Patent Publication Number: US-2012029425-A1

Title: Combined catheter tip and inflation balloon

Description:
PRIORITY CLAIM 
     The present application claims priority to U.S. Provisional Application Ser. No. 61/118,788, filed Dec. 1, 2008, and entitled “COMBINED BALLOON TIP”, which is herein incorporated by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The invention relates generally to a catheter including an inflation balloon proximate a catheter tip. More specifically, the present invention relates to a catheter tip and inflation balloon that can be combined through a molding process to create a combined tip assembly for attachment to a catheter body. 
     BACKGROUND OF THE DISCLOSURE 
     A medical catheter is essentially an artificial tube or lumen that is inserted into a body lumen to provide access to an area to be examined or treated. Typically, catheters comprise a treatment or manipulation apparatus at a proximal end that allows a medical professional to advance the catheter to the appropriate area and to examiner or provide medical treatment to tissue proximate the body lumen at that location. While a treatment end of the catheter is adapted to provide medical treatment within the body lumen, the treatment end can suffer from an inability to be easily navigated to the targeted tissue unassisted because of its diameter, rigidness or shape. In these instances, a tip can be attached to treatment end. Generally, the tip is smaller in diameter, softer or more flexible than the operational end so as to ease the movement of the catheter through the body cavity and minimize damage to the surrounding tissue as the catheter is navigated to the targeted tissue. 
     Depending upon the style of the catheter, attachment of the tip can be accomplished in different ways. The tip is typically affixed to the end of the catheter body by aligning the end of the tip with the end of the catheter body and bonding the ends of the tip and catheter body together with a bonding agent such as adhesive or plasticizer. Open ended catheters have an exposed catheter lumen that may be sufficiently large in diameter to allow at least a portion of the tip to be inserted into the catheter body. In contrast, closed ended or “blind ended” catheters have closed catheter lumen and cannot receive a portion of the tip into the catheter body. As a result, the tip and the blind ended catheter body must be aligned manually and retained in the aligned position until bonded together. 
     When the medical catheter is being used to dispense treatment to the targeted tissue, the distal treatment end can be fabricated to include a wide variety of delivery mechanisms. For example, a distal treatment end of a catheter body can include injection ports for delivering a therapeutic agent to the tissue, fiber optic ports for delivering laser energy to the tissue, temperature probes for delivering either heating or cooling at the tissue or even microwave antennas to provide targeted microwave energy to the tissue rather than transmitting the microwave energy through the patient&#39;s skin to attempt or reach the tissue. In addition to delivering therapy to the targeted tissue, components such as, for example, inflation balloons can be provided that help to fix the position of the distal treatment end relative to the targeted tissue or which seek to occlude the body lumen to prevent healthy tissue from being exposed to treatment intended for the targeted tissue. 
     In the event that an inflation balloon is included as part of the catheter, the inflation balloon is generally adhesively attached to the catheter at the appropriate location. Generally, the inflation balloon is positioned over an inflation lumen that extends the length of catheter such that a medical professional can introduce an inflation fluid at the appropriate time. Typically, the inflation balloon is bonded to the catheter following attachment of the catheter tip. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure relates to improvements in manufacturing catheters that include inflation balloons as part of their particular treatment. Generally, a catheter tip of the present invention is fabricated to include an inflation balloon that is formed/bonded to the catheter tip as part of an initial molding operation. Generally, the catheter tip is formed of a first high durometer polymer while the inflation balloon is formed using a second low durometer polymer. Utilizing a two-step molding operation, the first high durometer polymer can be injected to form the catheter tip and subsequently allowed to cool. Next, the second low durometer polymer is injected to form the inflation balloon and to bond the inflation balloon to the catheter tip so as to create an integrated catheter tip. Once the integrated catheter tip has been formed, the integrated catheter tip can be attached to the catheter body utilizing a conventional attachment method. With the integrated catheter tip now attached to the catheter body, no additional processing steps are required to attach the inflation balloon and consequently, the possibility of additional processing leading to damage to the catheter is removed. 
     In one aspect, the present invention is directed to a treatment catheter utilizing an inflation balloon as part of a desired treatment procedure. Generally, the treatment catheter comprises an elongated catheter body having a proximal manipulation end and a distal end. An integrated catheter tip is operably joined to the distal end. The integrated catheter tip comprises a molded assembly having a high durometer tip portion and a low durometer inflation balloon. The integrated catheter tip is formed utilizing a two step molding process in which a tip body is formed utilizing a first high durometer polymer that is subsequently allowed to col. The low durometer inflation balloon is formed by an injecting a second low durometer polymer such that the inflation balloon is properly positioned along the integrated catheter tip and no additional joining operations are required. 
     In another aspect, the present invention is directed to an integrated catheter tip comprising a high durometer tip portion and low durometer inflation balloon. The integrated catheter tip is fabricated using a two-step molding process such that the formation of inflation balloon also results in attachment of the inflation balloon to a high durometer catheter tip. The catheter tip is formed of a first high durometer polymer and subsequently allowed to cool. Once the catheter tip has cooled, a second low durometer polymer is injected to form the inflation balloon while simultaneously bonding the inflation balloon to the catheter tip so as to create an integrated catheter tip. Once the integrated catheter tip has been formed, the integrated catheter tip can be attached to the catheter body utilizing a conventional attachment method. 
     In yet another aspect, a method for forming a treatment catheter can comprise attaching an integrated catheter tip to a catheter body. Generally, the integrated catheter tip is formed by molding a tip portion from a first high durometer polymer. Next, a second low durometer polymer is injected to form an inflation balloon that is operably coupled to the tip portion. 
     The above summary of the invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The Figures and the detailed description that follows more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
         FIG. 1  is a side view of a treatment catheter according to a representative embodiment of the present disclosure. 
         FIG. 2  is a side view of an integrated catheter tip according to a representative embodiment of the present disclosure. 
         FIG. 3  is a section view of the integrated catheter tip of  FIG. 2  taken a line  3 - 3  of  FIG. 2 . 
         FIG. 4  is a side view of an integrated catheter tip according to a representative embodiment of the present disclosure. 
         FIG. 5  is a section view of the integrated catheter tip of  FIG. 4  taken a line  5 - 5  of  FIG. 4   
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE FIGURES 
     As illustrated in  FIG. 1 , a treatment catheter  100  of the present invention generally comprises a catheter body  102  and an integrated catheter tip  104 . Catheter body  102  generally includes a proximal manipulation end  106  and a distal attachment end  108 . Proximal manipulation end typically includes one or more ports  110  in communication with one or more discrete lumens defined within the catheter body. Utilizing ports  110 , a medical profession is able to deliver or otherwise administer treatment to a targeted treatment area when the integrated catheter tip  104  is positioned proximate the treatment area. 
     Referring to  FIGS. 2 and 3 , integrated catheter tip  104  generally comprises a tip body  112  having a tip attachment end  114  and a tip introduction end  116 . Tip attachment end  114  generally comprises at least one internal lumen  118  that is fluidly connected to one or more tip apertures  120  on an exterior surface  122  of the tip body  112 . Positioned intermediate the tip attachment end  114  and the tip introduction end  116  is an inflation balloon  124 . Inflation balloon  124  covers the corresponding tip aperture  120  and sealingly engages the exterior surface  122 . In some embodiments, inflation balloon  124  can completely surround the tip body  112  as shown in  FIGS. 2 and 3 , while in other alternative embodiments, inflation balloon  124  can be located about only a portion of the tip body  112  resulting in an offset configuration as shown in  FIGS. 4 and 5 . In an alternative embodiment, integrated catheter tip  104  can comprise a plurality of spaced apart inflation balloons  124  as shown in  FIGS. 4 and 5 . 
     Generally, the integrated catheter tip  104  is arranged such that tip attachment end  114  is operably connected to the distal attachment end  108  of catheter body  102  to form the treatment catheter  100 . With the integrated catheter tip  104  attached to the catheter body  102 , a medical professional directs the tip introduction end  116  into a body lumen, whereby the medical professional directs the tip introduction end to a tissue treatment area. With the integrated catheter tip  104  positioned proximate the tissue treatment area, an inflation fluid can be introduced through port  110 , through catheter body  102 , into the internal lumen  118  and out the tip aperture  120  to inflate the inflation balloon  124 . 
     The integrated catheter tip  104  is generally fabricated utilizing a two-step molding process such that the tip body  112  and inflation balloon  124  comprise a single, integral component. Generally, the tip body  112  is molded using a first high durometer polymer that is allowed to cool within the mold. Next, a second low durometer polymer is injected to form the inflation balloon  124 . In forming inflation balloon  124 , the inflation balloon  124  is simultaneously attached to the tip body  112  such that integrated catheter tip  104  is formed with no additional bonding or attachment being required. 
     Although specific examples have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement calculated to achieve the same purpose could be substituted for the specific example shown. This application is intended to cover adaptations or variations of the present subject matter. Therefore, it is intended that the invention be defined by the attached claims and their legal equivalents.