A regional anesthesia catheter used with a guide, for example a cannula, has a distal portion integrally connected to its main portion by a junction portion that has a cross-sectional profile different from the distal and main portions, so as to predispose the distal portion of the catheter to move in a given direction when it is not constrained by the guide. The cross-sectional profile of the junction portion may be configured in a particular shape, or be constructed to have a flexibility that predisposes the distal portion to bend, curve or move toward a given direction. A number of portions of a catheter may be configured to bend at a predefined direction. Further, a catheter may be configured to have a cross sectional profile or a predefined flexibility along its entire length to cause the catheter to move in a predefined direction.
