Abstract: A surgical obturator comprising an elongate shaft extending along an axis between a proximal end and a distal end, and a bladeless tip disposed at the distal end of the shaft having a conical surface forming proximally into an outer surface, the outer surface extending distally to a blunt point and having a pair of side sections. The side sections extend from the blunt point radially outwardly with progressive positions proximally along the axis. The conical surface facilitates insertion of the obturator with a reduced penetration force and minimizes tenting of the body wall. The conical surface further facilitates separation of different layers of the body wall and provides proper alignment of the tip between the layers. The surgical obturator may be constructed from a disposable or reusable material such as a metal or an autoclavable polymer.

Abstract: A medical grasping device (10) for vascular use, having an outer sheath (12), an elongate control member (50) extending within an outer sheath (12) to a distal tip section (54), and a proximal control assembly (22) including an actuation section (24) joined to the elongate control member (50). Adjacent to the distal tip section (54) is a grasping portion (70, 70?) that is extendable from the outer sheath (12) to create loops (74, 74?) for grasping a target object (T) for repositioning within the vascular system, or for removal from the patient, with loops being retractable into the outer sheath to hold the target object against the device (10) during movement of the device. Elongate control member (50) is preferably a cannula or tube having a lumen (58) extending completely therethrough for placement over a guide wire (28) already in the patient.

Abstract: The present invention is directed to a deployment system for an endoluminal device. The deployment system includes a confining sheath placed around a compacted endoluminal device. A deployment line is provided in the system that is an integral extension of the sheath. As the deployment line is actuated, the sheath retracts from around the compacted endoluminal device. As the sheath retracts from around the endoluminal device, material from the sheath may be converted into deployment line. Once the sheath is retracted from around the compacted endoluminal device, the endoluminal device expands in configuration and repairs vascular or cardiac structures of an implant recipient. Any remaining sheath material is removed from the implantation site along with the deployment line. The deployment system also includes an endo-prosthesis mounting member placed between the endoluminal device and an underlying catheter.

Abstract: A medical grasping device (1) has an elongate control member (9) with a grasping member (17) proximal to its distal tip. An outer sheath (3) with a passageway therethrough surrounds the elongate control member and is relatively movable with respect to the control member. A control assembly (2) disposed at a proximal end of said outer sheath has a fixed handle (5) and a sliding handle (7) and the proximal end of the elongate control member is fixed to the sliding handle to move the control member. The grasping member (17) has a plurality of pre-formed wire loops (50, 52, 54, 56) which self-deploy transversely upon emerging from said distal end of said outer sheath. Each wire loop is fastened to substantially opposite sides of the elongate control member so that each of said wire loops is substantially semi-circular upon full deployment and the respective ends (27, 29) of each wire loop extend substantially in opposite directions from the elongate control member.

Abstract: A laparoscopic port assembly includes a cannula unit including three cannulas each extending at an acute angle relative to a base. The cannulas are flexible for receiving respective angulated laparoscopic instruments. The cannula unit is rotatingly received in a port holder for rotation about a longitudinal axis of the holder, the holder being disposable in an opening in a patient's skin.

Abstract: Minimally invasive techniques are utilized in bypass grafting to implant an end portion of a graft in the body of a patent by (i) advancing a medical instrument within a circulatory system of the body, (ii) guiding a distal end of the medical instrument out of the circulatory system through an opening defined in the circulatory system, (iii) advancing the end portion of the graft within the medical instrument toward a surgical site, and (iv) securing the end portion of the graft to a blood vessel at the surgical site, wherein the graft includes resilient arms confined within the medical instrument that expand outwardly within the blood vessel following positioning of a graft end through an aperture in the blood vessel.

Abstract: An apparatus and method for introducing a medical device deployment system into the vasculature of a human body and then using the deployment system for placing a medical device at a preselected position within a vessel, and an apparatus and method for introducing a medical device deployment system into the vasculature of a human body and then subsequently retrieving the deployment system, where the apparatus and method include an introducer having a detachable and reattachable sheath disposed about a deployment catheter.

Abstract: An insertion tool for use in inserting a guide wire into a guide wire lumen of a catheter for use in a lumen of an endoscope. The insertion tool includes a main body having a main lumen and a funnel-shaped extension connected to and disposed atop the main body. The funnel-shaped extension having a funnel lumen. The funnel lumen has a top opening and a bottom opening. The funnel lumen tapering from the top opening to the bottom opening. The bottom opening positioned and sized to communicate with the guide wire lumen of the catheter such that, when the catheter is disposed in the main lumen, the guide wire may be easily inserted into the top opening of the funnel lumen and into the guide wire lumen of the catheter.

Abstract: A catheter for introduction and removal of fluids from a body and tunneling device therefor, the catheter has a body having a first conduit for removing fluid from the body and a second conduit for delivering fluid to the body wherein at least a part of each of the lumens is integrally formed within a first end of the body and extends along side one another. The first conduit extends beyond the second conduit and forms a terminal point of the first end and defines a first opening thereat and the second conduit extends to a point short of the terminal point defining a second opening. A bumper portion is adjacent the second opening extending toward the terminal point. Another part of each the first and the second lumens are disjoined and form part of a second Y-shaped end. The tunneling device has a channel to removably receive the catheter.

Abstract: There is disclosed herein a device (1) for moving an elongate member relative to an. elongate body through which it extends, the device comprising: a housing (10) connectable to the elongate body; a mover (20) associated with the housing and connectable to the elongate member for moving the elongate member relative to the housing and relative to a connected elongate body; and a pre-mover (40) for adjusting an elongate member connected to the mover relative to an elongate body connected to the housing in preparation for moving the elongate member with the mover. There is also disclosed a related surgical apparatus.

Abstract: One aspect of the present invention relates to a surgical instrument for placing a prosthesis into a target area of a living subject. In one embodiment, the surgical instrument includes a body member, a shaft extending away from the body member for securing the prosthesis, an engaging member engaged with the body member and the shaft, for engaging the prosthesis, and an actuator connected to the engaging member, for moving between a first position in which the engaging member is disengaged from the prosthesis and a second position in which the engaging member is engaged with the prosthesis.

Abstract: An angioplasty and stent delivery system to facilitate introduction and placement of a stent, including a catheter having an expandable distal portion constructed and arranged for expanding the outer diameter of the catheter from a contracted state to an expanded state: a stent positioned around the distal portion of the catheter having a contracted condition and being expandable to an expanded condition, and being sized in the contracted condition to closely surround the catheter in the contracted state, the expandable distal portion of the catheter including a balloon within which or over which there is included on a catheter shaft at least one axially movable or enlargeable body of a diameter larger than the catheter shaft to which the stent and balloon are fitted, as by crimping, for holding the stent in place until it is released therefrom by expansion of the balloon.

Abstract: A hand-held actuator device for releasing into the body from a delivery system a medical prosthesis, like a stent, comprising a frame (10) that acts as a housing, a reel (30) for receiving a wire (8), a manually operable slider (34) mounted to the frame and a one-way connection between the slider and the reel. Actuating the slider causes the reel to wind up the wire and release the medical prosthesis.

Abstract: A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

Abstract: A device (11) and method for preparation of a graft (13) and a fastener (12) for coupling to a vessel. The device includes a tubular body (22) with a gripping head (23) at a distal end to grip the graft and fastener. The graft is threaded through the fastener and an edge of the graft emerges out of the fastener. The gripping head has at least three segments (71) arranged around its axis. The segments can be brought closer or pushed away from each other to modify the external diameter of the head and to provide firm gripping of the fastener and the graft. The device further includes a pliant tongue (29) which may rotate around the tubular body. Radial positioning of the tongue may be controlled and the tongue may slide axiallly towards or away from the head.

Abstract: The apparatus for deployment of an intravascular therapeutic device, includes an elongated, flexible pusher member and a therapeutic device connected to a severable portion of a first connector member mounted to the flexible pusher member with an elongated second connector member connected to the therapeutic device. The first connector member or second connector member may be capable of being broken by heat, and a heat source is provided for heating and breaking the first connector member or the second connector member to release the therapeutic device.

Abstract: A mechanical device and/or chemical process is utilized to maintain luminal patency in conduits or other devices implanted in the lung or lungs of a patient. The mechanical device and/or chemical process ensures that air flows freely through a conduit implanted through an anastomosis into a lung. The device is suitable for use in conjunction with ventilation bypass treatments for chronic obstructive pulmonary disease.

Abstract: A mechanical device and/or chemical process is utilized to maintain luminal patency in conduits or other devices implanted in the lung or lungs of a patient. The mechanical device and/or chemical process ensures that air flows freely through a conduit implanted through an anastomosis into a lung. The device is suitable for use in conjunction with ventilation bypass treatments for chronic obstructive pulmonary disease.

Abstract: A coiled-sheet stent includes a tubular body having a longitudinal axis and a circumference, and a plurality of cylindrical bands formed in the tubular body, each band having a zig-zag pattern including a series of sequential diagonal elements connected to one another and extending about the circumference. A plurality of longitudinal connectors extend between and connect adjacent bands. The diagonal elements have an arcuate shape, all diagonal elements in each band being oriented in either a clockwise or counter-clockwise direction about the circumference. The tubular body is expandable between contracted and enlarged conditions, and the zig-zag pattern is expandable between unstretched and unstretched conditions, the zig-zag pattern being biased towards the stretched condition above a transition temperature, thereby at least partially defining the enlarged condition.

Abstract: Disclosed herein, among other things, is a system for providing pacing during revascularization. An embodiment of the system includes an angioplasty or stent delivery catheter system having a catheter, a balloon and an inflation device adapted to inflate and deflate the balloon for delivery of a stent. The embodiment also includes a programmable pulse generator and at least one electrode integrated with the angioplasty catheter system, where the pulse generator is connected to the electrode. In various embodiments, at least one integrated sensor is connected to the angioplasty catheter system. The sensor is adapted to sense a parameter indicative of flow restoration and trigger the pulse generator to begin pacing based on the parameter.

Abstract: An automatic vaccinator of eggs, consisting of a system for applying vaccine with a vaccine chamber in which vaccine bags are hung and with an air bag that, when expanded, forces the vaccine from the bags and through tubing to a distribution manifold and the injectors, so that the vaccine is delivered to the eggs, is disclosed. A pressure sensor is installed in the distribution manifold and connected to a regulator, measuring the pressure in the distribution manifold at the point farthest from the vaccine chamber and controlling the pressure in the air bag to maintain a uniform quantity of vaccine being injected into the eggs and turning off the vaccinator if the pressure falls below a critical level, signaling that the vaccine bags are empty. The mechanical unit includes a system to support, align and secure the injectors over the egg tray, composed of two plates that work independently, a support plate and an alignment plate.

Abstract: A delivery system has reduced profile in the catheter portion of the delivery system without compromising the pushability of the delivery system. The present invention also provides a structure which improves and simplifies the attachment of small catheter components to other structures forming the catheter portion the delivery system.

Abstract: A distal end of a stent graft fenestration or other special purpose catheter is guided to a location in a patient's vasculature based on input from a surgeon using a pre-operatively generated image of the patient's vasculature—this can be in proximity to an already implanted device. The movement of the catheter is controlled by a robotic surgical system based upon the input from the surgeon. The distal end of the catheter, at the location, is synchronized to the patient's cardiac cycle so the robotic surgical system maintains the distal end of the catheter at the location throughout a cardiac cycle of the patient. The surgeon is not required to precisely manipulate the catheter to maintain the distal end in the proper location throughout the cardiac cycle. The surgeon can focus on performing the desired procedure such as fenestrating the stent graft, endostapling or endosuturing, for example.

Abstract: A filter system for temporary placement of a filter in an artery or vein is disclosed. The filter system includes a guidewire that is first positioned across a lesion within a vessel. The guidewire may include a distal stop. A slideable filter is then advanced along the guidewire using an advancing mechanism, typically an elongate member slideable over the guidewire and contacting the filter. A capture sheath may be disposed about the filter during advancement. Once the filter is positioned downstream of the lesion, the capture sheath is withdrawn, allowing the filter to expand. Further distal advancement of the filter is prohibited by the stop. After expansion of the filter, the capture sheath and the advancing mechanism are withdrawn from the region of interest, and removed from the patient's vessel. The filter may then be retrieved using a capture sheath or exchanged for a second filter after removing the first filter.

Abstract: Over-the-scope stent introducers for detachably engaging at least a portion of the outside of an endoscope insert and for delivering a stent are provided. Embodiments include an inner member having a distal first end portion and a proximal second end portion and openings defining a channel. The inner member includes an outer surface, inner endoscope engaging surface, and stent abutting restraint disposed at the first end portion. Embodiments also include an outer member having a distal section and proximal section having openings defining a passageway sized to slideably receive at least a portion of the inner member, and a stent carrying inner chamber disposed at the distal section passageway and being configured to releasably contain a stent. In alternative embodiments, the inner and outer members are elongated to dispose substantially concentrically over a majority of an endoscope insert.

Abstract: Methods, system and apparatus for relieving pressure in an organ such as, but not limited to, the eye are disclosed. The method includes implanting a bioabsorbable channel into the selected area of the organ using a delivery apparatus.

Abstract: The disclosure concerns a device for positioning a stent in a natural canal after the passage through an obstacle at the level of a target organ. The device includes a stent, a pusher tube and a guide. The guide is conceived to push the stent through the lumen of the natural canal, and includes at least one flexible part having a predetermined longitudinal stiffness and a lateral flexibility consisting in a reversible deformation from a straight position to a bent position so as to follow the curve of the natural canal under the application of minimal external forces exerted by an operator. The disclosed device is particularly adapted to the technical field of urology.

Abstract: Endoprothesis delivery systems and methods for making an using the same. An example medical endoprosthesis delivery system may include an inner member. An outer member may at least partially surround the inner member. The inner member and the outer member may be configured so that an implantable medical endoprosthesis can be disposed therebetween. A coupling device may be coupled to a portion of the outer member so that, when there is substantially no slack in the coupling device, as the coupling device moves in a proximal direction the portion of the outer member moves in the proximal direction. An adjustable stop may be coupled to the coupling device so that, when there is slack in the coupling device, as the adjustable stop is moved in the proximal direction, the amount of slack in the coupling device can be reduced.

Abstract: A cannula for an ocular implant delivery system. In some embodiments, the cannula includes a tubular member having a curved portion, a distal opening surrounded by a distal opening surface, and a distal tip, the distal tip being adapted to be inserted into an anterior chamber of a human subject's eye, through trabecular meshwork and into Schlemm's canal of the eye, a proximal portion of the tubular member being adapted to extend from a location exterior to the eye when the distal tip is in Schlemm's canal of the eye, the cannula being further adapted to cooperate with an advancement mechanism to advance an ocular implant through the tubular member toward and through the distal opening into Schlemm's canal of the eye when the distal tip is disposed in Schlemm's canal.

Abstract: Disclosed is an expandable percutaneous sheath, for introduction into the body while in a first, low cross-sectional area configuration, and subsequent expansion to a second, enlarged cross-sectional configuration. The sheath is maintained in the first, low cross-sectional configuration by a tubular restraint. In one application, the sheath is utilized to provide access for a diagnostic or therapeutic procedure such as percutaneous nephrostomy or urinary bladder access.

Abstract: The present invention provides a medical grasping device including an an elongate control member, an outer sheath, and an actuation section. The elongate control member includes an atraumatic distal tip section, a proximal end portion, and a grasping portion positioned between the proximal end portion and the distal tip section. The outer sheath includes a distal end and a proximal end, and has a passageway that extends between the distal and proximal ends. The elongate control member is slidable within the passageway and its proximal end portion is connected to the actuation section. The actuation section is operated to move the grasping portion in and out of the distal end of the outer sheath and includes a retraction mechanism that biases the actuation section and hence the grasping portion toward a retracted state.

Abstract: In one embodiment, a neck bridge for bridging the neck of an aneurysm includes a junction region, a number of radially extending array elements attached to the junction region, and a cover attached to one or both of the junction region and an array element. The array elements are configured to be positioned within the aneurysm after the neck bridge is deployed from a delivery device. In a second embodiment, the neck bridge includes a junction region and a braided or mesh-like structure secured to the junction region. The braided or mesh-like structure is made from an elastic material.

Abstract: Disclosed are apparatuses and methods for delivering implants through a posterior aspect of a vertebral body such as a pedicle and placing the implant or performing a procedure into the anterior aspect of the vertebral body. A representative apparatus includes an outer cannula, and advancer tube and a drill assembly. It is envisioned that at least one of the outer cannula, the advancer tube or the drill assembly can be viewed in vivo using for example, a CT scan or fluoroscope. The present invention is also directed to an apparatus for forming an arcuate channel in bone material. The apparatus includes and advancer tube and a drill assembly.

Abstract: An introducer (10) includes release wires (42?) that constrain at least one stent (4?) whilst the remainder of a stent graft (18) is expanded during deployment. By allowing the constrained stent (4?) to expand after an adjacent stent (4), the constrained stent (4?) overlaps with the interior of the adjacent stent (4) where the stent graft (18) is deployed within a curved body lumen (70).

Abstract: A surgical access system for managing the minimally invasive access of treatment electrodes to an intervertebral disc, when treating spine abnormalities such as disc herniations. The system includes an access port and a cannula assembly. The access port provides atraumatic access to the target area for the cannula system and a subsequent treatment electrode. The access port also manages the insertion travel and penetration depth of the cannula assembly, so as to minimize unintended damage to local tissue during use. The cannula system includes an adjustable and removable stop to mate with the access port that limits the extension of the cannula beyond the distal tip of the access port and into the target tissue.

Abstract: The invention relates to a method of delivering and deploying a stent into a curvilinear cavity within a vertebral body or other bony or body structure. The invention also relates to devices that may be used to perform the steps to deliver and deploy a stent.

Abstract: A device (such as guidewire inserter) for easily and certainly inserting a medical long item having a curved tip into a tube such as catheter and sheath includes a tubular member having a bore for passage of a guidewire. The tubular member has a slit cutting across the wall over the total length of the tubular member. The proximal end of the tubular member has an aperture. The proximal end of the aperture has an open part and a connecting part adjacent thereto for the holder tube. There is a pair of wing-like protruded pieces projecting in the mutually opposite directions at both sides of the open part. The distal end of the tubular member has on its outer surface a pair of protruded rims, which project in the mutually opposite directions.

Abstract: Devices and techniques for establishing button-hole openings in arteriovenous fistula (or other target site located in the interior of a subject's body), without requiring the same nurse or technician to prepare the patient in the first several sessions, utilizing or encompassing a first button-hole forming device including in sequence: an external connection component; a scar-tissue forming component; and an indwelling cannula component. The first button-hole forming device has a lumen running through the longitudinal axis of the tube such that blood can be transported therethrough to or from the fistula (or other target site located in the interior of a subject's body) to a hemodialysis machine or other device.

Abstract: The present invention provides an embolic assembly delivery apparatus having superior flexibility characteristics at its distal end, that is, at the point of attachment of the embolic assembly to the delivery apparatus. It also provides a method of using the apparatus to deliver an embolic assembly to a target site in a patient's body.

Abstract: A method of determining the size and/or placement of screws or other instruments in pedicles during surgery in a selected spinal area, comprising generating a dimensionally true three-dimensional image of the bony spine in the selected spinal area; hollowing out the vertebra in the three-dimensional image with cortical wall thicknesses selected by a surgeon performing the surgery; determining the narrowest cross section (isthmus) within each pedicle; generating a straight line starting at the center of the isthmus and extending inwardly to a point centered within the anterior cortex so that it is positioned concentrically within the pedicle without touching the walls thereof, the line terminating inside the vertebral body a predetermined distance from the anterior inner cortical wall and extending outwardly in the opposite direction to penetrate the posterior pedicle cortex; expanding the line concentrically and radially to a cross sectional size that is less than that of the isthmus, the line being expanded

Abstract: A device for manual manipulation of a guidewire including a generally cylindrical, integrally formed, compressible element arranged along a longitudinal axis and being compressible transversely to the longitudinal axis and having first, second and third, respectively uncompressed, fully compressed and partially compressed operative orientations, the element in the fully compressed operative orientation defining an axial slot adapted for side mounting of the element onto a guidewire and the element in the partially compressed operative orientation being adapted for tightly engaging a guidewire in the slot such that axial and rotational movement of the element produces corresponding axial and rotational movement of the guidewire.

Abstract: Methods, system and apparatus for relieving pressure in an organ such as, but not limited to, the eye are disclosed. The method includes implanting a bioabsorbable channel into the selected area of the organ using a delivery apparatus.

Abstract: A catheter introducer system for endoscopy is disclosed which includes a steering section and a propulsion section located near the end of the catheter that is introduced in a body cavity, and a non-collapsible sheath defining a working channel. The propulsion section is designed to pull the rest of the catheter inside the body cavity, so there is no need to push the catheter along. The propulsion section further includes gripping members, such as inflatable balloons, that are axially movable relative to the catheter. The catheter can thus be made very flexible in bending, and a larger diameter catheter can be used without discomfort to the patient.

Abstract: A system and method places a percutaneous gastrostomy device into a body cavity of a patient using a magnetic gastrostomy tube and a medical detection sensing device. The magnetic gastrostomy tube has a ferromagnetic element attached to its distal end. Various embodiments allow a needle to be passed from the magnetic detection sensing device outside the patient toward a magnetic gastrostomy tube inside the patient or, alternatively, from the magnetic gastrostomy tube inside the patient toward the magnetic detection sensing device outside the patient. After a needle makes a hole between the outside of the patient and the body cavity, a medical wire may be passed through the hole, and the medical wire can then be used to place the percutaneous gastrostomy device.

Abstract: A catheter insertion device with a housing and an interior space. An access needle and a guide wire supported by and moveable relative to the access needle. A restraining element attached to a handle to limit the motion of the guide wire relative to the access needle. A catheter insertion device with a housing and an interior space. An access needle and a guide wire channel attached to the access needle. A guide wire supported by the guide wire channel. A handle attached to the guide wire to move the guide wire relative to the guide wire support channel. A method of introducing a catheter into a vessel by inserting a guide wire substantially contained within a housing into a vessel. Next, advance a catheter over the guide wire and into the vessel. Next, withdraw the guide wire out of the vessel and completely into the housing.

Abstract: The present invention provides for an apparatus to locate a blood vessel puncture having a bleed back entrance port near a first end, a bleed back exit port near a second end; and a lumen extending between the bleed back entrance port and the bleed back exit port, wherein said bleed back entrance port has a diameter substantially equal to or greater than the lumen diameter. The present invention further provides for a method for locating a blood vessel puncture by inserting a locator into a blood vessel lumen, the locator having a bleed back entrance port at a first end, a bleed back exit port at a second end, and a finger adjacent the bleed back entrance port, observing a blood flow out of the bleed back exit port, and withdrawing the locator out of the blood vessel lumen until the finger contacts the blood vessel wall.

Abstract: A bipolar instrument and a method for endoscopically controlled shortening and/or fragmentation of a stent located in the gastrointestinal tract, in the tracheobronchial system or in other hollow organs. The instrument includes a first electrode and a second electrode arranged at a distal end of the instrument and connected to and receiving current provided by a power source, and protective means connected to the electrode means. At least one wire of the stent can be severed at a particular location by the instrument. The protective means separates the wire from tissue of the gastrointestinal tract, tracheobronchial system or other hollow organs and/or secures the wire to the instrument during the severing of the wire. The instrument and the method minimize damage to tissue and risk to the patient during machining of stents.

Abstract: Large diameter self-expanding endoprosthetic devices, such as stents and stent grafts for delivery to large diameter vessels, such as the aorta, are disclosed having very small compacted delivery dimensions. Devices with deployed dimensions of 26 to 40 mm or more are disclosed that are compacted to extremely small dimensions of 5 mm or less, enabling percutaneous delivery of said devices without the need for surgical intervention. Compaction efficiencies are achieved by combining unique material combinations with new forms of restraining devices, compaction techniques, and delivery techniques. These inventive devices permit consistent percutaneous delivery of large vessel treatment devices. Additionally, small endoprosthetic devices are disclosed that can be compacted to extremely small dimensions for delivery through catheter tubes of less than 1 mm diameter.

Abstract: The present invention relates to the endoluminal repair of abdominal aortic aneurysms at the aortic and iliac bifurcation. In particular, a deployment system and graft are disclosed for deploying the bifurcated graft within both iliac branches, as well as the aortic trunk, from a single vascular access.

Abstract: A device for provides access to a surgical location within a patient. The device has an elongate body that has a proximal portion, a distal portion, a first slot segment, and a second slot segment that is angled relative to said first slot segment. The elongate body defines a passage for accessing the surgical location with surgical instruments. The elongate body has a contracted configuration for insertion into the patient and an expanded configuration for providing access to the surgical location. The cross-sectional area of the passage at a first location of the elongate body is greater than the cross-sectional area of said passage at a second location of the elongate body. A movable tab is configured to extend into the second slot segment when the elongate body is in the expanded configuration to retain the elongate body in the expanded configuration.