A method of using a catheter system which includes inserting a first distal end portion of an outer catheter into a first body lumen, coupling a first key joint component on an inner catheter with a second key joint component on a proximal end portion of the outer catheter to fix a rotational orientation of the inner catheter relative to a rotational orientation of the outer catheter about a longitudinal axis of the first body lumen, wherein the second key joint component runs along a partial length of the outer catheter, and wherein a distal end portion of the inner catheter includes a pre-formed bend that extends at a non-zero angle relative to the longitudinal axis of the first body lumen, and advancing the distal end portion of the inner catheter through a lumen of the outer catheter, away from the distal end portion of the outer catheter, and into a second body lumen, the second body lumen branching from the first body lumen.
