Patent Description:
A number of endoscopic and other intralumenal procedures require access from one body lumen into an adjacent body lumen. For example, a number of procedures may be performed by entering the gastrointestinal (GI) tract, particularly the esophagus, stomach, duodenum, small intestine, or large intestine, and passing tools from the GI tract into adjacent organs, ducts, cavities, and other structures, such as the bile duct, the pancreatic duct, the gallbladder, the urinary tract, a cyst or pseudocyst, an abscess, and the like. Such access into the adjacent body lumen will require forming a penetration or other access hole from within the first body lumen, through a wall of the first body lumen, through a wall of the second body lumen, and into the interior of the second body lumen. Moreover, depending on the procedure being performed, it will usually be necessary to place a catheter, a stent, a drainage tube, or the like through the penetrations that have been formed in each of the body lumens.

Of particular interest to the present invention, after a penetration has been formed from the first body lumen into a second body lumen, and a guidewire or other tracking device has been placed through such penetrations, it can be difficult to advance an interventional or other tool from the first body lumen, over the guidewire, into the second body lumen. It will be appreciated that most body lumens have relatively weak or flaccid wall structures. Many currently available interventional tools have atraumatic, blunt, or other distal ends which tend to push away the lumenal walls as they are engaged by the tool as the tool is advanced over the guidewire. This is particularly true of entry through the wall of the second body lumen into the interior thereof. Thus, even a successful placement of a guidewire from a first body lumen into a second body lumen does not guarantee successful introduction of a therapeutic or other device over the guidewire.

A particular problem can arise with translumenal penetration from the GI tract into an adjacent duct or lumen containing organ. Often, such access is necessary to place a catheter, stent, or other drainage device. Although the ductal structures such as the common bile duct and lumen containing organ such as the gall bladder are immediately adjacent to the stomach and small intestine, they are not attached and advancement of a guidewire or penetrating device into the gallbladder or bile duct from the stomach or small intestine can displace the target structure, resuling in leakage into the peritoneal cavity. Thus, it is desirable that lumenal apposition of the gallbladder or bile duct to the stomach or small intestine be achieved as soon as possible following first penetration and that it be maintained securely until the drainage catheter or stent can be placed.

For these reasons, it would be desirable to provide guidewires and other tracking devices which can be used to provide access from a first body lumen to a second body lumen in a manner which facilitates entry into the second body lumen. In particular, it would be desirable to provide guidewires and guidewire-like devices which can stabilize adjacent lumenal wall structures and prevent or inhibit leakage as a therapeutic or other tool is being introduced over the guidewire. Such tools and methods should be compatible with standard endoscopes and other sheaths which can be used to access a target location in the gastrointestinal tract or other body lumen. At least some of these objectives will be met by the inventions described hereinbelow.

Description of the Background Art. Guidewires and guidewire-like devices having inflatable occlusion balloons are described in <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>. Trocars and trocar-like devices having balloons and other deployable anchors are described in <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>. Other patents of interest include <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>. <CIT> discloses an anchor device for use with a stimulator. The anchor comprises an elongate body, an expandable distal portion having a sharp tip, a bipolar electrode pair, and a bumper located on a proximal portion of the elongate body. The expandable distal portion comprises a flexible disk for engaging the outer stomach wall. The disk has an inner surface that interfaces with the outer surface of stomach wall. <CIT> relates to a balloon catheter for the treatment of paranasal sinuses.

Some embodiments are recited in the dependent claims. No method by itself is falling within the scope of the claims.

The present disclosure provides methods and apparatus for establishing access tracts from a first body lumen to a second body lumen. In particular, the methods of the present disclosure will provide for apposition of the walls of the body lumen so that catheters, stents, and other tools can be advanced through the access tract with minimal or no leakage of the lumenal contents through the tract which is being formed. The apparatus comprises guidewires or guidewire-like devices having an anchor at or near their distal ends. The anchors may be deployed within the second or target body lumen so that the guidewire may be pulled or otherwise tensioned proximately to draw the wall of the second body lumen against the wall of the first body lumen. By maintaining a tension on the guidewire, the two walls may be maintained in close apposition in order to minimize or prevent leakage of the contents of both body lumens through the holes which have been formed in the lumenal walls. Such tissue apposition and stabilization also facilitates introduction of catheters and other tools over the guidewire or guidewire-like device while maintaining the tissue position and seal.

The anchors may take a variety of forms and will often be configured to provide a working space or a cavity on the interior side of the wall of the second body lumen. Such a working space or cavity allows advancement of a catheter, stent, or other working tool over the guidewire through the access tract and into the interior of the second body lumen without interference from the anchor. The apparatus may further include one or more deployable blade(s) for enlarging a tissue penetration as the guidewire is advanced. The guidewires may themselves have tissue-penetrating distal tips, in which case they can be used to form the initial penetration from the first body lumen to the second body lumen. Alternatively, the guidewires may have conventional "floppy" guidewire tips or other non-penetrating structures, where the guidewires may be introduced through a previously formed tissue tract formed by needles, trocars, or the like.

The methods and apparatus of the present disclosure may be used to form or to be passed through a preformed tissue access tract from any first body lumen to any adjacent second body lumen. Most commonly, the first body lumen will be part of the gastrointestinal (GI) tract including the esophagus, stomach, duodenum, small intestine, large intestine, and colon. The second body lumen will typically be a lumen or other cavity or structure which is adjacent to the gastrointestinal tract, including ducts such as the bile duct and the pancreatic duct, a lumen-containing organs such as the gallbladder and urinary bladder, solid tissue organs such as the pancreas, and liver, as well as diseased structures such as cysts, pseudocysts, abscesses, and the like. After access has been established, a variety of therapeutic or diagnostic tools may be introduced, typically by passing them coaxially over the guidewire in a conventional manner. The devices include catheters, stents, electrosurgical tools, drug delivery devices, implantable anchors, implantable pacing devices, and the like.

In a first aspect of the present disclosure, methods are provided for advancing a device from a first body lumen to a second body lumen. The methods comprise advancing a guidewire through the first body lumen to a target location. The guidewire is penetrated distally through a wall of the first body lumen at the target site and into the second body lumen through a wall of the second body lumen. Often, the guidewire will have a tissue-penetrating tip which allows the guidewire to form the first and second lumenal wall penetrations. Alternatively, the lumenal wall penetrations may have been previously formed using trocars, needles, or other tissue-penetrating devices. Initial placement of the guidewire will typically be achieved through an endoscope, sheath, or other tool which allows identification of the target location and steering or orientation of the guidewire toward the target location.

After the guidewire has been passed from the first body lumen, through the tissue tract and into the second body lumen, an anchor on the guidewire will be expanded within the second body lumen. By pulling the guidewire proximately, the expanded anchor may be engaged against the inner wall of the second body lumen to draw said wall against the wall of the first body lumen. The guidewire may continue to be pulled or may be fixed or immobilized in order to continue to apply tension to the guidewire and maintain the first and second lumenal walls in apposition. While the apposition is being maintained, a tool may be advanced over the tensioned guidewire from the first body lumen and into the second body lumen. Usually, tension will remain applied to the guidewire during the entire time the tool is being advanced. The first body lumen may be any body lumen, typically a lumen which is accessible through a natural body orifice, such as the gastrointestinal tract. The second body lumen will usually be an organ or other structure which is adjacent to the first body lumen, typically being one of the organs or structures listed above. The methods of the present disclosure will find particular use for accessing a pancreatic pseudocyst through the stomach or duodenum in order to place a stent or drainage catheter in order to drain the pseudocyst. The methods will also find use in accessing the bile and pancreatic ducts from the duodenum in order to drain the duct. The methods will find still further use in accessing the gallbladder from the duodenum or stomach in order to drain the gallbladder.

In most cases, the guidewire, or at least a portion thereof, will be sufficiently flexible so that it can be advanced through a sheath in the first body lumen and conform to the shape of the first body lumen. In other instances, however, the guidewire may be less flexible (more stiff), sometimes being substantially rigid, so that the first body lumen or other access passage will conform to the shape of the guidewire as it is being advanced.

In a preferred aspect of the present disclosure, expanding the anchor will comprise expanding an anchor having a concavity on a side adjacent to the wall of the second body lumen. The concavity allows a tool to be advanced so that its distal end is received within the concavity (i.e., the concavity provides a space that can accommodate the distal end of the tool as it advances through the tissue wall penetrations), without disrupting the anchor's deployment or its ability to continuously apply tension to the lumenal wall of the second body cavity. The anchors may have a variety of forms, including balloon anchors, mechanical elements, cage structures, or the like. The anchors may be symmetric so that they engage the second lumenal wall around an interface or lip which is generally circular and concentric with the access tract. In other cases, the anchor may be asymmetric so that it lies only on a single side of the access passage. In the latter cases, it may be possible to advance a catheter or other access tool over the guidewire with a distal end of the access tool passing on a portion of the guidewire where there is no anchor structure.

In certain exemplary embodiments of the present disclosure, the guidewire may include a deployable blade which may be opened prior to or during advancement of the guidewire through the tissue penetration. The deployable blade will enlarge the penetration which is being formed. Such an enlarged penetration can accommodate passage of larger therapeutic, diagnostic, or other tools. It will be appreciated, however, that an enlarged tissue penetration may require improved sealing while a treatment tool is being advanced and stabilized within the penetration.

In a second aspect of the present disclosure, a guidewire comprises a guidewire body having a distal end and a proximal end. An expansible anchor is disposed at or near the distal end of the guidewire body, and a blade is further disposed adjacent the expansible anchor. The blade will have a retracted configuration which conforms to the guidewire body and a deployed configuration having a cutting edge which extends outside of the guidewire body, Thus, advancement of the guidewire with the blade extended or deployed will enlarge the penetration by forming incision(s), usually aligned radially in the walls of the tissue tract in the tissue of the first and second body lumens. The construction and use of such cutting blades is described in detail in co-pending provisional application <CIT> (Attorney Docket No. <NUM>-<NUM>), the full disclosure of which is referred to.

The guidewire bodies will typically have a length in the range from <NUM> to <NUM>, more typically from <NUM> to <NUM>, and an outside'diameter, at least at the distal end, in the range from <NUM> to <NUM>, more usually from <NUM> to <NUM>. The guidewire body may have a solid core but will more typically have a hollow center in order to allow for inflation, expansion, or other manipulation of the anchor and optionally the blade(s). The anchor can take any of the forms discussed above, including balloons, cages, malecotts, self-deploying springs, flanges, cones, or the like. Similarly, a wide variety of different deployable blades may be provided. In its simplest form, the devices may include only a single blade mounted on a central pivot. Two, three, or four blades may alternatively be provided on individual pivots and may be deployed in a symmetric or asymmetric manner. Both the blades and the anchors may be self-deploying or alternatively may require separate deployment mechanisms in order to selectively expand and contract the anchors and/or blades. The blade will typically be disposed distally of the expansible anchor to allow the tissue tract to be enlarged prior to deployment and placement of the anchor. Alternatively, the blade and the anchor may be placed adjacent to each other, typically where the blade opens in a first radial orientation while the expansible anchor opens in a second radial orientation.

In a third aspect, the present disclosure comprises guidewires having a guidewire body with a distal end and a proximal end. An expansible anchor on the guidewire body has a retracted configuration which conforms to an external surface of the guidewire body and an expanded configuration that has a distal surface and a proximal surface. The proximal surface has a peripheral edge and a concave space or region within the peripheral edge. The concave space or region provides a working space when the peripheral edge of the anchor is drawn proximally against a tissue surface of the target body lumen. In particular, the working space allows a catheter, stent, or other tool or device to be advanced over the guidewire while the anchor continues to apply tension to maintain the first and second lumenal walls in apposition.

The particular dimensions of the catheter body are set forth above. The expansible anchor will typically have a peripheral diameter in the range from <NUM> to <NUM> and the cavity provided by the anchor will have a volume in the range from <NUM> to <NUM>. The cavity will usually have a generally conical shape with an apex attached to the catheter shaft and a peripheral base disposed generally concentrically about the catheter shaft at a location proximal to the apex. The guidewire may have either a tissue-penetrating tip, such as a sharpened tip, an electrosurgical tip, or the like. Alternatively or additionally, the distal tip of the guidewire body may be steerable.

Referring to <FIG>, a guidewire <NUM> constructed in accordance with the principles of the present disclosure comprises an elongate body <NUM> having a distal end <NUM> and a proximal end <NUM>. An expansible anchor is disposed near the distal end <NUM> of the catheter body <NUM> and may be expanded from a contracted configuration (shown in full line) which conforms closely to the exterior of the catheter body to an expanded configuration (shown in broken line) which will have a width or diameter significantly greater than the diameter of the catheter body, typically being at least twice as wide, often being at least four times as wide, sometimes being six times as wide or greater. The expansible anchor <NUM> may have any one of a variety of structures and geometries. The expansible anchor <NUM> is shown as an inflatable balloon having a conical geometry with the wide portion or base oriented in a proximal direction. Thus, the base will be able to engage and seal against the tissue in the second or target body lumen when the guidewire is drawn in a proximal direction.

A first exemplary guidewire <NUM> may have the dimensions and properties generally associated with conventional medical guidewires. For example, the catheter body <NUM> may be sufficiently flexible to conform to a tortuous path through a body lumen as it is advanced. It may comprise a steerable tip <NUM> at its distal end to permit the catheter to be advanced and steered through a body lumen. It may be solid or hollow, typically being hollow to allow inflation of the balloon <NUM> (typically using a valving structure as described in more detail with respect to <FIG>). Usually, it will be free of any structure at the proximal end which would prevent coaxial introduction of the catheter, stent, or other tool thereover. Alternatively, a removable hub or other structure (not shown) could be removably attached to the proximal end, for example for attaching to an inflation source for inflating the balloon.

A second exemplary guidewire structure <NUM> is illustrated in <FIG>. Guidewire <NUM> includes a catheter body <NUM> which may be stiffer, optionally being rigid, in contrast to the guidewire body <NUM> of guidewire <NUM>. For example, the guidewire body <NUM> may be formed from a relatively stiff hypotube over its entire length. Guidewire <NUM> is also illustrated to have both an anchor mechanism <NUM> and a blade mechanism <NUM>, with particular deployment mechanisms for both the anchor and blades being illustrated hereinafter. Other blade actuation mechanisms are described in detail in co-pending application <CIT> (Attorney Docket No. <NUM>-<NUM>), the full disclosure of which is referred to. The guidewire <NUM> also includes a self-penetrating tip <NUM>, which is illustrated as a faceted tip. Other sharpened tips and self-penetrating designs may be employed, including chamfered tips, electrosurgical tips, drilling tips, and the like.

Referring now to <FIG>, a guidewire <NUM> comprises a guidewire body <NUM> having an inflatable balloon anchor <NUM> at a distal end <NUM> thereof. The inflatable balloon anchor <NUM> will preferably be formed from polyurethane, silicone or other elastomeric material so that advancement of a catheter or other tool over the guidewire body <NUM> allows the distal end of the tool to deform a proximal surface <NUM> of the balloon so that a recess or cavity <NUM> may be formed to accommodate the tool, as shown in broken line. As it is generally desirable to maintain a small diameter on the guidewire body <NUM>, the guidewire <NUM> employs a single lumen <NUM> for inflation of the balloon. The balloon may be inflated by attaching a syringe or other inflation source to a proximal end (not shown) of the guidewire body <NUM> and closing the balloon inflation port <NUM> by drawing valve ball <NUM> proximally using valve wire <NUM> after the balloon has been inflated. In this way, the valve may be first open to permit inflation (as shown in broken line) and then closed to hold inflation within the balloon (as shown in solid line). It will be possible, of course, to place other valves within the single lumen <NUM>. For example, a valve mechanism similar to a tire valve may be placed at or near the proximal end of the guidewire body <NUM>. Inflation can' be introduced through the valve in a conventional manner (as for tires) and may be released by pressing the valve stem inward (again as is conventional with tire inflation mechanism). A wide variety of other single lumen balloon inflation and deflation mechanisms are known and described in the patent literature.

Referring now to <FIG>, a guidewire <NUM> includes a guidewire body <NUM> having an inflatable balloon <NUM> at a distal end <NUM> thereof. The balloon <NUM> is generally cylindrical but has a pre-formed wall indentation <NUM> which defines a cavity or working space <NUM> when the balloon is fully inflated. Such a pre-shaped balloon may be formed from elastomeric materials (eg. , silicone rubbers) but will more usually be formed from non-distensible materials such as polyethylene terephthalate, nylon, and the like). The cavity <NUM> is surrounded by a peripheral base or lip <NUM> which can engage a tissue wall surrounding a tissue penetration when the guidewire <NUM> is drawn proximally after it has been introduced into the body lumen and the balloon <NUM> has been inflated. The cavity <NUM> is useful to permit advancement of a catheter or other working tool through the tissue penetration or tract while the balloon <NUM> is being drawn against the tissue structure to apply tension to maintain apposition of adjacent tissue walls.

Referring now to <FIG>, a guidewire <NUM> includes a guidewire body <NUM> having an inflatable balloon anchor <NUM> and a pair of deployable blades <NUM>. Each blade has a forward cutting edge <NUM> which is disposed toward the tissue when the blade is fully deployed, as illustrated in <FIG>. The inflatable balloon anchor <NUM> may be inflated by a single internal lumen, as previously described, and the blades <NUM> may be shifted between a constrained configuration (where they are fully retracted within the catheter body <NUM>) and the deployed configuration which is illustrated. A wide variety of specific deployment configurations are illustrated in co-pending provisional application <CIT> (Attorney Docket No. <NUM>-<NUM>), which is referred to. The catheter <NUM> is shown with a sharpened, tissue-penetrating tip <NUM>, so the guidewire can be used to form the penetration, enlarge the penetration with the deployable blades <NUM>, and then seal the resulting enlarged tissue penetration with the balloon <NUM>.

Referring now to <FIG>, yet another guidewire <NUM> comprising a guidewire body <NUM> includes an asymmetric balloon anchor <NUM>. The balloon anchor <NUM> extends outwardly from the guidewire body <NUM> in only one radial direction, leaving other radial portions of the guidewire free from structure. Thus, a catheter <NUM> having an angled end <NUM> may be advanced over the guidewire <NUM> and at least partially past the deployable balloon anchor <NUM> by orienting the leading tip <NUM> of the catheter so that it passes on a side of the guidewire opposite to that of the asymmetric balloon (the side free from anchor structure). The guidewire <NUM> is shown having self-penetrating tip <NUM> but could also be configured to have a blunt, steerable, or other tip.

Referring now to <FIG>, guidewire <NUM> may be constructed to have a particularly small diameter (low profile) by forming an expansible anchor structure <NUM> integrally within the guidewire body <NUM>. The guidewire <NUM> comprises a hypotube or other small tubular structure. A distal portion of the tubular structure is split along three lines to form three separate elements <NUM> formed from an elastic material, typically an elastic material such as nitinol or stainless spring steel or alternatively an elastic polymer. The elements <NUM> are formed to lie in the radially constrained construction of <FIG> and may be radially expanded, as shown in <FIG>, by axially foreshortening the end of the guidewire body <NUM>, typically by pulling on a tensioning member <NUM> to draw the distal end <NUM> in a proximal direction. The guidewire <NUM> is shown to have a steerable tip <NUM> but could also have a tissue-penetrating tip.

Referring now to <FIG>, a guidewire <NUM> has an expansible anchor <NUM> in the form of a radially expanding braid. The braid will be formed as a tubular structure having a diameter similar to that of the guidewire body <NUM>. By drawing on a central member <NUM>, the distal tip <NUM> of the guidewire may be foreshortened to radially expand the braid <NUM>, as shown in <FIG>. The construction of suitable radially expansible braids are shown in a variety of patents, including <CIT> and <CIT>, the disclosures of which are referred to.

Referring now to <FIG>, a guidewire <NUM> comprises a guidewire body <NUM> having self-expanding anchor members <NUM> and a deployable blade <NUM>. The anchor members <NUM> are disposed on opposite sides of the guidewire body and have pre-shaped generally spiral structures. An external sheath <NUM> may be axially advanced and retracted to close and to deploy the anchors <NUM>. A deployable blade structure <NUM> is pivotally attached to be opened and closed within a slot <NUM> of the guidewire body <NUM>. Tethers <NUM> are provided to open and close the blade. Such blade mechanisms are described in more detail in co-pending provisional application <CIT> (Attorney Docket No. <NUM>-<NUM>), the disclosure of which is referred to.

Referring now to <FIG>, a guidewire <NUM> having a guidewire body <NUM> includes self-expanding ribbon anchors <NUM> which assume the illustrated shape when unconstrained and which may be collapsed into slots <NUM> (only one of which is illustrated) in the guidewire body <NUM> to allow the anchors to lie flat. They may be constrained by pulling on proximal ends of the anchors with tethers or using a constraining sheath. Cutting blade <NUM> is pivotally attached to move in and out of a second slot <NUM>, where the slots <NUM> and <NUM> are orthogonally opposed (lie at <NUM> degrees relative to each other) so that the anchors and blades may be deployed without interference. Guidewire <NUM> is shown with a self-penetrating tip <NUM> but could also have non-penetrating tips.

Referring now to <FIG>, a guidewire <NUM> includes a guidewire body <NUM> having a self-penetrating tip <NUM> at its distal end. A single slot <NUM> is formed in the body and a single deployable structure <NUM> is provided which can be rotated in and out of the slot. Rotation can be achieved using tethers, springs, or the like. The structure <NUM> serves as both a cutting blade and as an anchor. A distal or forward edge <NUM> of the structure is sharpened so that it may cut tissue as the guidewire is advanced. The proximal side of the structure <NUM> is configured to grip tissue as the guidewire is drawn proximally into the tissue.

Referring now to <FIG>, a guidewire <NUM> comprises a tubular guidewire body <NUM> having three axially extendable elements <NUM> therein. Each of the elements <NUM> has a tissue-penetrating tip <NUM> where the tips will be drawn together to form a unitary tissue-penetrating tip, as shown in <FIG>, for passing through the tissue layers to form the initial tissue penetration. After the guidewire <NUM> has been advanced into the target body lumen, however, the elements <NUM> may be axially advanced through the body <NUM> so that the tips, which are preformed to evert as shown in <FIG>, will turn backwards and engage the tissue as an anchor. Such an anchor may be retracted by proximally drawing the elements <NUM> relative to the guidewire body <NUM>.

Referring now to <FIG>, the methods according to the present disclosure will be described in more detail. As shown in <FIG>, an endoscope E may be advanced into an internal body space, such as the esophagus, to identify a target location T on a first tissue layer TL1. For example, the endoscope may include a viewing element <NUM> (typically an optical fiber or small camera) and an illuminating source <NUM> (typically an optical fiber or LED) to permit such visualization. The endoscope will also usually include a working channel <NUM> which may be used to advance a guidewire <NUM> in accordance with the principles of the present disclosure (<FIG>). Optionally, although not shown, a tissue penetration may be previously formed, for example by a trocar such as that described in co-pending application <CIT> (Attorney Docket No. <NUM>-<NUM>), the disclosure of which is referred to. As shown in <FIG>, however, the guidewire <NUM> in this example has a self-penetrating tip <NUM> and a penetration-enlarging deployable blade <NUM> so that advancement of the guidewire through tissue layers TL1 and TL2 provides lengthened incisions I1 and <NUM>. Penetration of the guidewire <NUM> through the incisions I1 and I2 does not in itself draw the tissue layers TL1 and TL2 together as is desired. To achieve the desired tissue apposition, the blade <NUM> is retracted and a conical anchor <NUM> is deployed, as shown in <FIG>. The guidewire <NUM> is drawn proximally so that the deployed anchor <NUM> engages the second tissue layer TL2 and draws that layer against the first tissue layer TL1 to form a tight apposition, as shown in <FIG>. While maintaining the apposition, a catheter C may be advanced through the working channel of the endoscope, over the guidewire, and through the incisions I1 and <NUM>, as shown in <FIG>. The catheter may be used for a variety of purposes, including drainage, stent placement, or the like. The conical balloon anchor <NUM> provides a working space <NUM> which allows the distal end <NUM> of the catheter C to pass through the tissue layer incisions I1 and I2 and into the working space <NUM> without disturbing engagement of the anchor <NUM> with the tissue, thus allowing tissue apposition to be maintained.

Claim 1:
An apparatus for establishing an access tract from a first body lumen to a second body lumen, comprising a guidewire (<NUM>) having a guidewire body (<NUM>) having an expansible anchor (<NUM>) at or near its distal end, wherein the anchor (<NUM>) is configured to be deployed within the second body lumen and to be pulled proximally to draw the wall (TL2) of the second body lumen against the wall (TL1) of the first body lumen, wherein the anchor (<NUM>) is symmetric and adapted to engage the wall (TL2) of the second body lumen around an interface or lip which is generally circular and concentric with the access tract, wherein the guidewire body (<NUM>) has a length in the range from <NUM> to <NUM>, and an outside diameter, at least at the distal end, in the range from <NUM> to <NUM>, wherein the guidewire body (<NUM>) comprises a hollow center, wherein the anchor (<NUM>) is disposed near the distal end of the guidewire body (<NUM>) and expandable from a contracted configuration, which conforms closely to the exterior of the guidewire body (<NUM>), to an expanded configuration, characterized in that the expanded configuration will have a width or diameter at least four times as the diameter of the guidewire body (<NUM>), and that the anchor (<NUM>) is a radially expanding braid.