A retractable syringe device includes: a handle including a hollow body for receiving a syringe through an opening of the handle, the hollow body including a syringe actuator that moves the syringe between a distal position and a proximal position; and an instrument distally extending from the handle, the instrument including a channel extending through the instrument, the channel configured to receive a needle coupled to the syringe. When the syringe is in the distal position, a distal end of the needle distally extends from the instrument, and when the syringe is in the proximal position, the distal end of the needle is retracted into the channel. The handle of the device can include a fixed or removable structure for removably coupling to a proximal end of a shaft of an endoscope.