Embodiments relate to delivery systems for accessing a blood vessel. The delivery systems include a shaped accessory sheath having a default shape that may be temporarily altered to facilitate insertion through a patient's blood vessel and returned to the default shape after insertion to facilitate a medical procedure. Some of the present accessory sheaths are configured to have their default shapes altered via a dilator having a stiffness greater than that of a corresponding portion of the accessory sheath. Others of the present accessory sheaths are configured to have their respective default shapes altered by a shape memory material (SMM) that alters shape responsive to changes in certain condition(s) such as temperature.

Apparatus and methods for an endovascular catheter that can be inserted within tortuous body anatomies and then selectively stiffened and fixed in place. In a particular embodiment, this stiffness is reversible. The stiffness or a comparable mechanical characteristic of the catheter assembly may be adjusted to a relatively low value during insertion (so that it easily navigates a guide wire or the like), and then subsequently adjusted to a relatively high value in situ to keep the catheter assembly substantially fixed in place (i.e., during delivery of an interventional device).

The invention provides a medical device including a resin tube having excellent branch selectivity while excellent pushability in a curved body cavity or an extremely narrow body cavity such as a blood vessel terminal region is maintained. Provided is a medical device having a medical device body to be inserted into a body cavity. The medical device body has an elongated resin tube, the resin tube includes a first region including a distal end part and a second region including a proximal end part, and the first region is more flexible than the second region.

Apparatus and methods for an endovascular catheter that can be inserted within tortuous body anatomies and then selectively stiffened and fixed in place. In a particular embodiment, this stiffness is reversible. The stiffness or a comparable mechanical characteristic of the catheter assembly may be adjusted to a relatively low value during insertion (so that it easily navigates a guide wire or the like), and then subsequently adjusted to a relatively high value in situ to keep the catheter assembly substantially fixed in place (i.e., during delivery of an interventional device).

An elongated device, e.g. an interventional guide wire or catheter, comprises an optical fiber (OF) arranged to allow transmission of light to phase change material (PCM) arranged long the elongated device, for optically heating the phase change material (PCM) to change its stiffness from one stiffness value to a different stiffness value. Using distributed tilted or blazed Bragg gratings with light wavelength dependent unique grating periods along the optical fiber, it is possible to provide a guide wire or catheter which can be stiffness controlled at selected longitudinal portions. Especially, it may be preferred to be able to control the behavior of the tip of a guide wire or catheter for optimal navigation, e.g. during a FEVAR procedure. Portions of phase change material (PCM-1, PCM 2) arranged inside a tube material T_M can be activated at selected longitudinal parts of the elongated device.

A rigidity variable apparatus includes: a rigidity variable member having a cylindrical shape, a bending rigidity of the rigidity variable member increasing by being heated; a heater having a cylindrical shape and arranged along the rigidity variable member on an inside of the rigidity variable member in a radial direction, the heater being configured to heat the rigidity variable member; a filler arranged so as to fill a gap between the heater and the rigidity variable member in the radial direction, the filler being configured to transfer heat from the heater to the rigidity variable member; and a tube arranged along the heater on an inside of the heater in the radial direction.