A surgical apparatus includes an elongate outer sheath dimensioned for positioning within a body lumen of a patient, a reference member and a removal device. The reference member is adapted for longitudinal movement relative to the elongate outer sheath between a first position at least partially disposed within a longitudinal lumen of the outer sheath and a second position at least partially exposed from the longitudinal lumen. The reference member is adapted to expand when in the second position to generally conform to an internal dimension of the body lumen. The reference member includes a radiopaque material for visualizing the reference member to assist in determining physical characteristics of the body lumen when in the second position. The removal device is adapted for longitudinal movement relative to the reference member, and is configured for disrupting at least a portion of the occlusion within the body lumen.