An access device (100) configured for accommodating passage of an instrument (10) with a curved end effector (12) includes a housing assembly (110) and a cannula member (120) extending from the housing. The cannula member includes a length and a plurality of rigid portions alternating with a plurality of flexible portions. The cannula member is configured to maintain a circular cross-sectional profile when a force is applied to the cannula member from the outside and to flex to an oblong cross-sectional profile when a force is applied to the cannula member from the inside.
