EP1755724A1

EP1755724A1 - Steerable vascular sheath

Info

Publication number: EP1755724A1
Application number: EP05760447A
Authority: EP
Inventors: Thomas Demarchi; Ghassan Sakakine; John R. Brustad; Donald L. Gadberry; Henry Kahle; Charles C. Hart; Nabil Hilal
Original assignee: Applied Medical Resources Corp
Current assignee: Applied Medical Resources Corp
Priority date: 2004-06-14
Filing date: 2005-06-14
Publication date: 2007-02-28
Also published as: CA2569378A1; AU2005254572A1; JP2008502433A; WO2005123169A1

Abstract

A vascular steerage access device is provided having an elongate body (81) and a steerable portion. The access sheath (80) has an outside diameter sufficiently small so that it may be inserted into a vessel and a sufficient length to extend through a patient's circulatory system. The access sheath may have two internal lumen, a first lumen sized and configured as an access to a surgical site and a second lumen sized and configured to contain a tensioning device (86) that, when acted upon, will deflect the steerable portion. The tensioning device may be directly or remotely attached to an actuation device that operates to control the tensioning and loosening of the tensioning device.

Description

STEERABLE VASCULAR SHEATH

CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of U.S. Patent Application No. 10/832,867, filed April 26, 2004 and claims benefit of U.S. Provisional Application No. 60/579,500, filed June 14, 2004, the entire disclosures of which are hereby incorporated by reference as if set forth in full herein. U.S. Patent Application No. 10/832,867 is a continuation-in-part of U.S. Patent Application No. 10/766,138, filed January 28, 2004 and 10/298,116, filed November 15, 2002, and claims benefit of U.S. Provisional Application No. 60/465,310, filed April 25, 2003, the entire disclosures of which are hereby incorporated by reference as if set forth in full herein.

BACKGROUND The present invention generally relates to surgical access devices and, more specifically, to sheaths that are steerable and applicable in vascular procedures. Sheaths and catheters have long been used to access body conduits such as the arterial and venous branches of the vascular system, urinary tract, body cavities such as the thorax and abdomen, and hollow viscous organs such as the stomach, intestines and urinary bladder. More specifically, sheaths and catheters have been used for fluid delivery, fluid recovery, implant delivery and for providing an access pathway for an instrument such as an endoscope. However, many endoscopes, for example, are flexible enough to bend but are not steerable or deflectable in a controlled and/or dynamic manner. As such, there is a desire in the art for a steerable access sheath that is able to perform intricate manipulations through vessels, body cavities and/or tissue. For some instruments, steering has been achieved, for example, by "pre- bending" the distal tip of a surgical device before insertion and then rotating the device once it has been inserted and has reached a branch artery inside the body. If the angle of the bend has to be adjusted, then the device may have to be removed, re-bent and reinserted. This may result in greater time spent in the body and thereby increase surgery time. Furthermore, since these sheaths and catheters navigate many hard-to-reach areas, it may be desirable that these devices be stiff and yet as flexible as possible. It may also useful that the sheaths and catheters are constructed with thin walls to minimize the diameter of the device and to maximize the radii of the internal lumen. If the access sheath is constructed with a thin wall made of a plastic or rubber material, the sheath may bend or twist during use. This may result in potential damage as the sharp edge of the kinked sheath may allow an endoscope or other device to complicate the surgical procedure. Moreover, a bent or kinked sheath may be useless because it cannot communicate and it may not allow the passage of an instrument. As such, there is a desire in the art for a steerable access sheath that is durable enough to provide sufficient strength and stiffness to be guided through a body cavity or tissue and, at the same time, be flexible enough to perform intricate manipulations through the body cavity or tissue.

SUMMARY A surgical access device or a vascular surgical access device, is provided having an elongate body with at least one steerable region. The elongate body also has a proximal end, a distal end and a lumen extending through the body and sized and configured to be inserted into a blood vessel. The device also comprises a tensioning device extending through the elongate body and connected to the at least one steerable region of the elongate body and an actuator connected to the tensioning device distally from the proximal end of the elongated body to control tension of the tensioning device to navigate the elongate body through a circulatory system. The tensioning device may be made of a kink resistant material such as Nitinol, a braided cable or any flexible strand or wire. The actuator may include a control knob to control the tensioning or loosening of the tensioning device. In one aspect, a vascular surgical access device is provided comprising a tube having a proximal end, a distal end, a steerable region, and an enlarged entry with the tube having a primary lumen and a first and second secondary lumen both extending through the tube. The device also has a first tensioning device connected to the steerable region and extending through the first secondary lumen and a second tensioning device connected to the steerable region and extending through the secondary lumen. An enlarged entry extending from the distal end of the tube forming a transition into the primary lumen of the tube from an exterior of the tube and a movable actuator disposed about the enlarged entry and connected to the first tensioning device and the second tensioning device and configured to rotate in one direction causing movement of the first tensioning device and rotate in an opposite direction causing movement of the second tensioning device are also provided. The steerable region may be deflected or steered through the action of the tensioning device, such that a pull wire imparts a pulling force on the steerable region of the tube, thereby causing the steerable region to deflect. In another aspect, a vascular surgical access device comprises an elongate tube having a proximal end, a distal end, a steerable region, and an enlarged entry. The elongate tube has a lumen extending through the elongate tube and is configured to operate in through femoral arteries, iliac arteries and uterine arteries. Tensioning means, e.g., a pull wire, is connected to the steerable region and extends through the lumen and actuator means, e.g., an hand-piece, is connected to the tensioning means and is configured to cause movement of the tensioning means to cause movement of the steerable region. Many of the attendant features of this invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols designate like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a surgical access device or steerable access sheath in accordance with one aspect of the invention; FIG. 2 is a cross sectional view of the access device of FIG. 1 ; FIG. 3 illustrates a dilator in accordance with one aspect of the present invention; FIG. 4 illustrates a surgical access device or steerable access sheath in accordance with one aspect of the present invention; FIG. 5 illustrates a surgical access device or steerable access sheath in accordance with another aspect of the present invention; FIG. 6 illustrates a surgical access device or steerable kink resistant access device in accordance with one embodiment of the present invention; FIG. 7 is a front view of the distal end of the access device of FIG. 6; FIG. 8 is a rear view of the proximal end of the access device of FIG. 6; FIG. 9 is an enlarged side view of the distal portion of the access sheath of FIG. 6; FIG. 10 is a side-section view of the distal portion of the access sheath of FIG. 9; FIG. 11 illustrates a steerable kink resistant access device of the present invention with its distal portion deflected; FIG. 12 is a top view of the distal portion of the access sheath of the present invention; FIG. 13 is a bottom view of the distal portion of the access sheath of the present invention; FIG. 14 illustrates the atraumatic distal end of the access sheath of the present invention; FIG. 15 illustrates an actuator of the access device of the present invention used to control the steerable region or portion of the access sheath; FIG. 16 illustrates the access device of the present invention guiding a scope into a kidney pole; FIG. 17 illustrates a perspective view of the distal portion of an access sheath having a flattened tensioning member; FIG. 18 illustrates a perspective view of an actuator or actuation hand- piece in accordance with another embodiment of the present invention; FIG. 19 is a side view of the actuation hand-piece of FIG. 18; FIG. 20 illustrates a perspective view of an actuation hand-piece of the invention including a directional indicator showing the direction of deflection or bending of the access sheath; FIG. 21 illustrates another perspective view of an actuation hand-piece of the invention including a directional indicator; FIG. 22 illustrates a side-elevation view illustrating a spring embodiment of the tube associated with the sheath of the present invention; FIG. 23A illustrates a side view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 23B illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 24 illustrates a cross-sectional view of the actuation hand-piece of FIGS. 23A-B; FIG. 25 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the invention; FIG. 26A illustrates a top view of a disassembled actuation hand-piece of FIG. 25; FIG. 26B illustrates a cross-sectional view of the actuation hand-piece of

FIG. 25; FIG. 27 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the invention; FIG. 28A illustrates a cross-sectional view of the actuation hand-piece of FIG. 27; FIG. 28B illustrates a perspective view of a disassembled actuation hand- piece of FIG. 27; FIG. 29 illustrates a perspective view of an actuator or actuation hand- piece in accordance with one embodiment of the invention; FIG. 30 illustrates a cross-sectional view of the actuation hand-piece of

FIG. 29; FIG. 31 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 32 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 33A illustrates a side view of an actuator or actuation hand-piece in accordance with one embodiment of the invention; FIG. 33B illustrates another side view of the actuation hand-piece of FIG. 33A; FIG. 34 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 35 illustrates a cross-sectional view of a connector in accordance with one embodiment of the present invention; FIG. 36 illustrates a cross-sectional view of the actuation hand-piece of FIG. 34; FIGS. 37A-B illustrate perspective views of a disassembled actuation hand-piece in accordance with one embodiment of the present invention; FIGS. 38A-B illustrate other perspective views of the disassembled actuation hand-piece of FIGS. 36A-B; FIG. 39 illustrates a cross-sectional view of the actuation hand-piece of FIG. 37; FIG. 40 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIGS. 41 A-B illustrate cross-sectional views of the actuation hand-piece of

FIG. 40; FIGS. 42-43 illustrate perspective views of embodiments of components of the actuation hand-piece of FIG. 40; FIG. 44 illustrates a view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 45 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 46 illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 47A illustrates a perspective view of an actuation hand-piece in accordance with one embodiment of the present invention; FIG. 47B illustrates a perspective view of one embodiment of components of the actuation hand-piece of FIG. 47A; and FIG. 48-51 illustrate cross-sectional views of embodiments of an access sheath in various stages of fabrication in accordance with the present invention.

DETAILED DESCRIPTION In FIGS. 1-4, the steerable access sheath 80 includes an elongate body 81 and, in one embodiment, a funnel or tapered entry 83. The elongate body 81 is substantially or completely steerable and may have a variable stiffness or flexibility or is fully pliable. The outside diameter of the elongate body is also sufficiently small so that it may be inserted into a reduced or minimally sized body cavity or conduit, e.g., a vein or artery. The access sheath 80 further includes a primary lumen 84 and a secondary lumen 85 both extending through the elongate body 81. The primary lumen 84 is sized and configured to provide an access pathway to a surgical site or a target site for the surgical procedure. For example, primary lumen 84 provides a conduit to advance a surgical instrument, e.g., a dilator, or diagnostic and therapeutic elements, e.g., a contrast agent, to the surgical or target site. The secondary lumen 85 is sized and configured to contain a tensioning device 86 such as a control or pull wire that, when acted upon, will deflect the elongate body 81 of the access sheath 80. In one embodiment, a secondary lumen is not utilized and thus the tensioning device 86 is directly included with the access sheath 80. For example, the tensioning device 86 may be secured to the access sheath or primary lumen and extend along the length of the access sheath or primary lumen to provide sufficient deflection of the elongate body 81 of the access sheath 80 via the tensioning device 86. In one aspect, tensioning device 86 may be embedded in the wall of the access sheath 80 and/or the primary lumen 84. The tensioning device 86 extends through the secondary lumen 85 and is attached to an actuator 87 at one end and to a distal portion of the elongate body 81 at the other end. The actuator 87 may include a thumb-actuated knob, a ring, as illustrated, or another type of device to control the tensioning device 86. As shown, a ring connected to a pull wire may be drawn proximally to provide tension to the tensioning device 86. When the ring is released, the pull wire moves distally to loosen tension or cause the tensioning device 86 to loosen to allow the access sheath to straighten or return back to a previous or initial form. As such, by manipulating the actuator 87, a user can steer the access sheath 80 to navigate circuitous or torturous conduits or cavities within the body to access the surgical site or point of interest. Additionally, the access sheath via the primary lumen provides a conduit or a channel from outside the body to the point of interest for the insertion and withdrawal of instruments, tissue or other items used for or in conjunction with the surgical procedure. It is appreciated that the actuator 87 may resemble, emulate, embody or otherwise incorporate the actuation hand-pieces described in previous or the following embodiments and may be in-line, offset or remote from the access sheath. Additionally, the access sheath may comprise a plurality of pull wires attached to a plurality of thumbwheels, axles, knobs or other types of movable components of an actuator or actuation hand-piece to deflect the access sheath in one or more different directions. In one particular embodiment, the funnel-shaped entry 83 is sized and configured to guide a dilator, an obturator and/or other instrumentation into a working channel to form a transition into the primary lumen of the access sheath 80. The funnel-shaped entry also includes or is connected to a connector to provide a conduit that connects the secondary lumen and tensioning device 86 to the actuator 87. In one embodiment, the entry 83 includes or is connected to a valve, such as a zero and/or septum valve, which is fixed or floats. The valve may also include deformable material, construction, gel or any combination thereof to form a seal around instruments and the like inserted in to the entry or to seal the entry after or prior to instruments and the like being removed or inserted in the entry 83. The access sheath 80 and various embodiments of access sheaths and actuators or actuation hand-pieces previously described, here now referred to as the access sheath, in accordance with one aspect of the invention is applicable in vascular procedures and in other procedures among other fields, such as cardiology, urology, radiology, electrophysiology and gastroenterology. For example, in interventional radiology or interventional nephrology in which guided imaging is utilized, the access sheath 80 being steerable and appropriately sized assists in the placement of instruments, solutions or agents used in these procedures. In one embodiment, the access sheath is combined with an instrument or device used to stretch or enlarge an opening, e.g., a dilator, which allows for gradual and atraumatic dilation of the artery or vein while the access sheath is being placed. Once the access sheath has been placed at a desired location, the dilator is removed and the access sheath is left in place. The access sheath allows for continued access to the desired area, for example, for the placement of surgical and/or therapeutic instruments or agents, while providing protection of the vessel. Continuous access provided by the access sheath may also reduces the need to re-locate a site or vessel. Additionally, with the access sheath being deflectable or steerable, the user may effectively and efficiently navigate the intricate and sometimes extensive circulatory system. As such, placement of instruments through the primary lumen of the access sheath at or proximal the operation site can be achieved by dynamically steering and/or continuously steering the access sheath. In another embodiment, the access sheath being steerable provides direct and proximal vascular access to circulatory vessels or specific organ or tissue to ensure that healthy blood flow or the ability to deliver therapeutic agents is maintained. For example, for hemodialysis, regular vascular access to circulatory system can be provided by the access sheath or for cancer, chemotherapy via vascular access to the circulatory system can be provided by the access sheath. The access sheath may also be useful in diagnostic radiography, which confirms the presence of an occlusion of vessels, e.g., lesion or thrombus formations. When performed at or near junction of an artery and a vein, such as a fistula, directing the contrast agent utilized such that the agent flows towards the downstream vessels of interest may be difficult. By deflecting or changing the shape of the access sheath to conform to the shape of the vessel(s), the access sheath allows the contrast agent to be directed in the antegrade flow of the artery and/or vein. In one aspect, an access sheath 80 with a long length, e.g., over 100 centimeters, may also be useful for specific surgical, therapeutic or diagnostic procedures for various diseases or conditions, e.g., embolization and in particular, uterine fibroid embolization. The access sheath being able to have a long length does not restrict the path taken to reach the tissue, vessel or area of interest. The steerable access sheath 80 also eases the navigation of the circuitous path from the femoral arteries, the iliac arteries to the uterine arteries. For example, by deflecting the access sheath 80 making the turn, bend or course change from one artery to another, e.g., from the iliac to the femoral artery or from the femoral artery to the uterine artery, is made easier. With the access sheath placed at or near the area of interest, the primary lumen provides the conduit for the insertion of agents, e.g., biocompatible occlusion particles, or other treatment or diagnostic agents, solutions or devices. The primary lumen of the access sheath 80 can also provide a fixed size to accommodate or overcome limitations imposed by the length of the surgical instrument to be inserted, the size of a vessel relative to the instrument and/or the blood flow around the instrument. In one embodiment, the distal end of the access sheath is tapered and thus has a smaller diameter than the proximal end of the access sheath. The primary lumen and secondary lumen diameters, however, remain substantially constant throughout the access sheath. In one embodiment, one or more coated wires are wound around the inner/outer periphery of the access sheath, the primary lumen and/or any combination thereof to strengthen the access sheath, such that a flexible, pre- bendable or otherwise not actively controllable instrument may be controllably deflected dynamically as the access sheath is controlled. Additionally, an actively deflectable surgical instrument may have a complicated construction providing components, e.g., optics or clamps, to perform its surgical function and components to perform the active deflection. Therefore, such instruments may be fragile or if broken may be expensive to replace or repair or still usable as a surgical instrument but not actively deflectable. Also, the vessel or body conduit accessed or the surgical procedure performed may impose size limitations to prevent the inclusive of deflectable components or mechanisms in the surgical instruments. As such, the access sheath may replace the components or use of the components in such surgical instruments or induce a broken instrument to be controllably deflected thereby reducing replacement, repair and/or construction costs, reducing wear and tear of such instruments and increasing the life of such instruments. Also, the reinforced access sheath allows the size and shape of the primary lumen to remain substantially constant throughout the access sheath, thereby reducing forces on instruments placed within the access sheath, which may extend the life of these instruments. The forces or stress accumulated along the access sheath that may cause kinks in the access sheath are also distributed along the access sheath due to the composite construction of the access sheath. Thus, kinks in the access sheath are reduced. The wire coil(s) may also allow the access sheath walls to be very thin without reducing durability or strength in the access sheath. Thus, the overall or outer diameter of the access sheath may be small, which may also reduce the incision or insertion point for the access sheath, without reducing the size or diameter of the primary lumen. As such, the access sheath of various embodiments of the present invention has thin walled portions, a large lumen, an atraumatic end, a kink resistant construction and/or any combination thereof. Additionally, the access sheath of various embodiments of the present invention has an extensive range of lengths from about 5.5 centimeters or less all the way up to 100 centimeters or more and various lengths there between, e.g., about 13 and 45 centimeters. The access sheath of various embodiments of the present invention is also strong, stiff and yet flexible enough to be intricately guided through the body conduits, cavities or tissue. Referring now to FIG. 5, an embodiment of an actuator or actuation hand- piece 90 adapted to be in line with the access sheath 80 is shown. The proximal end of the actuator 90 includes a funnel-shaped entry 91 connected within the actuator to access a working channel, which forms a transition into the primary lumen of the access sheath. The entry 91 is also sized and arranged to receive surgical instruments such as a dilator 82. A pull wire extending through a first secondary lumen of the access sheath 80 is attached to a first movable component, e.g., a threaded cylinder or ratcheted slider. Another pull wire extending through a second secondary lumen of the access sheath is also attached to a second movable component. The first secondary lumen extends through the access sheath along a first side of the access sheath. The second secondary lumen also extends through the access sheath 80 along a second side of the access sheath. The first side of the access sheath opposes the second side of the access sheath. A knob 92 surrounding the movable components is correspondingly threaded or otherwise arranged to engage the components, which allows a user with a twist or turn of the knob 92 in one direction, e.g., clockwise or proximally, to move one of the movable components linearly. For example, as the first movable component is moved proximally when the knob 92 is rotated clockwise or dragged proximally, the tensioning device connected to the first movable component also traverses towards the proximal end of the access sheath to impart a pulling force on the access sheath thereby deflecting the access sheath in a first direction. The knob 92 is also allowed to move in the opposite direction moving the first movable component distally to straighten the access sheath. As the knob 92 continues to move in the opposite direction and past a zero point 93, the knob 92 disengages from the first movable component and engages the second movable component. The tensioning device connected to the second movable component traverses proximally as the knob 92 traverses distally to impart a pulling force on the access sheath 80 thereby deflecting the access sheath in a different or opposing direction. The knob 92 moved in the opposite direction back towards the zero point 93 moves the second movable component distally to cause the tensioning device to loosen and thus allow the access sheath to straighten. The various access devices and their construction described below may also be applicable to the steerable access sheath described above. For example, the remote actuation hand-pieces to be described below can be used instead of the ring shown in FIG. 1. FIGS. 6-8 illustrate a surgical access device or steerable kink resistant access device 100 in accordance with the one embodiment of the present invention for use in, among other fields, cardiology, urology, radiology, electrophysiology and gastroenterology. Access device 100 comprises an access sheath 102 having a longitudinal axis 103 extending from a proximal end to a distal end, and a handle portion 104 operatively connected to the proximal end of the access sheath 102. The access sheath 102 includes an elongated body 105 and a steerable region or portion 106. It is appreciated that the steerable portion 106 may be formed anywhere along the access sheath 102. It is further appreciated that the steerable portion 106 and the elongated body 105 may have variable stiffness depending on the application of the access sheath 102. The access sheath 102 has an outside diameter sufficiently small so that it may be inserted into a body cavity or conduit. The access sheath 102 typically has two internal lumens, a primary lumen 112 and a secondary lumen 114, as illustrated in FIG. 7. The primary lumen 112 is sized and configured as an access to a surgical site or the target of a surgical procedure. In particular, primary lumen 112 operates to advance diagnostic and therapeutic elements to the surgical site or target. The secondary lumen 114 is sized and configured to contain a tensioning device 116 such as a control or pull wire that, when acted upon, will deflect the steerable portion 106 of the access sheath 102. The tensioning device 116 extends through the secondary lumen 114 and is attached to the actuator or handle portion 104 at one end and to a distal portion 107 of the steerable portion 106 at the other end. The handle portion 104 may include a thumb-actuated knob 118 controlling the tensioning device 116. For example, the knob 118 may be drawn proximally in a direction 119 to provide tension to the tensioning device 116 or cause the tensioning device to tense or distally in a direction 120 to loosen tension or cause the tensioning device 116 to loosen. In another embodiment of the present invention, FIGS. 18-21 illustrate an actuator or actuation hand-piece 500 having a proximally-facing portion 502, a distally-facing portion 504, hand-engaging extensions 506, and at least one thumbwheel member 508a, b. The proximally-facing portion 502 has a generally flat support surface and includes a funnel-shaped entry portion 510. The funnel- shaped entry portion 510 is sized and configured to guide an obturator and other instrumentation into a working channel within the hand-piece 500. The distally- facing portion 504 is connected to the access sheath 102. The working channel of hand-piece 500 is sized and configured to form a transition into the primary lumen 112 of the access sheath 102. The hand-engaging extensions 506 are sized and shaped to accommodate two extended human fingers in a holding position. The at least one thumbwheel 508 allows a user to deflect the steerable portion 106 of the access sheath 102. The steerable portion 106 may be deflected through the action of a tensioning device 116, such as a pull wire or control wire associated with the secondary lumen 114 within the access sheath 102. The tensioning device 116 may be connected to an axle positioned between two thumbwheels 508a and 508b or at least one thumbwheel and an opposing side of hand-piece 500. As the thumbwheels 508a and 508b are rotated, the tensioning device116 imparts a pulling force on the steerable portion 106 of sheath 102, thereby causing portion 106 to deflect. In one aspect of the present invention, directional indicators 512 may be placed on each of hand-engaging extensions 506 of hand-piece 500 to indicate the direction of distal deflection or bending of access sheath 102. It is appreciated that the actuator or actuation hand-piece of the invention may be remotely attached to the associated access sheath to control the tensioning and loosening of the tensioning device. In this case, the hand-piece may be connected to a flexible tubing or body, which is connected to the access sheath. By providing a remote access point or attachment, the thumbwheels of the hand-piece, for example, may be placed away from the surgical site so that they do not prevent or interfere with full insertion of the working length of the access sheath. It is further appreciated that the access sheath may comprise a plurality of pull wires attached to a plurality of thumbwheels of an actuation hand- piece to deflect the steerable portion of the sheath in different directions. In one embodiment of the invention, the access sheath 102 comprises an extruded multi-lumen plastic tube. Alternatively, the access sheath 102 may be molded from a plastic or rubber-like material. Preferred materials include polyvinyl chloride, polyester, silicone elastomer, natural or synthetic rubber, polyurethane or the like. The materials may range in hardness from around 40 Shore A to 70 Shore D. These materials are generally flexible and durable. In another embodiment of the invention as illustrated in FIG. 22, a structure such as a spring can be molded into the tube of the sheath to facilitate kink resistance. More specifically, the access sheath 102 may be formed with an inner plastic body 610, surrounded by a metal spring coil 612, which is further covered by an outer body 614. This particular embodiment of access sheath 102 provides a high degree of kink resistance. The inner body 610 provides a smooth surface within the sheath, which facilitates passage of instrumentation. The spring coil 612 adds kink resistance to the sheath tube, while the outer body 614 provides a suitable covering for the coils of the spring 612. In one aspect of steerability of the present invention, a tightly wound spring may be placed in the secondary lumen 114 of the access sheath 102 to facilitate movement of the tensioning device 116 inserted there through. The spring may be bonded or otherwise fixed to the secondary lumen 114. Among other features, the spring operates to isolate forces applied by the tensioning device 116, which is inserted through the spring and is attached to the distal portion 107 of the steerable portion 106. In particular, the spring adds stability and rigidity to the elongate body 105 when the tensioning device 116 is acted upon such that only the steerable portion 106 is bent or steered. Furthermore, the spring operates to direct the tension force applied on the device 116 to the steerable portion 106 so as to allow deflection of only the portion 106 and not the elongate body 105. That is, the tension force is isolated to the steerable portion 106, which may be formed anywhere along the access sheath 102. The spring may be coated with a lubricious material further facilitating movement of the tensioning device 116. The spring may line or cover the inner surface area of the entire secondary lumen 114 or just portions of the secondary lumen 114 to facilitate isolation of the tension force. The spring may be constructed from a 0.005-inch diameter wire that is tightly wound forming a closed wound spring having a 0.02-inch outer diameter. The distal 0.5 to 2 inches of the spring may be stretched to an open wound state such that the windings have an approximately 0.02-inch gap between them. This stretched portion of the spring facilitates isolation of the tension force applied by the tensioning device 116. The spring may be coated, for example, in a plastic jacket and bonded to the secondary lumen 114 from the proximal end of the spring to the proximal end of the stretched portion. The stretched portion is then left free to move and/or compress in the plastic jacket. The distal end of the stretched portion may be anchored to the distal end of the access sheath 102 along with the tensioning device 116. The distal end of the plastic jacket may also be bonded to the distal end of the access sheath 102 along with the tensioning device 116 and the spring although these elements do not require a common bonding point or bonding method. As discussed above, the proximal end of the access sheath 102 may be directly or remotely attached to handle portion 104 or actuator or hand-piece 500, which allows the operator to place tension on the tensioning device 116, such as a control or pull wire, while maintaining the position of the catheter. This tension causes the stretched portion of the 0.02-inch diameter spring to collapse and this, in turn, forces the sheath to bend in the region where the stretched portion of the spring is located. It is appreciated that the stretched portion may be formed anywhere along the catheter or surgical access device that may require bending, and is not limited to the distal end of the device. In addition, more than one deflection assembly of spring and tensioning device may be added to the access device to create deflection in different regions or planes. The amount of bending or deflection will in some way be proportional to the amount of force or tension placed on the tensioning device. The tensioning device 116 is, in one embodiment, a control or pull wire made of Nitinol, a braided cable or any flexible strand or wire. In one embodiment, the control wire is inserted through the spring such that it runs through the secondary lumen 114 as illustrated in FIG. 10. The proximal end of the tensioning device 116, e.g., a control or pull wire, is connected to ah actuator such as the knob 118 of the handle portion 104. The distal end of the control or pull wire, as previously described, is attached to the distal portion 107 of steerable portion 106. In another aspect of the invention as illustrated in FIG. 17, the tensioning device 416 may be a flattened or flat member extending through at least the steerable portion 106 of the access sheath 102. In another aspect of the present invention as illustrated in FIGS. 6 and 9- 10, the steerable portion 106 includes a plurality of radially and longitudinally spaced notches 108 and slits 110 disposed on opposite sides of each other facilitating radial deflection of the distal portion 107 in a desired direction or angle. The notches 108 and slits 110 are cut into the access sheath 102 across the longitudinal axis 103. The degree of deflection may vary greatly based on many factors such as the number, size, direction, shape and spacing of the notches 108 and slits 110. The notches 108 are cut deeper and wider at a distal end 150 than they are at a proximal end 152 of steerable portion 106. The slits 110 comprise of very shallow cuts to provide a reduction in resistance to stretching as the steerable portion 106 is bent or deflected toward the notches 108. As discussed above, the notches 108 and slits 110 may be of any desired width, length, depth and shape. The number of notches 108 and slits 110 in the steerable portion 106 can be varied in accordance with the use and flexure requirements of the access sheath 102. However, in one embodiment, the slits 110 are narrower and shallower than the notches 108 to provide a "weak- side/strong-side" arrangement of the steerable portion 106 so as to allow the access sheath 102 to be predisposed to bending in the desired direction. That is, when the control wire of the tensioning device 116 is drawn proximally as illustrated in FIG. 11, the more flexible side of the steerable portion 106, i.e., the side with notches 108, will give first thereby bending in the direction of the notches. Moreover, the distal end 150 of the steerable portion 106 with the deeper and wider notches 108 will bend first as the bending progressively moves toward the proximal end 152 having shallower and narrower notches. It is appreciated that the notches 108 may extend through the wall of the access sheath 102. Referring now to FIGS. 12 and 13, the opposing series of notches 108 and slits 110 are further illustrated. The notches 108, as discussed above, provide a "weak-side" or preferred bend path as the notches 108 are closed when bent. It can be seen that the notches 108 are wedge-shaped and have material removed from them. There is, therefore, sufficient room for the material adjacent to each notch to approximate, thereby shortening the length of the steerable portion 106 on the weak-side. In contrast, the slits 110 are shallow radial cuts made directly opposite the notches 108 with little or no material removed. The slits 110 provide the mechanical equivalent of increased plastic elasticity. That is, the slits 110 allow the material of the steerable portion 106 to stretch beyond the intrinsic properties of the material itself. As a result of this construction, the primary lumen 112 of the steerable portion 106 will not collapse when deformed or bent into a tight circular profile as can be seen in FIG. 11. In other words, the slits 110 will only open to provide an elongation of the "strong-side" and will not collapse to provide a shortening of the "strong-side". The material on either side of the notches 108 and slits 110 maintains the general elongate dimension and forms a continuum of the access sheath 102. In another embodiment of the invention as illustrated in FIG. 14, the distal end 200 of the steerable portion 106 has a generally rounded off wall section 205 providing an atraumatic insertion tip. With the current construction of the access sheath having a steerable distal portion, less pushing force is required to advance the access sheath since it may be deflected around, under or over anomalies and irregularities in a body cavity or conduit rather than being forced through the tortuous paths. Surgical instruments such as an ureteroscope 300 may be directed through a steerable access sheath as illustrated in FIGS. 11 and 16. For instance, the steerable access sheath may be used to pass the ureteroscope 300 into the upper and lower poles of the renal calices as generally illustrated in FIG. 16. It is appreciated that flexible ureteroscopes and other flexible endoluminal scopes, including completely passive scopes, may be accurately positioned with the assistance of the steerable access sheaths of the present invention. In another embodiment of the present invention, FIGS. 23-24 illustrate an actuation hand-piece or actuator 510 in line with the access sheath 102. The proximal end of the actuator 510 includes a funnel-shaped entry portion 516 that is sized and configured to guide an obturator, dilator, ureteroscope and other instrumentation into a working channel 518 within the actuator 510. The working channel 518 of actuator 510 is sized and configured to form a transition into the primary lumen 112 of the access sheath 102. The tensioning device 116 extending through the secondary lumen 114 is attached to a bracket 512. A proximal end of the tensioning device 116 is balled, crimped, or otherwise sized or deformed to secure the tensioning device 116 to the bracket 512. The bracket 512 is further connected to a slider 514. A lever 511 connected to the slider 514 allows a user to move the slider 514 and thereby control tensioning device 116. In FIG. 23B, the hand-piece 510 includes a pivotable lever 519 connected to lever 511. Pivotable lever 519 provides a counter actuation point relative to lever 511. In other words, as the lever 519 is moved distally, lever 511 moves proximally and vice versa. When the slider 514 is moved proximally, the tensioning device 116 imparts a pulling force on the steerable portion 106 (FIG. 6) of access sheath 102 thereby deflecting the steerable portion 106. The slider 514 also includes a plurality of teeth 515 that operatively engage corresponding teeth 517 along the inside of the hand-piece 510. Therefore, as the slider 514 is moved proximally and distally, this engagement allows incremental control of the deflection and straightening of the steerable region or portion 106 of the access sheath 102. Referring now to FIGS. 25-26, an embodiment of an actuator or actuation hand-piece 520 also adapted to be in line with the access sheath 102 is shown.

The proximal end of the hand-piece 520 includes a funnel-shaped entry portion

522 connected within the hand-piece 520 to access a working channel 524 which forms a transition into the primary lumen 112 of the access sheath 102. Tensioning device 116 extending through the secondary lumen 114 is attached to a threaded cylinder 526. A knob 527 surrounding the cylinder 526 is correspondingly threaded to engage the cylinder 526, which allows a user with a twist or turn of the knob 527 in one direction, e.g., clockwise, to move the cylinder 526 linearly, e.g., proximally. As a result, tensioning device 116 also traverses towards the proximal end of the hand-piece 520 to impart a pulling force on the steerable portion 106 thereby deflecting the steerable portion 106 of the access sheath 102. The knob 527 is also allowed to move in the opposite direction moving the threaded cylinder 526 distally to straighten the steerable portion 106 of the access sheath 102. Therefore, the hand-piece 520 provides a rotary or scroll type control of the deflection and/or straightening of the steerable portion 106 of the access sheath 102. In another embodiment of the present invention, FIGS. 27-29 illustrate an actuator or actuation hand-piece 530 in line with the access sheath 102, with the hand-piece 530 including a funnel-shaped entry portion 531. An axle 532 disposed within the hand-piece 530 is connected to a tensioning device from the access sheath 102 and connected to two thumb-actuated dials or wheels 533 and 534. In one embodiment, the wheels 533 and 534 are partially disposed within the hand-piece 530. The wheel 533 and/or wheel 534 control the tensioning device. For example, the wheel 533 turned clockwise causes the tensioning device to be drawn proximally to provide tension to the tensioning device, e.g., one or more a pull or control wires. The control wire(s) being drawn proximally wraps or winds around the axle 532 in the hand-piece 530. The wheels 533 and 534 also include ratchet wheels or a number of radially extending teeth 535 connected to or integrated with the wheels 533 and 534. The teeth 535 operatively engage with a corresponding lever or pawl 536 connected to a trigger 537. The pawl 536 engaged with the teeth 535 permits rotational movement of the wheels 533 and 534 in one direction, e.g., a clockwise direction, while preventing rotational movement in the opposite direction. As such, as the wheels 533 and 534 are turned clockwise, incremental control of the deflection of the steerable portion 106 of the access sheath 102 is provided as the axle 532 in the hand-piece 530 draws the tensioning device 116 proximally. The trigger 537, when actuated, pivots pawl 536 causing pawl 536 to disengage from teeth 535. As a result, the control wire(s) unwind or move distally from the axle 532 whereby the steerable portion 106 of the access sheath 102 straightens. Referring now to FIGS. 29-30, an actuator or actuation hand-piece 610 being connected yet offset from the access sheath 102 is shown. As such, the offset hand-piece may reduce the working length used in the access sheath or added to the access sheath with the hand-piece being in line with the access sheath. Additionally, the user may operate the hand-piece proximate to the access sheath to provide a tactile or visual feedback or reminder of the steerable portion 106 of the access sheath 102. The hand-piece 610, in one embodiment, includes or is connected to a connector 611 with a funnel-shaped entry portion 612 that is sized and configured to receive and guide instruments into/out of the access sheath 102. The secondary lumen 114 is separately connected to the hand-piece 610. Through connector 611 , in one aspect of the present invention, a conduit connects the secondary lumen 114 and tensioning device 116 to the hand-piece 610. The tensioning device 116 extending through the secondary lumen 114 is attached to slider 614. A lever 613 connected to the slider 614 allows a user to move the slider 614 that imparts a pulling force on the steerable portion 106 to deflect the steerable portion 106 or a reduction in tension on the steerable portion 106 allowing the steerable portion 106 of the access sheath 102 to straighten. The slider 614, in one aspect of the present invention, includes a plurality of teeth that operatively engage corresponding teeth along the inside of hand-piece 610 to provide incremental control of the deflection and/or straightening of the steerable portion 106 of the access sheath 102. FIG. 31 illustrates another embodiment of the present invention of an actuator or actuation hand-piece 620 offset from the access sheath 102. The hand-piece 620 includes a funnel-shaped entry portion 621 providing access to the primary lumen of the access sheath 102. The secondary lumen and the tensioning device of the access sheath 102 are also connected to the hand-piece 620. The tensioning device 116, for example, is attached to a movable handle member 622 that is pivotally connected to a stationary handle member 623. In one embodiment, the tensioning device is connected to a semi-circular plate or disc that rotates or pivots as the movable handle member is actuated. Manipulation of the movable handle member 622 allows a user to pull or release the tensioning device 116 to respectively deflect or straighten the steerable portion 106 of the access sheath 102. In one aspect of the present invention, a ratchet mechanism disposed within the hand-piece 620 or between the movable handle member 622 and the stationary handle member 623 is included to provide incremental control of the tensioning device 116 and thus the deflection of the steerable portion 106 of the access sheath 102. Referring now to FIGS. 32-33 illustrate an actuator or actuation hand- piece 630 and 630' situated offset from the access sheath 102. The actuation hand-piece 630 and 630' includes a funnel-shaped entry portion 631 and is connected to a tensioning device attached to an axle disposed within the hand- piece 630 and 630'. The axle is connected to two thumb-actuated knobs or wheels 632 and 633. As shown in FIGS. 33A-B, the wheels 632 and 633 are partially disposed within the hand-piece 630'. The wheels 632 and 633 control the tensioning device 116. For example, the wheel 632 and/or wheel 633 may be rotated to provide tension to the tensioning device 116, e.g., a control wire, or to loosen tension in the control wire. In one embodiment, the wheel 632 and 633 are connected to separate and independent control wires adapted to deflect the access sheath in an opposing manner and/or to deflect different portions of the access sheath. In one aspect of the present invention, a trigger 634, when actuated, locks the wheel 632 and/or wheel 633 thus preventing further movement of the tensioning device 116 and the deflection/straightening of the steerable portion 106 of the access sheath 102. Alternatively, the trigger 634 releases or disengages control of the tensioning device 116 from wheels 632 or 633 to allow the tensioning device to return to its original position. In FIGS. 34-36, one embodiment of an actuator or actuation hand-piece 710 of the present invention is remotely attached to an access sheath to control the tensioning and loosening of a tensioning device connected to the access sheath. As such, the actuator may be placed away from the surgical site or operating path or area so that the hand-piece does not prevent or interfere with the insertion of instruments along the working length of the access sheath. Additionally, the remote actuator does not occupy or add additional working space or length to the access sheath. Furthermore, another user may operate the actuator remotely allowing another user to focus on the surgical procedure, e.g., manipulating instruments to be or already inserted in the access sheath. Extended surgery time and confusion caused by switching between the actuator and other devices or simultaneously using the many devices may be reduced. The actuator 710, in one embodiment, is connected to a flexible body or conduit 711 , which is connected to the access sheath 102 via a Y-connector 712. The Y-connector 712 includes a funnel-shaped entry portion 713 that is sized and arranged to guide instruments into the primary lumen 112 of the access sheath 102. The Y-connector 712 also includes a channel 714 for connecting to the flexible conduit 711. The tensioning device 116 extends through the secondary lumen 114, channel 714, and flexible conduit 711 and is attached to an axle 715 disposed within the actuator 710. The axle 715 is connected to a dial or knob

716 that partially extends laterally from the hand-piece 710 with finger holds disposed radially throughout the knob 716. The other end of the axle 715 is rotatably connected to the hand-piece 710. The knob 716 allows a user to control the tensioning device 116. For example, when rotated in one direction, e.g., clockwise, the tensioning device 116 is drawn proximally to wrap or wind around the axle 715. A plurality of teeth

717 radially disposed on the knob 716 within the hand-piece 710 or disposed on a separate or embedded ratchet wheel operatively engages with a corresponding lever or pawl 718. The pawl 718 pivoting about a post connected to the hand- piece 710 and biased by a leaf spring 719 engages with the teeth to permit rotational movement of the knob 716 in one direction, e.g., clockwise, while preventing rotational movement in the opposite direction. As such, as the knob 716 is rotated, incremental control of the deflection of the steerable portion 106 of the access sheath 102 is provided as the axle in the hand-piece 710 draws the tensioning device 116 proximally. A trigger 720 when actuated pivots the pawl

718 to disengage the pawl 718 from the teeth 717. As a result, the tensioning device 116 is allowed to unwind or move distally from the axle 715. Thus, the steerable portion 106 of the access sheath 102 straightens. Referring now to FIGS. 37-39, another embodiment of an actuator or actuation hand-piece 730 of the present invention remotely attached to an access sheath 102 is shown. An axle 731 disposed within the hand-piece 730 is attached to the tensioning device 116. The axle 731 is also connected to a rotatable key or winged lever 732 extending laterally from one side of hand-piece 730. The lever 732 allows a user to control the tensioning device 116. For instance, when rotated in one direction, e.g., clockwise, the tensioning device 116 is drawn proximally to wrap or wind around the axle 731 in the hand-piece 730. A plurality of teeth 733 radially disposed around the axle 731 or disposed on a ratchet wheel surrounding the axle operatively engages with a corresponding pawl or cantilever arm 734. The arm 734 mounted on the hand-piece 730 and engaged with the teeth 733 permit rotational movement of the lever 732 and axle 731 in one direction while preventing rotational movement in the opposite direction. This engagement provides incremental control of the tensioning device 116 and thus also of the steerable portion 106 of the access sheath 102. The hand-piece 730 also includes a trigger lever 735 that is pivotally connected to a post in the hand-piece 730 and partially extends through a slot in the hand-piece 730. The lever 735 when actuated, e.g., pulled proximally, moves the cantilever arm 734 to disengage from the teeth 733 to allow the axle 731 to freely rotate. Therefore, the tensioning device 116 connected to the axle 731 unwinds and/or moves distally from the axle 731 causing the steerable portion 106 of the access sheath 102 to straighten. In FIGS. 40-43, another embodiment of an actuator or actuation hand- piece 740 of the present invention that is remotely attached to an access sheath 102 to control the tensioning and loosening of the tensioning device 116 is shown. Disposed within the hand-piece 740 is an axle 741 , which is attached to tensioning device 116. The axle 741 is connected to a slotted wheel 742 that is partially rotatable within the hand-piece 740. Generally opposing slots 743 and

744 are disposed in the slotted wheel through which respective dowels or pins

745 and 746 extend through and connect to distal ends of respective button arms 747 and 748. Proximal ends of button arms 747 and 748 extend through openings in the hand-piece 740. Operationally, when the button arm 748 is lowered, the button arm 747 rises as the slotted wheel 742 rotates clockwise. As a result, the tensioning device 116 connected to axle 741 is not drawn to the hand-piece 740, such that the steerable portion 106 of the access sheath 102 is substantially straight. When button arm 747 is lowered, the button arm 748 rises and the slotted wheel 742 rotates causing the tensioning device 116 to be pulled by rotating axle 741 such that the steerable portion 106 of access sheath 102 deflects. In one aspect of the present invention, the hand-piece 740 includes guides 749 for aligning and guiding traversal of the button arms 747 and 748 and slots (not shown) for assisting linear movement of the pins 745 and 746 as the button arms move. The slotted wheel 742 also includes one or more openings along the circumference of the wheel to permit rotation of the wheel without interfering with the guides 749. In another aspect of the present invention, the axle 741 is connected to a screw knob for adjusting the tension or pre-winding the tensioning device 116 around the axle 741. Referring now to FIG. 44, another embodiment of a remotely attached actuator or actuation hand-piece 750 is shown. In one aspect of the present invention, the hand-piece 750 fits within a user's hand in that a fist closing motion moves a t-bar 753 proximally deflecting the access sheath 102 and an opening motion moves the t-bar 753 distally allowing the access sheath 102 to straighten. For example, the hand-piece 750 includes finger-extension members 754 to provide one or more fingers on each member 754 to grasp the t-bar 753. A distally flared end 756 of a tube 751 is also provided for resting in the palm of a hand. Extending through a distal end of the tube 751 is the tensioning device 116 that attaches to plate 752 within the tube 751. The plate 752 is connected to the t-bar 753 that is slidably connected to tube 751. In one embodiment, an adjustment screw is connected to the t-bar 753 to adjust the location of the plate 752 relative to the t-bar 753 and within the tube 751. A set of teeth 755 within tube 751 operatively engages with a tooth or detent on t-bar 753 as the t-bar 753 moves. With the t-bar 753 moving proximally, plate 751 also moves proximally thereby pulling tensioning device 116 to cause the steerable portion 106 of the access sheath 102 to deflect. Similarly, as the t-bar 753 and plate 751 moves distally, the tensioning device 116 loosens and thus the steerable portion 106 straightens. As such, this engagement provides incremental control of the deflection and/or straightening of the steerable portion 106 of the access sheath 102. A spring-loaded button 757 on one end of the t-bar 753, when actuated, disengages the tooth on t-bar 753 from the teeth 755 within tube 751 allowing the t-bar 753 to move freely. FIGS. 45-46 illustrate another embodiment of the present invention of an actuator or actuation hand-piece 760 and 760' each remotely attachable to the access sheath 102. The hand-piece 760 and 760' are connected to a flexible body or tube 761 through which the tensioning device 116 extends. The tensioning device 116 is attached to a first handle member 762 that is pivotally connected to a second handle member 763. Actuation of the first handle member 762 allows a user to pull or release the tensioning device 116 to respectively deflect or straighten the steerable portion 106 of the access sheath 102. In one aspect of the present invention, a ratchet assembly is included to provide incremental control of the tensioning device 116 and thus the deflection of the steerable portion 106 of the access sheath 102. It is appreciated that the access sheath may comprise a plurality of pull wires attached to a plurality of thumbwheels, axles, knobs or other types of movable components of an actuation hand-piece to deflect the steerable portion of the sheath in different directions. Also, it is appreciated that the tensioning device may be hydraulic, pneumatic or electronic in nature and the actuation hand-piece may instead be foot, finger or otherwise sensor actuated and may include corresponding foot, finger or otherwise sensor extensions. In various embodiments, for example, the embodiments previously described and/or the embodiment of an actuation hand-piece 810 shown in FIGS. 47A-B, the tensioning device 116 is connected to a belt 811. The belt 811 acts as an intermediary between the tensioning device 116 and a movable component 818 in the hand-piece 810. The movable component may also be, for example, slider 514 or 614 (FIGS. 23B and 29), cylinder 526 (FIG. 25), movable handle member 622 (FIG. 31), axle 715 or 731 (FIGS. 36 and 37), and various other movable components fully or partially disposed within or otherwise part of an actuator or hand-piece which is connectable to the tensioning device 116. Through belt 811, stress or forces that may be applied by or result from the movable component 818 is displaced from the tensioning device 116. Therefore, stress experienced by the tensioning device 116 caused by the actuation of the hand-piece may be reduced. The belt 811 includes a number of apertures 812 for engaging teeth 813 radially disposed on the movable component 818 of the hand-piece 810. In one embodiment, the belt 811 includes teeth or protrusions for engaging corresponding apertures, teeth or protrusions of the movable component 818. With either engagement, incremental control of the tensioning device 116 is provided. As such, the belt 811 draws the tensioning device 116 proximally as the knob is rotated in one direction and rotating the knob in the opposite direction, allows the tensioning device to withdraw from the hand-piece 810. A pin or roller 814 may also be included to assist in the engagement of the belt 811 with a movable component 818 of the hand-piece 810. In one aspect of the present invention, the belt 811 is pliable. In another embodiment, a plate, bar, or a less flexible component may be connected to the belt 811 for drawing or releasing the belt 811 in conjunction with or without the movable component 818. A u-shaped lever 815 is connected to a knob 816 that is disposed on one or both sides of the hand-piece 810 and is connected to the movable component 818 in the hand-piece 810. Through actuation of the u-shaped lever 815, a user can control the movement/tension of the tensioning device 116 and thus the deflection and straightening of the steerable portion 106 of the access sheath 102. In one embodiment, a plate is connected to the u-shaped lever 815 and the belt 811 to draw and release the tensioning device 116. In one aspect of the present invention, a trigger 817, when actuated, locks the belt 811 , the movable component 818 or the u-shaped lever 815, thus preventing further movement of the tensioning device 116 and the deflection/straightening of the steerable portion 106 of the access sheath 102. Alternatively, the trigger 817 releases or disengages control of the tensioning device 116 from the belt 811 , the movable component 818 or the u-shaped lever 815 to allow the tensioning device 116 to return to its original position or state. Referring now to FIGS. 48-51 , embodiments of an access sheath in various stages of fabrication is shown. A wire 801 is wound around a support member or mandrel 802 in which the size and shape of mandrel generally defines the size and shape of primary lumen 112 of the access sheath 102. The mandrel, in one embodiment, is stainless steel and made of or is coated with a low friction material or surface, e.g., Teflon or various mold releases, allowing for the mandrel to be easily removed from the access sheath 102. The wire 801 is wound in an over counter fashion by using anchors or starting and stopping points substantially orthogonal of each other and thus winding the wire 801 in an oblique line along mandrel 802. As such, the wire 801 is wound such that the wire's tendency to unwind is counteracted. In one embodiment, prior to the addition of the wire 801 , the mandrel 802 is coated with or inserted into a plastic or PVC material tube to allow instruments and the like to be smoothly inserted into the primary lumen without interference from the wire 801. The wire 801 , in one embodiment, is a plastic coated wire and particularly, a stainless steel co-extruded wire with an approximate diameter of .006 inches fused, coated or otherwise included with a plastic material to make the total diameter of the wire 801 to be about .012 inches. The mandrel 802 including wire 801 is placed into or inserted into a control tube. Air, in one embodiment, is supplied, e.g., at 100 PSI, on the opposite end of insertion to assist insertion of the mandrel 802 by expanding the control tube. The control tube, in one embodiment, may be made of silicon or a material with a higher melting point than the plastic coating of wire 801. This assembly is then heated such that the plastic coating of wire 801 melts and adheres to itself to form a generally continuous tubular structure or major tube 803. The control tube is then removed. A minor tube 804 is placed on or included with the major tube 803. The minor tube 804 is longer than the major tube 803 and thus extends substantially further along the mandrel 802 than the major tube 803. Extending within a portion of the minor tube 804 is a generally tubular structure or inner tube 805 that is about as long as the major tube 803. In one embodiment, the inner tube 805 is made of polyimide and the minor tube 804 is made of carbothane that when heated adheres to the inner tube 805, the major tube 803 and other portions of the access sheath, which are described below, that surrounds the outer periphery of the minor tube 804. The inner tube 805 within the minor tube 804 is adapted to receive the support wire 806. The size and shape of the support wire 806 along with the inner tube 805 generally defines the size and shape of the secondary lumen 114 of the access sheath 102. In one embodiment, the support wire is a stainless steel wire with a diameter of about .12 inches. The support wire 806 is secured to a proximal end of the mandrel 802, threaded through the inner tube 805 and the minor tube 804 and secured to the distal end of the mandrel 802. In one embodiment, the support wire 806 secures the minor tube 804 to the major tube 803. The minor tube 804 extends along the mandrel 802 substantially more than the inner tube 805. In other words, the length of the minor tube 804 is longer than the inner tube 805. The minor tube 804 is also more flexible than the inner tube 805. As such, the portion from the end point of the inner tube 805 and/or the major tube 803 to near the end point of the minor tube 804 eventually defines the steerable portion 106 of the access sheath 102. In one embodiment, the minor tube 804 is shorter and less flexible than the inner tube 805. Thus, in this embodiment, the portion from the end point of the minor tube 804 and/or the major tube 803 to near the end point of the inner tube 805 eventually defines the steerable portion 106 of the access sheath 102. In one embodiment, the minor tube 804, inner tube 805 and the major tube 803 are placed into a final tube to enclose the minor tube 804 and inner tube 805 between the major tube 803 and the final tube. This assembly is placed into or inserted into a control tube such that the assembly adheres or bonds together and then the control tube is removed. In one embodiment, the minor tube 804 or the inner tube 805, whichever extends further, is rigid, e.g., a stainless steel tube, to assist in the deflection of the steerable region 106. As such, the rigidity of the minor tube 804 or inner tube 804 prevents the non-steerable portion of the access sheath 102 from bowing. As such, the tube shifts the force caused by the tensioning device 116 to deflect the steerable region directly towards or at the steerable region 106. Also, a rigid secondary lumen formed by the rigid tube may assist in the protection of the tensioning device and instruments inserted or withdrawn from the primary lumen. A wire 807 is wound around the minor tube 804, the inner tube 805 and the major tube 803. In one embodiment, where the final tube is utilized, the wire

807 is also wound around the final tube. In one embodiment, the wire 807 is similar in construction or composition as that of wire 801 and/or extends slightly beyond the distal end of the minor tube 804 or inner tube 805. A support tip, in one embodiment, is placed on a distal end or slightly beyond the distal end of the wire 807 to assist in securing the wire 807 around the minor tube 804 or inner tube 805 and/or to provide an atraumatic tip. The support tip may be a 75 Shore D material. The mandrel 802 with rest of the assembly is inserted into a control tube. As previously mentioned, air, in one embodiment, is supplied on the opposite end of insertion to assist insertion of the mandrel 802 by expanding the control tube. In one aspect, a support tube is used to temporarily encompass the control tube when the tube is pressurized in the event the tube breaks down. The control tube with the assembly is heated such that the plastic coating of wire 807 melts and adheres to itself to form a generally continuous tubular structure or tube 808. The control tube is then removed. In one embodiment, the control tube and assembly are heated at around 165 degrees plus or minus about five to ten degrees for about ten to fifteen minutes. As such, an access sheath 102 with a variable flexibility is created. The support wire 806 is disconnected from the mandrel 802. For example, the support wire 806 on the distal end of the mandrel 802 is cut and then the mandrel 802 is withdrawn from the access sheath 803. At or near the tip of the access sheath, a tensioning device, e.g., a pull wire, is attached and threaded to the minor tube 804 and inner tube 805 out the proximal end of the access sheath 102 for securing to an actuator. As such, the access sheath is deflectable and controllable. In one embodiment, the tensioning device is knotted or looped around an opening or cut in the access sheath, the support tip and/or between loops in the wire 807 and back through itself. A catch wire threaded through the inner tube 805 and the minor tube 804 hooks or otherwise attaches to the tensioning device. The catch wire is removed out the proximal end of the access sheath thereby threading the tensioning device through and out the proximal end of the access sheath 102. As it is appreciated the support wire 806 has a diameter sufficiently larger than the diameter of the tensioning device, the catch wire or loops and hooks of the catch wire to permit easy passage of these devices through the secondary lumen of the access sheath 102. A secondary support tip, in one embodiment, is placed on the distal end of the access sheath 102 to assist in securing the tensioning device to the access sheath and/or to provide an atraumatic tip. As shown in FIGS. 51A-C, the distal end 809a of the access sheath 102 is tapered and thus has a smaller diameter than the proximal end 809b of the access sheath 803. The primary lumen 112 and secondary lumen 114 diameters, however, remain substantially constant throughout the access sheath 102. Additionally, the tapering or reduced diameter of the access sheath is a result of the halting or non-extension of the inner tube 805 or minor tube 804, in one embodiment, and the major tube 803 along the length of the mandrel 802. As a result, the steerable portion 106 includes a reduced amount of materials and more flexible materials, and thus the steerable portion is easily deflected, bent, shaped or curved in response to the manipulation of the attached tensioning device while the other portion of the access sheath 102, including more material and less flexible material, remains substantially fixed, e.g., straight and substantially in the same plane, preventing any inadvertent or unintended movement of the access sheath. Additionally, since the steerable region 106 of the access sheath 102 is reinforced by wire 807, the steerable region 106 is strengthen such that a flexible, pre-bendable or otherwise not actively controllable instrument may be controllably deflected dynamically as the steerable region 106 is controlled. Additionally, an actively deflectable surgical instrument may have a complicated construction providing components, e.g., optics or clamps, to perform its surgical function and components to perform the active deflection. Therefore, such instruments may be fragile or if broken may be expensive to replace or repair or still usable as a surgical instrument but not actively deflectable. As such, the strengthen steerable region 106 may replace the components or use of the components in such surgical instruments or induce an broken instrument to be controllably deflected thereby reducing replacement, repair and/or construction costs, reducing wear and tear of such instruments and increasing the life of such instruments. Also, the reinforced access sheath 102 through wire 807 and/or wire 801 allows the size and shape of the primary lumen to remain substantially constant throughout the access sheath 102, thereby reducing forces on instruments placed within the access sheath which may extend the life of these instruments. The forces or stress accumulated along the access sheath that may cause kinks in the access sheath are also distributed along the access sheath due to the composite construction of the access sheath described above and are further counteracted by the wire coils, e.g., wire 807 and 803. Thus, kinks in the access sheath are reduced. The wire coils also allow the access sheath walls to be very thin without reducing durability or strength in the access sheath. Thus, the overall or outer diameter of the access sheath may be small, which may also reduce the incision or insertion point for the access sheath, without reducing the size or diameter of the primary lumen. As such, the access sheath of various embodiments of the present invention has thin walled portions, a large lumen, an atraumatic end, and a kink resistant construction and is strong, stiff and yet flexible enough to be intricately guided through the body cavity or tissue. In one embodiment, the wire coils are wound in a multifilar fashion with materials having alternating durometers. Various other examples of processes that may be used to manufacture the access sheath 102 or portions of the access sheath 102 are described in U.S. Patent Application Nos. 10/766,138 and 10/298,116, the disclosures of which are hereby incorporated by reference. It is appreciated that these processes or portions of the processes may be varied or combined with the previously described process and vice versa. For example, various ring-shaped elements, such as, plastic rings, metallic rings, un-reinforced plastic rings and metal reinforced plastic rings, and the like may be utilized instead of or in addition to the wires 803 and/or 807. Additionally, a separate mandrel may be utilized to separately form or define the primary and secondary lumens and combined to make the access sheath. In one embodiment of the present invention, various embodiments of access sheaths and actuators previously described, here now referred to as the access sheath, combined with an instrument or device used to stretch or enlarge an opening, e.g., a dilator, allows for gradual and atraumatic dilation of the ureter while being placed. Once the access sheath has been placed at a desired location, the dilator is removed and the access sheath is left in place. The access sheath allows for continued access to the desired area, for example, for the placement of an ureteroscope and other therapeutic instruments, while providing protection of the ureter. For instance, the access sheath may protect the ureter during the placement and removal of devices within the access sheath, during the removal of stone fragments or other tissue, and during the removal of a potentially cancerous biopsy specimen. Additionally, with the access sheath being deflectable or steerable, an urologist may effectively and efficiently locate stones and stone fragments within the kidney. When a stone burden is found in one of the calyces of the kidney, especially in the lower pole portion of the kidney; it may be difficult for the urologist to continue to go back to the same calyx or location to remove the burden. When there are many fragments within a calyx, many entries and exits may be performed to remove the burden. Also, when a stone or stone fragment is removed, the instruments and tissue, e.g., the scope and stone basket (with the stone or stone fragment) are removed as a single unit. The scope is then passed back through the sheath and manipulated to find the same calyx in order to remove the remaining burden. However, with the access sheath 102, the access sheath can be left deflected in place looking at the same calyx or location, while the scope and stone basket are removed. As a result, the urologist's procedure time may be reduced, as the urologist may not have to manipulate the ureteroscope to look for the same calyx each time. The amount of time saved may be significant, especially if there is a large stone burden within the kidney. Additionally, the likelihood of doing damage to the kidney due to the additional manipulation that takes place every time the ureteroscope is placed back into the kidney may be reduced. Thus, with the access sheath, one can keep the sheath deflected towards a particular calyx and remove the stone burden without having to find the calyx each and every time a fragment is removed. When the urologist manipulates an ureteroscope, the urologist may sometimes use the inside walls of the kidney to help deflect the ureteroscope to enter into a particular difficult locale. With the access sheath 102, instead of using the inside wall to help deflect the ureteroscope the access sheath may be used. Also, as previously mentioned, this will also help reduce the "wear and tear" on surgical instruments, such as ureteroscopes. The deflecting mechanism with the ureteroscope, if provided, can be damaged often and expensive repair. The use of the access sheath may reduce the damage to the ureteroscope when it is used to help manipulate the ureteroscope to desired locations within the kidney. The use of the access sheath 102 may also help a lesser-experienced urologist perform the same difficult procedure as their more experienced colleagues. In performing this procedure, the urologist may access the lower pole of the kidney in order to remove a stone burden. By performing this procedure in a retrograde fashion, one can reduce a patient's recovery time. If an urologist were neither skilled nor comfortable with using an ureteroscope in a retrograde fashion to remove a stone burden from a kidney's lower pole, the urologist would typically approach the stone burden in an antegrade fashion. This places a sheath percutaneously and thus may add additional recovery time for a patient as well as potentially increasing morbidity. But, with the access sheath 102 and an ureteroscope, an urologist may efficiently and effectively locate and remove a stone burden within the lower pole of a kidney. The access sheath can also be used in an antegrade fashion and will provide the same or similar features described above, however access in this manner may not be the preferred method. Accordingly, the present invention provides a vascular steerable access device. Although this invention has been described in certain specific embodiments, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that this invention may be practiced otherwise than specifically described, including various changes in the size, shape and materials, without departing from the scope and spirit of the present invention. Thus, embodiments of the present invention should be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS 1. A vascular surgical access device comprising: an elongate body having a proximal end, a distal end, at least one steerable region, and a lumen extending through the body and sized and configured to be inserted into a blood vessel; a tensioning device extending through the elongate body and connected to the at least one steerable region of the elongate body; and an actuator connected to the tensioning device distally from the proximal end of the elongated body to control tension of the tensioning device to navigate the elongate body through a circulatory system.

2. The device of claim 1 wherein an outer diameter of the elongate body is sized to be inserted into a blood vessel.

3. The device of claim 1 wherein the lumen has a pathway configured to advance one of a dilator and a contrast agent.

4. The device of claim 1 wherein the tensioning device is at least one pull wire.

5. The device of claim 1 wherein the tensioning device is a flexible flatten member.

6. The device of claim 1 further comprises an enlarged entry at the proximal end of the body and adapted to receive one of a dilator and obturator.

7. The device of claim 6 wherein the entry has a valve.

8. The device of claim 1 wherein the actuator further comprises one of a thumbwheel, a knob, a lever, a button, a handle, a t-bar, and a dial.

9. The device of claim 1 wherein the elongate body is deflectable by the tensioning device to conform to a shape of a vessel.

10. The device of claim 1 wherein the elongate body is deflectable by the tensioning device to direct a contrast agent in an antegrade flow of a vessel.

11. The device of claim 1 wherein the elongate body is at least 100 centimeters long.

12. The device of claim 1 wherein other steerable regions are disposed along non-adjacent portions of the elongate body.

13. The device of claim 1 wherein the distal end of the elongate body is tapered.

14. The device of claim 1 further comprising a secondary lumen through which the tensioning device is disposed and a spring fixed within the secondary lumen and wherein the tensioning device extends through the spring.

15. The device of claim 1 wherein the body comprises an inner plastic body, a spring coil and an outer plastic body.

16. The device of claim 15 wherein the inner plastic body is surrounded by the spring coil and covered by the outer plastic body.

17. The access device of claim 1 wherein the at least one steerable region has means for increasing elasticity of the steerable region.

18. The device of claim 1 wherein the elongate body is configured to operate in through femoral arteries, iliac arteries and uterine arteries.

19. A vascular surgical access device comprising: a tube having a proximal end, a distal end, a steerable region, and an enlarged entry, the tube including a primary lumen and a first and second secondary lumen both extending through the tube; a first tensioning device connected to the steerable region and extending through the first secondary lumen; a second tensioning device connected to the steerable region and extending through the secondary lumen; an enlarged entry extending from the distal end of the tube forming a transition into the primary lumen of the tube from an exterior of the tube; and a movable actuator disposed about the enlarged entry and connected to the first tensioning device and the second tensioning device and configured to rotate in one direction causing movement of the first tensioning device and rotate in an opposite direction causing movement of the second tensioning device.

20. The device of claim 19 wherein the first secondary lumen and the second secondary lumen are disposed on opposing sides of the tube.

21. The device of claim 19 wherein an outer diameter of the tube is sized to be inserted into a blood vessel and the primary lumen has a pathway configured to advance one of a dilator and a contrast agent.

22. The device of claim 19 wherein the tube is deflectable by the first tensioning device to direct a contrast agent in an antegrade flow of a vessel.

23. The device of claim 19 further comprising a plurality of steerable regions are disposed along non-adjacent portions of the tube.

24. The device of claim 19 wherein the tube is configured to operate in through femoral arteries, iliac arteries and uterine arteries.

25. A vascular surgical access device comprising: a elongate tube having a proximal end, a distal end, a steerable region, and an enlarged entry, the elongate tube having a lumen extending through the elongate tube and being configured to operate in through femoral arteries, iliac arteries and uterine arteries; tensioning means connected to the steerable region and extending through the lumen; and actuator means connected to the tensioning means and configured to cause movement of the tensioning means causing movement of the steerable region.