A syringe assembly comprising: a fluid barrel including a sidewall having an inside surface defining a fluid chamber for retaining fluid and having a first cross-sectional width, an open proximal end and a distal end including a distal wall; a plunger rod disposed within the fluid chamber comprising a distal end, a proximal end, a plunger rod body extending from the distal end to the proximal end, and a stopper disposed at the distal end of the plunger rod for forming a fluid-tight seal with the inside surface of the barrel; a retraction barrel disposed adjacent to the sidewall of the fluid barrel , the retraction barrel including a wall having an interior surface defining a needle chamber, an open proximal end, an open distal end including a barrier wall, an aperture between the wall of the retraction barrel and the sidewall of the fluid barrel permitting fluid communication between the fluid chamber and the needle chamber and a needle hub assembly comprising a needle hub, a needle cannula attached to the needle hub, the needle cannula being in fluid communication with the aperture and biased to move in a proximal direction; and a trigger element disposed within the needle chamber and rotatable within the retraction barrel independently from the plunger rod , characterized in that the trigger element including a trigger guard that prevents premature retraction of the needle cannula, the trigger element providing a trigger force causing the needle cannula to retract into the retraction barrel , and the plunger rod comprises a flat radial ring that deflects the trigger guard so that the trigger element may be moved in a distal direction for retracting the needle cannula. a fluid barrel including a sidewall having an inside surface defining a fluid chamber for retaining fluid and having a first cross-sectional width, an open proximal end and a distal end including a distal wall; a plunger rod disposed within the fluid chamber comprising a distal end, a proximal end, a plunger rod body extending from the distal end to the proximal end, and a stopper disposed at the distal end of the plunger rod for forming a fluid-tight seal with the inside surface of the barrel; a retraction barrel disposed adjacent to the sidewall of the fluid barrel , the retraction barrel including a wall having an interior surface defining a needle chamber, an open proximal end, an open distal end including a barrier wall, an aperture between the wall of the retraction barrel and the sidewall of the fluid barrel permitting fluid communication between the fluid chamber and the needle chamber and a needle hub assembly comprising a needle hub, a needle cannula attached to the needle hub, the needle cannula being in fluid communication with the aperture and biased to move in a proximal direction; and a trigger element disposed within the needle chamber and rotatable within the retraction barrel independently from the plunger rod , characterized in that the trigger element including a trigger guard that prevents premature retraction of the needle cannula, the trigger element providing a trigger force causing the needle cannula to retract into the retraction barrel , and the plunger rod comprises a flat radial ring that deflects the trigger guard so that the trigger element may be moved in a distal direction for retracting the needle cannula. <EOS>