A surgical system for penetrating tissue includes an obturator having an obturatorhousing and an obturator member extending from the obturator housing and havinga penetrating member adapted to penetrate tissue. The penetrating member definesan outer wall with an irregular surface dimensioned to facilitate passage throughtissue. The obturator may further include a stylet at least partially disposedwithin the obturator member. The stylet and the obturator member are adaptedfor relative longitudinal movement between a first relative position correspondingto an unarmed condition of the penetrating member and a second relative positioncorresponding to an armed condition of the penetrating member.
