A catheter assembly includes a main catheter branch and a side catheter branch. The main catheter branch includes a main balloon and a side balloon. The side catheter branch includes a transparent portion along at least a portion of a length of the side catheter branch. The transparent portion of the side catheter branch permits viewing of the side balloon through the transparent portion for alignment of the side balloon relative to the side catheter branch. The catheter assembly can further include a stent, wherein the stent includes a lateral branch opening. The transparent portion of the side catheter branch can also provide viewing of the side balloon through the side catheter branch to help align the side balloon with the lateral branch opening.