Medical instrument with injection needles

An instrument for a medical application, the instrument comprising:

• a body with a longitudinal axis;
• at least one needle;
• a channel fluidically connected to the at least one needle to bring a fluid to said at least one needle, the channel comprising a first part and a second part;
• and
• an actuator configured to move said at least one needle between a retracted position inside the body and an extended position protruding from the body, the actuator comprising a shaft, the first part of the channel extending within the shaft, the second part of the channel extending outside the shaft, a movement of the at least one needle between the retracted position and the extended position being performed by a rotation of the actuator and the shaft relative to the body,
• wherein the movement of the at least one needle between the retracted position and the extended position is rectilinear and perpendicular to the longitudinal axis,
• wherein the shaft includes a first set of teeth, and
• wherein said at least one needle includes a support having a second set of teeth cooperating with the first set of teeth.