<p>An medical device may include a guide extension catheter (114). The guide extension catheter may include a proximal member (116) having a proximal outer diameter. A distal sheath member (126) may be attached to the proximal member. The distal sheath member may have a proximal sheath portion (144) and a distal sheath portion (146). The proximal sheath portion may have an outer diameter greater than the proximal outer diameter. The proximal sheath portion may have a first cross-sectional profile. The distal sheath portion may have a second cross-sectional profile different from the first cross-sectional profile.</p>
