Abstract: The present disclosure relates to surgical seal, or valve, of the type adapted to releasably receive a surgical object. The seal disclosed herein defines an aperture that is configured to maintain a substantially fluid-tight seal with the surgical object upon its insertion, and includes at least one cable member connected to the seal that facilitates maintenance of the substantially fluid-tight seal during subsequent lateral manipulation of the surgical object.

Abstract: A cannula and surgical methods include a tubular body, for housing an endoscope having a lighted, viewing end disposed near the distal end of the body that is selectively covered by a blunt, transparent, tissue-separating tip. Endoscopic viewing through the tip is enhanced by inner walls that taper to a cusp adjacent the blunt tip in order to reduce visual distortion. Alternatively, a removable or deflectable tip exposes a probe and endoscope to facilitate viewing and dissection of connective tissue and lateral vessels along the course of a blood vessel for subsequent harvesting or other treatment of the isolated blood vessel. The dissection probe includes a partial ring for passing along the vessel and past lateral branching vessels under visualization through the endoscope and the transparent tip. Surgical procedures including making an initial incision, above an artery or other vessel to establish an initial portion of an elongated working cavity of bluntly-dissected tissue.

Abstract: According to one aspect of the present invention, there is disclosed a treatment sheath for endoscopic blood vessel harvesting, comprising a sheath main unit which can be inserted into a body through a cut skin portion in order to harvest a blood vessel in the body, a channel which is formed along a longitudinal direction in the sheath main unit and through which an endoscope is inserted so as to be insertable/detachable, a blood vessel holding member which is disposed at the sheath main unit and which holds the blood vessel to be harvested; and a blood vessel cutting device which is disposed at the sheath main unit and is positioned substantially symmetrically with the blood vessel holding member with respect to the channel and which cuts the blood vessel to be harvested.

Abstract: A surgical probe includes an articulated digit located at a distal end of a positioning shaft having a longitudinal axis. An actuator is located at a proximal end of the positioning shaft that is operatively connected to the articulated digit so as to move it between a continuous range of positions from an extended position to a substantially curved position while maintaining a kinesthetic relationship between a surgeon's finger engaging the actuator and the articulated digit. Preferably, the surgeons finger position and shape directly correspond to the position and shape of the articulated digit. A method is provided for probing, dissecting, and retracting anatomical structures.

Abstract: There are disclosed various embodiments of a combined balloon dissector with balloon tip cannula which are provided to facilitate forming an anatomical space within the body, such as, for example, an anatomical space in the abdominal cavity or extraperitoneal space for facilitating hernia repair surgeries. The combined balloon dissectors with cannula generally include a cannula assembly for anchoring the device to the abdominal wall and a dissector assembly having a dissection balloon at a distal end for separating tissue layers and forming an anatomical space. Various combinations of valve ports and sub-assemblies are disclosed for providing inflation fluid to the balloon tip cannula, and inflation fluid for the dissection balloon.

Abstract: A surgical probe includes an articulated digit located at a distal end of a positioning shaft having a longitudinal axis. An actuator is located at a proximal end of the positioning shaft that is operatively connected to the articulated digit so as to move it between a continuous range of positions from an extended position to a substantially curved position while maintaining a kinesthetic relationship between a surgeon's finger engaging the actuator and the articulated digit. Preferably, the surgeons finger position and shape directly correspond to the position and shape of the articulated digit. A method is provided for probing, dissecting, and retracting anatomical structures.

Abstract: The invention is directed to a bladeless trocar obturator to separate or divaricate body tissue during insertion through a body wall. In one aspect, the obturator of the invention comprises a 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 and having a generally tapered configuration with an outer surface, the outer surface extending distally to a blunt point with a pair of side sections having a common shape and being separated by at least one intermediate section, wherein each of the side sections extends from the blunt point radially outwardly with progressive positions proximally along the axis, and the shaft is sized and configured to receive an optical instrument having a distal end to receive an image of the body tissue. With this aspect, the tapered configuration facilitates separation of different layers of the body tissue and provides proper alignment of the tip between the layers.

Abstract: Surgical apparatus and method includes a cannula that houses an endoscope and supports a dilating element near a distal end of the cannula. The dilating element has a dimension which is greater than the diameter of the cannula for enlarging a surgical cavity in tissue as the cannula is advanced through tissue at a surgical site to provide working space adjacent a target vessel within which surgical instruments may be conveniently manipulated. The dilating element of oval sided shape permits surrounding tissue to be pushed away or otherwise displaced away from the target vessel atraumatically. A locking mechanism is disposed on the cannula, which accepts a succession of mating dilating elements of progressively larger dimensions for successive insertion and enlargement of a surgical cavity as required.

Abstract: A method of dissecting urethra obstructing tissue. The method includes capturing urethra obstructing tissue between portions of an implant and applying pressure on the tissue caught between the portions of the implant, for longer than 1 hour, until the tissue dies or falls off.

Abstract: A method and apparatus for dissecting a first layer of tissue from a second layer of tissue and thereafter holding open an anatomic space for the performance of a surgical procedure. The method includes steps of making an incision in a body, introducing a deflated balloon dissector into the incision, inflating the balloon dissector to effect dissection of the first layer of tissue from the second layer of tissue, deploying a retractor within the anatomic space in order to hold open the anatomic space, and optionally deflating or evacuating the balloon dissector to open a cavity for surgical manipulations. The apparatus includes a combined dissector-retractor having a balloon retractor disposed upon the surface of the balloon dissector and integrated therewith.

Abstract: A cannula (10) receives surgical instruments (120) for performing a surgical procedure on a body (130). The cannula (10) comprises a tube structure (12) defining a passage (16) through which the surgical instruments (120) are inserted into the body (130). The tube structure (12) has a proximal end (20) and a distal end (62). The tube structure (12) includes an expandable portion (40) for enabling an increase in the cross-sectional area of the passage (16) at the distal end (62). The expandable portion (40) of the tube structure (12), when expanded, has a conical configuration.

Abstract: A cannula (10) receives surgical instruments (120) for performing a surgical procedure on a body (130). The cannula (10) comprises a tube structure (12) defining a passage (16) through which the surgical instruments (120) are inserted into the body (130). The tube structure (12) has a proximal end (20) and a distal end (62). The tube structure (12) includes an expandable portion (40) for enabling an increase in the cross-sectional area of the passage (16) at the distal end (62). The expandable portion (40) of the tube structure (12), when expanded, has a conical configuration.

Abstract: A medical device tool for use in combination with an implantable medical device that is capable of being subcutaneously implanted in a patient. The tool has a unitary body having an upper portion and a lower portion and a proximal end and a distal end which has a working section having a leading peripheral edge, an intermediate section having a rounded outer edge, and a handle portion that is positioned at the proximal end of the tool and is capable of being maneuvered. The tool is configured for selective receipt of an implantable medical device.

Abstract: A method and apparatus for dissecting a first layer of tissue from a second layer of tissue and thereafter holding open an anatomic space for the performance of a surgical procedure. The method includes steps of making an incision in a body, introducing a deflated balloon dissector into the incision, inflating the balloon dissector to effect dissection of the first layer of tissue from the second layer of tissue, deploying a retractor within the anatomic space in order to hold open the anatomic space, and optionally deflating or evacuating the balloon dissector to open a cavity for surgical manipulations. The apparatus includes a combined dissector-retractor having a balloon retractor disposed upon the surface of the balloon dissector and integrated therewith.

Abstract: A system for the dissection of soft tissue is provided, the system comprising: a dissection tip, the tip having a rigid, non-absorptive, end shell; the rigid end shell having a textured exterior surface configured to purchase soft tissue and having at least one porosity; and the dissection tip being configured to be coupled to a suction source.

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: It is an object to provide an endoscopic heart surgery method with which it is possible to observe an endoscopic image with a stable field of view in the pericardial space. Provided is an endoscopic heart surgery method including an inserting step of inserting an inserted portion of an endoscope into a body from the subxiphoid area and inserting the inserted portion into the pericardial space by penetrating the pericardium in the vicinity of the heart apex; a moving step of advancing the inserted portion toward the base of the heart so that the inserted portion passes through the roof of the pericardial space and is moved toward the heart apex to a treated area in the pericardial space; and an observing step of observing the treated area with the endoscope.

Abstract: A minimally invasive surgical method includes inserting a first port that defines a first pathway to a first vertebra, advancing a first anchor through the first port to the first vertebra, inserting a second port that defines a second pathway to a second vertebra, advancing a second anchor through the second port to the second vertebra, positioning a first end of a fixation element in the first port, and advancing the first end of the fixation element subcutaneously through an opening in the first port and an opening in second port to the second anchor. A surgical access port includes a proximal end, a distal end, and a sidewall defining a lumen extending from the proximal end to the distal end. The port may include a first opening formed in the sidewall that defines a passageway for medical hardware from the lumen to external to the port.

Abstract: Systems and methods for separating pericardial tissue from the epicardium of the heart are disclosed. The apparatus includes a catheter comprising an elongated body, including a proximal end and a distal end and a lumen extending therebetween. The apparatus further comprises a needle carried at the distal end of the catheter. The needle includes a proximal end, a distal end, and a lumen extending between the proximal and distal ends, and is in fluid communication with the catheter lumen. The needle is of a length sufficient to penetrate myocardial tissue of the heart, from the endocardium to and through the epicardium. A coupling on the catheter is provided for communication with a fluid source, to facilitate flow of fluid through the catheter lumen and needle lumen. Fluid can thereby flow through the catheter and needle lumens to a location between the epicardium and pericardial tissue.

Abstract: Apparatus for creating an anatomic space in tissue in a body including an introducer device having a tubular member with a bore extending therethrough. A tunneling shaft assembly is slidably mounted in the bore of the introducer device. The tunneling shaft assembly includes a tunneling shaft having proximal and distal extremities. A blunt tip is secured to the distal extremity of the tunneling shaft. A balloon assembly is provided. The balloon assembly is removably secured to the tunneling shaft. The balloon assembly includes a deflated collapsed balloon. A sheath encloses the balloon and is carried by the tunneling shaft. The sheath has a weakened region extending longitudinally thereof permitting the sheath to be removed to release the balloon.

Abstract: A surgical instrument adapted and configured for use in minimally invasive surgical procedures includes a shaft, an end effector and a proximal handle. The longitudinal shaft has proximal and distal end portions, and defines a longitudinal axis of the surgical instrument. The distal end effector is connected to the distal end portion of the shaft, and is adapted and configured for performing a surgical task. The proximal handle portion is operably connected to the proximal end portion of the longitudinal shaft and has an actuatable portion operably connected to the end effector to result in movement of the end effector. The distal end portion of the shaft can be laterally offset from the longitudinal axis of the shaft and/or have one or more bends or curves formed therein. The proximal portion of the shaft can include at least one bend to allow for comfortable positioning of a surgeon's hands.

Abstract: Various embodiments are directed to a curved-jaw dissector device for use in endoscopic surgical procedures. The device may comprise an end effector, a flexible shaft extending proximally from the end effector; a handle coupled to the proximal portion of the flexible shaft; and a translating member extending from the handle, through the flexible shaft, to the end effector, wherein the translating member is coupled to the handle at an actuator having a first and a second position such that placing the actuator in the first position causes the end effector to be in the closed position and placing the actuator in the second position causes the end effector to be in the open position.

Abstract: Instruments, systems and methods are provided for performing submucosal medical procedures in a desired area of the digestive tract using endoscopy. Instruments include safe access needle injection instruments incorporating electrosurgical capability, a submucosal tunneling instrument, a submucosal dissection instrument, a mucosal resection device. Systems include a combination of one or more of such instruments with or without injectable agents. Embodiments of various methods for performing the procedures are also provided.

Abstract: Minimally invasive methods and devices for introducing a spinal fixation element into a surgical site in a patient's spinal column are provided. In one embodiment, a dissection tool is provided for separating muscles along a muscle plane without causing damage to the muscles. The dissection tool can also include a lumen extending therethrough for receiving a guide wire. The tool allows the guide wire to be positioned relative to a vertebra, and once properly positioned, the tool can be removed to allow a spinal anchor to be delivered along the guide wire and implanted into the vertebra.

Abstract: Balloon loaded dissection devices and methods for using such devices are disclosed. The devices include an elongate balloon and may be provided with a central lumen. The device may have a guide tube to provide columnar support. In a further aspect, the guide tube may have a spoon-shaped shroud attached to a distal end. The guide tube receives the guide rod, scope or other surgical instrument and may have a stop member. By using the guide rod or scope as a pushing member, the device may be advanced alongside the vessel it is desired to dissect free from attached tissue. A balloon cover may be provided to surround the balloon and facilitate compression of the balloon after it is deflated. In an additional feature, the guide rod and/or tubular member are plastically bendable into a curved shape such that the balloon dissector may be adjusted.

Abstract: An apparatus for tissue dissection and instrument anchoring and methods for using such apparatus are disclosed. The apparatus includes a cannula, a dissection balloon releasably attached to the cannula at the distal end, an anchoring balloon disposed on the cannula, and a means for inflating both balloons.

Abstract: A system includes a first electrode at a tip of a tunneling tool and a second electrode. The system includes a circuit configured to determine whether the tip of the tunneling tool is within subcutaneous fat tissue or muscle tissue of a patient based on a measurement of an impedance between the first electrode and the second electrode.

Abstract: Minimally invasive methods and devices for introducing a spinal fixation element into a surgical site in a patient's spinal column are provided. In one embodiment, a dissection tool is provided for separating muscles along a muscle plane without causing damage to the muscles. The dissection tool can also include a lumen extending therethrough for receiving a guide wire. The tool allows the guide wire to be positioned relative to a vertebra, and once properly positioned, the tool can be removed to allow a spinal anchor to be delivered along the guide wire and implanted into the vertebra.

Abstract: The disclosure pertains to a surgical implement that has a gripping end and a surgical end. The surgical end includes a first side, a second side opposite the first side and a pointed distal end wherein the first side and the distal end are blunt and the second side has a surgically sham cutting edge. This surgical implement can be utilized during surgical procedures to maintain an incision in an open position or enlarge or modify an incision to accommodate an endoscope and other surgical implements. The use of this surgical implement to cut, expand and maintain an open incision saves time and minimizes trauma to the tissue.

Abstract: Apparatus for creating an anatomic space in tissue in a body including an introducer device having a tubular member with a bore extending therethrough. A tunneling shaft assembly is slidably mounted in the bore of the introducer device. The tunneling shaft assembly includes a tunneling shaft having proximal and distal extremities. A blunt tip is secured to the distal extremity of the tunneling shaft. A balloon assembly is provided. The balloon assembly is removably secured to the tunneling shaft. The balloon assembly includes a deflated collapsed balloon. A sheath encloses the balloon and is carried by the tunneling shaft. The sheath has a weakened region extending longitudinally thereof permitting the sheath to be removed to release the balloon.

Abstract: Methods and devices for harvesting veins from the body. The methods and devices allow vein harvesting using laparoscopic procedures. A working space is created over the vein using standard laparoscopic procedures and a side-hooked wire is inserted into the working space and twisted to insert the side-hook under the vein. The wire is then pulled or drawn along the vein to separate the vein from the surrounding tissue. In an alternative embodiment, vein separation is accomplished by threading a soft rubber tube under the vein, grasping the ends of the tube so as to surround the vein, and then pulling the tube along the vein. In other embodiments, the working space is created with everting balloons.

Abstract: Devices, systems, methods and kits are provided for endoscopically accessing a body cavity and providing a directed pathway toward a target tissue within the cavity. The directed pathway is provided by a multi-catheter guiding system which is positioned in a desired configuration, generally directed toward the target tissue. Interventional devices may then be passed through the guiding system to the target tissue. Depending on the location of the target tissue and the desired angle of approach, the guiding system may be required to maintain one or more curves in one or more planes to properly direct the interventional devices. The multi-catheter guiding system of the present invention comprises an outer guiding catheter and a coaxially positioned inner guiding catheter, each of which independently form curvatures so that together the curves properly direct the interventional device.

Abstract: The present application relates to a tubular shaft instrument for separating tissue. The invention relates to a tubular shaft instrument that results in more reliable, cleaner separation of tissue. To achieve this, in contrast to conventional cutting devices, the blade is not displaced through the fixed tissue, but glides over the latter until a complete separation is ascertained.

Abstract: The present invention provides balloon dissection apparatus and methods of use in which an elongate balloon is utilized to dissect along a region that follows a naturally existing path alongside a vessel or structure, such as an artery, a vein, a lymphatic vessel, the trachea, the esophagus, or even a nerve bundle.

Abstract: Methods and devices described herein facilitate improved access of locations within the body by providing a variety of dissection modes on a single access device.

Abstract: A blunt dissector for separating a blood vessel from surrounding tissues in a body comprises a longitudinal rod having a proximal end, a distal end, and an internal passage for conducting insufflation gas between the proximal and distal ends. An interior sleeve is mounted within the longitudinal rod for receiving an endoscope at the proximal end. A transparent tip is mounted to the distal end of the longitudinal rod. A handle is mounted to the proximal end of the longitudinal rod. The longitudinal rod has an outer surface along substantially all of the longitudinal rod between the proximal and distal ends consisting essentially of a fluoropolymer.

Abstract: An improved tip and handle for a tunnelling instrument are provided along with an improved tunnelling instrument. The tip is configured for attachment to a tunnelling instrument and includes a first portion configured to form a tunnel, a second portion sized to fit within a tubular component to be placed in the tunnel, and a third portion configured for attachment of the tubular component. The handle is configured to be attached to and detached from a tunneller shaft of a tunnelling instrument, at any point along the length of the tunneller shaft. The tunnelling instrument comprises a pair of tips, a connection means for forming a link between the tips, and a tunneller shaft slidably engagable with the connection means and attachable to either of the tips. Various forms of use of the tunnelling instrument are also disclosed.

Abstract: A flexible cardiac catheter for sensing electrical activity within and administering therapy to a patients' heart has a series of flexible, conductive electrode bands positioned in grooves in the catheter's tubular body. The bands consist of alternating flexible and conductive elements, providing flexibility and overall versatility to the catheter. The electrode bands have controllable flexibility due to the elastic properties of the flexible elements and continuous uninterrupted electrical current conductance from the one-piece design of the conductive element. The synergy of the components of the composite flexible and conductive bands will help solve problems current electrode bands have and will allow for a freedom in the design of catheter electrode band configurations in the future.

Abstract: An Apparatus for the performance of a minimally invasive ventral hernia repair. The apparatus including a mechanical blunt dissector, fascial graspers, and a midline fascial stapling device. The mechanical blunt dissector is capable of performing a blunt dissection of the space between the External Oblique (EO) muscle and the Internal Oblique (IO) muscle. The device has a blunt spoonbill shaped set of plates with an open center (for improved endoscopic visualization during the dissection), connected to long arms which connect to a pair of hand grips. However, the blunt dissector may include a tapered blunt distal tip to the spoonbill element—more like a duck's bill—for advancing the mechanical dissector forward into the loose areolar connective tissue that exists between the EO and IO muscles. The apparatus further includes graspers formed of long endoscopic graspers that are modified to grasp and lock on to tissue as thick and tough as rectus fascia.

Abstract: Methods and devices for harvesting veins from the body. The methods and devices allow vein harvesting using laparoscopic procedures. A working space is created over the vein using standard laparoscopic procedures and a side-hooked wire is inserted into the working space and twisted to insert the side-hook under the vein. The wire is then pulled or drawn along the vein to separate the vein from the surrounding tissue. In an alternative embodiment, vein separation is accomplished by threading a soft rubber tube under the vein, grasping the ends of the tube so as to surround the vein, and then pulling the tube along the vein. In other embodiments, the working space is created with everting balloons.

Abstract: Methods and devices for treating female stress urinary incontinence are disclosed. The methods include transvaginally accessing the pelvic cavity and introducing a suburethral sling into the retropubic space. In some embodiments the ends of the sling are attached to an anatomical support structure. In other embodiments, the ends of the suburethral sling are not attached to an anatomical support structure. The devices include a surgical instrument for blunt dissection of the pelvic cavity which includes a curved shaft and a blunt distal end. A hook deployment device may optionally be attached to the surgical instrument.

Abstract: A method for surgical dissection, sizing and for expansion of a tissue pocket in a naturally occurring fascial cleft is disclosed for use in plastic surgery applications and other applications where it is desirable to dissect an anatomically defined and bounded tissue pocket, determine the appropriate size of a prosthesis to be implanted into the tissue pocket and, if necessary, further expand the tissue overlying the tissue pocket. An inflatable device which performs the three distinct functions of dissection, sizing and tissue expansion is used. In a preferred method, a dissecting balloon device is tunneled bluntly to a desired location within a fascial cleft in the female breast. The device is then inflated to dissect tissue layers adjacent the fascial cleft until ligaments defining boundaries of the fascial cleft are reached, to create a tissue pocket extending to the ligmentous boundaries.

Abstract: A tissue-separating catheter assembly comprises a rotatable shaft, having a distal shaft portion, and a tissue separator device extending along the shaft. The tissue separator device has a distal separator part at the distal shaft portion movable between a retracted state, towards the distal shaft portion, and an outwardly extending, operational state, away from the distal shaft portion. A pivot joint may be used to pivotally connect the distal separator end to the distal shaft portion. The distal shaft portion may comprise a distally-facing transition surface at a proximal end of the distal shaft portion. First and second energizable tissue separator elements may be used at the transition surface and the tip of the device, respectively.

Abstract: An apparatus for tissue dissection and instrument anchoring and methods for using such apparatus are disclosed. The apparatus includes a cannula, a dissection balloon releasably attached to the cannula at the distal end, an anchoring balloon disposed on the cannula, and a means for inflating both balloons.

Abstract: A surgical tool lifts an overlying layer of skin away from underlying bone to prepare the bone to accommodate a convex element of an implantable device. The tool includes a lifting shell for insertion between the skin and the bone so as to lift the skin away from bone. A tool base supports the lifting shell and is supported by the bone. A drill template opening in the tool base provides access for preparing the bone to accommodate the convex element.

Abstract: An endoscopic apparatus for dissecting a blood vessel includes a endoscopic barrel having a plurality of lumens, one of the lumens being dimensioned for receiving an endoscope, a handle disposed at a proximal end of the endoscopic barrel, at least two fingers having distally curved ends for dissecting and cauterizing the desired blood vessel, and a displaceable cone portion disposed over a distal end of the endoscopic barrel. The cone portion has a first position concealing the at least two fingers and a second, extended position exposing the at least two fingers. A control rod extends between the handle and each of the fingers such that movement of the control mechanism between a first position and a second position produces a predetermined movement of the respective finger.

Abstract: A system for minimally invasive medical procedures includes an elongate tubular access cannula comprising an elongate tubular member having a rigid proximal portion and an articulating portion. The tubular member has a first branch and a tubular bifurcation extending from the first branch, allowing simultaneous use of multiple instruments. A dissector suitable for use with the access cannula, or other access devices, for implantation of gastric bands or for other procedures includes a pre-curved distal portion having a dissection element such as a monopolar RF conductor and/or a dissection balloon, as well as a snare. In one method, the dissector is advanced around the posterior side of the stomach to form a tunnel in the connective tissue, and the snare is then extended from the dissector to engage a portion of the band and withdraw it through the tunnel.

Abstract: A method for the selective elevation and separation of tissues comprised of multiple layers and a surgical instrument for performing the method. The method may be performed without the requirement of a solid mechanical device insertion or transection through the mucosal layer. In particular, the method and surgical instrument may be used for the selected separation and/or resection of selected portions of benign or malignant tissues (e.g. defining tissue planes, polyp elevation and removal, submucosal tissue tunneling, endoscopic mucosa resection, etc).

Abstract: Described here are methods for forming one or more tracts in tissue. The tracts may be formed in any suitable or desirable tissue, and may seal relatively quickly without the need for a supplemental closure device. In some variations, the methods comprise advancing a tissue-locating member adjacent to a tissue wall, deforming at least a portion of the tissue wall with the tissue-locating member, and advancing a tissue-piercing member through the deformed tissue to form the tract, where the tract provides access for one or more tools. Also described here are methods of forming tracts through rotated or tented tissue. Any of the methods described here may also be used with tissue having at least one irregular surface.

Abstract: An obturator assembly for penetrating tissue and being at least partially positionable within a cannula assembly includes an obturator housing, an obturator shaft connected to the obturator housing and defining a longitudinal axis, a bladeless penetrating member adjacent the distal end of the obturator shaft and an obturator shield mounted about the obturator shaft and having a distal shield nose. The obturator shield is adapted for longitudinal movement between an extended position where the bladeless penetration member is substantially enclosed within the shield nose and a retracted position where the bladeless penetrating member is at least partially exposed from the shield nose.