Trocar assembly with obturator dissector

A surgical system for penetrating tissue to access an underlying operative site, which comprises:

• an obturator including:
• an obturator housing;
• an obturator member extending from the obturator housing, the obturator member defining a longitudinal axis along which the obturator member extends and having proximal and distal ends, the obturator member defining a “t”-shaped cross-section along a substantial length thereof, the obturator member being longitudinally fixed relative to the obturator housing;
• and
• a penetrating member mounted to the distal end of the obturator member, the penetrating member dimensioned to penetrate tissue, the penetrating member defining, from distal to proximal:
• a cylindrical element having a generally arcuate end surface and being dimensioned to extend along the longitudinal axis, the cylindrical element dimensioned to perform initial dissection of tissue;
• and
• a generally planar dissecting element spaced with respect to the longitudinal axis a predetermined distance from the end surface of the cylindrical element, the dissecting element including side surfaces obliquely arranged with respect to the longitudinal axis and depending outwardly from the cylindrical element, the side surfaces dimensioned to penetrate tissue subsequent to the initial dissection performed by the cylindrical element as the penetrating member is advanced within the tissue;
• and
• an outer member mounted about the obturator member and including a distal nose having a central aperture and at least one slot longitudinally spaced from the central aperture, the outer member being adapted for longitudinal movement relative to the obturator housing between a first distalmost position corresponding to a first operative condition of the penetrating member in which the cylindrical element of the penetrating member is at least partially exposed through the central aperture of the outer member to permit the initial dissection of tissue, and a second proximal position corresponding to a second operative condition of the penetrating member in which the side surfaces of the penetrating member are at least partially exposed through the at least one slot of the outer member.