Abstract:
A rapid exchange catheter having a vena cava filter and a method for percutaneous delivery of the rapid exchange vena cava filter for use in indicated medical situations in which prophylactic or therapeutic protection against pulmonary embolism are indicated.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority from U.S. Provisional Application Ser. No. 62/051,153, filed Sep. 16, 2014, herein incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention pertains generally to medical catheters and methods of percutaneous delivery of a catheter to a site within the body for diagnostic or therapeutic purposes. More particularly, the present invention relates to a rapid exchange catheter having a tethered or fixedly attached vena cava filter and a method for percutaneous delivery of the rapid exchange vena cava filter for use in indicated medical situations in which prophylactic or therapeutic protection against pulmonary embolism are indicated. 
         [0003]    The accepted standard of care for patients with venous thromboembolism (VTE) is anticoagulant therapy. Inferior vena cava (IVC) filters are reserved for those patients who fail anticoagulant therapy, or have a complication or contraindication to anticoagulant therapy. Until the early 1970&#39;s, the only method of IVC interruption was surgical, either by clipping, ligation or plication. The first clinical experience of an endoluminally-placed device to interrupt IVC flow was reported by Mobin-Uddin et al. in 1969. However, it was not until the introduction of a stainless steel umbrella-type filter by Greenfield et al. in 1973 that an effective method of endoluminally trapping emboli while simultaneously preserving IVC flow became possible. Indeed, for many years, the Greenfield filter set a benchmark by which newer filters were measured. Early generations of filters were inserted by surgical cut-down and venotomy. Eventually filters were able to be inserted percutaneously: initially through large 24 Fr sheaths, though newer generations of filters are able to be delivered through 6 Fr systems. Percutaneous delivery through a 6 Fr introducer minimizes the likelihood that surgical intervention to close the access site will be required when the system is withdrawn from the patient. 
         [0004]    Despite the safety and efficacy of modern day filters, systemic anticoagulation remains the primary treatment for VTE. Either unfractionated or low molecular weight heparin followed by three months of oral anticoagulation in patients with proximal deep venous thrombosis (DVT) is approximately 94% effective in preventing pulmonary embolism (PE) or recurrent DVT. The routine placement of IVC filters in addition to anticoagulation in patients with documented DVT was investigated by Decousus et al. in a randomized trial. Decousus H, Leizorovicz A, Parent F, et al. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis.  N Engl J Med  1998; 338:409-415. This study revealed that the use of a permanent filter in addition to heparin therapy significantly decreased the occurrence of PE within the first 12 days compared to those without a filter. However, no effect was observed on either immediate or long-term mortality, and by 2 years, the initial benefit seen in the group of patients with filters was offset by a significant increase in the rate of recurrent DVT. 
         [0005]    Despite the efficacy of anticoagulant therapy in the management of VTE, there are certain situations and conditions in which the benefits of anticoagulation are outweighed by the risks of instituting such a therapy. These include contraindications and complications of anticoagulant therapy. In such circumstances, there may be absolute or relative indications for filter insertion. 
         [0006]    Currently, there are several different types of U.S. Food and Drug Administration (“FDA”) approved vena cava filters. These include the Bird&#39;s Nest filter (Cook Incorporated, Bloomington, Ind.), Vena Tech LGM filter (B. Braun, Bethlehem Pa.), Vena Tech LP (B. Braun), Simon Nitinol filter (Bard, Covington, Ga.), Titanium Greenfield filter (Boston Scientific, Natick Mass.), Over-the-Wire Greenfield filter (Boston Scientific), TrapEase filter (Cordis Corp.) and the Günther Tulip filter (Cook Inc.). 
         [0007]    Well-founded concerns over the long-term complications of permanent IVC filters, particularly in younger patients in need of PE prophylaxis with a temporary contraindication to anticoagulation, has led to the development of temporary and retrievable filters. Temporary filters remain attached to an accessible transcutaneous catheter or wire. These have been used primarily in Europe for PE prophylaxis during thrombolytic therapy for DVT. Currently these devices are not approved for use in the United States. Retrievable filters are very similar in appearance to permanent filters, but with modifications to the caval attachment sites and/or hooks at one end that can facilitate their removal. Retrievable filters that are currently available in the United States include the Günther Tulip (Cook Inc.), Opt Ease (Cordis Corp.), and Recovery nitinol filters (Bard Peripheral Vascular, Tempe, Ariz.) Lin P H, et al., Vena caval filters in the treatment of acute DVT.  Endovascular Today  2005; January: 40-50. The time limit of retrievability is in part dependent on the rate of endothelialization of the device, which typically occurs within 2 weeks, but may occur within five days or as much as 30 days. However, differences in design may extend the time period in which the filter may be safely retrieved. 
         [0008]    Currently no consensus exists as to which patients have an indication for a retrievable filter. However, it is generally accepted that patients at high risk for pulmonary embolism or with documented PE and with a temporary contraindication to anticoagulation are candidates. 
         [0009]    Certain circumstances preclude the placement of a filter in the infrarenal IVC. This includes thrombus extending into the infrarenal IVC, renal vein thrombosis or pregnancy. The safety of suprarenal placement of IVC filters is well documented, with no reported instances of renal dysfunction and no differences in the rates of filter migration, recurrent PE or caval thrombosis. 
         [0010]    Pulmonary embolism may complicate upper extremity DVT in 12-16% of cases. In patients who have such a complication or contraindication to anticoagulation, a filter can be safely placed immediately below the confluence of the brachiocephalic veins. However, misplacement of an SVC filter is theoretically more likely than with an IVC filter because of the relatively short target area for deployment. 
         [0011]    The most common imaging modality used for filter insertion is fluoroscopy, performed either in an interventional suite or an operating room. Bedside placement of filters has inherent advantages, particularly for critically ill patients in intensive care settings where transport can be avoided. Portable fluoroscopy, surface duplex ultrasound and intravascular ultrasound (IVUS) have all been used to assist with bedside filter placement. 
         [0012]    Vena cava filter placement frequently occurs concomitantly with central access line placement. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention relates to a central access catheter having a vena cava filter at a distal end, a port proximal the filter and a port distal the filter and plural infusion ports. Accordingly, it is an objective of the present invention to provide a rapid exchange catheter coupled to a vena cava filter that is useful both as a central venous access catheter for administration of intravenous fluids, bioactive agents, contrast agents, flushing agents, pressurized fluids for mechanical thrombolysis and/or withdrawal of blood samples and for capture of thrombus or emboli. 
         [0014]    Another aspect of the present invention is to provide a filter geometry in which the proximal portion of the filter, relative to the axis of blood flow, has larger interstitial openings to permit thrombus or embolic material to flow into the filter, while the distal portion of the filter, again relative to the axis of blood flow, has relatively smaller interstitial openings that capture the thrombus or embolic material within the filter. Another way to view this aspect is that the structure of the filter includes a greater open surface area exposed to the flow of embolic material into the filter at its proximal end, while the distal end has smaller open surface area exposed to the flow of embolic material to capture the embolic material in the distal end of the filter member. 
         [0015]    Yet another aspect of the present invention is to provide an asymmetrical vena cava filter in which the vena cava filter has a distal end that is asymmetrical relative to a proximal end of the filter. In accordance with this aspect of the invention, the vena cava filter includes a first conical section and a second conical section, with each of the first and second conical sections forming one of the proximal end or distal end of the filter. Each of the first and second conical sections taper long the longitudinal axis of the catheter member such that an apex of each conical section is generally co-axial with the longitudinal axis of the catheter member and the catheter member passes through a central longitudinal axis, and both apices of the first and second conical sections, respectively. 
         [0016]    It is yet another aspect of the invention to provide a rapid exchange vena cava filter catheter in which a proximal aspect of the catheter has a first diameter and a distal aspect of the catheter has a second larger diameter than the proximal aspect of the catheter. 
         [0017]    It is still yet another aspect of the invention to provide a rapid exchange vena cava filter catheter having a rapid exchange guide wire port passing through the distal aspect of the catheter. The rapid exchange guide wire port further includes a seal that permits a guide wire to be passed into and through a central lumen of the catheter, and exit through the rapid exchange guide wire port, while the seal substantially seals the rapid exchange guide wire port such that medically significant fluid flow does not pass through the rapid exchange guide wire port during use within the body. 
         [0018]    Still another objective of the present invention is to provide a contrast port medial along a length of the rapid exchange vena cava filter catheter. The contrast port is positioned in a medial position along the length of the rapid exchange vena cava filter catheter in order to allow for sufficient distance between the contrast port and the vena cava filter member for dispersion of a contrast medium within the blood flow to optimize visualization of the vena cava filter member, any region proximal to the filter member, and any thrombus captured by the vena cava filter member. 
         [0019]    A further object of the present invention is to configure the medial contrast port such that a flow of contrast agent out of the contrast port occurs only when the contrast agent is introduced at or above a predetermine pressure, while allowing other fluids introduced below such threshold predetermined pressure to pass through the central lumen of the catheter system and bypass the contrast port. 
         [0020]    These and other objects, features and advantages of the present invention will be more apparent to those skilled in the art from the following more detailed description of the invention with reference to the accompanying Figures. In the accompanying Figures, like reference numerals refer to similar features across multiple embodiments of the invention. It will be understood by those skilled in the art that while the Figures describe the present invention with reference to exemplary embodiments, the present invention is intended to be limited only by the claims appended hereto. Moreover, it will be understood by those skilled in the art that various features of the invention may be described with reference to one or more embodiments and are intended to be applicable to each embodiment described in the specification and within the scope of the appended claims. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0021]      FIG. 1  is a perspective view of a rapid exchange vena cava filter catheter in accordance with the present invention. 
           [0022]      FIG. 2A  is a fragmentary cross-sectional view of a section of the inventive rapid exchange vena cava filter catheter illustrating a rapid exchange guide wire port and a medial contrast port. 
           [0023]      FIG. 2B  is a fragmentary top view taken from direction of arrow  2 B in  FIG. 2A  and is a section of the inventive rapid exchange vena cava filter catheter illustrating a rapid exchange guide wire port and a medial contrast port. 
           [0024]      FIG. 2C  is a fragmentary top view taken from direction of arrow  2 C in  FIG. 2A  and is a section of the inventive rapid exchange vena cava filter catheter illustrating a rapid exchange guide wire port and a medial contrast port. 
           [0025]      FIG. 3A  is a side elevational view of a medial contrast port in accordance with the present invention. 
           [0026]      FIG. 3B  is a transverse cross-sectional view taken along line  3 B- 3 B of  FIG. 3A . 
           [0027]      FIG. 4  is a side view of a section of the inventive rapid exchange vena cava filter catheter with the sheath shown in phantom illustrating the rapid exchange guide wire port, the medial contrast port and an in-line flow restrictor insert within a lumen of the inventive catheter. 
           [0028]      FIG. 5  is a perspective view of another embodiment of a rapid exchange guide wire port of the inventive rapid exchange vena cava filter catheter. 
           [0029]      FIG. 6  is a cross-sectional view taken along line  6 - 6  of  FIG. 5 . 
           [0030]      FIGS. 7A-7C  are sequential perspective views depicting a method of assembling the rapid exchange guidewire port depicted in  FIG. 5 . 
           [0031]      FIG. 8A  is a top elevational fragmentary view of a proximal hub of the inventive rapid exchange vena cava filter in accordance with the present invention. 
           [0032]      FIG. 8B  is an exploded perspective view of the proximal hub of the rapid exchange vena cava filter in accordance with the present invention. 
           [0033]      FIG. 9A  is a side elevational view of the proximal hub of the inventive rapid exchange vena cava filter catheter in accordance with the present invention. 
           [0034]      FIG. 9B  is a top plan view of the proximal hub of the inventive rapid exchange vena cava filter catheter in accordance with the present invention. 
           [0035]      FIG. 10  is a side elevational view of a vena cava filter member of the inventive rapid exchange vena cava filter catheter in accordance with the present invention. 
           [0036]      FIG. 10A  is a cross-sectional view taken along line  10 A- 10 A of  FIG. 10 . 
           [0037]      FIG. 10B  is a cross-sectional view taken along line  10 B- 10 B of  FIG. 10 . 
           [0038]      FIG. 11  is a side elevational view of another embodiment of the vena cava filter member of the inventive rapid exchange vena cava filter catheter in accordance with the present invention. 
           [0039]      FIG. 12  is a cross-sectional view taken along line  12 - 12  of  FIG. 11 . 
           [0040]      FIG. 13  is a cross-sectional view taken along line  13 - 13  of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]    In accordance with the present invention, there is provided a rapid exchange vena cava filter catheter  100 . Rapid exchange vena cava filter catheter  100  includes generally a vena cava filter member  110  that is coupled to an elongate member  120 , such as an elongate wire  120 . The vena cava filter member  110  is more fully described with reference to commonly owned U.S. Pat. Nos. 8,613,753, 8,668,712, 8,771,226, 8,777,977, 8,777,981 and/or 8,808,323, each of which is hereby incorporated by reference. Briefly, the vena cava filter member  110  is formed of a plurality of strut members forming first and second conical sections of the filter member  110 . The first and second conical sections define proximal and distal ends of the filter member  110 . Each of the first and second conical sections have a base and an apex, with the apices of each of the first and second conical sections forming one of the proximal and distal ends of the filter member  110 , with the base of each conical section being positioned intermediate the proximal and distal ends of the filter member  110 . 
         [0042]    The rapid exchange vena cava filter catheter  100  also includes a catheter sheath member formed from a proximal catheter sheath  114  and a distal catheter sheath  112 . At a proximal end of the proximal catheter sheath  114  is provided a proximal hub  116 . The catheter sheath member has a central longitudinal lumen that extends from and is in fluid flow communication with the proximal hub. The central longitudinal lumen of the catheter sheath extends to a distal end  119  of the catheter sheath member and terminates at a distal opening in the distal catheter sheath  112 . An elongate wire  120  passes through the catheter sheath member and extends at its proximal end from the proximal hub and is coupled near its distal end to the filter member  110 . In another embodiment, the elongate wire  120  may be a tube, including, for example a single lumen or a multi-lumen tube to provide an additional lumen the rapid exchange or dual lumen design configurations. As used herein, the term elongate wire  120  is intended to encompass a wire or a tube. The elongate wire  120  is capable of being longitudinally translated within and through the catheter sheath member in order to push the filter member  110  out of the distal end  119  of the catheter sheath member and also retract the filter member  110  back into the distal end  119  of the catheter sheath member. An atraumatic tip  122  is provided at a very distal end of the elongate wire  120  to facilitate navigation of the rapid exchange vena cava filter catheter  100  through the vasculature or other anatomic passageway. 
         [0043]    A rapid exchange guide wire port  118  is provided in the catheter sheath member and is positioned generally at the transition between the proximal catheter sheath  114  and the distal catheter sheath  112 . The rapid exchange guide wire port  118  permits a guide wire  102  to exit from the rapid exchange guide wire port  118 . 
         [0044]    Each of the first and second conical sections of the filter member  110  are asymmetrical relative to each other. For example, a length of the first conical section will be either greater than or less than a length of the second conical section. Additionally, the number and configuration of struts forming the first conical section will be different than the number and configuration of struts forming the second conical section of the filter member  110 . It has been found advantageous to configure the filter member  110  such that whichever of the first and second conical sections are oriented toward the direction of fluid flow within the body structure, i.e., retrograde relative to the fluid flow, that section have a lower number of struts and interstitial openings between struts in that section be of a relatively larger open surface area relative to the other section that is oriented away from the direction of fluid flow within the body structure, i.e., antegrade relative to the fluid flow. For example, when delivered infra-renal within the inferior vena cava by a femoral approach, blood flow is in a cephalic direction, i.e., toward the patient&#39;s head, thus, the conical section of the filter member  110  that tapers toward an apex that is retrograde to the blood flow within the inferior vena cava, i.e., pointed caudal relative to the patient, will be configured to have interstitial spaces relatively larger than the conical section of the filter member  110  that tapers toward and apex that is antegrade to the blood flow with in the inferior vena cava, i.e., pointed cephalic relative to the patient, which will be configured to have interstitial spaces that are relatively smaller in order to capture thrombus.  FIGS. 10 and 11 , described in greater detail hereinafter, illustrate this described configuration and orientation of the filter member  110 . 
         [0045]    The rapid exchange guide wire port  118  is depicted in  FIGS. 2A-2B  in greater detail. As discussed above, the rapid exchange guide wire port  118  consists of a large opening in the side wall of the rapid exchange catheter member. It will be understood that port  118  may be positioned at any longitudinal position along the length of the rapid exchange catheter member. However, for purposes of illustration and in accordance with one aspect of the present invention, rapid exchange guide wire port  118  is positioned at the transition between the proximal catheter sheath member  114  and the distal catheter sheath member  112 . Proximal catheter sheath member  114  has a transverse diameter D 2  that is smaller than a transverse diameter D 1  of the distal catheter sheath member  112 . Alternatively, the catheter could be configured to have a substantially uniform diametric profile along the entire longitudinal length of the device depending on geometry required. The port  118  is positioned at the diametric transition between the proximal catheter sheath member  114  and the distal catheter sheath member  112 . 
         [0046]    Because of its relatively large open surface area necessitated by its function, the guide wire port  118  must be sealed to prevent undesired fluid flow out of or into the port  118 . In order to seal port  118 , a resilient seal  130  is provided within the lumen  113  of the distal catheter sheath member  114  that seats against a luminal wall surface surrounding the rapid exchange guide wire port  118 . Resilient seal  130  is deformable in order to accommodate passage of a guide wire past the seal and through the port  118  opening, while still providing a substantially fluid tight seal to reduce or prevent fluids from passing through the port  118  opening. Resilient seal  130  preferably has a tapered section  134  that projects distally toward the vena cava filter member  110 , yet permits fluid to flow from lumen  113  in the distal catheter sheath member  112  past or through the resilient seal  130  and into a second lumen  135  in communication therewith within the proximal catheter sheath member  114 . In accordance with one aspect of the invention, resilient seal  130  consists of a generally tubular member that has a proximal end  132  which is generally cylindrical and capable of being joined to the proximal catheter sheath member  114 , and a distal end  134  that has a generally tapered frustroconical shape, tapering distally and ending in a distal seal opening  138 . Alternatively, the resilient seal  130  may have a generally tubular shape with one wall surface of the seal  130  forming a diametrically enlarged bulge  131  toward an intermediate aspect of the seal  130  which then tapers toward the distal end  134  and opens at distal seal opening  138 . The diametrically enlarged bulge  131  seats against the luminal wall surface perimeter rapid exchange guide wire port  118  to seal port  118 . 
         [0047]    The resilient seal  130  has a seal lumen  135  that is in fluid communication at it proximal end  132  with the lumen  115  of the proximal catheter sheath member  114  and at its distal end  134 , distal seal opening  138  is in fluid communication with lumen  113  of the distal catheter sheath member  112 . In this manner, fluid introduced into proximal lumen  115  will pass through the resilient seal lumen  135  and into the distal lumen  113  of the distal catheter sheath member  112 , without exiting the rapid exchange guide wire port  118 . 
         [0048]      FIGS. 5-6  illustrate an alternative embodiment of a resilient seal  200  and  FIGS. 7A-7C  represent a manner in which resilient seal  200  is disposed within the rapid exchange vena cava filter catheter  100 . In accordance with the alternative embodiment of resilient seal  200 , there is provided a resilient seal member  210  having a generally tubular cylindrical shape having a seal lumen  235  that passes through the resilient seal member  210  and opens at each end thereof. A proximal end  214  of the resilient seal member  210  is configured with an outer diameter sized to be inserted within and be coupled to an inner diameter of the proximal catheter sheath member  114 . Thus, as depicted in  FIGS. 7A and 7B , a proximal end  214  of the resilient seal member  210  is engaged within the distal end of lumen  115  of the proximal catheter sheath member  114 . The proximal end  214  of the resilient seal member  210  may be joined to the proximal catheter sheath member  114  by any suitable method of creating just coupling, including, without limitation, reflow, thermal welding, ultrasonic welding, adhesive, interference or such other means for joining two components of a catheter device as are known in the art. Once the resilient seal  210  is joined to the proximal catheter sheath member  114 , the distal catheter sheath member  112  may be engaged over the resilient seal  210 , such that the guide wire port  118  is positioned over a portion of the resilient seal  210 , and the distal catheter sheath member  112  and the proximal catheter sheath member  114  are joined by any suitable method of creating just coupling, including, without limitation, reflow, thermal welding, ultrasonic welding, adhesive, interference or such other means for joining two components of a catheter device as are known in the art. 
         [0049]    A distal end  216  of the resilient seal member  210  has a beveled wall surface  212  that tapers distally toward the vena cava filter member  110  forming a guide wire ramp. In this manner, as the vena cava filter catheter  100  is passed over a guide wire  102 , the guide wire  102  passes through distal lumen  113  of the distal catheter sheath member  112 , and will be deflected by the beveled wall surface  212  that forms a ramp, the resilient seal  210  will deform to guide the guide wire  102  toward and out the rapid exchange guide wire port  118 . In another embodiment, the guide wire ramp may be configured to facilitate guidance of the wire through the rapid exchange pathway, such as, for example, by forming a bevel or concave profile of the guide wire ramp. 
         [0050]    The elongate wire  120  traverses the distal lumen  113  of the distal catheter sheath member  112 , the seal lumen  235  and the proximal lumen  115  of the proximal catheter sheath member  114 . While not shown in  FIG. 5 or 6 , the resilient seal member  210  may also optionally be employed in conjunction with the contrast port opening  142 , sleeve  144  and contrast fluid outlet opening  146  as depicted in and described above with reference to  FIGS. 2-3B . Moreover, while not shown in  FIG. 5 or 6 , the resilient seal member  210  may also optionally be employed in conjunction with the flow restrictor member  160  as depicted in and described above with reference to  FIG. 2 . Similarly, while not shown in  FIG. 5 or 6 , the resilient seal member  210  may also optionally be employed in conjunction with all of the contrast port opening  142 , sleeve  210 , contrast fluid outlet opening  146 , and flow restrictor  160 , as depicted in and described above with reference to  FIGS. 2-3B . 
         [0051]    Optionally, a contrast port  142  is provided in the rapid exchange vena cava filter catheter  100 . Contrast port  142  may be disposed in a wall of the proximal catheter sheath member  114  and communicate with the lumen  115  of the proximal catheter member  114 . It has been found desirable to position the contrast port  142  sufficiently proximal the filter member  110  so that adequate dispersion of a contrast medium will occur at the position of the filter member  110  for visualization of the filter  110  and its placement, or for visualization of the region proximal to the filter member. In accordance with the exemplary embodiment of the invention depicted in  FIG. 2 , the contrast port  142  is positioned proximal the rapid exchange guide wire port  118  and near a distal end  140  of the proximal catheter sheath member  114 . 
         [0052]    A flow restrictor member  160  having a restrictor lumen  162  may optionally be provided and interposed intermediate the contrast port  142  and the rapid exchange guide wire port  118 . The restrictor lumen  162  is of a smaller diameter relative to the proximal lumen  115  of the proximal catheter sheath member  114  and is also smaller in diameter relative to the distal lumen  113  of the distal catheter sheath member  112 . In this manner, flow restrictor member  160  permits regulation of pressures at which contrast medium is either emitted from contrast port  142  or pressures at which fluids, including contrast medium, flow through the restrictor lumen  162 , through the resilient port seal  130  and through the distal lumen  113  of the distal catheter sheath member  112 , exiting the rapid exchange vena cava filter catheter  100  at its distal end  119 . It will be appreciated that at higher injection pressures, fluids, such as contrast medium, will encounter a back pressure exerted by the flow restrictor member  160  and will flow primarily out of the contrast port  142 , with a secondary flow passing through restrictor lumen  162  and into the distal section of the catheter  100 . At lower injection pressures, fluid will primarily flow distally through the restrictor lumen  160  and into the distal section of the catheter  100 . It will be understood by those skilled in the art that the relative diameter and length of the restrictor lumen  160  relative to the diameter of the proximal lumen  115  and distal lumen  113  will determine the pressure above which the primary fluid flow will exit the contrast port  142 . 
         [0053]    Contrast port  142  may have an opening size dimensioned to regulate the outflow of contrast medium there through. However, in order to facilitate dispersion of the contrast medium in the blood flow, it has been found desirable to sheath the contrast port  118  with a sleeve  144  that circumferentially covers the proximal catheter sheath member  114  and covers the contrast port, while allowing a fluid flow channel  150  between an inner surface of the sleeve  144  and the outer surface of the proximal catheter sheath member  114 . A contrast fluid outlet opening  146  is provided in the sleeve  144  and is spaced apart from the contrast port  142 . One example is to position the contrast fluid outlet opening  146  180 degrees opposite from the contrast port  142  about the circumferential axis of the catheter sheath member  114 . This position allows for the contrast medium to flow bidirectionally about the entire circumference of the catheter sheath member  114 . Where the contrast fluid outlet opening  146  is formed as a slot oriented parallel to the longitudinal axis of the catheter sheath member  114 , the contrast medium will flow out of the contrast fluid outlet opening  146  in a substantially laminar flow. The contrast fluid outlet opening  146  may be a single or plural circumferentially oriented slots, helical slots, longitudinally oriented slots, circular openings, polygonal openings, or other shaped openings as are appropriate to provide for dispersion of a contrast medium as it is released from the contrast port  142 . 
         [0054]    The sleeve  144  is preferably joined to the vena cava filter catheter  100  at proximal and distal aspects of the sleeve  144 , leaving the fluid flow channel  150  in an unjoined intermediate aspect of the sleeve  144  that overlays the contrast port  142  and is in fluid communication with the contrast fluid outlet opening  146 . 
         [0055]    As illustrated in  FIGS. 4 and 6 , the elongate wire  120  traverses the proximal lumen  115  of the proximal catheter sheath member  114 , passes through the flow restrictor lumen  162 , if the flow restrictor member  160  is present, through the lumen  135  of the resilient seal  130  and then into the distal lumen  113  of the distal catheter sheath member  115 . As noted above, the proximal end of vena cava filter member  110  is coupled to the distal end of the elongate wire  120 . 
         [0056]    Turning now to  FIGS. 8A to 9C , a proximal hub  300  in accordance with the present invention is illustrated. The proximal hub  300  forms the proximal end of the rapid exchange vena cava catheter  100  and is the proximal terminus of the proximal catheter sheath member  114  and the elongate wire  120 . The proximal hub  300  also provides fluid access for fluid injection into the proximal lumen  115  of the proximal catheter sheath member  114 . 
         [0057]    The proximal hub  300  includes first section  310  and a second section  320  that cooperate with each other. The first section  310 , which is preferably a distal section of the proximal hub  300 , is formed of a housing  311  having a first channel  312  and a second channel  314 . First channel  312  has a receiving section  315  in a distal portion of the first channel  312  and a proximal section  317 . A proximal end of the proximal catheter sheath member  114  engages and seats within the receiving section  315  of the first channel  312  and is in fluid flow communication with the proximal section  317 . The proximal lumen  115  of the proximal catheter sheath member  114  is in fluid flow communication with the proximal section  317  of the first channel  312 . The second channel  314  has a proximal receiving section  319  and a distal section  321 . An extension line  316  engages and seats within the proximal receiving section  319  and is in fluid flow communication with the distal section  321  of the second channel  314 . Distal section  321  of the second channel  314  joins in fluid flow communication with the distal section  317  of the first channel  312 . 
         [0058]    It has been found desirable that the first channel  312  be co-axial with a central longitudinal axis L of the proximal hub  300  and that the second channel  314  be angularly displaced from the central longitudinal axis L by an angle α. Angle α is preferably greater than 0 and less than or equal to 90 degrees, preferably between 15 and 45 degrees from the central longitudinal axis L. 
         [0059]    The first housing  310  further includes a seating recess  350  that accommodates a hemostatic seal seating member  352  therein. Seating recess  350  is co-axial with the central longitudinal axis L and has a bore  354  in fluid communication with the proximal section  317  of the first channel  312 . Seating recess  350  has a generally annular shape and has a proximal receiving recess  356  in a proximal aspect of the seating recess  350 . Bore  354  tapers proximally and opens to the proximal receiving recess  356 . 
         [0060]    There is also provided a hemostatic sealing member  340  that has a distal projection  342  and a sealing member  345  interfacing between the distal projection  342  and the proximal receiving recess  356  of the seating recess  350  in the first housing  310 . The hemostatic sealing member  340  further has a bore  344  passing through the hemostatic sealing member  340  and through the distal projection  242  that communicates with bore  354  in the seating recess. Finally, hemostatic sealing member  340  further includes an engagement section  348  having enlarged receiving bore  346  in a proximal aspect of the hemostatic sealing member  340  that communicates with the bore  344 . 
         [0061]    Finally, the first section  310  includes at least one, preferably two, apertures  311  for securing the proximal hub  300  to the patient. In the illustrated embodiment in  FIGS. 8A-9C , apertures  311  are present in suture wings that project outwardly from the first section  310 . 
         [0062]    The second section  320  removably engages with the first section  310 , such as by a threaded connection or a luer-type connection. Second section  320  is rotatably connected with a distal end of the elongate wire  120  (not shown in  FIG. 8A ), such as by a swage fitting. Second section  320  includes a rotatable cap housing  322  that removably couples to the first section  310 , such as by engagement and disengagement with the engagement section  348  of the hemostatic sealing member  340 . The distal end of the elongate wire  120  is connected within a wire bore  332  in a connecting fitting  330 . Connecting fitting  330  is rotatably coupled to the rotatable cap housing  322 , such that rotational movement of the rotatable cap housing  322  does not translate rotational forces to the connecting fitting  330  or to the elongate wire  120 , but rather permits rotational coupling and decoupling of the rotatable cap housing  322  from the first section  310  of the proximal hub  300  and then allows for longitudinal translation of the elongate wire  120 , the rotatable cap housing  322  and the connecting fitting  330  relative to the first section  310 . It will be understood that this longitudinal translation of the elongate wire  120  serves to push the vena cava filter member  110  coupled to the distal end of the elongate wire  120  out of the distal end  119  of the distal catheter sheath member  112  and also to retrieve the vena cava filter member  110  within the distal end  119  of the distal catheter sheath member  112 . 
         [0063]    In accordance with one embodiment of the proximal hub  300 , the first section  310  and the seating recess  350  may optionally be fabricated of pliant or resilient materials. In this embodiment, proximal hub  300  may have resilient or pliant opposing first and second surfaces  315 ,  317 , respectively. By fabricating the seating recess  350  of a pliant or resilient material, bore  354  may be dimensioned to bear against the elongate wire  120  and exert a pressure that creates drag when the elongate wire  120  is translated through the bore  354 . Deformation of the seating recess  350  will deform the bore  354  and release some of the pressure bearing against the elongate wire  120 . In use, the medical practitioner may depress first and second surfaces  315 ,  317  to deform the first section  310  and the seating recess  350  therein, thereby deforming the bore  354  surrounding the elongate wire  120  passing there through and releasing pressure by the bore  354  bearing against the elongate wire  120  to allow for smoother longitudinal translation of the elongate wire  120  through the proximal hub  300 . 
         [0064]    One embodiment of the filter member  110  is illustrated in its diametrically expanded configuration in  FIG. 10 . In this embodiment, filter member  110  consists of a plurality of strut members  12  arranged to form a first generally conical end  18  and a second generally conical end  20  of the filter member  110 . The plurality of strut members  12  define wall surfaces of the filter member  110  and delineate a first space  22  and a second space  24  within the filter member  110  for capturing thrombus sequestered from the circulating blood flow by at least some of the plurality of strut members  12 . 
         [0065]    In addition to forming a first generally conical end  18  and a second generally conical end  20 , optionally, some of the plurality of strut members  12  may be arranged to form an intermediate section  16  of the second generally conical end  20  of the filter member  110 . The intermediate section  16  is characterized by having interstitial openings  19  that are smaller relative to the interstitial openings  15  of the first generally conical end  18  or the interstitial openings  13  of the second generally conical end  20 . 
         [0066]    The first generally conical end  18  may form either the proximal or the distal end of the filter member  110  depending upon the orientation of the filter on the catheter and the anatomical approach for which the rapid exchange vena cava filter catheter  100  is intended, e.g., femoral or jugular. In forming the first generally conical end  18 , a plurality of first strut members  62 , for example three, are coupled at their proximal end to the proximal end  18  of filter member  110  and each extends distally relative to the longitudinal axis of the rapid exchange vena cava catheter  100 . Each of the first strut members  62  is an elongate member that projects away from the central longitudinal axis of the catheter  100  and terminates in a distal end section  63  that defines a base of the first generally conical end  18 . A plurality of second strut members  64  extend from a distal end of the second generally conical end and extend proximally form a distal end ofare coupled at their distal end to the distal end  20  of filter member  110  and each extends proximally relative to the longitudinal axis of the catheter  100 . A plurality of third strut members  66  form the intermediate section  26 , if present, and at least some of the plurality of third strut members  66  are joined at their distal ends to a proximal end of at least some of the plurality of second strut members  64 , and at least some of the plurality of third strut members  66  are joined at their proximal ends a distal end of at least some of the plurality of first strut members  62 . A hoop member  70 , which may be formed from some of the plurality of third strut members  66 , extends circumferentially to define a circumferential axis of the filter member  110  and has a series of continuous undulations defining a series of peaks  75  and valleys  77  about the circumference of filter member  110 . Each of the plurality of first strut members  62 , the plurality of second strut members  64  and the plurality of third strut members  66  are coupled to the hoop member  70  at different points about its circumferential axis and intermediate the proximal end  18  and the distal end  20  of the filter member  110 . 
         [0067]    The plurality of first strut members  62  are preferably evenly offset from each other. For example, where three first strut members  62  are employed, each will be offset by approximately 120 degrees about the circumference of the filter member  110 . The plurality of second strut members  64  are also preferably evenly offset from each other. Thus, for example, if twelve second strut members are employed, each will be offset by approximately thirty degrees about the circumference of the filter member  110 . 
         [0068]    It will be understood that each of the plurality of first strut members  62 , plurality of second strut members  64 , plurality of third strut members  66  and the hoop member  70  are preferably fabricated of biocompatible materials, such as shape memory alloys, superelastic materials or elastic materials, including, without limitation, titanium, vanadium, aluminum, nickel, tantalum, zirconium, chromium, silver, gold, silicon, magnesium, niobium, scandium, platinum, cobalt, palladium, manganese, molybdenum and alloys thereof, such as zirconium-titanium-tantalum alloys, cobalt-chromium-molybdenum alloys, nitinol, and stainless steel. 
         [0069]      FIGS. 10-10B and 11-13  illustrate two alternate attachments of the filter member  410 ,  510  to the elongate wire  120 . In each embodiment, the filter member  410 ,  510  is attached to a distal end of the elongate wire  210  by means of an attachment tube  40 . A filter attachment member  30 , such as that described in U.S. Pat. No. 8,808,323, which is hereby incorporated by reference, is employed to couple the filter member  410 ,  510  to the attachment tube  40 . 
         [0070]    As illustrated in  FIGS. 10-10C , attachment tube  40  has a guide wire lumen  27  that extends from a distal end of the attachment tube  40  and passes through the atraumatic tip  122 . Guide wire lumen  27  terminates proximal to the filter attachment member  30  in the guide wire port  118 . A second lumen  29  is provided in the attachment tube  40  that extends and opens to a proximal end of the attachment tube  40 . The distal end of the elongate wire  120  is received within the second lumen  29  and the elongate wire  120  is secured therein. The guide wire port  118  aligns with a port  118   a  disposed on the distal catheter sheath  114  when the filter member  110  is in contracted state. 
         [0071]    Like with filter  410 , and as illustrated in  FIGS. 11-13 , filter  510  is also coupled to a filter attachment tube  40 . In this embodiment, however, filter attachment tube  40  has a guide wire lumen that passes along an entire longitudinal length of the filter attachment tube  40  and opens distally at the atraumatic tip  122  and proximally at the proximal end of the filter attachment tube  40 . Like with filter  410 , a second lumen  29  is provided in the attachment tube  40  that extends and opens to a proximal end of the attachment tube  40 . The distal end of the elongate wire  120  is received within the second lumen  29  and the elongate wire  120  is secured therein. 
         [0072]    It is contemplated that the elongate wire  120  may be made of any suitably biocompatible metal, such as nickel-titanium alloy, chromium-molybdenum alloy, stainless steel or the like. The elongate wire  120  may optionally be reinforced with a winding of another metal wire or may be coated with a polymer and/or a bioactive agent, such as an antithrombotic agent. It is further contemplated that the proximal and distal catheter sheaths  114 ,  112 , may be made of any suitably biocompatible polymer, such as polyurethane, polytetrafluoroethylene, polyether block amide (PEBAX®, Arkema, Paris, France), and may also optionally be coated or covered with another polymer and/or a bioactive agent, such as an antithrombotic agent. It is also contemplated that the vena cava filter member  110 ,  410 ,  510  may be made of any suitably biocompatible metal or polymer, as are known in the art. Finally, the attachment tube  40  may be made of any suitably biocompatible metal, such as nickel-titanium alloy or polyether block amide (PEBAX®, Arkema, Paris, France). 
         [0073]    It will be understood by those skilled in the art that the foregoing description of the inventive rapid exchange vena cava filter catheter is made with reference to exemplary embodiments only. Such exemplary embodiments are not intended to be, nor should be construed to be limiting of the scope of the invention, which is defined solely by the claims appended hereto.