In some examples, a catheter comprises an inner liner, an outer jacket, and a structural support member positioned between at least a portion of the inner liner and the outer jacket. The inner liner, the outer jacket, and the structural support member define a catheter body that comprises a proximal portion having a first outer diameter, a distal portion having a second outer diameter less than the first outer diameter, the distal portion including a distal end of the catheter body, and a medial portion positioned between the proximal portion and the distal portion, the medial portion tapering from the first outer diameter to the second outer diameter.