Expandable guide sheath and apparatus and methods for making them

Abstract

Apparatus and methods are provided for providing access to a body lumen. The apparatus includes a tubular member including a proximal end, a distal end sized for insertion into a body lumen, and a lumen extending between the proximal and distal ends. A pushable stiffening member extends from the distal end of the tubular member, the elongate member terminating in a distal tip. An expandable sheath extends along at least a portion of the stiffening member, the sheath being expandable from a contracted condition to minimize a profile of the sheath to allow insertion along with the stiffening member into a body lumen, and an enlarged condition wherein the sheath at least partially defines a lumen communicating with the tubular member lumen. In one embodiment, the sheath includes an outer lumen and an inner lumen floating within the outer lumen, and the stiffening member is carried in the inner lumen.

Description

[0001] This application claims benefit of provisional applications Ser. Nos. 60 / 508,489, 60 / 508,490, and 60 / 508,491, all filed Oct. 2, 2003, and 60 / 551,901, filed Mar. 9, 1004. The entire disclosures of these applications are expressly incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention relates generally to apparatus and methods for delivering instruments and / or agents during a medical procedure, and, more particularly, to guide sheaths for accessing body lumens and / or delivering instruments into body lumens of a patient, and to methods for making and using them. BACKGROUND [0003] Minimally invasive procedures have been implemented in a variety of medical settings, e.g., for vascular interventions, such as angioplasty, stenting, embolic protection, electrical heart stimulation, heart mapping and visualization, and the like. These procedures generally rely on accurately navigating and placing instruments within a patient's vasculature. [0004] During s...

AI Technical Summary

Benefits of technology

[0010] In accordance with another embodiment, a method is provided for accessing a body lumen using an apparatus including a tubular proximal portion and an expandable distal portion having a size smaller than the proximal portion. The distal portion is advanced into a patient's body, e.g., vasculature, with an expandable sheath thereon in a contracted condition. The proximal portion has sufficient length such that a distal end of the proximal portion may reach a first location within the patient's body, e.g., including relatively large body lumens, passages, or chambers, such as the vena cava, right atrium, and / or coronary sinus. With the proximal portion reaching the first location, the distal portion may extend into relatively smaller body lumens, such as the coronary veins, to a target location that is to be accessed. The expandable sheath may be expanded, thereby providing a substantially continuous lumen through the proximal and distal portions to the target location.

[0020] Once a distal end of the sheath attains a target location, the expandable sheath may be expanded to an enlarged condition such that the outer lumen extends through the body lumen to the target location. One or more instruments, e.g., a cardiac pacing lead, may be advanced through the outer lumen of the expandable sheath into the target location. Because the inner lumen, and consequently, the elongate member, are at least partially floating within the outer lumen, the stiffening member may move relative to the outer lumen as the expandable sheath extends through tortuous anatomy, thereby reducing the risk of the expandable sheath kinking or buckling. After the one or more instruments are delivered into the target location, the apparatus may be removed.

Problems solved by technology

There are many risks involved with advancing instruments over a guidewire.

For example, a catheter or other instrument may skive or otherwise damage a wall of a vessel, particularly as the instrument passes through narrow passages or tortuous anatomy involving sharp bends.

Such instruments also risk dislodging embolic material or even perforating the vessel wall.

However, the instrument(s), e.g., guide sheath, lead, etc., may have a relatively large cross-section and / or may have a relatively blunt distal tip, making it difficult to advance such instruments as deeply as desired into such small vessels.

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