According to a general aspect, an insertion device can include an elongate barrel having an opening defined in a distal end; a lumen defined within the elongate barrel, the lumen being accessible through the opening; and an obturator disposed within the lumen of the elongate barrel. The obturator can be movable within the lumen between a proximal position in the elongate barrel and a distal position in the elongate barrel. The obturator, in its distal position in the elongate barrel, can be configured to receive a needle via the opening. The obturator, in its proximal position in the elongate barrel, can be configured to secure the needle within the elongate barrel.