Slitting tool

A tool for slitting an elongate sheath from about an elongate member that is disposed within a longitudinally extending lumen of the sheath includes a longitudinally extending tail portion projecting rearward of a slitting edge and a nose portion of the tool; a lower surface of the nose portion is disposed beneath the slitting edge for engaging a portion of the elongate member. The tail portion of the tool, approximately aligned with the sheath lumen when the lower surface engages the elongate member and a leading edge of the nose portion is within the sheath lumen, is sized to fit within the sheath lumen after the sheath is slit by the slitting edge. A passageway between the nose portion and the tail portion allows a proximal segment of the elongate member to bend away from the tail portion when the elongate member is engaged by the nose portion.

FIELD OF THE INVENTION

The present invention pertains to slitting tools and more particularly to slitting tools facilitating removal of an elongate sheath or catheter from about an elongate member disposed therein.

BACKGROUND OF THE INVENTION

Sheaths, or catheters, are commonly used in minimally invasive medical procedures, for example, to provide a pathway for the introduction of elongate medical devices into the vascular system of a patient. Many medical devices, introduced in such a manner, through a lumen of the sheath, are intended to indwell within the patient for a prolonged period, for example, extending from a number of days to many years. After the indwelling medical device has been inserted within the lumen of the sheath, for positioning within the patient, it is desirable to remove the sheath from the patient without dislodging the indwelling device.

A number of slitting tools, known to those skilled in the art, are used to remove sheaths from about indwelling medical devices. However, these tools present one or more difficulties to the user, for example, with respect to handling.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides practical illustrations for implementing exemplary embodiments of the present invention.

FIGS. 1A-Bare an end view and a side plan view, respectively, of a slitting tool10, according to one embodiment of the present invention; andFIG. 1Cis a section view through line A-A ofFIG. 1B.FIGS. 1A-Cillustrate tool10including a nose portion16, a handle portion17, a slitting edge12extending between nose portion16and handle portion17, a longitudinally extending tail portion14, and a passageway15disposed between nose portion16and tail portion14, and extending upward into handle portion17.FIGS. 1A-Bfurther illustrate nose portion16including a lower surface11and a leading edge13. According to the illustrated embodiment, slitting edge12is part of a metallic blade member120mounted in handle17; according to alternate embodiments, slitting edge is an integral part of material forming tool10as a whole. Tool10may be formed of a rigid plastic, a ceramic, a metallic material or a combination thereof.

According to the illustrated embodiment, lower surface11of nose portion16is adapted to engage an elongate member100, andFIG. 1Cshows elongate member100extending from nose portion16into passageway15such that a proximal segment100′ of member100bends away from tail portion14. With reference toFIGS. 1B-C, passageway15extends from nose portion16up into handle17, being flanked on either side by a sidewall150; passageway15further extends into grooves15′, which are formed along opposing outer surfaces17′ of handle17and either of which can accommodate segment100′. An operator, gripping handle17of tool10, may hold proximal segment100′ of elongate member100in one of channel grooves15′, as illustrated inFIG. 2.

FIG. 2is a schematic plan view, including a partial section, depicting a method for using slitting tool10according to some embodiments of the present invention.FIG. 2illustrates elongate member100, for example, an implantable medical electrical lead, disposed within a lumen25of a sheath200; sheath200is shown including a tubular sheath wall20terminated at a proximal end by a hub22.FIG. 2further illustrates a first thumb25and forefinger26of an operator holding slitting tool10and proximal segment100′ of member100, while a second thumb205and forefinger206hold a hub handle220to pull sheath200, per arrow A, against slitting edge12of tool10. Nose portion16of tool10is shown engaging elongate member100while proximal segment100′ bends through passageway15that extends along an operator grip zone19, which, on opposing surfaces17′ of handle17, is generally located in the zone indicated by cross-hatching. According to the illustrated embodiment, tail portion14of tool10is approximately aligned with sheath lumen25and is sized to fit within sheath lumen25, when slit, so that tail portion14will ride within sheath lumen25after slitting edge12cuts through hub and sheath wall20. According to some embodiments, tail portion14further includes a profile closely conforming with slit sheath lumen25, for example as illustrated inFIG. 3B.

FIG. 3Ais a top view of the slitting tool, shown inFIGS. 1A-C, cutting through a portion of sheath wall20; andFIG. 3Bis a section view through section line B-B ofFIG. 3A.FIGS. 3A-Billustrate sheath200having been pulled, per arrow A, so that sheath wall20has been slit by tool slitting edge12(FIGS. 1A-Band2) and tool tail portion14is disposed within lumen25, downstream of slitting edge12; slit edges32of sheath wall20emanate from slitting edge12beneath tool handle17, shown by dashed lines, and extend downstream of tool10; fingers25,26and associated hand of the operator holding tool10(FIG. 2) are not shown so that the view of tool10and slit edges32of sheath wall20is not obstructed.FIG. 3Bfurther illustrates a profile of tail portion14, formed by a continuous exterior surface extending thereabout, which closely mates with slit sheath lumen25; a width P of tail portion14may be approximately equal to or slightly greater than a pre-slit diameter of sheath lumen25, or may be up to two times greater than the pre-slit diameter of lumen25.FIG. 3Bfurther illustrates tool10including a shank18joining handle17to tail portion14; according to some embodiments, a thickness T of shank18is greater than approximately 0.01 inch and less than width P of tail portion14.

According to embodiments of the present invention, tail portion14may serve to stabilize tool10as it cuts through sheath wall20and may further prevent slit edges32from collapsing toward one another in a way which may cause slit sheath lumen25to ‘grab’ elongate member100, as sheath200is pulled, per arrow A, thereby dislodging a distal end of member100. An effective length of tail portion14, for stabilizing tool10as it cuts through sheath wall20, may be approximately equal to or greater than ½ inch. Although, inFIG. 2, tail portion14is illustrated extending proximally from operator grip zone19of handle portion17, embodiments of the present invention are not so limited.

FIGS. 4A-Bare a side plan view and an end view of a slitting tool40according to another embodiment of the present invention.FIGS. 4A-Billustrate tool40including a nose portion46, a handle portion47, a slitting edge42extending between nose portion46and handle portion47, and a longitudinally extending tail portion44.FIGS. 4A-Bfurther illustrate nose portion46including a lower surface41extending from a leading edge43to a passageway45that extends from between nose portion46and tail portion44, upward into handle portion47. According to the illustrated embodiment, to facilitate loading of elongate member100into passageway45, for example, as shown inFIG. 4A, tail portion44is split into a first leg404A and a second leg404B.FIG. 4Bshows each leg404A, B including a foot44A and44B, respectively; feet44A, B together form a tail profile, to mate with a slit lumen of a sheath or catheter, when legs are forced, per arrows B, together, as shown with dashed lines; the resulting profile is similar to that of solid tail14illustrated inFIG. 3B. Legs404A, B would be forced together in such a way when a sheath is pulled past slitting edge42of tool40such that tail44is enclosed by the slit lumen of the sheath.

FIG. 5Ais a schematic showing an alternate embodiment of a slitting tool50in a position for slitting sheath200; andFIG. 5Bis an end view ofFIG. 5A.FIG. 5Aillustrates tool50including a nose portion56, a handle portion57, a slitting edge52, extending between nose portion56and handle portion57, and a longitudinally extending tail portion54, which is joined to handle portion57by a shank58.FIG. 5Afurther illustrates nose portion56engaging elongate member100and a passageway55, disposed between nose portion56and tail portion54, allowing proximal segment100′ of elongate member100to bend away from tail portion54. According to the illustrated embodiment, fingers25and26, associated with the hand of the operator, hold segment100′ against an operator grip zone59of handle57, the extent of which generally corresponds to the cross-hatched area shown inFIG. 5B.

In the foregoing detailed description, the invention has been described with reference to specific embodiments. However, it may be appreciated that various modifications and changes can be made without departing from the scope of the invention as set forth in the appended claims.