US20020165581A1 - Vascular sealing device and method - Google Patents

Abstract

The present invention relates generally to the area of vascular sealing, and more particularly to a device having an inflatable bladder member placed in conjunction with the exterior of the vessel wall for preventing blood flow.

Description

FIELD OF THE INVENTION
• The present invention relates generally to vascular catheterization and more particularly to vascular closure devices, which are used to stem bleeding from surgical procedures that penetrate blood vessels.[0001]
BACKGROUND OF THE INVENTION
• Minimally invasive techniques have become the method of choice for the treatment of certain cardiovascular diseases. During interventional cardiology procedures, small plastic tubes called catheters are inserted into the vasculature through a leg or an arm. These catheters are threaded to the appropriate location for the diagnostic or therapeutic procedure. The access or opening in the artery or vein is created by using the so-called Seldinger technique. The Seldinger procedure begins with the insertion of a hollow needle through the skin to puncture the desired blood vessel. Next a guidewire is inserted through the needle into the blood vessel. At this point the needle is withdrawn and the guidewire remains in place. An introducer sheath or cannula is placed over the guidewire and inserted into the vessel to dilate or stretch the vessel to the required diameter for catheter insertion. The introducer also seals against blood pressure, thus preventing bleeding from the puncture site while allowing access to the cannulated vessel. The introducer remains in place until the procedure is completed. After the procedure, the introducer is removed leaving a wound in the skin and an opening in the blood vessel. This injury is subject to significant bleeding because the patient usually receives blood thinners or anticoagulants to minimize or prevent clot formation during the intervention. While these medications make the procedure safer, they also make sealing the puncture site upon removal of the introducer more difficult. The effect of blood thinners is to reduce the clotting capacity of the blood meaning that it will take longer for cuts and injuries to heal. Historically, after removal of the introducer, manual pressure has been applied for up to several hours to the puncture site and subsequently the canulated extremity is immobilized for up to a full day until sufficient healing has occurred.[0002]
• Using manual pressure increases hospital staff time, increases health care costs, is uncomfortable for the patient, and increases the time to ambulation. Vascular sealing devices have been developed to address these issues. U.S. Pat. Nos. 4,744,364; 4,852,560, and 4,890,612 describe a mechanical umbrella which is inserted into the opening of the vessel and seals against blood flow from the inside of the vessel. U.S. Pat. Nos. 5,391,183 and 5,437,631 describe a plug which mechanically fills the hole in the extremity with a material while allowing natural healing of the vessel to occur. U.S. Pat. No. 5,413,571 teaches a device, which enters the vessel to be sealed. Both of these methods have the added risk of potentially injecting foreign materials into the blood vessel which may cause added complications. U.S. Pat. No. 5,613,974 describes a method to mechanically seal the puncture site in the artery or vein with sutures much like closing an incision in the skin. These methods typically require a skilled person, require significant time and are relatively expensive. U.S. Pat. Nos. 5,728,132 and 5,626,601 describe the use of hemostatic agents such as fibrin activated blood to provide a mechanical seal at the wound site. The patients' blood is typically drawn prior to the procedure and activated before injection into the puncture site. For various reasons each of the above-described methods have not been fully accepted by the medical community. Consequently, there is a continuing need to develop devices which address wound closure to reduce times and health care costs.[0003]
SUMMARY
• Several embodiments of the inventive vascular closure device are shown. In each embodiment, the device includes at least one relatively non-deformable surface member and a conformable and distensible member or portion. Typically the conformable member is implemented as a balloon structure that is inflated with a liquid or gaseous medium. This inflation fluid increases the fluid pressure in the balloon which counteracts the fluid pressure of the punctured vessel. The resulting forces on the balloon are opposed by tissue structures that transfer the load to the surrounding subcutaneous tissue structures. Additional structures may be added to the device to supplement these functions as typified by an adhesive patch or ribs.[0004]
• Additionally, the balloon functions to supply a flexible external cover over the opening in the vessel with sufficient force to maintain the cover against the opening in the vessel. This seals the subcutaneous hole caused by the puncture and prevents loss of blood, all of which allows natural healing to occur in the opening created in the vessel. After the wound is healed, the sealing device may be removed by grasping the non-deformable portion and withdrawing the device. At this time normal wound care management treatments are applied.[0005]
• In an alternate embodiment the device may remain in place and degrade biologically.[0006]
• In addition, the device may be coated with agents to provide a secondary therapy such as drugs for enhancement of clotting or prevention of infections. These agents may also elute from the distensible conformal member.[0007]
• The use of this device permits the cutaneous structures to heal more quickly without excessive bleeding and also allows for the patient to ambulate more quickly.[0008]
BRIEF DESCRIPTION OF THE DRAWINGS
• The several illustrative embodiments of the device shown in the figures share structural elements and like reference numerals are used to identify identical structure throughout the views, wherein:[0009]
• FIG. 1[0010]ashows a first embodiment device placed near a vessel;
• FIG. 1[0011]bshows a first embodiment device inflated to seal a vessel;
• FIG. 2 shows a second embodiment of the device;[0012]
• FIG. 3 shows a third embodiment of the device;[0013]
• FIG. 4 shows a first embodiment of the device;[0014]
• FIG. 5 shows a fourth embodiment of the device;[0015]
• FIG. 6 shows a fifth embodiment of the device; and[0016]
• FIG. 7 shows a sixth embodiment of the device.[0017]
DETAILED DESCRIPTION
• FIG. 1[0018]ais a schematic drawing that shows a first embodiment of thedevice10 inserted into asurgical wound12 in thepatient16. In the figure, thesurgical wound12 was used to provide access to thevessel14 located subcutaneously in tissues24, a distance “d” away from the surface of the skin. In the figure, thedevice10 has been inserted into thewound12 after the cannula or vascular introducer has been removed.
• The[0019]device10 can be conceptually divided into at least two sections or portions to facilitate a discussion of the structure and operation of thedevice10. The distal tip of thedevice10 is formed as a distensibleconformable member18 or portion. Theconformable member18 is connected to a second portion called thesurface member22. After insertion into thewound12 area the device is activated and “filled” through aseptum27. The “filled” state is shown in FIG. 1b.
• As seen in FIG. 1[0020]b, thedistensible member18 expands from the unactivated shape shown in FIG. 1ato the distended shape seen in the figure and thus interacts with the soft tissue24 of thewound12 to support and to position the conformable distensiblemember18 near thevessel14. In this embodiment thedistensible member18 lengthens in an axial direction along theaxis11 as a fluid (gas or liquid) is introduced through the septum27(FIG. 1a). In this embodiment, ribs typified byrib25, located near thesurface member22 may provide an opposing force or “traction” to the expanded distal conformabledistensible member18. Thesurface member22 may also provide skin closure and also provide a seal against the leakage of blood. Thesurface member22 also provides a convenient location to grasp thedevice10 for removal after thevessel14 has closed. Theseptum27 may be used to deflate thedistensible section18 to facilitate removal.
• In general the conformable and[0021]distensible member18 at the distal tip expands to cover the incision in thevessel14 with a flexible, membrane structure creating a sealing structure which, in conjunction with the surrounding tissue24, effectively seals theblood vessel14 and displaces blood from the wound area thus preventing bleeding from the skin of thepatient16. Although it is difficult to quantify the forces involved bothsurface member22 anddistensible member18 carry the complimentary forces which resist the pressure of theblood vessel14 communicated through the distalconformable member18. It is likely that three separate sealing mechanisms are at work in thedevice10. In one instance thedevice10 closes off thevessel14 in a manner analogous to direct pressure on the wound. In another aspect, blood “leaking ” from the vessel is contained within thewound12 and thedevice10 prevents this blood from “leaking” out of the wound by closing off the skin which equalizes the pressure in the wound with the pressure in thevessel14. In another aspect, the device forms a seal over the opening in the vessel preventing leaking from the vessel into the wound but allowing flow to continue through the vessel. In all instances, pressure in the device opposes the blood pressure in the vasculature. Once thevessel14 stops bleeding thedevice10 is removed allowing for the use of a conventional bandage and wound care treatments. In the intervening time, the patient may be ambulatory as the device will conform to anatomical changes caused by motion of the extremity.
• FIG. 2 shows a specific implementation of a second embodiment of the[0022]device10 where three functional features are implemented as a two piece construction with four distinct physical elements. The pieces are a ring orcollar36 and anadjustable stem34. These two pieces can be moved with respect to each other. Thestem34 is adjustable within thecollar36. In the figure annular locking ribs typified byrib38 interacts with acomplimentary rib40 on thecollar36 structure to permit adjustment. A conventional screw thread may be used instead of the ribbed structure.
• This version of the[0023]device10 includes adistinct stem34 which includes aseptum valve30, which communicates to the interior of aballoon32. The balloon inflates to form the distal conformable distensible member. The balloon merges into thestem section34 which has a variable thickness wall. In use, the physician can size the device length (“d” in FIG. 1a) to a particular patient by positioning thestem34 within thecollar36 then inserting the device into the wound. In operation,balloon member32 expands to provide the covering and seal of the opening in the blood vessel. Once again the inflation fluid may be either a viscous liquid or a gas. When lightly inflated in free space the balloon member distends into the shape indicated by the dottedline37. It should be clear that the distal distensible member may have other expanded shapes within the scope of the disclosure.
• FIG. 3 shows a third specific implementation of the[0024]device10 formed as a unitary structure. In this embodiment a very flexible anddistensible balloon member32 accommodates the depth “d” of the vessel. In general thedevice10 may grow in length alongaxis11 and grow in girth in a non-uniform way along theaxis11. In contrast to the FIG. 2 design, the balloon is both longer and has a fixed thickness thin wall over most of its extent. Thestem portion34 is relatively shorter stiffer and integrated with thesurface contacting collar36. Anadhesive layer39 may be provided on thesurface collar36 to adhere the collar to the skin of the patient. In this design the stiffness of the stem is determined primarily by the needed to push thedevice10 into the wound. In operation theballoon32 is inflated and conforms to the vessel. The sides of the balloon also engage the tissue near the vessel and provide a seal against the tissue surfaces.
• FIG. 4 shows a specific embodiment of the device identical to the one illustrated in FIG. 1[0025]aand FIG. 1b. In this view the unconstrained shape under inflation is shown in dottedoutline43. In this version of the device, unitary ribs, illustrated byrib42 on the stem interact with the tissue structure near the vessel. In this embodiment theballoon32 expands the ribs into contact with the tissue structure thus holding the device in the wound and providing the requisite complimentary force to resist the expansion of the distalconformable balloon member32. In contrast to other embodiments this version should be less influenced by inflation pressure.
• FIG. 5 shows an alternate fourth embodiment of the[0026]device10, which includes a septum/inflation lumen50 connecting thesurface portion48 to a donut shapeddistal balloon54. In this version of the device, a throughlumen52 is provided so as to maintain access to the vessel. In use, the physician may withdraw the bulky catheter devices and yet retain anintervention device56, typically a guidewire, in the vessel for later use or reentry at the same insertion site. In this embodiment theballoon54 seals against the vessel and theinterventional device56 as indicated by the dottedline44. It should be appreciated that the donut balloon structure can be used with either the adjustable length structures shown as well as the fixed length embodiments.
• FIG. 6 shows another version of the[0027]device10 where the gentle force functionality is carried out by adeformable gel material60. In this version thestem portion62 includes a material which is soft enough to conform to the shape of the vessel and provide a contiguous seal at the site of the incision. This material may also be shaped to the anatomical structures of the soft tissue to form an effective seal and provide the required complimentary forces. It is preferred in this embodiment to have aballoon membrane63 to isolate the gel from the blood although this membrane may be permeable so as to elute a secondary therapy such as a clotting agent or antibacterial medication. The surface shading58 on the distend dotted outline of the balloon is intended to indicate a bactericide or other drug or coating. In this particular drawing the device has no increase in volume but rearranges the interior material64 to form the conformable distensiblemember63. It should be noted that the drug material could elute or emerge from the interior of thedevice10 through a porous membrane forming thedistensible member63.
• FIG. 7 shows an alternate embodiment of the device which includes an expandable[0028]foam core member71 which increases in volume in the presence of blood i.e. swells in the presence of blood or simply remains flowable when the device is placed in the wound. In this device the swelling is localized to the vessel interaction area. Theconcave surface70 shows the device in the inserted and inactivated state, while the dottedoutline72 shows the localized swelling mode. The structure outline73 is the distensible member when swollen. Any of a variety of materials has the propensity to increase in volume when exposed to blood including hydrogels and hydrophylic materials.
• Each of the various embodiments of the device may be enhanced by the inclusion of particular coatings. It is believed that antimicrobial coatings will reduce clinical issues presented by the insertion of a device after surgery. Although numerous organic and nonorganic coatings may be used it is expected that photoactivated materials such as that supplied by SurModics, formerly BSI, will be especially suitable.[0029]
• In all of the embodiments, the device may be constructed from conventional thermoplastic or thermoelastic plastics such as “Pellathane” and silicones. It may also be desirable to form all or part of the device from a biodegradable thermoplastic material such as polyglatide. Depending on composition among other variables such a device will degrade in the body within a short period of time not more than several weeks.[0030]

Claims (4)

What is claimed is:

13. A method of treating a wound comprising the steps of: inserting a distensible member defining a closed volume into a wound; and filling said distensible member to seal said wound.

14. The method of claim13 wherein said filling step continues to enlarges the volume of the distensible member.

15. The method of claim13 wherein said filling step continues to lengthens said conformable distensible member along its axis.

16. The method of claim13 wherein said method includes removing device at completion of sealing

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