An introducer used to provide a route through which a catheter or other medical device is inserted so as to gain access to a subcutaneous vessel of a patient is disclosed. The introducer is configured so as to minimize the amount of force needed to enter and dilate a vessel, thus reducing trauma to the vessel and the patient. In one embodiment, an introducer is disclosed, comprising a sheath and a dilator. The sheath includes a tubular portion that defines a lumen. The dilator includes an elongate body and a tapered distal tip and is configured to be removably disposed within the lumen of the tubular portion of the sheath. The dilator elongate body defines a cylindrical recess proximally extending from the tapered distal tip. The cylindrical recess configured to receive therein the tubular portion of the sheath when the dilator is disposed within the tubular portion of the sheath.

A sheath for inserting a cannula of an endoscope into a cavity of a patient is described herein. The sheath comprises an introducer, a support channel and a pull-tab. The introducer has an open end being sized and shaped to accept a tip of the cannula and a tip end adapted to be deflected in an outward direction by the tip of the cannula passing into the introducer. The support channel is adapted to receive a shaft of the cannula and guide the tip of the cannula into the introducer; and the pull provides a finger hold for a user to grasp the sheath. In some aspects, the introducer includes a plurality of extending segments having a normally closed position defining a conical exterior shape of the introducer, with the plurality of tapered segments adapted to be separated by the tip of the cannula passing through the introducer.

A catheter system for atraumatic placement along a guidewire includes: a catheter including a cylindrical catheter body that defines a longitudinally extending interior lumen; and a guide device. The guide device includes: a conduit member for insertion into the interior lumen of the catheter body; a leading structure connected to a forward end of the conduit member, the leading structure including a cone and a sleeve extending forward from the cone; and an inner guide hole extending longitudinally through the leading structure and conduit member. In use, the guide device and catheter body are coaxially arranged, the cone is forward of the catheter, and the sleeve extends forward from the cone. The cone includes a shoulder, and a tapered exterior that increases diametrically from the sleeve to the shoulder. The shoulder abuts a distal end of the catheter to register insertion of the guide device in the catheter.

A medical insertion device includes an introducer assembly, a needle, and a housing. The introducer assembly includes a dilator coaxially disposed in a sheath, the dilator removably engaged to the sheath in an insertion configuration. The needle is coaxially disposed in the dilator, the needle having a distal tip and a proximal end coupled to a needle hub. The housing may be removably engaged to the dilator. The needle hub is movably disposed in the housing between a first locked position, a second locked position, and a third locked position.

An example dilator is disclosed. The example dilator includes a hub and an elongate shaft having a distal end region, a proximal end region and a cross-sectional profile. Additionally, the proximal end region of the elongate shaft is coupled to the hub and the elongate shaft is configured to extend through at least a portion of a lumen of an expandable introducer sheath. Additionally, the cross-sectional profile of the elongate shaft includes at least one engagement portion and at least a portion of the expandable introducer sheath extends into the at least one engagement portion of the dilator.

A valve bypass tool, and a biostimulator transport system having such a valve bypass tool, is described. The valve bypass tool includes an annular seal to seal against a protective sheath of the biostimulator transport system. The valve bypass tool is slidably mounted on the protective sheath and includes a bypass sheath to insert into an access introducer. The valve bypass tool can lock onto the access introducer by mating a locking tab of the valve bypass tool with a locking groove of the access introducer. The locking tab can have a decent that securely fastens the components to resist decoupling when the biostimulator transport system is advanced through the access introducer into a patient anatomy. Other embodiments are also described and claimed.

A vascular access sheath includes an inner support structure extends from a hemostasis valve toward a distal end section of the access sheath. An outer polymer is disposed over the inner support structure, where the outer polymer has an exterior surface extending from the hemostasis valve to a distal tip of the access sheath. The outer polymer has a consistent thickness along the access sheath and defines a greater durometer an intermediate section of the access sheath than at the proximal and distal end sections of the access sheath. The outer polymer also has a secondary lumen disposed between the exterior surface and the central lumen, where the secondary lumen extends at least partially along the length of the access sheath and is configured to receive a wire to reinforce the stiffness of the intermediate section of the access sheath.

Disclosed herein is a catheter, which in some embodiments includes a distal section configured to enter a skin insertion site. The distal section can include a tapered junction having one or more dilation structures configured to dilate the skin insertion site. The distal section can further include a distal portion extending from a distal end of the tapered junction, the distal portion having a diameter smaller than a proximal portion of the catheter. In combination, the tapered junction, the one or more dilation structures, and the specific actions of the user urging the catheter into the insertion site can result in an improved fit of the catheter in the insertion site.

A puncture needle can comprise an elongate portion, a puncture component associated with a distal end of the elongate portion, and a spacer associated with a distal portion of the elongate portion, where the spacer can be configured to contact a wall of the delivery catheter lumen to prevent contact between the puncture component and the wall. A puncture needle can comprise an elongate portion and a puncture component associated with a distal end of the elongate portion, where the puncture component comprises a blade edge on a distal edge, and where the puncture component is configured to be advanceable through a lumen of a delivery catheter without the blade edge sticking to a wall of the lumen.

The device includes a dilator having a locking mechanism configured to limit a distance a guidewire can be advanced out of a distal end of the dilator.