An obturator for use in penetrating tissue includes an elongate member defining a longitudinal axis, and having a proximal end and a distal end and a penetrating member adjacent the distal end of the elongate member. The penetrating member has a distal penetrating tip dimensioned to pass through tissue. The penetrating member defines an external wall leading toward the penetrating tip. The external wall includes a plurality of raised elements extending at least radially outwardly relative to the longitudinal axis and being in general longitudinal alignment. Adjacent raised elements are spaced along the longitudinal axis to thereby accommodate tissue displaced during passage of the penetrating member through tissue. The raised elements are dimensioned to be generally atraumatic to tissue. The raised elements may define an arcuate profile.
