Device and a method for guiding a boring tool, a guide wire or an instrument into engagement with an occlusion in a vessel or a wall of the vessel in the body of a human or animal subject

A balloon catheter (1) including a device (3) adjacent the distal end (12) of a catheter (10) for guiding a boring tool (5) or other instrument into an occlusion (6) in a vessel (8), includes a guide element (30) adjacent the distal end (12). A penetrating element (33) having a first guide bore (38) terminating in a distal cutting edge (40) is rotatable in a second guide bore (45) extending through the guide element. External threads on the penetrating element (33) are engageable with internal threads in the second guide bore (45), so that by rotating the penetrating element (33) the distal cutting edge (40) is urged outwardly to penetrate the occlusion (6). With the penetrating element (33) securely engaged in the occlusion (6), a boring tool (5) and other instruments can then be sequentially guided through the catheter (10) and the first guide bore (38) directly into the occlusion.

The present invention relates to a device for guiding a guide wire, a boring tool, and/or an instrument into engagement with an occlusion in a vessel or a wall of the vessel or other part of the vessel in the body of a human or animal subject, and the invention also relates to a method for guiding a guide wire, a boring tool and/or an instrument into engagement with an occlusion in a vessel or a wall of the vessel or other part of the vessel in the body of a human or animal subject. This invention also relates to a catheter and a to balloon catheter comprising the device.

Devices for unblocking an occlusion in a remote vessel in the body of a human or animal subject or for use in the unblocking of such an occlusion are known, such devices are typically used for unblocking or for use in the unblocking of an occlusion in an artery or a vein, which may be a cardiovascular artery or vein or a peripheral blood vessel. However, it will be understood by those skilled in the art that such devices may be used for unblocking an occlusion in any vessel, be it remote or otherwise, or be it a blood vessel or otherwise, in the body of a human or animal subject. Such devices comprise a balloon catheter, and when the balloon is located in the occluded vessel the balloon is inflated for anchoring the distal end of the catheter in the vessel adjacent the occlusion. A boring tool or a guide wire is urged through the catheter of the balloon catheter and is guided by the anchored catheter into the occlusion. Such devices are disclosed in U.S. published Patent Application Specification No. 2009/0306597 and in PCT published Patent Application Specification No. WO 2012/123930. However, it has been found that when the boring tool or guide wire, having formed an opening through or into the occlusion, has been withdrawn from the occlusion, the distal end of the balloon catheter may slip out of alignment with the opening formed through or into the occlusion, thereby making it difficult if not impossible to direct other boring tools, guide wires, stent carriers or other instruments into the opening already formed through or into the occlusion.

There is therefore a need for a device for guiding a guide wire, a boring tool or an instrument into engagement with an occlusion in a vessel, a wall of a vessel or other part of a vessel in the body of a human or animal subject which addresses this problem, and there is also a need for a method for guiding a guide wire, a boring tool or a surgical instrument into engagement with an occlusion in a vessel, a wall of a vessel or other part of a vessel in the body of a human or animal subject which addressed this problem. The present invention is directed towards providing such a device and a method, and the invention is also directed towards providing a balloon catheter which comprises the device.

According to the invention there is provided a device for guiding one of a guide wire, a boring tool and an instrument into engagement with one of an occlusion in a vessel and a wall of a vessel, the device comprising a penetrating element extending between a proximal end and a distal end and terminating at the distal end in a distal cutting edge for cutting into the one of the occlusion and the wall of the vessel, and having a first guide bore extending therethrough for accommodating and guiding the one of the guide wire, the boring tool and the instrument into engagement with the one of the occlusion and the wall of the to vessel, and an external portion comprising an external screw thread, a guide element having a second guide bore extending therethrough for accommodating and guiding the penetrating element into engagement with the one of the occlusion and the wall of the vessel, at least a portion of the second guide bore comprising an internal screw thread for engaging and co-operating with the external screw thread of the penetrating element, the guide element being configured for anchoring in the vessel with a distal end of the second guide bore thereof adjacent the one of the occlusion and the wall of the vessel, so that with the guide element anchored in the vessel, by rotating the penetrating element in the second guide bore, the penetrating element is urged by the co-operating action of the external and internal screw threads into penetrating engagement with the one of the occlusion and the wall of the vessel.

Preferably, the penetrating element comprises an engagement means configured to engage an operating means for rotating the penetrating element in the second guide bore. Advantageously, the engagement means of the penetrating element comprises a releasable engagement means configured to releasably engage the operating means.

In one aspect of the invention the operating means for rotating the penetrating element in the second guide bore of the guide element is provided. Preferably, the operating means is releasably engageable with the engagement means of the penetrating element.

In one aspect of the invention the engagement means of the penetrating element comprises one of a pair of interengageable complementary formations and the other one of the pair of the interengageable complementary formations is located on the operating means. Preferably, the one of the interengageable complementary formations located on the operating means is located adjacent the distal end thereof.

In another aspect of the invention one of the interengageable complementary formations comprises at least one spade element, and the other one of the interengageable complementary formations comprises at least one engagement groove engageable with the corresponding spade element. Preferably, the engagement means of the penetrating element comprises the engagement groove of the pair of interengageable complementary formations. Advantageously, the engagement groove extends radially from and longitudinally into the penetrating element adjacent the proximal end thereof. Preferably, a pair of radially extending engagement grooves are provided, the radially extending engagement grooves extending radially from the first guide bore extending through the penetrating element on respective opposite sides thereof.

In one aspect of the invention the at least one spade element extends radially from the operating means for engaging a corresponding radially extending engagement groove in the penetrating element. Preferably, a pair of spade elements extend radially from the operating means on respective opposite sides thereof for engaging corresponding ones of the engagement grooves.

In another aspect of the invention the operating means comprises an elongated spigot extending longitudinally therefrom for engaging the first guide bore of the penetrating element for facilitating delivery of the penetrating element through the second guide bore of the guide element to the internal screw thread of the second guide bore. Preferably, the spade element extend on respective opposite sides of the spigot of the operating means.

In another aspect of the invention the distal cutting edge of the penetrating element extends around the first guide bore of the penetrating element. Preferably, the penetrating element comprises an elongated tubular element extending between the distal cutting edge and the proximal end thereof.

In one aspect of the invention the penetrating element is of length between the proximal end and the distal cutting edge thereof in the range of 5 mm to 60 mm. Preferably, the penetrating element is of length between the proximal end and the distal cutting edge thereof in the range of 10 mm to 40 mm. Advantageously, the penetrating element is of length between the proximal end and the distal cutting edge thereof of approximately 20 mm.

In another aspect of the invention the maximum outer transverse cross-sectional dimension of the penetrating element lies in the range of 0.28 mm to 0.76 mm. Preferably, the maximum outer transverse cross-sectional dimension of the penetrating element lies in the range of 0.40 mm to 0.60 mm. Advantageously, the maximum outer transverse cross-sectional dimension of the penetrating element is approximately 0.50 mm.

In one aspect of the invention the first guide bore is of circular transverse cross-section. Preferably, the distal cutting edge of the penetrating element is substantially circular.

In one aspect of the invention the penetrating element comprises a cylindrical wall and the external screw thread is located on the outer surface of the cylindrical wall.

In another aspect of the invention a limit means is provided on the penetrating element for limiting the travel of the penetrating element in a direction distally outwardly of the second guide bore of the guide element. Preferably, the limit means of the penetrating element comprises an unthreaded limit portion of the outer surface of the penetrating element proximal of the external screw thread thereof.

Advantageously, the unthreaded limit portion of the outer surface of the penetrating element is of diameter at least greater than the diameter of the root of the external screw thread thereof. Ideally, the unthreaded limit portion of the outer surface of the penetrating element is located adjacent the proximal end of the external screw thread on the penetrating element.

In another aspect of the invention one of the outer and inner surfaces of the wall of the penetrating element adjacent the distal end thereof converges distally towards the other one of the inner and outer surfaces of the wall of the penetrating element to define the distal cutting edge. Preferably, the outer surface of the wall of the penetrating element adjacent the distal end thereof converges towards the inner surface thereof to define the distal cutting edge. Alternatively, the inner and outer surfaces of the wall of the penetrating element adjacent the distal end thereof converge towards each other to define the distal cutting edge.

In one aspect of the invention the first guide bore of the penetrating element defines a first central guide axis, and the external screw thread of the penetrating element defines a first central thread axis. Preferably, the external screw thread of the penetrating element is configured so that the first central thread axis extends substantially parallel to the first central guide axis. Advantageously, the external screw thread of the penetrating element is configured so that the first central thread axis substantially coincides with the first central guide axis.

In another aspect of the invention the second guide bore of the guide element defines a second central guide axis, and the guide element defines a main central axis.

In a further aspect of the invention the guide element is configured for anchoring in the vessel with the second central guide axis of the second guide bore extending substantially parallel to the second central axis of the guide element. Preferably, the guide element is configured with the second central guide axis extending substantially parallel to the main central axis of the guide element. Advantageously, the guide element is configured with the second central guide axis substantially coinciding with the main central axis of the guide element.

In another aspect of the invention the guide element is configured with the second central guide axis of the guide element extending at an angle greater than zero to the main central axis thereof.

In another aspect of the invention the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 5° to 90° to the main central axis of the guide element. Preferably, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 10° to 80° to the main central axis of the guide element. Advantageously, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 15° to 75° to the second central axis of the guide element. Ideally, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 20° to 70° to the main central axis of the guide element. Preferably, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 25° to 65° to the main central axis of the guide element. Advantageously, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 30° to 60° to the main central axis of the guide element.

Preferably, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 35° to 55° to the main central axis of the guide element. Advantageously, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 40° to 50° to the main central axis of the guide element. Ideally, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of approximately 45° to the main central axis of the guide element.

In one aspect of the invention an internal screw thread is located in the first guide bore of the penetrating element configured to engage and co-operate with a corresponding external screw thread on one of a boring tool, a guide wire and an instrument.

In another aspect of the invention an anchoring means is provided for anchoring the guide element in a vessel. Preferably, the anchoring means comprises an expandable element expandable within the vessel. Advantageously, the expandable element comprises an inflatable balloon.

Preferably, the expandable element defines a longitudinally extending central axis, the central axis defined by the expandable element substantially coinciding with the main central axis of the guide element.

In another aspect of the invention the guide element is located adjacent a distal end of an elongated catheter. Preferably, the catheter defines an elongated main lumen extending longitudinally therethrough and communicating with the second guide bore of the guide element for accommodating the operating means to the penetrating element. Advantageously, the main lumen extending through the catheter is substantially aligned with the second guide accommodating bore of the guide element.

In another aspect of the invention the catheter comprises a balloon catheter, the element being located adjacent the distal end of a balloon catheter, and the balloon of the balloon catheter forming the anchor means of the guide element. Preferably, a portion of the main lumen of the catheter adjacent the balloon defines a main lumen central axis.

In one aspect of the invention the second central guide axis of the guide element extends substantially parallel to the main lumen central axis. Preferably, the second central guide axis of the guide element substantially coincides with the main lumen central axis.

Alternatively, the second central guide axis of the guide element extends at an angle greater than zero to the main lumen central axis.

Preferably, the second central guide axis of the guide element diverges distally from the main lumen central axis.

Advantageously, the second central guide axis of the guide element extends substantially perpendicularly from the main lumen central axis.

The invention also provides a balloon catheter comprising an elongated catheter extending between a to proximal end and a distal end and having an elongated main lumen extending longitudinally therethrough from the proximal end to the distal end, an inflatable balloon located on the catheter for anchoring the catheter in a vessel in a body of a human or animal subject, the catheter terminating adjacent the distal end thereof in the device according to the invention with at least a portion of the guide element of the device located within the balloon and a distal portion of the guide element extending from the balloon.

In one aspect of the invention the anchoring means for anchoring the guide element of the device comprises the balloon of the balloon catheter.

In another aspect of the invention the device extends distally from the catheter. Preferably, the main lumen extending through the catheter is substantially aligned with the second guide accommodating bore of the guide element. Advantageously, the main lumen is of transverse cross-sectional area for accommodating the penetrating element therethrough.

Advantageously, the main lumen is of transverse cross-sectional area for accommodating the operating means therethrough.

In one aspect of the invention a portion of the main lumen of the catheter adjacent the balloon defines a main lumen central axis.

In another aspect of the invention the second central guide axis of the guide element extends substantially parallel to the main lumen central axis. Preferably, the second central guide axis of the guide element substantially coincides with the main lumen central axis.

Alternatively, the second central guide axis of the guide element extends at an angle greater than zero to the main lumen central axis.

In one aspect of the invention the guide element is configured with the second central guide axis of the guide element extending at an angle in the range of 5° to 90° to the main lumen central axis of the guide element.

In another aspect of the invention the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 15° to 75° to the second central axis of the guide element. Preferably, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 25° to 65° to the second central axis of the guide element. Advantageously, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of 30° to 60° to the second central axis of the guide element. Ideally, the guide element is configured with the second central guide axis of the guide element configured to extend at an angle in the range of approximately 45° to the second central axis of the guide element.

In another aspect of the invention the second central guide axis of the guide element diverges distally from the main lumen central axis.

In another aspect of the invention the second central guide axis of the guide element extends substantially perpendicularly from the main lumen central axis.

In another aspect of the invention the operating means for rotating the penetrating element in the guide element is provided extending longitudinally through the main lumen extending through the catheter the operating means being releasably engageable with the penetrating element for rotating the penetrating element in the guide element to urge the penetrating element into engagement with the one of the occlusion and the wall of the vessel. Preferably, the operating means is of length to extend from the penetrating element through the main lumen of the catheter to extend outwardly of the catheter adjacent the proximal end thereof.

In one aspect of the invention the balloon is located adjacent the distal end of the catheter.

Preferably, the catheter extends through the balloon and defines with the balloon an annular hollow interior region for receiving an inflating medium. Preferably, an inflating lumen extends longitudinally through the catheter from the proximal end thereof and communicates with the hollow interior region of the balloon within the balloon.

The invention also provides a method for guiding one of a guide wire, a boring tool and an instrument into engagement with one of an occlusion in a vessel and a wall of the vessel in the body of a human or animal subject, the method comprising providing a penetrating element terminating in a distal cutting edge for cutting into and penetrating the one of the occlusion and the wall of the vessel, providing a first guide bore extending through the penetrating element for accommodating and guiding the one of the guide wire, the boring tool and the instrument into engagement with the one of the occlusion and the wall of the vessel, and providing an external screw thread on the penetrating element, locating the penetrating element in a second guide bore extending through a guide element and engaging the external screw thread of the penetrating element with internal screw thread in the second guide bore of the guide element, anchoring the guide element in the vessel with a distal end of the second guide bore of the guide element adjacent the one of the occlusion and the wall of the vessel, rotating the penetrating element in the second guide bore of the guide element for urging the penetrating element into penetrating engagement with the one of the occlusion and the wall of the vessel, and guiding the one of the guide wire, the boring tool and the instrument through the first guide bore of the penetrating element into engagement with the one of the occlusion and the wall of the vessel. Preferably, the penetrating element is rotated in the second guide bore of the guide element by an operating means engaged with the penetrating element adjacent the proximal end thereof. Advantageously, the operating means is releasably engaged with the penetrating element.

In one aspect of the invention the operating means is urged through the second guide bore in the guide element for engaging the penetrating element.

In another aspect of the invention an internal screw thread is provided in the first guide bore of the penetrating element for engaging and co-operating with a corresponding external screw thread on one of a boring tool, a guide wire and an instrument, and the one of the boring tool, the guide wire and the instrument is rotated in the first guide bore of the penetrating element with the external screw thread of the boring tool engaged with the internal screw thread in the first guide bore of the penetrating element for urging the boring tool through the first guide bore of the penetrating element.

In another aspect of the invention the guide element is anchored in the vessel by an expandable element engageable with the vessel. Preferably, the expandable element comprises an inflatable balloon. Advantageously, the expandable element comprises a balloon of a balloon catheter, the balloon being located on the distal end of the catheter for locating and anchoring the guide element in the vessel.

In another aspect of the invention the guide element extends distally from the distal end of the catheter.

Preferably, the guide element is formed by a distal portion of the catheter.

Advantageously, the guide element is located adjacent the distal end of the catheter with at least a portion of the guide element extending into the balloon, and a distal portion of the guide element extending from the balloon.

In another aspect of the invention the operating means is configured for delivering the penetrating element through a main lumen of the catheter and the second guide bore of the guide element to the internal screw thread of the second guide bore.

In a further aspect of the invention the balloon of the balloon catheter is urged into the vessel and is anchored in the vessel with the distal end of the guide element adjacent the occlusion or the wall of the vessel by inflating the balloon therein.

Preferably, travel of the penetrating element in a direction distally outwardly of the second guide bore of the guide element is limited by a limit means.

The advantages of the invention are many. A particularly important advantage of the invention is achieved by virtue of the fact that once the penetrating element is engaged in the occlusion or the wall of the vessel, a direct path from the second guide bore of the guide element, and in turn the first guide bore of the penetrating element into the opening or bore formed through or into the occlusion or wall of the vessel is continuously maintained by the penetrating element, since the penetrating element is in continuous engagement and alignment with the opening or bore in the occlusion or vessel wall. This, thereby allows boring tools, guide wires and other instruments to be replaced by other boring tools, guide wires and instruments without any danger of the first guide bore of the penetrating element going out of alignment with the opening or bore formed into or through the occlusion or vessel wall. This is a particularly important advantage where it is desired to locate, for example, a stent in an occlusion after a bore or opening has been formed through the occlusion in order to maintain the bore or opening through the occlusion open. In such cases, it is normal to form a bore or opening through the occlusion by one or more boring tools, and then subsequently place a stent in the bore by use of a stent delivery catheter. By virtue of the fact that the penetrating element continuously maintains a direct path into the bore formed through the occlusion after the boring tool has been removed, a guide wire can be passed through the first guide bore of the penetrating element directly into the bore or opening extending through the occlusion, and a stent delivery catheter can then be passed over the guide wire through the first guide bore of the penetrating element directly into the opening or bore extending through the occlusion for in turn placing the stent within the opening or bore extending through the occlusion.

Referring to the drawings, and initially toFIGS. 1 to 10thereof, which are not to scale, there is illustrated a balloon catheter1according to the invention, indicated generally by the reference numeral1, which comprises a device also according to the invention and indicated generally by the reference number3for guiding, for example, a boring tool5into engagement with, for example, an occlusion6in a remote vessel8in the body (not shown) of a human or animal subject, seeFIGS. 8 to 10for forming a bore9into or completely through the occlusion6. The occlusion6in this embodiment of the invention is an occlusion formed by a build-up of plaque in the vessel8, which in this case is a peripheral blood vessel, but may be an artery of the cardiovascular system of the subject. However, it will be readily apparent to those skilled in the art that the balloon catheter1and the device3may be used for guiding any surgical or other instrument into engagement with an occlusion, a wall of a vessel or any other part of a vessel to which it is required to guide one or more boring tools, instruments, guide wires or the like to a specific location in an occlusion or a wall of a vessel. The vessel may be remotely or otherwise located in the body of the human or animal subject.

The balloon catheter1comprising an elongated catheter10of circular transverse cross-section extending between a proximal end11and a distal end12. The catheter10may be of any suitable material, and the material in some cases will be dependent on the location and type of vessel in which the occlusion is located. An anchoring means for anchoring the catheter10and in turn the device3in the vessel8, in this embodiment of the invention, comprises an expandable element, namely, an inflatable balloon14located on the catheter10adjacent the distal end12thereof. The balloon14extends around the catheter10and defines with the catheter10an inflatable hollow interior region or annulus15. The balloon14is of a flexible resilient material, and when inflated is substantially cylindrical, although it will be appreciated that when inflated in a vessel, the balloon14will tend to assume the shape of the vessel. In this embodiment of the invention the catheter10is formed by extrusion and comprises an inner tubular member17of circular transverse cross-section and an outer tubular member18also of circular transverse cross-section, which extends around and is coaxial with the inner tubular member17. Longitudinally extending ribs (not shown) which are equi-spaced apart circumferentially around the inner tubular member17extend radially from the inner tubular member17to the outer tubular member18for retaining the inner and outer tubular members17and18spaced apart from each other and coaxially with each other.

A proximal end20of the balloon14is sealably secured to and around the outer tubular member18adjacent a distal end21thereof, and a distal end23of the balloon14is sealably secured to and around the inner tubular member17thereof adjacent a distal end24thereof so that the balloon14is sealably secured to the catheter10. A plurality of inflating lumens25are formed between the inner and outer tubular members17and18by the ribs (not shown) and extend longitudinally through the catheter10from the proximal end11of the catheter10to the distal end21of the outer tubular member18and communicate with the inflatable annulus15of the balloon14for accommodating air or other suitable inflating medium, for example, a saline solution, for inflating the balloon14. The inner tubular member17defines an elongated main lumen27of circular transverse cross-section, which extends longitudinally through the catheter10from the proximal end11to the distal end12thereof for accommodating the boring tool5, a guide wire and/or other instruments for treating and/or opening the occlusion6. The main lumen27defines a main lumen central axis28.

A guide element30of circular transverse cross-section extending between a proximal end31and a distal end32is located and rigidly secured in the main lumen27adjacent the distal end12of the catheter10. The distal end32of the guide element30substantially coincides with the distal end12of the catheter10, and the guide element30extends into the main lumen27from the distal end12of the catheter10, so that the majority of the guide element30is located within the balloon14. The guide element30may be of a polymer material or of a suitable steel, for example, a stainless steel material. A cylindrical penetrating element33for engaging and penetrating into the occlusion6is urgeable through the main lumen27of the catheter10from the proximal end11thereof to the distal end12thereof as will be described in more detail below, and is urgeable through and from the distal end32of the guide element30into penetrating engagement with the occlusion6, as will also be described below.

The penetrating element33comprises an elongated tubular member34of stainless steel material and of circular transverse cross-section extending between a proximal end35and a distal end36. The tubular element34of the penetrating element33comprises a cylindrical wall37which defines a first guide bore38of circular transverse cross-section extending through the penetrating element33for accommodating the boring tool5therethrough and for guiding the boring tool5into the occlusion6, as well as for accommodating and guiding guide wires and instruments into the occlusion6. The first guide bore38defines a longitudinally extending first central guide axis39which coincides with the central geometric axis of the penetrating element33.

The penetrating element33terminates at its distal end36in a distal cutting edge40which extends around the side wall37of the penetrating element33for penetrating into the occlusion6. The cutting edge40is formed by tapering the outer cylindrical surface42of the side wall37adjacent the distal end36so that the outer surface42converges distally inwardly at43towards the inner surface44of the side wall37, which forms the first guide bore38, to form with the inner surface44the cutting edge42as a circular cutting edge42extending around the first guide bore38adjacent the distal end36of the penetrating element33.

A second guide bore45of circular transverse cross-section extends axially through the guide element30for guiding the penetrating element33into engagement with the occlusion6. The second guide bore45defines a second central guide axis47, which in this embodiment of the invention coincides with the main lumen central axis28.

External screw threads49are provided on the outer cylindrical surface42of the penetrating element33and are engageable with internal screw threads50formed in the guide element30. Accordingly, by rotating the penetrating element33in the second guide bore45with the external screw threads49of the penetrating element33engaged and co-operating with the internal screw threads50of the second guide bore45, the penetrating element33is urgeable inwardly and outwardly through the distal end12of the catheter10.

A limit means for limiting the distance the penetrating element33can travel distally through the distal end32of the guide element30comprises an unthreaded limit portion51of the outer surface42of the penetrating element33located adjacent a proximal end56of the external screw threads49thereof. The unthreaded limit portion51of the penetrating element33is of diameter at least greater than the diameter of the root of the external screw threads49, and in this case substantially similar to the maximum outer diameter of the external screw threads49of the penetrating element33, so that when the unthreaded limit portion51of the penetrating element33abuts a proximal end59of the internal screw threads50further outward distal movement of the penetrating element33is prevented.

An operating means, in this embodiment of the invention comprising an elongated operating member52is provided for rotating the penetrating element33in the second guide bore45for urging the penetrating element33inwardly and outwardly of the second guide bore45. The operating member52is configured for extending into and through the main lumen27of the catheter10to the penetrating element33. The operating member52comprises an elongated operating element53of the construction of a torsional guide wire and extends from a proximal end54to a distal end55, and is configured to be rotatable in the main lumen27, for in turn rotating the penetrating element33. The distal end55of the operating element53terminates in one of a pair of interengageable complementary formations, one of which pair of interengageable complementary formations comprises a pair of spade elements57which extend distally longitudinally from and radially outwardly from the operating element53. The spade elements57are configured for releasably engaging the other one of the pair of the interengageable complementary formations which in this embodiment of the invention is provided by an engagement means formed by a pair of engagement grooves58which extend longitudinally into the proximal end35of the penetrating element33and radially from the first guide bore38extending through the penetrating element33on respective opposite sides thereof.

The operating member52is also configured for delivering the penetrating element33through the main lumen27of the catheter10to the guide element30and into engagement with the internal screw threads50of the guide element30, and in this embodiment of the invention the operating member52comprises an elongated spigot60of circular transverse cross-section extending distally longitudinally from the distal end55of the operating element53. The spigot60is of diameter substantially similar to the diameter of the first guide bore38of the penetrating element33, so that the spigot60is a relatively tight sliding fit in the first guide bore38of the penetrating element33for retaining the penetrating element33on the spigot60during delivery of the penetrating element33through the main lumen27of the catheter10to the guide element30. The spade elements57extend radially from the spigot60on respective opposite sides thereof, so that when the spigot60is fully engaged in the first guide bore38of the penetrating element33, the spade elements57engage with the corresponding engagement grooves58of the penetrating element33.

The operating element53is of sufficient length to extend from the penetrating element33when the external screw threads49of the penetrating element33are engaged in the internal screw threads50of the guide element30with the unthreaded limit portion51of the penetrating element33in engagement with the proximal end59of the internal threads50of the guide element30, to the proximal end11of the catheter10with the proximal end54of the operating element53extending outwardly of the proximal end11of the catheter10, in order to facilitate gripping of the operating element53adjacent the proximal end54for rotating thereof, and in turn for rotating the penetrating element33.

In this embodiment of the invention the length of the penetrating element33from the distal cutting edge40to the proximal end35is approximately 40 mm. The outer diameter of the penetrating element33is approximately 0.50 mm while the diameter of the first guide bore38extending through the penetrating element33is approximately 0.45 mm. However, it will be readily apparent to those skilled in the art that the penetrating element33may be of any suitable length outer diameter and internal diameter, and the dimensions of the penetrating element33will largely depend on the procedure with which it is being used, and for example, the length of the penetrating element33from the distal cutting edge40to the proximal end35may range from as low as 5 mm to as high as 60 mm, while the outer diameter of the penetrating element33may range from 0.28 mm to 0.76 mm, and the diameter of the first guide bore38of the penetrating element33may range from 0.229 mm to 0.71 mm.

Additionally, in this embodiment of the invention the guide element30is of length from the proximal end31to the distal end32approximately 15 mm, and the outer diameter of the guide element30is of length approximately 0.55 mm, while the diameter of the second guide bore45is approximately 0.50 mm. However, like the penetrating element33, these dimensions of the guide element30will vary depending on the procedure with which the device is being used. In general, it is expected that the length of the guide element30from the proximal end31to the distal end32may range from 5 mm to 40 mm, while the outer diameter of the guide element30may range from 0.33 mm to 0.81 mm, and the diameter of the second guide bore45may range from 0.28 mm to 0.76 mm.

In use, to unblock an occlusion6in a vessel8of the cardiovascular system of the subject, a standard guide wire of the type which will be well known to those skilled in the art is entered into the arterial system of a subject, typically through the femoral artery and is urged from the femoral artery through the arterial system of the body of the subject and eventually into the vessel8in which the occlusion6is located. The insertion and guiding of such a guide wire to an occlusion in a vessel of the cardiovascular system of a subject will be well known to those skilled in the art. When the guide wire has been guided to the occlusion6in the vessel8, the balloon catheter1with the balloon14deflated is then urged over the guide wire through the arterial system of the subject until the distal end12of the catheter10and the balloon14are located in the vessel8adjacent the occlusion6.

The balloon14is then inflated in the vessel8for anchoring the catheter10in the vessel8with the distal end12of the catheter10located adjacent the occlusion6, and substantially centrally aligned with the occlusion6. The balloon14is inflated by delivering a suitable inflating medium, for example, air, a saline solution or the like through the inflating lumens25of the catheter10into annulus15of the balloon14. With the balloon14inflated and rigidly anchored in the vessel8and with the distal end12of the catheter10adjacent the occlusion6, the guide wire is then removed from the catheter10.

The penetrating element33is mounted on the spigot60of the operating member52with the spigot60engaged in the first guide bore38of the penetrating element33. The penetrating element33is then delivered through the main lumen27of the catheter10by the operating member52until the external screw threads49of the penetrating element33engage the internal screw threads50of the guide element30. If the spade elements57of the operating member52are not engaged in the engagement grooves58of the penetrating element33, the operating member52is rotated and urged towards the penetrating element33until the spade elements57engage the engagement grooves58.

Further rotation of the operating member52in a clockwise direction, assuming the external screw threads49of the penetrating element33and the internal threads50of the guide element30are right-hand threads, urges the penetrating element33outwardly through the distal end32of the guide element30. Rotation of the penetrating element33by the operating member52is continued until the distal cutting edge40of the penetrating element33engages and penetrates into the occlusion6, so that the penetrating element33is in tight secure penetrating engagement with the occlusion6. By virtue of the fact that the distal end12of the catheter10is rigidly anchored in the vessel8by the balloon14, as the penetrating element33is being rotated, the penetrating element33is urged outwardly through the distal end32of the guide element30against the anchoring action of the balloon14into the occlusion6with the distal cutting edge40of the penetrating element32cutting into the occlusion6in order to securely engage the occlusion6.

When the penetrating element33is in secure penetrating engagement with the occlusion6, the operating member52is withdrawn through the main lumen27. The boring tool5is then urged through the main lumen27of the catheter10and in turn through the first guide bore38of the penetrating element33which guides the boring tool5directly into the occlusion6for boring through the occlusion6and opening a channel9through the occlusion6. On removal of the boring tool6, further boring tools and/or other instruments may be passed through the main lumen27of the catheter10and in turn through the first guide bore38of the penetrating element33and guided by the first guide bore38directly into the already opened channel through the occlusion6for enlarging the channel through the occlusion6or for carrying out further procedures.

Once a channel has been opened through the occlusion6to the desired cross-section, the boring tool5and/or other boring tools are removed through the main lumen27. If desired a stent may be delivered through the main lumen27of the catheter10through the first guide bore38in the penetrating element33and in turn into the channel which has been opened through the occlusion6. Typically, a stent would be delivered to the channel through the occlusion6with the stent in a collapsed state carried on a balloon of a stent delivery balloon catheter. The stent delivery balloon catheter with the stent in the collapsed state on the deflated balloon of the balloon catheter would be urged through the main lumen27of the catheter10and in turn through the first guide bore38of the penetrating element33until the stent was located in the channel through the occlusion6. The balloon of the stent delivery balloon catheter is then inflated to expand the stent into engagement with the channel formed through the occlusion6and for further opening the channel and for retaining and maintaining the channel extending through the occlusion6.

On completion of the location of a stent in a channel through the occlusion6, the balloon or the stent delivery balloon catheter is deflated and the stent delivery balloon catheter is removed through the main lumen27of the catheter10. The operating member52is then again urged through the main lumen27of the catheter10until the spigot60engages the first guide bore38extending through the penetrating element33and the spade elements57engage in the engagement grooves58of the penetrating element33. The operating element52is then rotated in an anticlockwise direction for withdrawing the penetrating element33from the occlusion6and into the guide element30. The balloon14of the balloon catheter1is deflated, and the balloon catheter1with the penetrating element33withdrawn into the guide element30and the operating member52are then removed through the arterial system of the subject.

Referring now toFIG. 11which is not to scale, there is illustrated a balloon catheter according to another embodiment of the invention indicated generally by the reference numeral70, which also comprises a device also according to the invention and indicated generally by the reference numeral71for guiding one of a boring tool, a guide wire and/or an instrument into an occlusion in a vessel, or into a wall of a vessel. The balloon catheter70and the device71are substantially similar to the balloon catheter1and the device3, respectively, described with reference toFIGS. 1 to 10, and similar components are identified by the same reference numerals. The only difference between the balloon catheter70and the device71on the one hand, and the balloon catheter1and the device3on the other hand, is that the device70extends from the catheter10within the balloon14at an angle α and extends through a cylindrical portion72of the balloon14. The balloon catheter70and the device71is particularly suitable for guiding a boring tool, a guide wire or other instrument into a wall of a vessel, or into an occlusion in a vessel branched from a vessel in which the balloon14of the balloon catheter70is located.

In this embodiment of the invention the inner tubular member17of the catheter10is branched at74within the balloon14. One portion75of the inner tubular member17is aligned with the remainder of the inner tubular portion17and extends through the balloon14to the distal end23of the balloon14. The other branch76of the inner tubular member17extends at the angle α to the branch75, and in turn the remainder of the inner tubular element17, and a distal end78of the branch76extends through the cylindrical portion72of the balloon14. In this embodiment of the invention the main lumen27extends through the inner tubular member17to the location74at which the inner tubular member17is branched, and in turn continues through the branch76of the inner tubular member17. The guide element30is tightly and securely located in the branch76of the inner tubular member17with the distal end32of the guide element30terminating adjacent the distal end78of the branch76. In this embodiment of the invention the second central guide axis47defined by the second guide bore45of the guide element30extends at the angle α to the main lumen central axis28of the catheter10adjacent the balloon14. The angle α defined between the second central guide axis47and the main lumen central axis28may be of any value greater than 0° and just less than 180° and will depend on the application for which the balloon catheter70is required. In cases where the penetrating element33is to guide a boring tool or other instrument into a side wall of a vessel in which the balloon14is located perpendicularly to the side wall of the vessel, typically, the angle α defined between the second central guide axis47and the main lumen central axis28of the catheter10would be approximately 90° as illustrated inFIG. 11. However, if it were desired to guide a boring tool or other instrument into a side wall of a vessel at an angle less than or greater than 90° the angle α defined between the second central guide axis47and the main lumen central axis28of the catheter10would be set at an appropriate angle for guiding the boring tool or instrument into the wall of the vessel at the desired angle. Similarly, in cases where the balloon catheter70is required to guide a boring tool or other instrument into an occlusion in a vessel branched from the vessel in which the balloon14of the balloon catheter70is located, the branch portion76would extend from the inner tubular member17of the catheter10with the angle α defined between the second central guide axis47and the main central axis28of the catheter10being substantially similar to the angle at which the vessel with the occlusion therein extends from the vessel within which the balloon14of the balloon catheter70is located.

In this embodiment of the invention the guide element30is of length between its proximal end31and its distal end32of approximately 5 mm, and the length of the penetrating element33between its proximal end35and its distal end36is approximately 20 mm, althoughFIG. 11is not to scale.

Otherwise, the balloon catheter70and the device71are similar to the balloon catheter1and the device3, respectively.

In use the balloon catheter70is urged through the arterial system of a subject until the balloon14of the balloon catheter70is located in the appropriate vessel, and the balloon catheter70is orientated in the vessel until the distal end78of the branch76of the inner tubular member17is aligned with the location in the wall of the vessel into which a bore is to be formed or until the distal end78of the branch76of the inner tubular member17is aligned with the branched vessel in which the occlusion to be bored is located. Once the distal end78of the branch76of the inner tubular member17is aligned with the appropriate area of the vessel wall or an occlusion in a branched vessel, the balloon14is then inflated, and with the operating member52the penetrating element33is rotated with the external threads49of the penetrating element33engaging the internal threads50of the guide element30for urging the distal cutting edge40of the penetrating element33into penetrating engagement with the wall of the vessel or the occlusion in the branched vessel as the case may be. Thereafter operating and use of the balloon catheter70and the device71is similar to that already described with reference to the balloon catheter1and the device3thereof.

Referring now toFIG. 12, which is not to scale, there is illustrated a balloon catheter according to another embodiment of the invention indicated generally by the reference numeral80, which also comprises a device also according to the invention indicated generally by the reference numeral81for guiding one of a boring tool, a guide wire, and an instrument into an occlusion in a vessel or into a wall of a vessel. In this embodiment of the invention the device81is illustrated for guiding a boring tool82into an occlusion in a vessel. The balloon catheter80is substantially similar to the balloon catheter1and similar components are identified by the same reference numerals. Additionally, the device81is also substantially similar to the device3, and similar components are also identified by the same reference numerals.

The main difference between the balloon catheter80and the balloon catheter1is that the penetrating element33as well as being provided with external screw threads49for engaging the internal screw threads50of the guide element30, is also provided with internal screw threads84located in the first guide bore38of the penetrating element33for engaging corresponding external screw threads85on the boring tool82. The provision of the internal screw threads84in the first guide bore38of the penetrating element33permits the boring tool82to be urged out of the penetrating element33and into an occlusion in a vessel by rotating the boring tool82in the first guide bore38of the penetrating element33. In this embodiment of the invention the boring tool82terminates in a penetrating point87for penetrating into the occlusion, so that as the boring tool82is urged through the first guide bore38by rotation of the boring tool82in the penetrating element33, the penetrating point87is urged into and through the occlusion.

In this embodiment of the invention the internal screw threads84in the first guide bore38of the penetrating element33are located towards the proximal end of the first guide bore38, however, it will be readily apparent to those skilled in the art that if desired the internal screw threads84may extend throughout the full length of the first guide bore38. The external screw threads85on the boring tool82may extend over only a short length of the boring tool, or over a longer length. The length which the external screw threads85extend along the boring tool82, will largely be determined by the distance through which the boring tool82is to be urged outwardly of the penetrating element33, and will also be dependent on the length of the internal screw threads84in the first guide bore38of the penetrating element33. However, in general, it is envisaged that a reasonable length of the distal portion89of the boring tool82will be provided free of the external screw threads85so that the boring tool82will be able to penetrate through the full length of an occlusion without the external screw threads85engaging the occlusion.

The boring tool82as will be understood by those skilled in the art is secured to and extends from the distal end of an elongated carrier element, typically, an elongated torsional guide wire which is configured to extend from the boring tool82through the catheter10of the balloon catheter80to the proximal end11thereof and outwardly of the catheter10from the proximal end11thereof to permit manual rotation of the proximal end of the torsional guide wire for rotating the boring tool82within the first guide bore38of the penetrating element33.

In use the penetrating element33is initially engaged with the occlusion through which a channel is to be formed therethrough, in a similar manner as already described with reference to the balloon catheter1and the device3with reference toFIGS. 1 to 10. Once the penetrating element33has been engaged in the occlusion, the operating member52is removed through the catheter10. The boring tool82is then introduced into the main lumen27of the catheter10at the proximal end11thereof. The boring tool82is then urged through the main lumen27and in turn into the first guide bore38of the penetrating element33by the torsional guide wire, until the external screw threads85of the boring tool82engage the internal screw threads84of the penetrating element33.

The boring tool82is then rotated in the first guide bore38of the penetrating element33by rotating the torsional guide wire to which the boring tool82is attached for urging the boring tool82through the first guide bore38of the penetrating element33, and in turn directly into the occlusion from the first guide bore38. Assuming that the internal and external screw threads84and85are right hand threads, the boring tool82is rotated in a clockwise direction for in turn urging the boring tool82into the occlusion. Thus, in this embodiment of the invention the penetrating element33guides the boring tool82directly into the occlusion, and furthermore the boring tool82is urged into the occlusion by the co-operating action of the internal and external screw threads84and85as the boring tool82is rotated in the first guide bore38of the penetrating element33, so that the boring tool82is urged into and through the occlusion against the anchoring action of the balloon14in the vessel.

Otherwise, the balloon catheter80and the device81are similar to the balloon catheter1and the device3described with reference toFIGS. 1 to 10, and their operation is likewise similar.

A particularly important advantage of the balloon catheter80and the device81is that as well as the penetrating element33being urged into penetrating engagement with the occlusion by the penetrating element being urged against the anchoring action of the balloon14of the balloon catheter80which is anchored in the vessel, the boring tool82is also urged into the occlusion against the anchoring action of the balloon14.

It is envisaged that instead of the boring tool82being secured to the distal end of a guide wire, the boring tool82could be provided with an engagement means at a proximal end thereof, which would be engageable by an operating member somewhat similar to the operating member52for rotating the boring tool82in the first guide bore38of the penetrating element33. For example, it is envisaged that the boring tool82may be provided with a transversely extending engagement slot at its proximal end for engaging a spade element on the end of a torsional guide wire for rotating the boring tool82in the first guide bore38of the penetrating element33. It is also envisaged that the in such a case, a stop means may be provided on the proximal end of the boring tool82in order to prevent the boring tool82passing completely through the first guide bore38of the penetrating element33through the distal end36of the penetrating element33. It is envisaged that such a stop means would be located on the boring tool82, and would be substantially similar to the enlarged portion51of enlarged diameter of the penetrating element33, and the enlarged portion of enlarged diameter of the boring tool82would be located adjacent a proximal end of the external screw threads85of the boring tool82and would engage the proximal end of the internal screw threads84in the first guide bore38to prevent further movement of the boring tool82through the first guide bore38of the penetrating element33towards the distal end36thereof.

While particular constructions of balloon catheters have been described, any other suitable construction of balloon catheter may be used. It will be appreciated that while the interengageable complementary formations which provide for releasable engagement of the operating member52with the penetrating element33have been described as comprising a pair of spade elements extending from the operating member52which are engageable with corresponding radial engagement grooves in the penetrating element, any other suitable pair of interengageable complementary formations may be provided. It will also of course be appreciated that the engagement grooves may be provided on the operating member while the spade elements would be provided on the penetrating element.

While the penetrating element has been described as comprising a circular cutting edge formed by tapering the outer cylindrical surface of the penetrating element distally inwardly to form the cutting edge with the inner surface of the first guide bore extending through the penetrating element, it will be appreciated that the cutting edge may be formed by diverging the inner surface of the first guide bore of the penetrating element distally to the cylindrical outer surface of the penetrating element to form the circular cutting edge adjacent the distal end of the penetrating element. It will also be appreciated that the cutting edge may be defined by tapering the outer cylindrical surface of the penetrating element distally inwardly and also diverging the inner surface of the bore extending through the penetrating element outwardly to form the cutting edge between the tapering and diverging surfaces of the penetrating element.

It is also envisaged that the cutting edge instead of being formed by a smooth knife type cutting edge, could be formed by a serrated type cutting edge.

While the devices according to the invention have been described as comprising a guide element located in a main lumen of a balloon catheter adjacent the distal end of the catheter, it is envisaged that the guide element may be integral with the catheter of the balloon catheter, in which case the internal threads would be formed in the main lumen adjacent the distal end of the catheter.

It is also envisaged that the guide element could be provided as a separate element, and would be adapted for mounting on or coupling to the distal end of a balloon catheter with the second guide bore aligned with and communicating with the distal end of the main lumen of the balloon catheter. A proximal portion of the guide element could be adapted for releasably coupling to the balloon catheter whereby the proximal portion of the guide element would be configured to releasably grip a distal portion of the catheter of the balloon catheter, or would be releasably engageable with the balloon of the balloon catheter, and would be configured to expand with the balloon of the balloon catheter as the balloon of the balloon catheter is inflated.

Indeed, it is envisaged in certain embodiments of the invention that the second guide bore extending through the guide element need not necessarily be coaxial with the penetrating element, in other words, the second central axis defined by the second guide bore could be offset relative to the main central axis of the catheter, but in general would extend parallel to the central axis of the penetrating element.

While the devices has been described for use in unblocking an occlusion in a peripheral blood vessel, it will be readily apparent to those skilled in the art that the device may be used for unblocking any occlusion in any vessel, be it an arterial or venal vessel of a subject, cardiovascular vessel or any other vessel of the subject. Additionally, it is envisaged that while the devices have been described for guiding a boring tool into engagement with an occlusion, it will be readily apparent to those skilled in the art that the devices according to the invention may be used for guiding any element into engagement with an occlusion, for example, any surgical instrument, a guide wire or any other such instrument. It will also be appreciated that the devices according to the invention may be used for guiding an instrument, a guide wire, a boring tool or the like into engagement with a wall of a vessel or indeed any other part of a vessel whereby the penetrating element would be initially urged into penetrating engagement with the wall of the vessel or other part of the vessel, and the surgical instruments, boring tools, guide wires and the like would then be guided into the wall of the vessel or other part of the vessel through the first guide bore extending through the penetrating element which would be in penetrating engagement with the wall of the vessel or other part thereof.

While some of the elements of the balloon catheters and the devices according to the invention have been described as being of specific materials, it will be readily apparent to those skilled in the art that other suitable materials may be used. It will also be appreciated that while the penetrating element and the guide element of the balloon catheters and the devices have been described as being of specific dimensions, it will be readily apparent to those skilled in the art that the dimensions of the penetrating element and the guide element, and indeed any other elements of the balloon catheter and the device will largely be dependent on the application for which the balloon catheter and the device are to be used.