  42 . In this embodiment, catheter tube  14  extends across the former location of inflow gap  40  of the first embodiment and is continuous thereacross to form tapered flexible tip  38  in which fluid jet emanator  52  is secured in the manner previously described. The mode of operation closely parallels that of the preferred embodiment of  FIG. 1 , whereby inflow orifice  122 , instead of inflow gap  40 , is used to receive cross stream jets  120 . 
       FIG. 10 , a second alternative embodiment, is an illustration similar to  FIG. 8  showing a rheolytic thrombectomy catheter  10   b , where all numerals correspond to those elements previously described or as otherwise described herein. An additional feature of rheolytic thrombectomy catheter  10   b  is a fluid jet emanator  52   a  corresponding in general design to that of fluid jet emanator  52  shown in  FIG. 11 , but including features which provide for the emanation of outwardly directed high velocity fluid radial jets  124   a - 124   n  therefrom. 
       FIG. 11  is an illustration similar to  FIG. 5  showing a fluid jet emanator  52   a , where all numerals correspond to those elements previously described or as otherwise described herein. Additional uniformly aligned and spaced orifices  126   a - 126   n , preferably in radial and perpendicular orientation with respect to the longitudinal axis, are arranged about a peripheral circumference of fluid jet emanator  52   a  and are in communication with an internal manifold (not shown) and with jet orifices  112   a - 112   n  and provide for outwardly directed emanation of high velocity fluid radial jets  124   a - 124   n  therefrom. In the alternative, the orientation of orifices  126   a - 126   n  can be randomly angulated with respect to perpendicular orientation in order to provide high velocity fluid radial jets  124   a - 124   n  at other than perpendicular emanation therefrom and directed as desired. 
       FIG. 12  is an illustration similar to  FIG. 9  showing the distal end of rheolytic thrombectomy catheter  10   b  and the arrangement of an inflow orifice  122  and the arrangement of jet orifices  126   a - 126   n  of fluid jet emanator  52   a  in relation to self-inflating balloon  42 . Also shown is the plurality of holes  128   a - 128   n  extending through the wall of the distal portion of catheter tube  14  in corresponding alignment with jet orifices  126   a - 126   n . High velocity fluid radial jets  124   a - 124   n  ( FIG. 11 ) emanate through the jet orifices  126   a - 126   n  and through the plurality of holes  128   a - 128   n  in order to provide treatment distal to the general flow of cross stream jets  120 , as shown and described in  FIG. 13 . 
       FIG. 13  is an illustration similar in operation to  FIG. 7  showing flexible rheolytic thrombectomy catheter  10   b  in the performance of the method and use thereof. For purposes of illustration, inflow orifice  122  is oriented toward the viewer. The use of radially directed high velocity fluid radial jets  124   a - 124   n  from radial jet orifices  126   a - 126   n  provides for jet impingement of the thrombotic deposits or lesions  118  adjacent to the region of inflow orifice  122  in order to provide a substantially unrestricted path for the flow of cross stream jets  120  and particulate  118   a  into inflow orifice  122  for further maceration and/or carriage of fluids and particulate proximally through inflated balloon  42   a  and catheter tube  14  or for recirculation. Additionally, drugs for treatment or for lysing of the thrombotic deposits or lesions  118  can also be delivered via radial jet orifices  126   a - 126   n  in addition to outflow orifices  44   a - n , in order to soften the thrombotic deposits or lesions  118  in the region adjacent to inflow orifice  122  and outflow orifices  44   a - n , thereby benefiting and making the use of cross stream jets  120  more effective. The drugs are delivered through the high pressure tube  50  to the sites of the thrombotic deposits or lesions  118 . 
     Various modifications can be made to the devices of the present disclosure without departing from the apparent scope thereof.