A catheter includes a rolling membrane defining an inner volume that can be pressurized. The rolling membrane is configured to roll out in a longitudinal direction (D) into a rolled-out state. An inner shaft is attached to the rolling membrane. The membrane can roll out in a longitudinal direction along a vessel of a patient.

Some embodiments relate to an apparatus comprising an elongate flexible tube sized to be received within a tract and having a proximal end and a distal end; a drive mechanism coupled to the proximal end of the tube; and a liquid column extending from the proximal end to the distal end; wherein the drive mechanism is configured to cause movement of the liquid column within the tube to impart forward momentum to the tube and thereby promote advancement of at least the distal end of the tube within the tract when at least the distal end is received within a part of the tract.

Retraction and aspiration devices, systems, and methods are disclosed herein. One aspect of the present technology, for example, is directed toward an apparatus for use with a catheter system configured to enable intravascular delivery of an interventional device to a treatment site in a blood vessel. The apparatus can include a housing configured to be releasably coupled to a proximal portion of the catheter system and an actuation mechanism coupled to the housing. The actuation mechanism can include a lever movably coupled to the housing, a locking portion configured to engage a portion of the catheter system, and a pressure source coupled to the housing and the actuation mechanism. Movement of the lever simultaneously activates the pressure source to generate pressure, and moves the locking portion to engage and retract at least a portion of the catheter system.

Some embodiments relate to an apparatus comprising an elongate flexible tube sized to be received within a tract and having a proximal end and a distal end; a drive mechanism coupled to the proximal end of the tube; and a liquid column extending from the proximal end to the distal end; wherein the drive mechanism is configured to cause movement of the liquid column within the tube to impart forward momentum to the tube and thereby promote advancement of at least the distal end of the tube within the tract when at least the distal end is received within a part of the tract.

A tubular structure having variable support includes a tubular member and a structural support member with a flexible tubular member over the structural support member, such that the flexible tubular member can engage and disengage or squeeze and release the structural support member. The structural support member can be a tubular mesh, stent, framework, skeleton, braid or other flexible framework. A fluid passage can be used to inflate and deflate the flexible tubular member. Methods of assembly and methods of use are also described.

Techniques described herein relate to a catheter platform for carrying a medical device into inside a body. The catheter platform may include a catheter, which during use, is inserted into a body lumen. The catheter platform may include at least two extensile protrusions extending from opposite walls of the catheter and configured to expand outwardly in opposite directions to be in touch with the walls of the body lumen to aim the medical device and provide stability of the catheter. In an embodiment in which the body lumen is blood vessel, the catheter platform is configured to preserve the cross-section of the lumen such that the effect on the blood flow is minimized. A variety of applications may be enabled by the catheter platform, including therapy, measurement, or other procedures that may require the medical device to be left inside the body for an extended time period.

A catheter assembly may include a catheter adapter having a proximal end, a distal end, and a lumen extending therebetween. A wedge adapter may be retained within the lumen and have a wedge coupled thereto. The wedge may be configured to retain an end of a catheter such that a tip of the catheter extends through the distal end of the catheter adapter. A control feature may extend through an end or side wall of the catheter adapter. The control feature may be configured to manipulate the wedge to control a position of the tip of the catheter to open a fluid path within a vasculature.

Apparatuses and associated methods relate to a coaxial stream delivery device having an inlet section and an outlet section in fluid communication via a plenum chamber. In an illustrative example, an inner radius of the plenum chamber may monotonically decrease distally along a longitudinal axis. The inlet section may include an inner tubular wall extending along the longitudinal axis. At least one bridge may extend radially inward from the inner tubular wall to coaxially align an inner conduit within the inner tubular wall relative to the longitudinal axis. The at least one bridge may define a annular sector apertures bounded by the inner tubular wall and an outer wall of the inner conduit. Various embodiments may advantageously be disposed in a fluid path to coaxially align a therapeutic fluid stream entering the inner conduit within a sheath fluid stream entering the annular sector apertures.