Abstract:
A power injection system comprises an introducer needle including a lumen extending therethrough to a non-coring distal tip and an anchoring device extendable laterally from the introducer needle distal tip, the anchoring device including a port contacting surface engaging one of an inner surface of the port and an inner surface of a septum to anchor the introducer needle within a subcutaneous port.

Description:
PRIORITY CLAIM 
       [0001]    The present claims priority to U.S. Provisional Patent Application Ser. No. 60/973,950 filed on Sep. 20, 2007 entitled “Co-Access Port Introducer”. The entire disclosure of this application is expressly incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The treatment of chronic diseases often requires repeated and prolonged access to the vascular system. The more frequently these procedures must be repeated, the more impractical and dangerous it becomes to insert and remove a needle from a vein at every session. Thus, patients are often fitted with a semi-permanent catheter which remains in place in communication with the vascular system between sessions. Proximal ends of these catheters which remain accessible (e.g., via subcutaneously implanted ports) are often sealed with valves such as Pressure Actuated Safety Valves (PASV&#39;s). These PASV&#39;s open only when a fluid pressure within the catheter exceeds a preselected threshold pressure and re-seal when the fluid pressure drops below this threshold pressure. 
         [0003]    Most procedures for infusing fluids through such semi-permanent catheters (e.g., delivering chemotherapy agents, antibiotics, drugs and/or blood products) involve low flow rates and injection pressures. However, for certain applications it is necessary to introduce fluid into the catheter at pressure and flow rates higher than those commonly used for such therapeutic infusions. For example, power injection of contrast media used in visualization techniques require flow rates and pressures in excess of those for which most conventional catheter systems and ports are suited. These procedures, commonly referred to as power injection procedures, have typically required a separate, more robust catheter than those used in conventional infusion techniques. If a power injection is carried out via a typical port, the high back pressure generated will often force the needle back out of the port. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is directed to a power injection system comprising an introducer needle including a lumen extending therethrough to a non-coring distal tip and an anchoring device extendable laterally from the introducer needle distal tip, the anchoring device including a port contacting surface engaging one of an inner surface of the port and an inner surface of a septum to anchor the introducer needle within a subcutaneous port. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0005]      FIG. 1  is a schematic illustration showing a port, an introducer needle and an anchoring needle according to a first embodiment of the invention; and 
           [0006]      FIG. 2  is a schematic illustration showing a port, an introducer needle and an anchoring needle according to a second embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0007]    The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The invention relates to devices used to supply pressurized fluid to a catheter. More specifically, the invention relates to a method and device to connect a power injection device to a catheter through a port, while retaining the device in place and protecting a valve of the catheter from damage. 
         [0008]    According to the invention, the port is fitted with a soft septum that can be easily pierced by the needle of a conventional or a power injection syringe while, for power injection procedures, a non-coring needle is used to pierce the septum and an anchoring needle is introduced through the non-coring needle to retain the device in place during the procedure. 
         [0009]    As shown in  FIG. 1 , an access system  100  according to an exemplary embodiment of the invention includes a port  102  with a connector  104  for fluid connection to a catheter  112 . The port  102  includes a septum  110  closing a fluid chamber  106  and an outlet  104  connecting the fluid chamber  106  to the catheter  112 . When the port  102  and catheter  112  are not used, the septum  110  seals the opening to the fluid chamber  106 , to prevent fluid leakage from the catheter and the introduction of contaminants thereinto. 
         [0010]    A needle or other syringe is inserted through the septum  110  to introduce fluids into or withdraw fluids from the catheter  112  via the fluid chamber  106 . According to the invention, the needle is retained inside the port  102  against the back pressure exerted by the fluid in the fluid chamber  106  by an anchoring device. For example, the anchoring device may be deployed from a larger diameter hollow needle that pierces the septum  110 . 
         [0011]    According to the exemplary embodiment of  FIG. 1 , the access system  100  comprises an introducer needle  120  that pierces the septum  110  while minimizing damage to the septum material. As would be understood in the art, the size and tip shape of the introducer needle  120  and the material of the septum  110  are selected to ensure that the hole  114  formed in the septum  110  by the introducer needle  120  is re-sealed once the needle  120  has been removed by the natural bias of the material of the septum  110 . For example, the introducer needle  120  may be a non-coring needle. 
         [0012]    The anchoring device according to the present invention is inserted into the fluid chamber  106  via a lumen  126  extending through the introducer needle  120 . As shown in  FIG. 1 , the anchoring device may comprise an anchoring needle  124  which, when deployed, extends distally beyond a squared off opening  122  of the introducer needle  120 . The anchoring needle  124  preferably curves into the port  102  such that back pressure applied by the fluid therein presses the extended portion of the anchoring needle  124  against inner surface of the fluid chamber  106  and/or an inner surface of the septum  110 . The fluid back pressure thus helps to retain the anchoring needle  124  in place by opposing a force tending to eject the anchoring needle  124  and the introducer needle  120  from the port  102  holding the introducer needle  120  in place within the port  102 . A proximal end of the anchoring needle  124  is coupled to the introducer needle  120  so that the anchoring needle  124  may move distally and proximally relative to the introducer needle  120 . 
         [0013]    Once the anchoring needle  124  has been deployed, power injection procedures may be performed. In one exemplary embodiment, fluid is injected through the lumen  126  and out of the opening  122  into the fluid chamber  106  around an outer surface of the anchoring needle  124 . Alternatively, the introducer needle  120  may be withdrawn and another injection needle may be advanced into the fluid chamber  106  over the anchoring needle  124 , which acts as a guidewire. The power injection then takes place through a lumen of the injection needle  120  around the anchoring needle  124  or through the lumen of the injection needle  120  after the anchoring needle  124  has been pushed against a wall thereof. 
         [0014]    As shown in  FIG. 2 , an introducer needle  130  according to a different embodiment of the invention includes a non-coring tip  140  cut at an angle relative to a longitudinal injection axis of the needle  130  to further reduce the possibility of damaging the septum  110  when it is pierced. In a preferred embodiment, the non-coring tip  140  is cut at an angle of 60° to 90° relative to the longitudinal axis of the needle 90°. In this embodiment, the anchoring needle  134  is advanced through the lumen  136  to exit into the fluid chamber  106  via an angled opening  132 . The operation of the power injection apparatus is then substantially similar to that described above with reference to  FIG. 1 . 
         [0015]    After the procedure has been completed, the anchoring needle  124  is withdrawn proximally until a distal tip thereof is received within the lumen  126  while the introducer needle  120  remains within the fluid chamber  106 . The anchoring needle  124  may be completely withdrawn from the introducer needle  120  at this point or may remain within the lumen  126  as the introducer needle  120  is removed from the fluid chamber  106  allowing the septum  110  to seal the puncture  114 . Any additional devices such as additional injection needles are also removed from the port  102  and the body at this point leaving the catheter  112  sealed within the body. 
         [0016]    To prevent damage to a valve of a valved catheter or port, anchoring needle  124  of the present invention may be extended to maintain such a valve in an open position during the procedure. After the procedure has been completed, the anchoring needle  124  is withdrawn allowing the valve to close under its natural bias. These valves are often located near the port  102  (e.g., in the outlet  108 ). Thus, for a given application, a length of the anchoring needle  124  is selected to enable a distal end  128  thereof to be advanced distally beyond the distal tip of the introducer needle  120  across the fluid chamber  106  and through the valve. The distal end  128  is preferably formed as a smooth blunt shape to minimize the chance of damage to the valve. In the case of a PASV, the distal end  128  is passed through a slit in the membrane pushing opposite edges of the slit away from one another to hold the valve open. Fluid from the power injection then passes through the PASV without unduly stressing the membrane. As would be understood by those skilled in the art, the anchoring needle  124  is preferably shaped so that, as the distal end  128  leaves the confinement of the lumen  126 , a bias of the material of the anchoring needle  124  bends the distal end  128  to extend laterally away from an axis of the introducer needle  120 . The physician may then rotate the anchoring needle to point the distal end  128  toward the valve (e.g., toward the outlet of the port  102 ). Those skilled in the art will understand that the proximal end of the anchoring needle  124  may include visual or tactile indications of the orientation of the distal end  128  facilitating aiming of the distal end  128  toward the valve. Alternatively, the anchoring needle  124  and the lumen  126  may be shaped so that only one insertion orientation is possible. For example, as would be understood by those skilled in the art, a key or other shape protruding from the anchoring needle  124  may mate with a corresponding recess in the lumen  126  so that an orientation of the anchoring needle  124  relative to the introducer needle  120  will always be known. 
         [0017]    In addition, the physician may control a height at which the distal end  128  traverses the fluid chamber  106  by adjusting a height of the distal end of the introducer needle  120  relative to a base of the fluid chamber  106  to aim the distal end  128  toward a desired portion of the valve. For example, for a PASV with a substantially central slit, the physician may wish to engage a center of the membrane or an area a predetermined distance from the center. To do this, the physician may insert the introducer needle until is contacts the base of the fluid chamber  106  and then withdraw the introducer needle  120  by a desired distance so that the distal end  128  exits the introducer needle  120  at the desired height. Then, as the anchoring needle  124  is advanced distally through the lumen  126 , the distal end traverses the fluid chamber toward the valve along a desired trajectory which results in the distal tip  128  engaging the valve at the desired height. 
         [0018]    The present invention has been described with reference to specific exemplary embodiments. Those skilled in the art will understand that changes may be made in details, particularly in matters of shape, size, material and arrangement of parts. Accordingly, various modifications and changes may be made to the embodiments. The specifications and drawings are, therefore, to be regarded in an illustrative rather than a restrictive sense.