Radial telescoping guide apparatus for delivery of a flexible instrument and methods of use

An apparatus for guiding an elongated flexible instrument, the apparatus comprising:

• a telescoping support assembly including a proximal end, a distal end, and a plurality of support members extending along a longitudinal axis between the proximal end and the distal end, each of the plurality of support members comprising a ring having an inner surface, an outer surface, and at least one flange, the at least one flange of each of the plurality of support members extending from the inner surface of the ring to define a central passageway extending along the longitudinal axis and having a substantially constant width transverse to the longitudinal axis;
• wherein the central passageway is configured to receive the elongated flexible instrument;
• and
• wherein the telescoping support assembly is configured to selectively transition from a compressed configuration to an expanded configuration along the longitudinal axis while each support member of the plurality of support members is interlocked with at least one other support member of the plurality of support members, and is adapted to support the elongated flexible instrument as the elongated flexible instrument is advanced along the longitudinal axis.