An apparatus is provided having a steerable and removable sheath for use with an optical catheter wherein the sheath with the catheter therein is to be positioned in a pathway leading to a body cavity of a patient for observation and/or treatment. The apparatus comprises an elongated, bendable, hollow body having a distal end, a proximate end and a plurality of channels extending from the proximate end to the distal end. An optical catheter is extendable through one of the channels in the body having a distal end aligned with the distal end of the body and a proximate end extending outwardly beyond the proximate end of the body. The catheter conforms to the shape and movement of the body. A deflectable means is provided adjacent the distal end of the second of the channels to deflect the distal end of the body in a desired direction. A substantially rigid wire is extendable through the second channel to straighten the body during insertion of the sheath in the passageway of the patient and for manipulating the deflectable means after insertion to deflect the body in a desired direction for examination and/or treatment.