Deflectable Sheath With Inflatable Balloon

A steerable intravascular catheter includes a handle assembly having opposed proximal and distal end portions and defining a longitudinal axis therebetween. An elongated sheath extending from the distal end portion of the handle assembly has opposed proximal and distal end portions, and includes a tubular body wall forming a central lumen for accommodating the introduction of a device and a fluid lumen radially outward from and parallel to the central lumen. The distal end portion of the elongated sheath is deflectable relative to the proximal end portion of the elongated sheath. A rotatable actuation assembly is associated with the handle assembly for controlling deflection of the distal end portion of the elongated sheath. An inflatable occlusion balloon is positioned on an outer surface of the distal end portion of the elongated sheath. The fluid lumen of the elongated sheath is in fluid communication with an interior of the balloon.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention relates to intravascular catheters, and more particularly, to a guided intravascular catheter device having an inflatable balloon mounted on its distal end and a steering assembly for accurately placing the distal end of the sheath and balloon at a targeted location in a patient's body.

2. Description of Related Art

There are instances where physicians must introduce diagnostic and therapeutic devices into the body, such as diagnostic and therapeutic electrodes, ultrasound transducers and other surgical tools. The diagnostic and therapeutic devices are often carried by catheters, which allow physicians to gain access to the body in a minimally invasive manner by way of bodily lumens. In cardiac treatment, for example, a catheter is advanced through a main vein or artery into the region of the heart that is to be treated.

One method of introducing diagnostic and therapeutic devices into the body is to introduce a tubular member (typically a “catheter sheath”) into the vicinity of the targeted region. A diagnostic or therapeutic catheter device is then passed through the sheath to the targeted region. If necessary, the diagnostic or therapeutic catheter device may be removed after its function is performed, but the sheath can be left in place, so that other catheters or other devices can be advanced to the targeted region to complete the diagnostic and/or therapeutic procedure. One such device commonly advanced to the targeted region through the catheter sheath is a balloon occlusion catheter. Balloon occlusion catheters can be used to occlude vessels to temporary block up a vessel to then deploy contract media and or a drug to a certain location inside the human body or vascular system. Traditional balloon occlusion catheters can be introduced into the vascular system through a central lumen of the catheter sheath.

Catheter sheaths can be steerable. Examples of steerable sheaths and devices are disclosed in commonly assigned U.S. Pat. Nos. 9,498,602, 9,572,957 and 9,907,570 to Osypka et al. While these devices are well suited for the precise placement of diagnostic or therapeutic devices within a patient's body, these steerable sheath devices do not include a balloon for treatment.

There is a need, therefore, for an improved guiding sheath with a distally mounted inflatable balloon, which allows the distal section of the sheath to be deflected, is easy to navigate as a delectable guiding sheath, is efficient to fabricate and easy to use.

SUMMARY OF THE INVENTION

A steerable intravascular catheter includes a handle assembly having opposed proximal and distal end portions and defining a longitudinal axis therebetween. An elongated sheath extends from the distal end portion of the handle assembly and has opposed proximal and distal end portions. The elongated sheath includes a tubular body wall forming a central lumen for accommodating the introduction of a device and a fluid lumen radially outward from and parallel to the central lumen. The distal end portion of the elongated sheath is deflectable relative to the proximal end portion of the elongated sheath. A rotatable actuation assembly is operatively associated with the handle assembly for controlling deflection of the distal end portion of the elongated sheath. An inflatable occlusion balloon is positioned on an outer surface of the distal end portion of the elongated sheath. The fluid lumen of the elongated sheath is in fluid communication with an interior of the balloon.

In accordance with some embodiments, the steerable intravascular catheter includes an inflation port positioned on the handle assembly in fluid communication with the fluid lumen for allowing the inflatable occlusion balloon to be inflated and deflated.

The elongated sheath can include a pull-wire lumen radially outward from and parallel to the central lumen. The steerable intravascular catheter can include an elongated pull-wire extending through the pull-wire lumen of the elongated sheath and terminating within the distal end portion of the elongated sheath. It is contemplated that the elongated pull-wire can have a proximal end operatively connected to the handle assembly and a distal end anchored to the distal end portion of the elongated sheath. In some embodiments, the steerable intravascular catheter includes a pull-wire anchor ring mechanically coupling a distal end of the elongated pull-wire to the distal end portion of the elongated sheath.

The distal end portion of the elongated sheath can be made from a softer material than the proximal end portion of the elongated sheath to accommodate deflection. The elongated sheath can define a circumference and a predetermined usable length (UL) extending from the proximal end portion of the elongated sheath substantially to the distal end portion of the elongated sheath. The predetermined UL can range from 30 cm to 120 cm.

The rotatable actuation assembly can include a rotatable control knob operatively connected to a proximal end of the elongated pull-wire. Rotation of the rotatable control knob can pull or release the elongated pull-wire and can cause the distal end portion of the elongated sheath to deflect away from the longitudinal axis or back toward the longitudinal axis. The handle assembly can include a drive mechanism for actuating the elongated pull-wire in response to bi-directional angular rotation of the rotatable control knob. Bi-directional angular rotation of the rotatable control knob about the longitudinal axis of the handle assembly can effectuate reciprocal axial movement of the elongated pull-wire and corresponding angular deflection of the distal end portion of the elongated sheath.

In accordance with some embodiments, the handle assembly can include a hemostatic valve operatively connected to the central lumen. The hemostatic valve is designed to minimize blood loss and prevent air embolisms. The handle assembly can include a luer type locking connection on a proximal end of the central lumen. The handle assembly can include a flush port in fluid communication with the central lumen to flush the central lumen. The proximal end portion of the elongated sheath can extend entirely through the handle assembly and terminate at a sealed access port communicating with the central lumen defined by the tubular body wall.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made to the appended drawings wherein like reference numerals identify similar structures or features of the subject invention. For purposes of explanation and illustration, and not limitation, there is illustrated inFIG. 1Aa new and useful steerable intravascular catheter constructed in accordance with a preferred embodiment of the subject invention and designated generally by reference numeral10. Other embodiments of the steerable intravascular catheter10in accordance with the disclosure, or aspects thereof, are provided inFIGS. 1B, 2 and 2A, as will be described. The steerable intravascular catheter10is adapted and configured to facilitate the intracardiac, renal and/or peripheral placement of diagnostic and therapeutic devices during a surgical procedure.

As shown inFIG. 1A, the steerable intravascular catheter10includes a handle assembly13having opposed proximal and distal ends defining a longitudinal axis A-A therebetween. An elongated sheath1extends from the distal end portion of handle assembly13. The elongated sheath1has opposed proximal and distal end portions and includes a tubular body wall22. The distal end portion6of the elongated sheath1is deflectable relative to the proximal end portion7of the elongated sheath1. The deflectable distal end portion6of the elongated sheath1is made from a softer material than the proximal end portion (e.g. the stiffer sheath section7) of the elongated sheath1to accommodate deflection. The handle assembly13includes a rotatable actuation assembly17for controlling deflection of the deflectable distal end portion6of the elongated sheath1. An inflatable occlusion balloon24is positioned on an outer surface of the deflectable distal end portion6of the elongated sheath1. The elongated sheath1defines a circumference C and a predetermined usable length (UL) extending from the start of the proximal end portion7of the elongated sheath1by the handle assembly13substantially to the distal most end of the distal end portion6of the elongated sheath1. The predetermined UL can range from 30 cm to 120 cm.

Procedures such as the endovascular treatment of peripheral occlusions with mechanical aspiration/thrombectomy systems are made more efficient and easier to perform with the steerable sheath device10. The combination of the elongated sheath1, the mounted inflatable occlusion balloon24, and the ability to mechanically deflect the distal tip portion6to appropriately steer the system into the correct target vessel allows for an increase in efficiency over traditional catheter sheaths.

As shown inFIGS. 1A, 2 and 2A, the tubular body wall22defines a central lumen9and a fluid lumen3radially outward from and parallel to the central lumen9. The fluid lumen3of the elongated sheath1is in fluid communication with an interior26of the inflatable occlusion balloon24. The fluid lumen3is schematically shown as a dashed line inFIG. 1Afor the sake of clarity. Those skilled in the art will readily appreciate that the fluid lumen3is tubular shaped and extends within the tubular body wall22from a longitudinal position proximate to an inflation port16, along the length of the elongated sheath1, to a port160defined in the tubular body wall22within the interior26of the balloon24. The inflation port16is positioned on the handle assembly13in fluid communication with the fluid lumen3allowing the inflatable occlusion balloon24to be inflated and deflated. Those skilled in the art will readily appreciate that a connecting tube or the like can extend from the fluid lumen3in the tubular body wall22to the inflation port16. To inflate the balloon24, an inflation fluid, such as saline solution or a contrast medium, is supplied to the interior26of the balloon24through the inflation port16using an inflation syringe, or the like. To deflate the balloon24, the inflation syringe can provide a pulling vacuum to the interior26of the balloon24through the inflation port16and the balloon24returns to its deflated state.

With continued reference toFIGS. 1A, 2 and 2A, the elongated sheath1includes a pull-wire lumen2radially outward from and parallel to the central lumen9. The steerable sheath device10includes an elongated pull-wire4extending through the pull-wire lumen2of the elongated sheath1and terminating within a distal end portion6of the elongated sheath1. For sake of clarity,FIG. 1Aonly shows the elongated pull-wire4, without the pull-wire lumen2. Those skilled in the art will readily appreciate that, in the embodiment shown in the figures, the pull-wire lumen2has a tubular shape and extends within the tubular body wall22from a longitudinal position proximate a distal end of a manually rotatable control knob18, described in more detail below, and down along the length of the elongated sheath1to a pull-wire anchor ring5. The elongated pull-wire4is positioned within the pull-wire lumen2and has a proximal end that extends out of the pull-wire lumen2and is operatively connected to the handle assembly13and a distal end is anchored to the distal end portion6of the elongated sheath1at the pull-wire anchor ring5. The pull-wire anchor ring5mechanically couples a distal end of the elongated pull-wire4to the distal end portion6of the elongated sheath1. In the embodiment ofFIG. 1A, the pull-wire anchor ring5is mounted proximate to a distal tip25of the distal end portion6.

With continued reference toFIG. 1A, the manually rotatable control knob18of the rotatable actuation assembly17is operatively connected by way of a drive mechanism150to a proximal end of the elongated pull-wire4. Manual rotation of rotatable control knob18pulls or releases the elongated pull-wire4by way of the drive mechanism150, described below, and causes the distal end portion6of the elongated sheath1to deflect away from the longitudinal axis A-A or back toward the longitudinal axis A-A. The handle assembly13includes a drive mechanism150for actuating the elongated pull-wire4in response to bi-directional angular rotation of the rotatable control knob18, as described in more detail below.

As shown inFIG. 1A, the drive mechanism includes a worm gear153mounted for reciprocal longitudinal movement within the interior cavity of the handle assembly13relative to the elongated sheath1. The drive mechanism150further includes an axially rotatable drive nut151meshed with threads of the worm gear153for effectuating reciprocal longitudinal movement of the worm gear153. The rotatable control knob18is directly connected to the drive nut151in the interior cavity of the handle assembly13. The rotatable control knob18can be configured for gripping and rotation by a user to rotate the drive nut150and move the worm gear (e.g. work coil)153. When the drive nut150is rotated by way of rotation of the rotatable control knob18, the worm gear153rotates and moves longitudinally in either a distal or a proximal direction. A distal end portion155of the handle assembly13is fixed relative to the elongated sheath1, such that the rotatable control knob18can be rotated with respect thereto.

With continued reference toFIG. 1A, in the handle assembly13, the pull-wire4extends out of the tubular body wall22near a distal end26of the manually rotatable control knob18so that it can be coupled to the worm gear153. The pull-wire4is coupled to the worm gear153, e.g. coupled by way of a set screw, such that axial translation of the worm gear153pulls or releases the pull-wire4thereby causing deflection of the distal end portion6. InFIG. 1A, the worm gear153is advanced to a distal position such that the worm gear153abuts the inner surface of the handle assembly13such that the worm gear153cannot be advanced further in the distal direction. This position can be associated with a straight condition of the sheath1(shown in solid lines). The worm gear153can be advanced proximally by rotation of the drive nut151to pull the pull-wire4and deflect the distal end portion6of the sheath1(as shown in the broken lines). The softer distal sheath end6in its deflected position is designated by numeral8.

Bi-directional angular rotation of the rotatable control knob18about the longitudinal axis A-A of the handle assembly13effectuates reciprocal axial movement of the elongated pull-wire4and corresponding angular deflection of the distal end portion6of the elongated sheath1, as shown schematically by the arcuate arrow B inFIG. 1A. Deflection of the distal end portion6can be defined by the deflection curve diameter (DCD), which can range from 7 mm to 50 mm. In some embodiments, the distal tip25of the distal end portion6can be deflected up to 180 degrees, or more. In other words, it can go from facing a distal direction to facing a proximal direction. While shown and described in conjunction with the drive mechanism150, other suitable drive mechanisms can be used, e.g. those shown and described in commonly assigned U.S. Pat. Nos. 9,498,602, 9,572,957 and 9,907,570 to Osypka et al., which are hereby incorporated by reference in their entirety.

As shown inFIGS. 1A, 2 and 2A, the proximal end portion of the elongated sheath1extends entirely through the handle assembly13and terminates at a sealed access port11communicating with the central lumen9defined by the tubular body wall22. The handle assembly13includes a hemostatic valve14operatively connected to the central lumen9. The hemostatic valve14is designed to minimize blood loss and prevent air embolisms. The handle assembly13includes a luer type locking connection20, e.g. fitting, on a proximal end of the central lumen9. The handle assembly13includes a flush port19in fluid communication with the central lumen9to flush the central lumen9. The central lumen9can include a PTFE liner15. The tubular body22of the sheath1can have an outer diameter (OD) ranging from 6 to 30 French (F). An inner diameter (ID) of the tubular body22that defines, in-part, the central lumen9can range from 5 to 26 F. The hemostatic valve14, luer type locking mechanism20and flush port19can be similar to those described in commonly assigned U.S. Pat. Nos. 9,498,602, 9,572,957, 8,974,420 and 9,907,570 to Osypka et al., all of which are hereby incorporated by reference in their entirety.

FIG. 2Ais an enlarged schematic cross-sectional view of the elongated sheath1shown inFIG. 2, but, for the sake of clarity, without the PTFE liner15for the central lumen9and without the pull-wire4in the pull-wire lumen2. As particularly shown, the tubular body wall22has an inner surface22A spaced from an outer surface22B by a thickness of the wall22. The fluid lumen2resides in the thickness of the tubular body wall22and extends along a longitudinal axis B-B. Similarly, the pull-wire lumen3resides in the thickness of the wall22and extends along a longitudinal axis C-C.

FIG. 2Bis an enlarged view of a portion of the elongated sheath1shown inFIG. 2Ashowing the partial elliptical shape of the inner surface22A of the tubular body wall22adjacent to the pull-wire lumen2. The partial elliptical shape comprises or is part of an ellipse that is depicted with dashed lines in the drawing and is defined by a semi-minor axis30A that extends from a center point32coincident with the longitudinal axis B-B of the pull-wire lumen2to a vertex point34A at the inner surface22A and an opposed semi-minor axis30B that extends from the center point32to a vertex point34B at the outer surface22B. An imaginary extension of the semi-minor axes30A,30B intersects the longitudinal axis A-A of the handle assembly13of the steerable intravascular catheter10.

Opposed semi-major axes36A and36B of the ellipse comprising the partial elliptical shape of the inner surface22A of the tubular body wall22adjacent to the pull-wire lumen2extend from the center point32at the longitudinal axis B-B to opposed vertex points38A and38B located between the inner and outer surfaces22A and22B of the tubular body wall22. The opposed vertex points38A and38B are at a right angle or normal to the semi-minor axes30A,30B. As shown in the drawing, a major length of each of the semi-major axes36A and36B is at least 10% greater than a minor length of each of the semi-minor axes30A,30B.

FIG. 2Cis an enlarged view of a portion of the elongated sheath1shown inFIG. 2Ashowing the partial elliptical shape of the inner surface22A of the tubular body wall22adjacent to the fluid lumen3. The partial elliptical shape comprises or is part of an ellipse that is depicted with dashed lines in the drawing and is defined by a semi-minor axis40A that extends from a center point42coincident with the longitudinal axis C-C of the fluid lumen3to a vertex point34A at the inner surface22A and an opposed semi-minor axis40B that extends from the center point42to a vertex point44B at the outer surface22B. An imaginary extension of the semi-minor axes40A,40B intersects the longitudinal axis A-A of the handle assembly13of the steerable intravascular catheter10.

Opposed semi-major axes46A and46B of the ellipse comprising the partial elliptical shape of the inner surface22A of the tubular body wall22adjacent to the fluid lumen3extend from the center point42at the longitudinal axis C-C to opposed vertex points48A and48B located between the inner and outer surfaces22A and22B of the tubular body wall22. The opposed vertex points48A and48B are at a right angle or normal to the semi-minor axes40A,40B. As shown in the drawing, a major length of each of the semi-major axes46A and46B is at least 10% greater than a minor length of each of the semi-minor axes40A,40B.

The benefit of providing the tubular body wall22with a partial elliptical shape adjacent to at least one, and preferably both, of the pull-wire lumen2and the fluid lumen3is that there is an increased thickness to the wall22along the respective minor axes30A,30B and40A,40B in comparison to a conventional tubular body construction. This helps to improve the structural integrity of the wall adjacent to the pull-wire and fluid lumens2,3so that the tubular wall has a robust construction that is less likely to rupture or fail during use.

While the steerable intravascular catheter device of the subject invention has been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications may be made thereto without departing from the spirit and scope of the subject disclosure.