Abstract:
A vascular access device for infusion of fluids into a patient. The device includes an introducer sheath having one or more side holes and the sheath can be used with a catheter in place through the sheath, with a dilator in place through the sheath, or with the sheath vacant. The device provides for a significant volume of infused fluid to exit the side holes. The side holes allow for the infusion of fluids, such as medications, to be directed to specific patient locations rather than to have the entire volume of infused fluid exit the distal end of the sheath tube.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to medical devices suitable for use in delivering fluids to a patient. More particularly, the invention relates to an introducer sheath which will include side holes configured such that the holes appear longitudinally and circumferentially along the sheath tubing to provide an outlet for medications injected into the sidearm of the sheath. The holes will allow medication to be directed to specific locations rather than to have the entire volume of medication exit the distal end of the sheath tube. 
     The clinical utility of the infusion sheath relates to the ability to infuse medications, specifically medications intended to counteract vasospasm. Vasospasm is a common problem, particularly in the transradial catheterization technique. The result of vasospasm is difficulty in sheath removal and accompanying patient discomfort at the end of a catheterization procedure. To minimize or eliminate vasospasm, physicians will commonly administer a ‘cocktail’ of medications. An example of such a cocktail would be a mixture of Verapamil, Nitroglycerine, and Xylocaine, Verapamil being an antispasmotic agent. This mixture would be injected through the sideport of the sheath, often prior to withdrawing the sheath, to minimize vasospasm and discomfort. With current sheath designs, the fluid will exit in its entirety out the end of the sheath. With a 21 cm sheath, this presents the potential for the drugs to be significantly distant from where the spasming may be taking place. The tendency of the medications will be to flow in the direction of the blood flow which will be back towards the proximal end of the sheath tubing (for example, flowing from the elbow area back towards an insertion site in the wrist). However, the sheath tubing is large in relation to the radial artery lumen size and therefore may obstruct the medications from getting to the specific portion of the radial artery which is spasming. It is important to note that prior to performing a radial artery procedure, the physician must first ascertain whether the patient has good collateral blood flow into the hand. This is so that if the radial artery is not providing sufficient flow due to sheath obstruction, the ulnar artery can continue to provide sufficient circulation. 
     The infusion sheath design of the present invention overcomes these clinical problems. By providing infusion ports along a significant portion of the sheath tubing, the drugs can exit the sheath at the point where spasming may be occurring and have a quicker, and perhaps, more effective response. Some prior art teachings disclose side holes or slits which communicate with specifically designated lumens within the wall of the sheath. The present invention allows for a sheath which maintains the critical aspects of being able to have appropriate wall thickness such that insertability and the size of the puncture are not compromised. The design of the sheath and a dilator, which, in some instances, will be used in combination with the sheath, to accommodate this objective is significantly different than other known configurations in sheaths or catheters. 
     SUMMARY OF THE INVENTION 
     The present invention is directed toward a vascular device adapted for infusion of fluids into a patient comprising an elongated tubular member having a proximal end, a distal end and a wall extending between the proximal end and the distal end, the wall having an inner surface and an outer surface, at least one lumen extending between the proximal end and the distal end and communicating with the inner surface, with the at least one lumen being adapted to receive a fluid, and one or more apertures disposed in the wall along a length between the proximal end and the distal end for providing fluid communication between the inner surface and the outer surface and adapted for conveying the fluid between the at least one lumen and an environment surrounding the outer surface. The apertures might be disposed circumferentially about the wall, as for example, in a helical pattern, or the apertures might be disposed longitudinally along the wall, as for example, in one or more rows. The apertures may have a diameter in a range of from about 0.025 mm to about 0.600 mm. Preferably, the apertures might have a diameter of about 0.125 mm. The apertures might be spaced from about 1 mm to about 200 mm apart. Preferably, the apertures might be spaced about 10 mm apart. The tubular member might have a length in a range of from about 10 cm to about 25 cm. Further included is a means for delivering the fluid to the lumen. 
     The invention further embodies a vascular device for infusion of fluids into a patient comprising a first elongated tubular member having a proximal end, a distal end, a first lumen extending therethrough and a first wall having an outer surface and extending between the proximal end and the distal end, a second tubular member having a second wall and being positioned within the lumen to define a space between the first wall and the second wall, the space being adapted to receive a fluid, the second tubular member being sized and configured to create a fluid seal proximate the distal end of the first tubular member, and one or more apertures disposed in the first wall between the proximal end and the distal end for providing fluid communication between the space and an environment surrounding the outer surface of the first wall, wherein fluid introduced into the space exits the device substantially only through the one or more apertures along the length of the outer surface of the first wall. The apertures might be disposed circumferentially about and longitudinally along the first wall. The second tubular member is preferably a dilator which comprises a first portion having a first cross section and a second portion having a second cross section, with the first cross section being greater than the second cross section. The first cross section at a first predetermined location has a cross section being at least equal to the lumen at the first predetermined location. The second cross section at a second predetermined location has a cross section being less than the lumen at the second predetermined location. The dilator might include at least one groove disposed in an outer surface along a length of the dilator. The dilator might further comprise a closed distal end and a second lumen therein communicating with the space, the second lumen being adapted to receive the fluid and delivering the fluid to the space. The second wall of the dilator might comprise one or more second lumens disposed in the second wall communicating with the space, the one or more second lumens being adapted to receive the fluid and delivering the fluid to the space. 
     The invention still further embodies a vascular device for infusion of fluids into a patient comprising a first elongated tubular member having a proximal end, a distal end and a lumen extending therethrough, a first wall extending between the proximal end and the distal end, with the first tubular member having a through opening at the distal end, a second tubular member having a second wall and being positioned within the lumen to define a space between the first wall and the second wall, the space being adapted to receive a fluid, with a portion of the second member extending through the opening at the distal end of the first tubular member, and one or more apertures disposed in the first wall between the proximal end and the distal end for providing fluid communication between the space and an environment external of the device, wherein a portion of the fluid introduced into the space exits the device through the one or more apertures along the length of the first wall. Preferably the second tubular member is a catheter and the apertures are disposed circumferentially about and longitudinally along the first wall. 
     In yet another embodiment of the invention embraces a vascular device for infusion of fluids into a patient comprising a first elongated tubular member having a proximal end, a distal end and a lumen extending therethrough, a first wall having an outer surface and extending between the proximal end and the distal end, a second tubular member having a second wall and being positioned within the lumen to define a space between the first wall and the second wall, the space being adapted to receive a fluid, and one or more apertures disposed in the first wall between the proximal end and the distal end for providing fluid communication between the space and an environment surrounding the outer surface of the first wall, wherein fluid introduced into the space exits the device substantially only through the one or more apertures along the length of the outer surface of the first wall. Preferably, the second tubular member is a dilator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partial, elevation view of an embodiment of a vascular access device in accordance with the principles of the present invention and illustrating an infusion sheath with side holes for the delivery of fluid into a patient. 
     FIG. 2 is a partial, elevation view of a dilator adapted for use with the access device of FIG.  1 . 
     FIG. 3 is a partial, sectional view, in elevation, of the device of FIG. 1 with the dilator of FIG. 2 inserted into the infusion sheath. 
     FIG. 3A is an enlarged sectional view of the area signified by  3 A of FIG.  3 . 
     FIG. 3B is an enlarged sectional view of the area signified by  3 B of FIG.  3 . 
     FIG. 4 is an elevation view of a modified dilator. 
     FIG. 4A is an enlarged, cross sectional view of the dilator of FIG. 4 taken along sight line  4 A— 4 A. 
     FIG. 5 is a partial, sectional view, in elevation, of the device of FIG. 1 with a catheter inserted into the infusion sheath. 
     FIG. 5A is an enlarged sectional view of the area signified by  5 A of FIG.  5 . 
     FIG. 5B is an enlarged sectional view of the area signified by  5 B of FIG.  5 . 
     FIG. 6 is a partial, sectional view, in elevation, of the device of FIG. 1 with another modified dilator inserted into the infusion sheath. 
     FIG. 6A is an enlarged sectional view of the area signified by  6 A of FIG.  6 . 
     FIG. 6B is an enlarged sectional view of the area signified by  6 B of FIG.  6 . 
     FIG. 6C is an enlarged sectional view of the area signified by  6 C of FIG.  6 . 
     FIG. 7 is a partial, sectional view, in elevation, of the device of FIG. 1 with another modified dilator inserted into the infusion sheath. 
     FIG. 7A is an enlarged, cross sectional view of the device of FIG. 7 taken along sight line  7 A— 7 A. 
     FIG. 7B is an enlarged sectional view of the area signified by  7 B of FIG.  7 . 
     FIG. 7C is an enlarged sectional view of the area signified by  7 C of FIG.  7 . 
     FIG. 7D is an enlarged sectional view of the area signified by  7 D of FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The description herein presented refers to the accompanying drawings in which like reference numerals refer to like parts throughout the several views. Referring to FIG. 1, in accordance with the principles of the present invention, there is illustrated a partial (shortened), elevation view of a first embodiment of a vascular access device  10 . The device  10  includes an infusion sheath  12  with distal end portion  12   a  having a distal end  12   b  and side holes  14  for the delivery of fluid, such as medicaments, into a patient. Sheath  12  has a lumen  11  (not shown in this view but shown in at least FIG.  3 ). Fluids or medications might be injected, in the direction as indicated by the dashed line with arrow F, by syringe or the like through a stopcock  16  attached to a sidearm  18  at one end and delivered through sidearm  18  to sheath  12  via attachment of sidearm  18  to a hub  20  located at an end of sheath  12 . The holes  14  are located such that infusion will be provided along a substantial length of the sheath  12  tubing that is actually in an artery when the artery is being accessed. A gap  13  will exist between the hub  20  and a first hole  14  such that fluid infusion will take place only within a patient&#39;s body but generally it will not take place in subcutaneous tissue. The holes  14  are in communication with the main lumen  11  of the sheath. 
     The side holes  14  of sheath  12  are extremely small. The holes can range from about 0.025 mm to about 0.600 mm in diameter and preferably about 0.125 mm. The holes can be displayed in the sheath wall in a variety of ways, for example, circumferentially, helically, or longitudinally. Hole sizing is important for at least two design aspects. The first is that because of the length of the sheath tubing, typically from about 10 cm to about 25 cm, having larger holes would have the affect of the majority of the fluid exiting the holes proximally located, namely toward hub end  20 . The small holes create enough resistance such that it is possible to get very balanced flow out of as many as 17 side holes. The holes might be spaced from about 1 mm to about 200 mm apart and suitably about 10 mm apart. The second key aspect of the size of these holes is that one cannot compromise the strength of the sheath tubing. Sheaths are inherently very thin walled to allow for good insertability and minimal puncture size. By putting holes in such a thin wall tubing, there is a likelihood that the strength of the tubing will be compromised. This weakness can take the form of kinking or buckling of the tubing. The very small holes employed as part of the invention will minimize, and most likely eliminate, this likelihood. The process utilized to create these holes will likely be some means, such as, for example, by drilling or by a laser drilling operation. 
     A dilator  22  as shown in FIG. 2 would be suitable for use with device  10 . The dilator of FIG. 2 has a first portion or segment comprising a first, enlarged section  24 , a second portion or segment comprising a second, reduced section  26 , a proximal end portion  28  having a hub  30 , and a distal end portion  32  having a distal tip  34 . 
     Turning to FIG. 3, there is illustrated device  10  with dilator  22  inserted into lumen  11  of sheath  12 . Although holes  14  of sheath  12  are not shown in this view, it should be understood that the holes are present and they are configured and spaced as provided in connection with the description of FIG.  1 . Dilator hub  30  coacts with sheath hub  20  to maintain the position of the dilator within the sheath. FIG. 3A is an enlarged sectional view depicting dilator  22  with a portion of reduced section  26  located in sheath  12  and further depicts space  15  created between outer wall surface  23  of dilator  22  and innerwall surface  25  of sheath  12 . Section  26  is sized and configured such that it is smaller in cross section than lumen  11  to create space for the passage of fluid. It is the space  15  which receives fluid F directed through the sidearm  18  and passes the fluid through sheath holes  14  (not shown in this view) for delivery of the fluid to the environment surrounding sheath  12 . FIG. 3B is an enlarged sectional view depicting distal end portion  12   a  of sheath  12  and showing enlarged dilator portion  24  forming a seal  36  to create a fluid barrier at the distal end of the sheath. At the location of seal  36 , the diameter of enlarged dilator section  24  is at least equal to lumen  11  at the distal end  12   b  of sheath  12  and may be slightly larger to create a fluid tight friction seal. Substantially all introduced fluid F will exit side holes  14 . 
     It is important to control the flow of medications in this application. Current sheaths do not have infusion side holes and allow for a gap between a catheter inserted through the sheath and the sheath itself. This has the benefit of allowing for pressure monitoring or a slow infusion of fluids. This gap would allow for some amount of the medication to escape out the distal end of the sheath. To prevent this, the aforementioned dilator of the present invention effectively seals off the end of the sheath. This forces the medication to flow out the infusion ports rather than the distal end of the sheath. The outside diameter of a dilator could be ground down in the area where it matches up with the infusion ports but a standard dilator outside diameter could be employed at the sheath tip such that there is a blockage which prevents fluids from flowing out the end. While a likely process to reduce the outside diameter of the dilator will be a grinding operation, others means of allowing for this flow could be employed such as grooves (FIG. 4) extruded into the dilator tubing or any other means by which fluid can be made to flow through or around the dilator and exit the side holes. 
     Next turning to FIG. 4, there is illustrated a modified dilator  22   a  suitable for use with device  10  in a manner such as that depicted in FIG.  3 . Dilator  22   a  has a first segment comprising a first section  24   a , a second segment of reduced section  26   a , a proximal end portion  28   a  having a hub  30   a , and a distal end portion  32   a  having a distal tip  34   a . Second segment  26   a  includes one or more grooves  38  cut longitudinally therein along outer wall surface  23   a  of dilator  22   a . Section  26   a  is sized and configured such that it might have essentially the same outer dimension at  23   a  as that of lumen  11 , namely the diameter of section  26   a  at  23   a  might essentially be the same as the diameter of lumen  11 . It should be understood that grooves  38  would create a space or passageway which would perform the function of space  15  for the passage of fluid. Dilator  22   a  further includes a lumen  40  which might be a through lumen, that is, it might pass through distal tip  34   a  or it might terminate prior to distal tip  34   a . Depiction of the device in use with device  10  would be similar to the illustration of FIG. 3. A fluid seal would be created at location  36  like that depicted in FIG.  3  and fluid would be delivered as in connection with the illustration of FIG. 3 for passage along grooves  38  for exit through sheath side holes  14 . 
     FIG. 5 illustrates another embodiment  10   a  of the invention wherein there is shown a partial (shortened) sectional view, in elevation, of device  10  with a catheter  42  having hub  44  inserted into lumen  11  of infusion sheath  12 . As was discussed in respect to FIG. 3, although holes  14  of sheath  12  are not shown in this view, it should be understood that the holes are present and they are configured and spaced as provided in connection with the description of FIG.  1 . Catheter hub  44  can be gripped by a user to advance and manipulate catheter  42  into and through sheath  12 . FIG. 5A is an enlarged sectional view depicting catheter  42  located in sheath  12  and further depicts space  15   a  created between outer wall surface  43  of catheter  42  and innerwall surface  25  of sheath  12 . Catheter  42  is sized and configured such that it is smaller in cross section than lumen  11  to create space  15   a  for the passage of fluid around outer wall surface  43 . As with the use of the aforementioned dilator, it is the space  15   a  which receives fluid F directed through the sidearm  18  and allows, in this embodiment, passage of at least a portion of the fluid through sheath holes  14  (not shown in this view) for delivery of the fluid to the environment surrounding sheath  12 . FIG. 5B is an enlarged sectional view depicting distal end portion  12   a  of sheath  12  and showing catheter  42  passing through distal end  12   b  of sheath  12 . There is a clearance or space  15   b  between distal end  12   b  and catheter wall  43 . Thus, while some of the introduced fluid F will exit side holes  14 , fluid will also exit through distal end  12   b.    
     Turning next to FIG. 6., there is shown yet another embodiment  10   b  of the invention. Here there is depicted a device like that discussed in respect to FIG. 3 but employing another modified dilator  46 . Dilator  46  includes a lumen  48 , a closed distal end  50  and one or more holes  52  disposed along the dilator wall  54 . The dilator also includes a hub  30   b  which is like hub  30 ,  30   a  previously mentioned. In this embodiment, fluid F′ is typically delivered into lumen  48  at hub  30   b  for passage through lumen  48  and out holes  52  for delivery to side holes  14  (not shown) of sheath  12 . If desired, one could deliver fluid through stopcock  16  as disclosed in respect to embodiments of devices  10  and  10   a.    
     FIG. 6A is an enlarged sectional view depicting dilator  46  located in sheath  12  and further depicts space  15   c  created between outer wall surface  23   b  of dilator  46  and innerwall surface  25  of sheath  12 . Dilator  46  is shown to be sized and configured such that it is smaller in cross section than lumen  11  to create space  15   c  for the passage of fluid around outer wall surface  23   b . However, it should be understood that there need be no space created when fluid F′ is delivered provided that dilator holes  52  are in fluid communication with sheath holes  14 . Should it be desired to deliver fluid F as in the aforementioned embodiments, then a space would be required and, as with the use of the aforementioned embodiments, fluid F would be directed through the sidearm  18  for passage of the fluid through sheath holes  14  (not shown in this view) for delivery of the fluid to the environment surrounding sheath  12 . 
     FIG. 6B is an enlarged sectional view depicting distal end portion  12   a  of sheath  12  and showing a dilator portion  24   a  much like enlarged dilator portion  24  discussed above. At distal end  12   b , dilator  46  forms a seal  36   a  to create a fluid barrier at the distal end of the sheath. At the location of seal  36   a , the diameter of dilator section  24   b  is sized to be at least equal to lumen  11  at the distal end  12   b  of sheath  12  and may be slightly larger to create the fluid barrier. FIG. 6C is an enlarged sectional view showing lumen  48  and closed distal end  50  of dilator  46 . All introduced fluid, either F or F′, will exit side holes  14 . 
     Turning lastly to FIG. 7, there is shown yet another embodiment  10   c  of the invention. Here there is depicted a device like that discussed in respect to FIG. 3 but employing still another modified dilator  56 . Dilator  56  includes a lumen  40   a , an open distal end portion  32   b , one or more additional lumens  58  disposed in dilator wall  60 , and one or more holes  62  disposed along the dilator wall  60 . The dilator also includes hubs  30   c  through which fluid F′ and F″ might be delivered. In this embodiment, either fluid F′ or F″ might be delivered into one or more lumens  58  for passage through lumen(s)  58  and out holes  62  for delivery to side holes  14  (not shown) of sheath  12 . Additionally, if desired, one could deliver fluid through stopcock  16  as disclosed in respect to embodiments of devices  10  and  10   a.    
     FIG. 7A is an enlarged cross sectional view depicting dilator  56  located in sheath  12  and further depicts dilator lumens  40   a  and  58 , opening  62  and space  15   d . FIG. 7B shows space  15   d  created between outer wall surface  23   c  of dilator  56  and innerwall surface  25  of sheath  12 . Dilator  56  is shown to be sized and configured such that it is smaller in cross section than lumen  11  to create space  15   d  for the passage of fluid around outer wall surface  23   c . However, it should be understood that there need be no space created when either fluid F′ or F″ is delivered to lumen  58  provided that dilator holes  62  in wall  60  are in fluid communication with sheath holes  14 . Should it be desired to deliver fluid F via stopcock  16  as in some of the aforementioned embodiments, then a space would be required and as with the use of the aforementioned embodiments fluid F is directed through the sidearm  18  for passage of the fluid through sheath holes  14  (not shown in this view) for delivery of the fluid to the environment surrounding sheath  12 . 
     FIG. 7C is an enlarged sectional view depicting distal end portion  12   a  of sheath  12  and showing a dilator portion  24   c  much like enlarged dilator portion  24  discussed above. At distal end  12   b , dilator  56  forms a seal  36   b  to create a fluid barrier at the distal end of the sheath. At the location of seal  36   b , the diameter of dilator section  24   c  is sized to be at least equal to lumen  11  at the distal end  12   b  of sheath  12  and may be slightly larger to create the fluid barrier. In this view, lumen  58 , opening  62  and space  15   d  are additionally illustrated. FIG. 7D is an enlarged sectional view provided to show the structural features of the distal end portion  32   b  of dilator  56  with lumens  40   a ,  58  and distal tip  34   b . Substantially all introduced fluid, F, F′ or F″, will exit side holes  14  (not shown). 
     As a non-limiting example of the principles of the invention in use, a dilator will be snapped into place in the sheath-dilator assembly and the assembly will be used to introduce the sheath into the vessel of a patient as per any standard procedure. At that time, if the physician desires to inject medication of any type, the dilator would be left in place. The medication would be injected through the stopcock attached to the sidearm of the sheath. With the dilator in place and a fluid seal established at the distal end of the sheath, this would allow all or substantially all of the medication to flow out the apertures in the sheath wall. When the sheath is introduced and the physician does not intend to take advantage of the primary feature of infusion mainly through the side holes, namely fluid delivery predominantly along the sheath wall, the dilator would be withdrawn. The sheath would then used as a conventional sheath and medication would flow primarily through the end of the sheath although some fluid would flow out the side holes. If at any time during the procedure the physician wishes to take advantage of the enhanced feature of fluid delivery along the sheath wall instead of substantially through the end of the sheath, he would use the infusion sheath feature, the dilator would be re-inserted, snapped into place, and medication injected as above. As an alternative, the physician may choose to infuse medication with a catheter in place (after the dilator had been previously removed and a catheter inserted). If this is the case, medication would be injected into the stopcock as noted above. A portion of the medication would flow out the side holes and a portion would likely flow out the end of the sheath.