Sheath based blood vessel puncture locator and depth indicator

The present invention discloses a sheath based puncture locator and depth indicator. The present invention provides for locating a blood vessel puncture site and determining the depth of the puncture of the blood vessel extravascularly using the introducer sheath that is already in place within the tissue tract. The present invention also provide for positioning the introducer sheath extravascularly or outside the blood vessel, controlling the blood vessel puncture site, and delivering a hemostasis promoting material to a blood vessel puncture site.

FIELD OF THE INVENTION

The invention relates to delivering hemostasis promoting material to a blood vessel puncture site. More particularly, the invention relates to a sheath based blood vessel puncture locator and depth indicator to accurately deliver an absorbable sponge material to seal a blood vessel puncture site.

DESCRIPTION OF THE RELATED ART

A large number of diagnostic and interventional procedurals involve the percutaneous introduction of instrumentation into a vein or artery. For example, coronary angioplasty, angiography, atherectomy, stenting of arteries, and many other procedures often involve accessing the vasculature through a catheter placed in the femoral artery or other blood vessel. Once the procedure is completed and the catheter or other instrumentation is removed, bleeding from the punctured artery must be controlled.

Traditionally, external pressure is applied to the skin entry site to stem bleeding from a puncture wound in a blood vessel. Pressure is continued until hemostasis has occurred at the puncture site. In some instances, pressure must be applied for up to an hour or more during which time the patient is uncomfortably immobilized. In addition, a risk of hematoma exists since bleeding from the vessel may continue beneath the skin until sufficient clotting effects hemostasis. Further, external pressure to close the vascular puncture site works best when the vessel is close to the skin surface and may be unsuitable for patients with substantial amounts of subcutaneous adipose tissue since the skin surface may be a considerable distance from the vascular puncture site.

More recently, devices have been proposed to promote hemostasis directly at a site of a vascular puncture. One class of such puncture sealing devices features an intraluminal anchor which is placed within the blood vessel and seals against an inside surface of the vessel puncture. The intraluminal plug may be used in combination with a sealing material positioned on the outside of the blood vessel, such as collagen. Sealing devices of this type are disclosed in U.S. Pat. Nos. 4,852,568; 4,890,612; 5,021,059; and 5,061,274.

Another approach to subcutaneous blood vessel puncture closure involves the delivery of non-absorbable tissue adhesives, such cyanoacrylate, to the perforation site. Such a system is disclosed in U.S. Pat. No. 5,383,899.

The application of an absorbable material such as collagen or a non-absorbable tissue adhesive at the puncture site has several drawbacks including: 1) possible injection of the material into the blood vessel causing thrombosis; 2) a lack of pressure directly on the blood vessel puncture which may allow blood to escape beneath the material plug into the surrounding tissue; and 3) the inability to accurately place the absorbable material plug directly over the puncture site.

The use of an anchor and plug system addresses these problems to some extent but provides other problems including: 1) complex and difficult application; 2) partial occlusion of the blood vessel by the anchor when placed properly; and 3) complete blockage of the blood vessel or a branch of the blood vessel by the anchor if placed improperly. Another problem with the anchor and plug system involves reaccess. Reaccess of a particular blood vessel site sealed with an anchor and plug system is not possible until the anchor has been completely absorbed because the anchor could be dislodged into the blood stream by an attempt to reaccess.

A system which addresses many of these problems is described in U.S. Pat. No. 6,162,192 which delivers a hydrated pledget of absorbable sponge material to a location outside the blood vessel to facilitate hemostasis. However, this system involves the removal of the introducer sheath used during the intravascular procedure and the insertion of a dilator and introducer into the tissue tract vacated by the introducer sheath to place the absorbable sponge. It would be desirable to reduce the number of steps involved in delivery of a hemostasis promoting material by allowing the material to be delivered through an introducer sheath already in place within the tissue tract and used in the intravascular procedure.

Accordingly, it would be desirable to provide a system for accurately locating the blood vessel wall at a puncture site and for properly placing a hemostasis plug over, the puncture site where the locating and placing steps are performed through the introducer sheath already in place in the blood vessel.

SUMMARY OF THE INVENTION

The present invention discloses a sheath based puncture locator and depth indicator. The present invention provides for locating a blood vessel puncture site and determining the depth of the puncture of the blood vessel extravascularly using the introducer sheath that is already in place within the tissue tract. The present invention also provide for positioning the introducer sheath extravascularly or outside the blood vessel, controlling the blood vessel puncture site, and delivering a hemostasis promoting material to a blood vessel puncture site.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention are described herein in the context of a sheath based blood vessel puncture locator and depth indicator. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations of the present invention as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts.

A system for delivering hemostasis promoting material of the present invention allows the hemostasis promoting material to be delivered to a blood vessel puncture site by fluid pressure. The system allows the hemostasis promoting material to be delivered through an introducer sheath which is already in place within a tissue tract. This system includes a control tip which is insertable through the introducer sheath to locate and occlude the blood vessel puncture site and a hydration chamber for receiving and delivering the hemostasis promoting material to the blood vessel puncture site.

Although the present invention is particularly designed for delivering a hemostasis promoting material in the form of an absorbable sponge through the introducer sheath by fluid pressure, it should be understood that the system may also be used for delivering other hemostasis promoting materials which are useful for sealing a puncture site. The use of an absorbable hydrated sponge material allows the delivery of more absorbable sponge material down through a smaller sheath by allowing the sponge material to be hydrated and compressed. Once delivered, the absorbable sponge rapidly expands to fill the entire width of the tissue tract and provides hemostasis at the puncture site.

In the context of the present invention, “pledget” means a piece of sponge formed into a generally elongated shape having a size which allows delivery in a hydrated state through a delivery cannula or introducer to a site of a puncture in a blood vessel.

“Sponge” means a biocompatible material which is capable of being hydrated and is resiliently compressible in a hydrated state. Preferably, the sponge is non-immunogenic and may be absorbable or non-absorbable.

“Absorbable sponge” means sponge which, when implanted within a human or other mammalian body, is absorbed or resorbed by the body.

“Hydrate” means to partially or fully saturate with a fluid, such as saline, water, contrast agent, thrombin, therapeutic agents, or the like.

The system ofFIG. 1includes an introducer sheath10, a hydration chamber12with an attached control tip14, a coupler16, and a syringe18. The introducer sheath10is an intravascular access sheath as is conventionally used for procedures such as coronary angioplasty and stenting procedures. The introducer sheath10includes a proximal hub22connected to a tubular sheath24. A vent tube26is in fluid communication with an interior of the hub22for purposes of providing a visual bleed back indication which will be discussed in further detail below. In the embodiment illustrated inFIG. 1, a vent cap28is provided for opening and closing the vent tube26manually. However, other vent opening and closing mechanisms will be described in further detail below with respect toFIGS. 3B–3G.

The hydration chamber12is configured to receive a pledget of absorbable sponge material for hydration of the pledget and delivery of the pledget through the introducer sheath10. A proximal end of the hydration chamber12includes a flange36or other connecting element for receiving the coupler16. A distal end34of the hydration chamber12connects to the proximal hub22of the introducer sheath12. The control tip14has an enlarged distal end40configured to be received in the puncture in the blood vessel and to control blood flow through the puncture in the blood vessel. The enlarged distal end40is connected to a smaller diameter control tip tube42which extends from the enlarged distal end through the distal end of the hydration chamber12and out a side of the hydration chamber12to a proximal end44of the control tip. The enlarged distal end40of the control tip performs the multiple functions of controlling blood flow through the blood vessel puncture, providing an indication of the position of the distal end of the introducer sheath, and guiding the hemostasis promoting material delivery system over a guidewire.

The coupler16allows the syringe18to be connected to the hydration chamber12. Removal of the coupler16from the hydration chamber12allows the pledget of absorbable sponge material to be easily inserted into the hydration chamber in its dry form. Upon connection of the coupler16to the hydration chamber12the conventional syringe18will be connected to the coupler16for injection of fluid into the hydration chamber. The coupler16includes a seal54and two or more locking tabs48which lock over the flange36of the hydration chamber and are releasable by pressing on two wings50of the coupler. Stops52on the interior surfaces of the wings50prevent the coupler16from being removed from the hydration chamber12when a syringe18is mounted on the coupler. It should be understood that many other coupler designs may also be used without departing from the present invention.

In use, the system ofFIGS. 1,2, and3A is assembled with a sponge placed inside the hydration chamber12and a syringe18containing water, saline solution, or other fluid attached to the hydration chamber by the coupler16. The sponge is hydrated and staged or moved, to a position at the distal end of the hydration chamber as will be described in further detail below. The syringe18is preferable capable of generating a high pressure with a relatively low plunger force such as a 1 cc syringe.

The introducer sheath10is placed in the blood vessel puncture of a patient in a conventional manner for performance of the intravascular procedure. After the intravascular procedure, the introducer sheath10and a guidewire (not shown) are maintained in place extending into the blood vessel. The control tip14is threaded over the proximal end of the guidewire and the hydration chamber12and control tip14are advanced into the introducer sheath until the hydration chamber distal end34is engaged with the hub22of the introducer sheath10. Bleed back is observed by a variety of methods which will be described below with respect toFIGS. 3A–3G. In the embodiment ofFIG. 3A, the vent cap28is removed from the vent tube26to observe bleed back. The introducer sheath10, hydration chamber12, and control tip14, are withdrawn together slowly from the puncture site until the bleed back observed from the vent tube26stops. The bleed back stops when the enlarged distal end40of the control tip44is positioned in the blood vessel puncture preventing blood from escaping from the puncture. The distance d between the distal end of the tubular sheath24and the enlarged distal end40of the control tip14is selected so that the point at which bleed back stops indicates that the distal end of the introducer sheath10is located at a desired delivery location for delivery of the hemostasis promoting material to the blood vessel puncture site. The distance d will be selected to correspond to the size of the pledget to be delivered to the puncture site and will be selected such that the hemostasis promoting material is located in the tissue tract adjacent the blood vessel without extending into the lumen of the blood vessel.

FIG. 3Aillustrates a first embodiment of a vent tube26with a vent cap28for observing bleed back. When the vent cap28is removed from the vent tube26blood is able to pass from the distal end of the introducer sheath10through the introducer sheath and out of the vent tube. The vent tube26has a relatively small diameter which is selected to provide a very noticeable spurt or stream of blood to indicate bleed back has occurred. In contrast, the observance of bleed back from a larger tube such as the introducer sheath would result in an oozing or dripping bleed back indication which is difficult for the user to use as a precise indicator of position. According to one preferred embodiment, the vent tube26has an inner diameter of about 0.4 mm to about 2 mm, preferably about 1 mm.

FIG. 3Billustrates an alternative to manually placing the vent cap28into the vent tube26after bleed back has been used to locate the desired position for delivery of the hemostasis promoting material. InFIG. 3B, a flapper valve56is positioned over an inlet of the vent tube26inside the introducer hub22. The flapper valve56responds to the sudden extreme pressures of delivering of the hemostasis promoting material and closes over the inlet to the vent tube26. Any of the known types of flapper valves may be used in the embodiment ofFIG. 3B.

FIG. 3Cillustrates a further alternative embodiment for opening and closing the vent tube26.FIG. 3Cillustrates a hydration chamber12A with an extended cylindrical distal end60. In the position illustrated inFIG. 3C, the inlet to the vent tube26is opened. Upon advancement of the hydration chamber12A with respect to the introducer sheath10by rotation of the hydration chamber the distal end60of the hydration chamber covers the inlet to the vent tube26, as shown inFIG. 3D.

FIGS. 3E,3F, and3G illustrate three further embodiments of a two position hydration chamber which may be advanced after bleed back is observed to cover the inlet to the vent tube26and prevent exhaust through the vent tube during delivery of the hemostasis promoting material.FIG. 3Eillustrates a modified coupler16A which can be connected to the hydration chamber12and is advanced to two different positions by locking on two sequential annular rings64provided on a introducer sheath10A.

In the embodiment illustrated inFIG. 3Fthe two positions of the hydration chamber12with respect to the introducer sheath10are provided by a coupler16B having two sets of locking tabs66for locking the coupler16in two locations on the introducer sheath10.

FIG. 3Gillustrates an alternative embodiment of a sheath hub70having an inner locking annulus or flange72at a proximal end. A distal end74of a hydration chamber76is provided with two locking grooves78which snap into the locking annulus72. In the first position shown inFIG. 3G, the vent tube26is opened. When the hydration chamber76is advanced further into the introducer sheath70the distal end74of the hydration chamber passes the vent tube26and prevents pressure loss.

FIGS. 4–6illustrate an alternative embodiment of a system for delivering hemostasis promoting material to a blood vessel puncture site including another option for observing bleed back.FIG. 4illustrates an introducer sheath110, a hydration chamber112, a control tip114, a coupler116, and a syringe118. According to this embodiment, a vent tube126extends from a side of a distal end of the hydration chamber112. The vent tube126may be provided with a vent cap128for manually opening and closing the vent tube126. Alternatively, the vent tube closure system illustrated inFIG. 3Bmay be used. In the embodiment illustrated inFIGS. 4–6, the introducer sheath110may be any of those introducer sheaths which are currently used and may be connectable to the hydration chamber112by a lure lock connection as shown or by a coupler16or other coupling mechanisms as necessary. As shown most clearly in the cross sectional view ofFIG. 6, the hydration chamber112includes a large inner diameter at a proximal end132and a small inner diameter distal end134. The vent tube126is provided along the smaller inner diameter distal end134of the hydration chamber112distally of a tapered portion136of the hydration chamber. In this embodiment, the hydrated sponge should have a distal end which is positioned just proximally of the vent tube inlet so that the sponge does not block the inlet of the vent tube restricting the bleed back pathway. The system ofFIGS. 4–6, provides the advantage that the hydration chamber112and control tip114may be used with any of the known introducer sheaths110which may be in use in any particular intravascular procedure.

FIGS. 7–9illustrate an alternative system for delivering hemostasis promoting material using a known introducer sheath210with an attached side port.FIG. 7illustrates the introducer sheath210, the hydration chamber212with the attached control tip214, a coupler216, and a syringe218. The hydration chamber212may be connected to the introducer sheath210by a lure lock connection as described above or by an additional coupler216in the event that the introducer sheath210is not provided with a proximal lure connector.

The introducer sheath210ofFIG. 7includes a side port220which is used to view bleed back from the blood vessel puncture site. Connected to the side port220is a conventional stop cock valve222which is moveable between the open position illustrated inFIG. 7and a closed position illustrated in phantom inFIG. 7.

As discussed above, preferably the bleed back is viewed when exiting a vent having a relatively small diameter. Accordingly, a small diameter vent tube226is preferable connected to one of the ports224of the side port220. The vent tube226has a relatively small diameter and thus provides the desired blood spurt as a bleed back indicator. The vent tube226may be connected to one of the ports224by any of the known connectors or may be provided integrally with the port. In use, of the embodiment ofFIGS. 7–9, the stop cock122is opened to observe bleed back passing through the introducer sheath and out the vent tube226. The introducer sheath210and hydration chamber212are then withdrawn slowly until the bleed back is stopped by the presence of the enlarged distal end240of the control tip214in the blood vessel puncture. Once bleed back has stopped the stop cock222is closed to prevent fluid pressure loss from the introducer sheath210while the syringe plunger is depressed to advance the sponge through the introducer sheath210to the desired delivery location at the blood vessel puncture site.

FIGS. 10–13illustrate a further alternative embodiment of a system for delivering hemostasis promoting material in which a hydration chamber312is connected to a side port320of an introducer sheath310. The vent tube326is connected to another port of the side port320. The stop cock322is movable between an open delivery position shown inFIG. 10and a closed bleed back position shown in phantom inFIG. 10. In the closed bleed back position, bleed back is allowed through the vent tube326. In the open delivery position the hemostasis promoting material is delivered from the hydration chamber312to the introducer sheath.

As shown in the cross sectional view ofFIG. 13, when the stop cock322is in the open delivery position, the hemostasis promoting material will pass from the hydration chamber312through the stop cock322and the side port320and into the introducer sheath310for delivery to the blood vessel puncture site.

FIG. 12illustrates the connection of the control tip314to a proximal plug330which is connectable by a coupler316to the hub332of the introducer sheath310. The hemostasis promoting material is delivered through the side port320ofFIG. 12and into the hub332of the introducer sheath310and then is delivered through the introducer sheath to the puncture site.

FIGS. 14–21illustrate the preparation and use of the system for delivering hemostasis promoting material to a blood vessel puncture site. AlthoughFIGS. 14–21illustrate the procedure which is used with the embodiment ofFIGS. 1–3A, a similar procedure would be used with the other embodiments described above.FIGS. 14 and 15illustrate the hydration and staging of a pledget20of sponge material in the hydration chamber12. Once the pledget20is inserted into the hydration chamber12and the coupler16and syringe18have been connected to the proximal end of the hydration chamber, the pledget is ready to be hydrated and staged. For the staging procedure a staging tube100is used to position a distal end of the pledget20and prevent the pledget from being expelled from the hydration chamber12. The staging tube100includes a tube102having a longitudinal slit (not shown) and preferable including a handle104. The staging tube100uses a longitudinal slit to allow the staging tube to be mounted onto the shaft of the control tip14since the staging tube100will not fit over the enlarged distal end40of the control tip. Once the staging tube100is placed over the shaft of the control tip14, it is advanced into the distal end of the hydration chamber12to the first position shown inFIG. 14. In the position illustrated inFIG. 14saline or other fluid is injected at high pressure into the hydration chamber12by the syringe18to hydrate the pledget20. The staging tube100is then moved to the position illustrated inFIG. 15and additional fluid is injected by the syringe18to advance the pledget20into the distal end of the hydration chamber.

It should be noted that in embodiments of the invention employing a vent tube in a hydration chamber, the pledget20should be staged with a distal end of the pledget positioned proximally of the inlet to the vent tube to prevent the pledget from blocking the bleed back vent. Once the pledget20has been hydrated and staged at a desired position in the hydration chamber12, the hemostasis promoting material delivery system is ready to deliver the pledget to the puncture site.

FIG. 16illustrates a blood vessel106with a puncture108and overlying tissue109. InFIG. 16, the introducer sheath10and a guidewire30are in position in the blood vessel puncture108following an intravascular procedure.

In the step illustrated inFIG. 17, the control tip14has been inserted over the guidewire30and into the introducer sheath10and the distal end34of the hydration chamber12has been connected to the hub22of the introducer sheath. The vent cap28is then removed from vent tube26and the spurt of blood B called bleed back is observed from the vent tube.

In the next step illustrated inFIG. 18, the combination of the introducer sheath10, the hydration chamber12, and the control tip14are slowly withdrawn from the puncture site until bleed back is no longer visible from the vent tube26. When bleed back is no longer present this indicates that the enlarged distal end40of the control tip14is located in the blood vessel puncture108and is preventing blood from passing through the blood vessel puncture and into the introducer sheath10.

FIG. 19illustrates a step of injecting the hemostasis promoting material or pledget20to the blood vessel puncture site by fluid pressure applied by the syringe18. The hemostasis promoting material substantially fills the tissue tract at a space between the puncture in the blood vessel and the location of a distal end of the introducer sheath10. The pledget material, once delivered, rapidly expands to fill the tissue tract and promotes hemostasis of the blood vessel puncture.

As shown inFIG. 20, the hydration chamber12, the control tip14, and the guidewire30are then removed from the puncture site with the introducer sheath10held in place to stabilize the hemostasis promoting material20during removal of the remaining structures. The introducer sheath10is then removed leaving the hemostasis promoting material in the tissue tract as shown inFIG. 21. Alternatively, the hydration chamber12, control tip14, guidewire30, and introducer sheath10may be withdrawn together from the puncture site.

Turning now toFIGS. 22–31there is shown an alternative embodiment wherein a pledget handling system is substituted for the hydration chamber12shown and described above.FIG. 22shows the pledget handling system400with its proximal end coupled to the syringe18and the control tip extending from its distal end. The pledget handling system400includes a pledget chamber402, a valve system404and a coupling system406.

FIG. 23shows the valve system404and the coupling system406. The valve system404includes a handle410, and the coupling system406includes two arms412, and the handle410and arms412can be manipulated by a user to control the operation of the device. A bleed back tube414and the proximal end of the control tip44are also shown in this Figure.

FIG. 24shows a cross section view of the pledget handling system400, in which section lines have been omitted for the purpose of clarity. The pledget handling system400includes cylindrical chamber420connected at its proximal end to a syringe-communication cannula422and at its distal end to a valve-entry port424. At the distal end of the valve-entry port424there is a cylindrical valve chamber426which contains flow-control member428. The flow-control member428is essentially a truncated cylinder in configuration, having part of its distal side (in theFIG. 24orientation) missing and also having a semi-cylindrical vent port430formed in its upper surface. The flow-control member428also has a semi-cylindrical cut-out portion429. The flow-control member428is sized and shaped to be in close engagement with the valve chamber426so that when the flow-control member428is in the orientation shown inFIG. 24fluid cannot flow from the valve-entry port424into the valve chamber426. The flow-control member428is directly connected to the handle410(by a post, not shown) so that a user can rotate the flow-control member428by rotating the handle410.

At its distal end the valve chamber426is coupled to a valve-exit port432which is designed to receive introducer sheath10. The coupling system406includes cylindrical cannula coupler432and the arms412are connected to the body of the coupling system by posts434which are made of a resilient material.

Turning now toFIG. 25there is a schematic illustration of the pledget handling system400in operation. It should be understood that the pledget20has been inserted into the chamber420, the syringe and the introducer sheath10have been connected to the pledget handling system400and the device is ready for the hydrating step. The user rotates the valve arm412so that the flow-control member428is in the orientation shown inFIG. 25so that it prevents fluid flow from the valve-entry port424to valve exit port432. The user can then hydrate the pledget by operating the syringe to introduce fluid into the chamber420.

After completing the hydrating step the user can continue to the staging step, which is illustrated inFIGS. 26 and 27. In this step the user rotates the valve arm412so that the flow-control member428is in the orientation shown inFIGS. 26 and 27. In this orientation the flow-control member428prevents fluid flow from flowing from the valve-entry port424to valve exit port432. However, in this orientation the vent port430is in communication with and allows a small amount of fluid to flow from the valve-entry port424. The vent port430is also in fluid-flow communication with an exit port, not shown, which extends to the outside of the pledget handling system400, so that fluid can flow from the cut-out portion429to exit the pledget handling system400. Thus, during the staging step, as best shown inFIG. 27, fluid flows through the chamber causing the pledget to travel toward the distal end of the chamber420while fluid flows through the exit port and out of the device at a slow rate. The cut-out portion is small in size so that it permits fluid flow but does not allow for passage of the pledget.

Also, it should be noted that a bleed back channel440is connected in fluid flow communication with the valve chamber426, and a bleed back tube442is connected in communication with the bleed back channel440. Thus, it can be seen that when the flow-control member is in the staging position, blood which flows through the valve exit port432then flows through the chamber426and then out of the device through bleed back tube442. Thereby a user is given notice of bleed back. Also, the tube442can be rotated with respect to the pledget handling system400to allow the user to change the direction of the tube442to direct blood away from him/her self or away from others in the vicinity.

Once the user has completed staging of the pledget, the next stage of delivery can be commenced, as shown inFIGS. 28 and 29. In the delivery step the user rotates the flow-control member to the positions as shown and applies pressure to fluid in the syringe. This causes the hydrated pledget to travel through the valve chamber426and then from the pledget handling system400and through the introducer sheath10. Turning now toFIGS. 30 and 31, the coupling system406is described. The coupling system includes two arms412, one coupled to each side of the pledget handling system400by posts434. Each arm412has an engagement bracket450at its distal end. The posts are formed of resilient material so that the arms operate as levers with the posts434as fulcrums. Thus, to operate the coupling system the user applies pressure with the fingers to the proximate portions of the arms412to force them toward one another which in turn forces the engagement brackets450away from each other. Then the user can locate the distal end of an introducer sheath10between the brackets442and release the proximal ends of the arms412so that the brackets then engage the sheath10. InFIG. 30the coupling system is shown attached to a conventional sheath452made by the Terumo company. While inFIG. 31the coupling system is shown attached to a conventional sheath454made by the Cordis company. It can be seen that the coupling system406is capable of being used with a variety of conventional sheaths.

Although the present invention has been described and illustrated with bleed back provided between the introducer sheath10and the control tip14, an alternative way of obtaining bleed back involves providing a hole in the control tip and bleed back through the internal lumen of the control tip. According to this alternative bleed back system, a bleed back hole is provided in the enlarged distal end40of the control tip14at a location close to the proximal end of the enlarged portion. The bleed back hole communicates with the lumen of the control tip body and allows bleed back to be viewed at the proximal end44of the control tip which extends out of the side wall of the hydration chamber12.

It is preferred that the distance d between the distal end of the introducer sheath and the enlarged distal end40of the control tip14in each of the foregoing embodiments be selected so that the point at which bleed back stops is the desired delivery location for delivering the hemostasis promoting material to the blood vessel puncture. Alternatively, the introducer sheath10, hydration chamber12, and control tip14may be withdrawn an additional predetermined amount to the desired delivery location after bleed back stops.

The transverse cross sectional profile of all of the foregoing structures can be any desired shape, including square, oval, triangular, and preferable circular. The materials out of which the introducer sheaths, hydration chamber, control tip, and couplers are constructed are preferably selected to be relatively rigid and biocompatible, and more preferably are biocompatible polymers, biocompatible metals and metal alloys, and combinations thereof.

The present invention also provides for positioning the introducer sheath in a desired extravascular location, controlling the blood vessel puncture site, and delivering a hemostasis promoting material to a blood vessel puncture site. The present invention may include a control tip dilator insertable through the introducer sheath to locate and seal the blood vessel puncture site by delivering a hemostasis promoting material to the puncture site.

FIG. 32is a side cross sectional view illustrating a blood vessel puncture site with an introducer sheath and guidewire positioned in the blood vessel puncture. The introducer sheath500and guidewire504are positioned in the blood vessel puncture506following an intravascular procedure. The introducer sheath500may be an intravascular access sheath as is conventionally used for procedures such as coronary angioplasty and stenting procedures.

Once the user has completed staging of the pledget, the next stage of delivery can be commenced, as shown inFIGS. 28 and 29. In the delivery step the user rotates the flow-control member to the positions as shown and applies pressure to fluid in the syringe. This causes the hydrated pledget to travel through the valve chamber426and then from the pledget handling system400and through the introducer sheath40. Turning now toFIGS. 30 and 31, the coupling system406is described. The coupling system includes two arms412, one coupled to each side of the pledget handling system400by posts434. Each arm412has an engagement bracket450at its distal end. The posts are formed of resilient material so that the arms operate as levers with the posts434as fulcrums. Thus, to operate the coupling system the user applies pressure with the fingers to the proximate portions of the arms412to force them toward one another which in turn forces the engagement brackets450away from each other. Then the user can locate the distal end of an introducer sheath10between the brackets450and release the proximal ends of the arms412so that the brackets then engage the sheath10. InFIG. 30the coupling system is shown attached to a conventional sheath452made by the Terumo company. InFIG. 31the coupling system is shown attached to a conventional sheath454made by the Cordis company. It can be seen that the coupling system406is capable of being used with a variety of conventional sheaths.

FIG. 34is a side cross sectional view illustrating the determination of the depth of a puncture of the blood vessel with a sheath and a dilator. The depth of the puncture may be measured with external digital puncture control520as shown inFIG. 34or without as shown inFIG. 35. The sheath may first be positioned as shown inFIG. 33. A user may then apply digital pressure520over the puncture506as is traditional during device exchanges. The sheath500may then be grasped518at the skin surface516and withdrawn until the bleed back hole510exits the skin516. The depth of the puncture506may be determined by distance Sc, if external digital pressure is applied, or Su(shown inFIG. 35), if no external digital pressure is applied. Scand Suis the distance between the bleed back hole510and the point where the sheath500was grasped518at the skin surface. Since Scis the depth of the blood vessel in a compressed state and Suis the depth of the blood vessel in an uncompressed state, it is important to note that Scwill be less than Sudue to the compression of the tissue above the blood vessel. Knowing the depth of the puncture may be important in determining how deep to place other devices such as extravascular depth markers or extravascular delivery systems.

Those of ordinary skill in the art will now realize that a marker, which may be an axially movable member such as an o-ring, may be placed at the skin surface around the sheath500. Alternatively, depth indicator markers may be pre-marked on the sheath500to locate the depth and location of the puncture. Depth indicator markers may also be placed on the dilator512if the distal extension t is greater than the depth of the puncture. Moreover, it is preferable that the distal extension t be greater than or equal to Suor Scto provide control of the blood flow of the puncture506during and after the determination of the depth and location of the puncture506.

FIG. 35is a side cross sectional view illustrating a sheath positioned extravascular the puncture of the blood vessel using a control tip dilator to control the puncture site. The control tip dilator524may have an enlarged distal end526configured to be received in the puncture in the blood vessel and to control blood flow through the puncture in the blood vessel. The control tip dilator524has a distal extension t and a proximal transition extension d2, the distance between the distal end of the sheath514and the lumen of the blood vessel508. The enlarged distal end526is connected to a smaller diameter control tip tube528that extends proximally from the enlarged distal end526. The enlarged distal end526of the control tip524performs the multiple functions of controlling blood flow through the blood vessel puncture and providing an indication of the position of the distal end of the introducer sheath514.

InFIG. 35, the sheath500may be used to provide bleed back indication to the user. The sheath500may be withdrawn until blood stops entering the distal end514of the sheath500and the proximal transition end528of the control tip dilator controls the blood flow through the puncture506. The sheath500is then located extravascular or outside the blood vessel. Moreover, the location of the blood vessel puncture506relative to the distal end of the sheath514is now known. Thus, removal of the control tip dilator allows for ease of delivery of hemostasis promoting materials to seal the puncture site506since the sheath500is in the proper location for delivery of the hemostasis promoting material. In a preferred embodiment, external digital pressure as described above with reference toFIG. 34may be applied prior to removal of the control tip dilator. The control tip dilator may then be removed and the hemostasis promoting material delivered through the sheath while the site is controlled by external digital pressure. After delivery of hemostasis promoting material, external pressure may be released.

The control tip dilator524may also be used to locate the depth of the puncture506with external digital pressure or without external digital pressure as was described above using the dilator. A user may apply digital pressure over the puncture as is traditional during device exchanges. The sheath and control tip dilator are grasped at the skin surface and withdrawn until the proximal transition end528of the control tip dilator exits the skin. The depth of the puncture, either Scor Su, can then be determined, Scand Sunow being the distance between the proximal transition end of the control tip dilator and where the sheath was grasped or marked at the skin surface. Those of ordinary skill in the art will now realize that a marker may be placed at the skin surface around the sheath, or depth indicator markers may be pre-marked on the sheath or control tip dilator to locate the depth and location of the puncture.

In an alternative embodiment, the location and depth of the puncture of a blood vessel may be determined using only the sheath.FIG. 36is a side cross sectional view illustrating a sheath positioned extravascular the puncture of the blood vessel. During a surgical procedure, the sheath500and guidewire504are positioned intravascular the blood vessel as shown inFIG. 1. In this position, blood flows from the blood vessel, enters the distal end514of the sheath and exits the proximal end526of the sheath500. As shown inFIG. 36, the depth or location of the puncture506of the blood vessel may be located by applying external digital pressure522directly over the puncture506. The sheath500may be withdrawn until blood stops exiting the proximal end of the sheath526due to the external digital pressure522thereby closing the distal tissue tract from blood flow. At this point, the distance e of the sheath500to the puncture506may be approximately between 2 mm to 6 mm. The sheath is then grasped at the skin surface and withdrawn until the distal tip exits the skin. The depth of the puncture Scmay then be determined by the following formula:
Sc=Sd+e(1)
where Sdis the distance between the distal end514of the sheath and the point where the sheath500was grasped at the skin surface. Those of ordinary skill in the art will also realize that a marker may be placed at the skin surface around the sheath500, or depth indicator markers may be pre-marked on the sheath500to locate the depth and location of the puncture.

Alternatively, once the sheath500is withdrawn until blood stops entering the distal end514, the sheath500is located extravascular or outside the blood vessel508which is a beneficial position to have the sheath. The location of the blood vessel puncture relative to the distal end of the sheath is now known. This which allows for ease of delivery of hemostasis promoting materials to seal the puncture site since the sheath500is in the proper location for delivery of the hemostasis promoting material.

Although the present invention has been described as a system for delivering hemostasis promoting material to a blood vessel puncture site which is delivered over a guidewire to the puncture site, the system may also be used without a guidewire in which case the lumen of the control tip may be omitted. Alternatively, the guidewire504may be replaced using any guiding or locating member having an outer diameter smaller than the distal opening and lumen of the access sheath. Devices such as guide catheters, dilators, and floppy tip catheters may be used and may or may not include guidewire lumens. In the above embodiments inFIGS. 32–26, at least 0.0005 in2of the cross sectional area of the access sheath lumen and distal opening may remain unoccupied. Preferably, at least 0.001 in2may remain unoccupied and more preferred, 0.002 in2may remain unoccupied.

It is preferred that the distance d and e in the embodiments ofFIGS. 32–36be selected so that the point at which bleed back stops is the desired delivery location for delivering the hemostasis promoting material to the blood vessel puncture. Alternatively, the introducer sheath, and control tip dilator or dilator may be withdrawn an additional predetermined amount to the desired delivery location after bleed back stops.

The entire system illustrated in the drawings may be provided in a kit or the parts may be provided individually for use with known introducer sheaths and syringes.

The hydration chamber12may be designed to be received interchangeably on one or more of a variety of different sheaths having different hub configurations. For example, some of the known introducer sheaths have hubs which include internal flanges, external flanges, internal threads, external threads, and/or locking detents. The hubs of some of these known sheaths are designed for connection to a correspondingly shaped dilator.

One example of a hemostasis promoting material for use in the systems of the present invention is commercially available Gelfoam from UpJohn. However, other forms of gelatin foam sponge may also be used which are modified from the commercially available Gelfoam to achieve reduced friction between the delivery system and the gelatin foam sponge. Once such modification is to change an amount of cross linking agent added to the gelatin to improve the delivery properties of the sponge.

Although the system of the present invention is particularly designed for use with an introducer sheath which has already been placed at a blood vessel puncture site, the system may also be used by removing the introducer sheath used in a procedure and replacing the procedure introducer sheath with a new introducer sheath which is connectable to the hydration chamber12. For ease of introducing the introducer sheath and hydration chamber together, the control tip is preferably withdrawn partially into the introducer to act as a dilator for insertion of the system.

For all of the embodiments of the control tip herein, the outer diameter of the central portion of the enlarged control head is between about 5 French and about 9 French, preferable between about 6 French and about 7 French. The length of the enlarged control head, between the distal most end and the proximal end of the proximal tapered portion, is between about 1.5 inches (3.8 cm) and about 3 inches (7.6 cm), preferably between about 1.5 inches and about 2 inches (6.4 cm), and more preferably about 1.875 inches (4.8 cm). Control heads of these dimensions are well suited for controlling puncture sites as described herein, particularly puncture sites used during Seldinger-type vascular access.

While the invention has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention.