Abstract:
A shunt system quick connector assembly to quickly connect and disconnect a catheter to a hydrocephalus shunt system comprising a valve in a valve housing. The catheter is affixed to the quick connector assembly. The quick connector assembly snaps over an external barb on the valve housing of the shunt system with an audible sound, so that the surgeon knows that connection has been made. The connector assembly can be operated quickly, minimizing the time for the surgical procedure and the opportunity for infection. The connector assembly has smooth surfaces to minimize the growing of tissue into the connection.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Benefit is claimed under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/614,641, filed Sep. 30, 2004, the disclosure of which is incorporated by reference herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     N/A 
     BACKGROUND OF THE INVENTION 
     Hydrocephalus is a disease that causes excessive cerebral spinal fluid (CSF) to build up in the ventricle of the brain. Treatment involves the surgical implantation of a shunt system into the skull to divert CSF from the ventricle to another part of the body, such as the peritoneal cavity or the right atrium of the heart. The shunt system includes a valve that regulates the flow of CSF. Two catheters are connected to the shunt: a proximal catheter inserted directly into the ventricle allows the CSF to flow into the shunt, and a distal catheter leads from the shunt under the skin to discharge the CSF to the drainage point. 
     The valve in the shunt system controls the direction of fluid flow and the pressure in the ventricle. A Codman Hakim programmable shunt includes a pressure differential valve the pressure of which can be adjusted non-invasively by a surgeon after implantation if necessary. 
     Both the proximal and distal catheters are connected to the shunt by suturing. The surgeon slips the catheter over a barb connection on the shunt and reinforces the connection with a knot above the burr. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a quick connector assembly that provides a connection between a catheter and a valve housing in a hydrocephalus shunt system. In the shunt system, a barb element having a external barb protrudes from the valve housing. 
     The quick connector assembly includes a connector body through which a fluid passage extends. The catheter is affixed to one end of the connector body. The quick connector assembly also includes a resilient holding element comprising a radially inwardly projecting member, such as an annular snap ring, locking rib, or resilient arms. The external barb slips past the holding element with an audible sound, such as a click or snap, and is retained by the holding element with at least a portion of the barb element sealed by a sealing element within the connector body to prevent leakage of fluid. The audible sound allows the surgeon to hear when the connection has been made. The connector assembly can be disconnected by simply pulling the connector assembly away from the barb element. 
     The present quick connector assembly eliminates some of the time and struggle involved with suturing a catheter to the shunt. Shortening surgery time and limiting contact with the shunt system also minimizes opportunities for infection. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is an exploded isometric view of a shunt quick connector assembly of the present invention; 
         FIG. 2  is a cross sectional view of the quick connector assembly of  FIG. 1  connected to a ventricular barb element of a shunt system; 
         FIG. 3  is a cross sectional view of the shunt system quick connector assembly of  FIG. 1  connected to a catheter and the ventricular barb element of a shunt system; 
         FIG. 4  is an exploded isometric view of a further embodiment of a quick connector assembly of the present invention; 
         FIG. 5  is a cross sectional view of the quick connector assembly of  FIG. 4 ; 
         FIG. 6  is an isometric view of a yet further embodiment of a quick connector assembly of the present invention; 
         FIG. 7  is a cross sectional side view of a still further embodiment of a quick connector assembly of the present invention; 
         FIG. 8  is a cross sectional side view of a still further embodiment of a quick connector assembly of the present invention; 
         FIG. 9  is a cross sectional side view of a still further embodiment of a quick connector assembly of the present invention; 
         FIG. 10  is a cross sectional side view of a still further embodiment of a quick connector assembly of the present invention; and 
         FIG. 11  is a cross sectional side view of a still further embodiment of a quick connector assembly of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to a quick connector assembly for use with a shunt system, such as a Codman Hakim programmable shunt or any other shunt system. Referring to the embodiment of  FIGS. 1-3 , a shunt system  34  includes a valve housing from which a barb element  33  protrudes. The barb element includes an external barb  32 . The quick connector assembly  10  of the present invention includes a connector body  12  through which a fluid passage  24  extends. A catheter  40  is affixed to one end  38  of the connector body. At least a portion of the barb element  33  is inserted into the opposite end of the connector body and is retained therein by a resilient holding element  18 . The holding element has a radially inwardly projecting member(s) (described further below) that is able to resile or spring back to its original position after passage of the external barb of the barb element. A sealing element  22  seals the barb element within the connector body to prevent leakage of fluid. 
     More particularly, in the embodiment of  FIGS. 1-3 , the connector body  12  includes a main body portion  14 . A retaining insert  16  for retaining the holding element, such as a snap ring  18 , and a washer or retainer  20  for retaining the sealing element, such as an O-ring  22 , are located within the main body portion. The fluid passageway  24  extends through the connector body from an entrance opening  26  to an exit opening  28 . The main body portion includes a female portion  30  in which is inserted the barb element  33  having the external barb  32  of the shunt system  34 . The female portion has a smooth outer surface  36 , which keeps the connector body from being overly intrusive when implanted in a patient so that surrounding tissue is less likely to “root” in the connection. The main body portion also includes a male portion  38  that is affixed to the catheter  40 , such as with a suitable adhesive. The catheter is preferably permanently affixed to the assembled connector body during manufacture. 
     In the embodiment illustrated, the interior of the female portion  30  of the main body portion  14  includes three sections  42 ,  44 ,  46  each defined by an interior wall  42   a ,  44   a ,  46   a  and separated by shoulders or steps  42   b ,  44   b . A third shoulder or step  46   b  separates the third section  46  from the male portion  38 . The retaining insert  16  fits snugly against the first wall  42   a  within the first section  42  and extends from the entrance opening  26  to the first step  42   a . The retaining element is preferably affixed, such as with adhesive, to the interior of the female portion. The washer  20  fits snugly against the second wall  44   a  within the second section  44  and adjacent the second shoulder  44   b . The O-ring  22  is located between the washer  20  and the third shoulder  46   b.  The O-ring prevents fluid from leaking from the barb element back through the connector assembly. The washer retains the O-ring in place within the main body portion. The retaining insert  16  is shaped to conform to the outer shape of the barb element  33 , which assists in preventing bending moments from weakening the barb element  33 , pulling the barb element from the quick connector assembly, or creating a gap between the barb and the sealing element. 
     In the embodiment illustrated, the holding element for the external barb is the snap ring  18 , which is constructed of a semi-elastic, biocompatible material. The snap ring is located within the second section  44  of the female portion and is retained there by the retaining insert  16 . The retaining insert keeps the snap ring from shifting axially along the main body portion. The external barb  32  of the barb element  33  is retained beneath the snap ring, thereby retaining the barb element in the connector body. The snap ring is preferably split so that it can readily expand into the annular region of the second section  44  as the barb element passes by. The holding element is resilient so that it can expand as the barb element passes by and then return to its original position to retain the barb element within the connector body. 
     In this manner, a shunt system with an external barb can be pushed into the connector body and can snap into place beneath the snap ring with an audible sound, assuring the surgeon that the connection has been made. To disconnect the catheter, the surgeon merely pulls on the connector assembly with a sufficient force to move the external barb past the snap ring. 
     Preferably, for a hydrocephalus shunt system, the quick connector assembly is able to withstand the expected pulling forces and pressures as evidenced by ISO standard 7197. This standard requires that the connector withstand a hanging 2.2 pound weight for one minute and an internal pressure of 1.75 psi for five minutes. 
     In another embodiment, illustrated in  FIGS. 4 and 5 , a quick connector assembly  80  is formed with a single piece connector body  82 . A female portion  84  includes an internal sealing surface  86  that tapers from the entrance opening  88  to a narrower portion  90  of the passage through the male portion  92 . The barb element (not shown in  FIGS. 4 and 5 ) is inserted into the female portion. The sealing surface  86  is preferably smooth to provide a fluid tight seal with the external barb. A snap ring  94  is located within an annular groove  96  formed in the internal sealing surface  86 . The groove keeps the snap ring from shifting axially along the main body and also keeps tension between the barb and sealing surface to facilitate a proper seal. The external barb of the shunt is retained beneath the snap ring, thereby retaining the shunt barb in the female portion. The snap ring is preferably includes a split  98  so that it can readily expand into the annular retaining groove  96  in the connector body. The snap ring, in conjunction with the connector body, keeps the external barb of the shunt securely fixed to the smooth sealing surface within the connector body. This is accomplished because the snap ring is only able to expand and contract within the connector body when the barb is inserted into the housing. For ease of assembly, the outer edge  102  of the snap ring may be angled and the edge  104  of the entrance opening  88  of the connector body may be rounded. 
     In another embodiment, a hole  108  may be provided through the connector body to the annular retaining groove. See  FIG. 6 . A tool is inserted into the hole to spread the snap ring open at the split, thereby allowing the catheter to be easily pulled out. In a further alternative, the snap ring may be formed integrally with the connector body. 
       FIG. 7  illustrates a further embodiment in which a quick connector assembly  120  having a holding element in which a pair of lever arms  122  are fixed to a main body  124  of the connector assembly with resilient fulcrum extensions  126 . The lower end of each lever arm includes a tooth  128  that catches under the external barb  130  of the barb element  132  of a shunt system. To disconnect the shunt system, the lever arms are squeezed inwardly about their upper ends  134 . Two lever arms are shown, but any desired number could be provided, particularly if greater contact area with the barb element were desired. The interior surface is conical or tapered to sit snugly on the barb element to create a seal therewith. A catheter is affixed to the opposite end  136  of the main body  134 . 
       FIG. 8  illustrates a further embodiment of a quick connector assembly  150 , similar to that of  FIG. 7 , in which locking arms  152  are connected to the connector body  153  by cross members  154 . Two locking arms are shown, but any desired number could be provided, particularly if greater contact area with the barb element were desired. The cross members cover the tops of the arms to prevent or minimize the arms from snagging or catching on anything. To disconnect the connector assembly, the arms are pinched together. 
       FIG. 9  illustrates a further embodiment of a quick connector assembly  160  having locking arms  162 , such as described with respect to  FIG. 8 . A collar  164  having collar arms  168  is slipped over the end of a connector body  170 . Ribs  172  on the ends of the collar arms  168  press on the body  170  to provide a seal against the barb element  174  of a shunt system. Disconnection is made by pressing the collar  164  downwardly, thereby dislodging the locking arms  162  from the barb element. To provide a smooth outer surface, a shell  178  can be added to the connector assembly of  FIG. 9 . See  FIG. 10 . The shell helps to reduce tissue growth to the connector assembly. 
     A further one-piece embodiment of a quick connector assembly  190  is illustrated in  FIG. 11 . The outer surface  192  of the connector body  194  includes a finger grip region  196 . A locking ring or rib  198  is formed integrally with an internal surface within a female portion  202 . The internal surface can include a tapered or conical section  204  to provide a seal with the barb element (not shown). 
     The quick connector assembly can be manufactured in any suitable manner such as by injection molding, and can be made of any suitable biocompatible material, such as silicone or a silicone-based material or polyethersulfone. The material must resist corrosion. Preferably, the materials are selected for compatibility with sterilization by ethylene-oxide (EtO) and steam processes. A metal material, such as stainless steel, can be used, although plastic and silicone-based materials are preferred if the materials should not be detected by MRI scanning. These materials are also fairly easy to manufacture, such as by injection molding. The shunt connection can be impregnated with antibiotics to prevent or minimize infection. The shunt connection can be impregnated with barium or can include a barium stripe to allow the shunt to be visible on X-rays. 
     The present quick connector assembly features a positive locking system to ensure that the surgeon makes a proper connection. The connection provides an audible sound, such as a click or snap, allowing the surgeon to hear that the connection has been made. 
     The shunt connector assembly provides a simpler procedure for implanting shunts by eliminating some of the time and struggle involved with suturing the catheter to the shunt. Shortening surgery time and limiting contact with the shunt also minimizes opportunities for infection. If a shunt needs to be replaced, reinstallation time is also minimized by the ability to leave the catheters in place and simply swap out the shunt. The quick connector assembly can be used on either the proximal or distal (inlet or outlet) side of the valve housing of a shunt system. 
     The invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.