A cannula may include a cannula bowl having an opening to receive an instrument configured to be advanced through the cannula, and a cannula tube extending distally from the cannula bowl. The cannula tube may have a proximal end opening, a distal end opening disposed at an opposite end of the cannula from the proximal end opening, and lateral wall defining a passage extending from the proximal end opening to the distal end opening. The lateral wall can have outer dimensions defining a waisted portion with smaller outer dimensions than a region disposed proximally or distally to the waisted portion along a length of the cannula tube.