Patent Document

BACKGROUND OF THE INVENTION 
     The present invention relates to a system for use in the treatment of vascular disease. Vascular disease is a common condition which causes the development of a stenosis, or narrowing, of the vasculature. The resulting reduction in blood circulation in the stenotic vessel may cause a variety of medical problems. 
     A common treatment of stenosis involves the delivery of a stent via a delivery device, such as a catheter, to the region of the stenosis. Stents are typically a tubular device which can be expanded from a first collapsed state to a second expanded state. The stent may be crimped down over a balloon which is disposed about a distal region of the catheter. The stent delivery catheter advances the stent to the delivery site, at which time the balloon is inflated, causing the stent to expand to its deployed state in which the stent engages the inner walls of the blood vessel, thereby maintaining the vessel in an unrestricted state. 
     Stenotic lesions may also form at a bifurcation, which is a region of the vasculature where a parent vessel is bifurcated into at least two branch vessels. Bifurcated lesions pose additional challenges for medical treatment. Such cases may require the deployment of two stents in the bifurcated region or, alternatively, a single stent have a first diameter portion for deployment in the parent vessel and a second diameter portion for deployment in the branch vessel. 
     To assist in the deployment of a bifurcated stent device for treatment of a bifurcation lesion, a specialized catheter can be used which may include a dual balloon stent deployment system. A parent balloon can deploy a first diameter portion of the stent in the parent vessel, while the sidebranch balloon can deploy a second stent diameter portion in a branch vessel. Each of the two balloons is in fluid communication with its own lumen. The lumens are connected to separate inflation devices which deliver inflation fluid through the lumens to inflate the balloons. 
     What would be desirable is a stent delivery catheter system in which the user could inflate both balloons separately and/or simultaneously without having to disconnect or reconnect the inflation device. It would also be desirable to have a means for indicating to the user which of the dual balloons is deflated at any given time. 
     SUMMARY OF THE INVENTION 
     The present invention pertains to a stent delivery catheter system with a dual balloon valve control and pressure indicator. In one embodiment, the system includes a dual balloon/dual inflation lumen catheter having an accessory device attached at its proximal end. The accessory device includes a single luer connection point for an inflation device, a bifurcated fluid line for delivering inflation fluid to each balloon separately, and two additional luer connection points which connect the accessory device to the inflation lumens in fluid communication with the parent and sidebranch balloons, respectively. The branch of the bifurcated fluid line which leads to the sidebranch balloon may extend at an angle from the branch which leads to the parent balloon. A one-way stopcock is mounted on the branch of the bifurcated fluid line connecting the inflation device with the parent balloon. 
     In a preferred embodiment, a second one-way stopcock is added to the branch of the fluid line leading to the sidebranch balloon. In yet another embodiment, the one-way stopcocks are replaced by a single 3-way stopcock placed at the bifurcation point of the accessory device fluid lines. 
     A pressure indicator may be placed on either or both of the fluid lines of the above embodiments. The indicator can show the user which of the balloons is deflated at any given time. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a dual balloon/dual inflation path stent delivery catheter including a dual balloon valve control accessory having a main fluid line and a branched fluid line with a stopcock; 
         FIG. 2  illustrates a cross-sectional view of a pressure indicator; 
         FIG. 3  illustrates a dual balloon valve control accessory for a dual balloon/dual inflation path stent delivery catheter having a main fluid line with a stopcock and a sidebranch fluid line; 
         FIG. 4  illustrates a dual balloon valve control accessory for a dual balloon/dual inflation path stent delivery cathether having a three-way stopcock located at the bifurcation point of the main and sidebranch fluid lines; 
         FIG. 5  illustrates a cross-sectional view of the three-way stopcock shown in  FIG. 4  in which fluid is prevented from entering either fluid line; 
         FIG. 6  illustrates a cross-sectional view of the three-way stopcock shown in  FIG. 4  in which fluid is allowed to enter either fluid line; 
         FIG. 7  illustrates a cross-sectional view of the three-way stopcock shown in  FIG. 4  in which fluid is allowed to enter only a first fluid line; and 
         FIG. 8  illustrates a cross-sectional view of the three-way stopcock shown in  FIG. 4  in which fluid is allowed to enter only a second fluid line. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a preferred embodiment of a dual balloon/dual inflation path stent delivery catheter system  10 , including a valve control accessory device  11  and catheter  24 . Accessory device  11  includes a main fluid line  12  and a sidebranch fluid line  16 . Sidebranch fluid line  16  diverges from main fluid line  12  at bifurcation point  20 . Main fluid line  12  includes a luer connection point  22  at its proximal end adapted to engage a source of inflation fluid. Catheter  24  includes a manifold  25  having a main shaft  26  and a sidebranch shaft  28 . Sidebranch shaft  28  converges with main shaft  26  at bifurcation point  30 . 
     A luer connection point  32  is located at the distal end of main fluid line  12  of accessory device  11 , and is adapted to engage an opening  34  at the proximal end of main shaft  26 . Luer connection point  36  is located at the distal end of sidebranch fluid line  16 , and is adapted to engage opening  38  at the proximal end of sidebranch shaft  28 . 
     A first one-way stopcock  48  is disposed about mainbranch  12  proximal to luer connection point  32 . A second one-way stopcock  50  is disposed about sidebranch  16  proximal of luer connection point  36 . Accessory device  11  may also include finger grip  52  disposed about bifurcation point  20 , which makes valve control accessory  11  easier to hold by reducing the chance of having it spin in use. 
     A sidebranch balloon  40  is in fluid communication with sidebranch fluid line  16  of accessory device  11  through an inflation lumen disposed within tubular member  42 . A parent balloon  44  is in fluid communication with main fluid line  12  of accessory device  11  through an inflation lumen disposed within tubular member  46 . 
     The fluid lines of valve control accessory  11  can be flexible or rigid, and may be formed from any suitable material well known to those of skill in the art. Stopcocks  48  and  50  similarly may be formed from materials known to those of skill in the art. 
     In use, the catheter system of  FIG. 1  allows the user to use one inflation device to inflate or deflate the balloons separately or simultaneously, without having to disconnect or reconnect the inflation device. Catheter  24  may be advanced through the vasculature to the site of a lesion in a bifurcated vessel such that the bifurcated stent is properly positioned within the bifurcated vessel. 
     Once the catheter is in position, stopcock  50  may be turned to the “open” position and a source of inflation fluid attached to luer connecter  22  is used to introduce fluid into inflation lumen  42 , causing sidebranch balloon  40  to inflate, thereby expanding into its deployed position that portion of the stent that is in the sidebranch vessel. Inflating the sidebranch balloon  40  first serves to properly align the opening in the stent with the sidebranch vessel. Inflating the parent balloon without inflating the sidebranch balloon can be undesirable in that a portion of the stent could be deformed. 
     Sidebranch balloon  40  may then be deflated in order to temporarily restore blood flow through the sidebranch vessel. Next, stopcock  48  and stopcock  50  are both turned to the “open” position, such that inflation fluid may also flow through main fluid line  12  and into inflation lumen  46 . Both sidebranch balloon  40  and parent balloon  44  are thereby inflated simultaneously so as to fully deploy the stent. Sidebranch balloon  40  and parent balloon  44  are then deflated simultaneously. Catheter  24  is then withdrawn, leaving the stent in place within the bifurcated vessel. 
     The presence of stopcocks on both the main fluid line  12  and the sidebranch fluid line  16  serves to isolate the parent balloon  44  from the sidebranch balloon  40 , thereby providing the flexibility to allow the user to inflate and deflate each balloon in a variety of ways. For example, the balloons could be inflated to different pressures. 
     A significant feature of valve control accessory  11  is the branching off of sidebranch fluid line  16  from the main fluid line  12  in the shape of a “y.” This provides an intuitive reminder to the user that the sidebranch fluid line  16  is in fluid communication with the sidebranch balloon  40 . Such a configuration can reduce the chance of the user making an error with respect to which stopcock regulates inflation fluid flow to which balloon. 
       FIG. 2  illustrates a cross-sectional view of a preferred embodiment for a pressure indication device  54  which may be utilized in conjunction with all embodiments of the dual balloon valve control accessory of the present invention. Device  54  may be disposed on fluid line  12  distal of stopcock  48 . Pressure indicator device  54  includes a housing  56  and a cap  58 , which may be opaque. Cap  58  serves to securely hold the internal components of pressure indicator device  54  within the housing  56 . An elastomeric component  60  is disposed within housing  56  and may be formed from any suitable elastomeric material. Pressure indicator device  54  also includes an opening  62  into inflation lumen  14  at its base. A diaphragm  64 , which may be formed from any suitable elastomeric material, serves to prevent inflation fluid from lumen  14  from entering the inside of housing  56  via opening  62 . 
     In use, the flow of inflation fluid through lumen  14  past pressure indicator device  54  subjects elastomeric diaphragm  64  to pressure, such that it flexes, causing the upward deformation of elastomeric component  60 . The upward deformation causes elastomeric component  60  to protrude above the cap  58 , as shown. The protrusion of elastomeric component  60  provides a visual indication to the user of the catheter that the catheter is under pressure. The protrusion also provides a tactile indicator of pressure in the form of an easily felt bump on the cap  58 . When the inflation fluid is no longer under pressure, elastomeric diaphragm  64  relaxes and returns to its unflexed position, causing elastomeric diaphragm  64  to assume a non-deformed position such that elastomeric component  60  no longer protrudes from cap  58 . 
     Generally, it is desired that both balloons be deflated before the catheter system is withdrawn from the vasculature. Since the embodiment of  FIG. 1  allows each balloon to be inflated or deflated independently, the presence of pressure indicator  54  enhances the ability of the user to check whether both balloons are deflated before the catheter system is removed from the patient. Pressure indicator  54  may also be formed as a separate piece to be connected in-line on any device where pressure indication is desired. 
       FIG. 3  illustrates an alternative embodiment of a valve control accessory for a dual balloon/dual inflation path stent delivery catheter. Valve control accessory  111  is similar in most respects to valve control accessory  11  of  FIG. 1  with regard to formation and use, except that no stopcock is present on sidebranch fluid line  116 . Stopcock  148  is disposed about main fluid line  112 . This embodiment allows the user to regulate the flow of inflation fluid through the main fluid line  112 , but not the sidebranch fluid line  116 . Since, as described above, the sidebranch balloon is generally desired to be inflated first during use, this configuration ensures that the sidebranch balloon will always be inflated before the parent balloon, so long as stopcock  148  is closed. 
       FIG. 4  illustrates yet another embodiment of the present invention. Valve control accessory  211  is similar to valve control accessory  11  of  FIG. 1 , except that a single three-way stopcock  66  at bifurcation point  220  replaces individual one-way stopcocks in the main fluid line  212  and sidebranch fluid line  216 . Stopcock  66  can be formed from two mating core pins within a mold that would be pulled out in a parallel direction. 
       FIGS. 5-8  illustrate cross-sectional views of the various positioning possibilities of three-way stopcock  66 . In  FIG. 5 , stopcock  66  is shown in the “off” position, in which inflation fluid is prevented from flowing through either main fluid line  212  or sidebranch fluid line  216 . In  FIG. 6 , stopcock  66  is shown in the “on” position, in which inflation fluid is allowed to flow through either main fluid line  212  or sidebranch fluid line  216 .  FIG. 7  illustrates stopcock  66  in the “left on” position, in which inflation fluid is allowed to flow only through main fluid line  212 .  FIG. 8  illustrates stopcock  66  in the “right on” position, in which inflation fluid is allowed to flow only through the sidebranch fluid line  216 . 
     It will be understood that this disclosure, in many respects, is only illustrative. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. For example, any of the embodiments above may be made as an integral part of an inflation device, making the connection between the line from the inflation device to the luer connector of the valve control accessory into a permanent, non-separable connection. Additionally, an inflation device could be manufactured with two flexible parallel lines permanently attached to the distal end of the inflation device&#39;s barrel. Luer connection points would be placed on the distal ends of the lines for connecting to the balloons. Stopcocks could be placed in just one line, between the barrel and a distal luer connection point, or in both lines. Also, the bifurcated fluid lines of the valve control accessory device may assume a configuration different from the “y” shape illustrated in FIG.  1  and FIG.  3 . For example, the bifurcation may be symmetrically shaped. Accordingly, the scope of the present invention is as defined in the language of the claims.

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