A needle for insertion into a living body along a tortuous path comprises an elongate body extending between a proximal end which, during use, remains external to the body and a distal end which, when in an operative configuration, is positioned adjacent to a target structure within the body, a distal portion of the needle including a lumen extending therethrough to a tissue receiving opening at the distal end, the lumen having an inner diameter of at least 0.035 inches and a bending stiffness no greater than 0.08 Nm2.