A radially expandable trocar, port or cannula system is provided for use in minimally invasive surgeries. The cannula creates a port access with an initial small internal diameter. The passage of the cannula devices is defined by a plurality of elongate rigid members. A number of mechanisms are provided for expanding the passage of the cannula devices, by moving the plurality of elongate rigid members towards a larger radial location, thereby creating a larger internal diameter for the port. The elongate rigid members can be prevented from unintended movement when the system is at the un-expanded state, during expansion and when it is expanded to the desired larger diameter. Exemplary embodiments include methods of preventing gas loss from the tissue that would occur through the gaps created during expansion.

A method is disclosed. The method includes providing a plurality of blades, movably connecting the plurality of blades to an outer member via a plurality of arm members, disposing the plurality of blades in a human or animal body, and moving the plurality of blades from a first position outward to a second position when the plurality of blades are disposed in the human or animal body. The plurality of blades are disposed further from each other in the second position than the first position. Moving the plurality of blades outward from the first position to the second position includes moving the plurality of arm members. Moving the plurality of blades includes maintaining equidistance between the plurality of blades as the plurality of blades move from the first position to the second position.

A medical instrument includes a handle, a trocar in communication with the handle, and a cannula in communication with the trocar and the handle. The cannula is engaged (locked) with the handle when linearly displaced proximally towards the handle and, the cannula is disengaged (unlocked) from the handle when linearly displaced distally away from the handle. The cannula is linearly reciprocated, between the locked position and the unlocked position, along a linear travel path defined parallel to a longitudinal axis of the trocar such that the cannula is prohibited and permitted to articulate about the longitudinal axis of the trocar, and relative to the handle, respectively. Advantageously, the cannula is locked and unlocked from the trocar by without requiring an external force exerted generally transverse to trocar and/or cannula—thereby permitting a user to lock/unlock the cannula, relative to the trocar, with one hand.

Medical devices for accessing the central nervous system, as well as making and using medical devices, are disclosed. An example medical device may include an expandable access sheath having a proximal end region and a distal end region. The expandable access sheath may be designed to shift between a first configuration and an expanded configuration. The expandable access sheath may include a tubular body having one or more axial support members disposed along the tubular body. The medical device may include an expansion member designed to shift the expandable access sheath between the first configuration and the expanded configuration.

An example introducer is disclosed. An example introducer includes an inner liner including a lumen, a distal region and at least one folded portion extending along the distal region. The introducer also includes a reinforcing member having a length and including at least one spine extending along the length of the reinforcing member. The introducer also includes a sheath disposed along at least a portion of the introducer, wherein the sheath includes at least one perforation, wherein material adjacent to the at least one folded portion is removed from a distal portion of the introducer to form a tip region. The introducer also includes a tip member disposed along the tip region.

An access device for accessing an intervertebral disc having an outer shield comprising an access shield with a larger diameter (˜16-30 mm) that reaches from the skin down to the facet line, with an inner shield having a second smaller diameter (˜5-12 mm) extending past the access shield and reaches down to the disc level. This combines the benefits of the direct visual microsurgical/mini open approaches and the percutaneous, “ultra-MIS” techniques.

An access device for accessing an intervertebral disc having an outer shield comprising an access shield with a larger diameter (˜16-30 mm) that reaches from the skin down to the facet line, with an inner shield having a second smaller diameter (˜5-12 mm) extending past the access shield and reaches down to the disc level. This combines the benefits of the direct visual microsurgical/mini open approaches and the percutaneous, “ultra-MIS” techniques.

A depth limiter that is configured to couple with a cannula of a surgical access device. The depth limiter includes first and second user contact portions and first and second biasing features. The first biasing feature includes a first resilient portion and a first gripping surface. The second biasing feature includes a second resilient portion and a second gripping surface. The first and second resilient portions are configured to move the respective first and second gripping surfaces from a fixed configuration to a movable configuration when the respective first and second user contact portions are actuated. In the fixed configuration, the first and second gripping surfaces collectively restrict axial movement of the depth limiter by directly contacting the cannula. In the movable configuration, the first and second gripping surfaces extend parallel to a longitudinal axis and allow for axial movement of the depth limiter relative to the cannula.

A guide tube is used for guiding an instrument through a hole within tissue of a patient. The guide tube includes a cannula member defining a passage extending therethrough along an axis. The passage is operable to receive the instrument and guide the instrument through the hole within the tissue of the patient. The guide tube also includes an expansion member that is moveably coupled to the cannula member to selectively move radially between a retracted position and an expanded position relative to the axis of the cannula member. The expansion member is at least partially insertable into the hole when the expansion member is in the retracted position. The expansion member is operable to engage with a surface of the hole when the expansion member is in the expanded position.

A dilation introducer for orthopedic surgery is provided for minimally invasive access for insertion of an intervertebral implant. The dilation introducer may be used to provide an access position through Kambin's triangle from a posterolateral approach. A first dilator tube with a first longitudinal axis is provided. A second dilator tube may be introduced over the first, advanced along a second longitudinal axis parallel to but offset from the first. A third dilator tube may be introduced over the second, advanced along a third longitudinal axis parallel to but offset from both the first and the second. An access cannula may be introduced over the third dilator tube. With the first, second, and third dilator tubes removed, surgical instruments may pass through the access cannula to operate on an intervertebral disc and/or insert an intervertebral implant.