A follicular unit extraction device comprises a handpiece for holding a follicle punch at its distal end which extends from the handpiece and terminates distally in a cutting edge. The punch is releasably coupled to a motor-driven drive shaft within the handpiece for rotation therewith. A portion of the driveshaft is tubular, and houses a piston that can move towards and away from the punch. An ejector pin is also supported within the tubular portion of the driveshaft distally of the ejector piston and is positioned to move towards the cutting edge of the punch when pushed by the piston. The handpiece and driveshaft have respective fluid inlet ports. The clearance between the piston and driveshaft interior, and the clearance between the ejector pin and punch interior, define a fluid path for conducting fluid entering the handpiece and drive shaft via inlet ports so that the fluid exits the punch at its cutting edge. The clearances limit the quantity of fluid exiting the punch to the small amount needed to protect the follicle to be extracted. Means are provided for selectively increasing the flow rate of the fluid entering the handpiece beyond the limit imposed by said clearances to thereby increase the fluid pressure within the driveshaft, moving the piston distally and, consequently, moving the pin towards the cutting edge of the punch to eject impacted graft or debris. Bias means returns the piston proximally when the flow rate is reduced below the level required to overcome the bias means.L'invention concerne un dispositif d'extraction d'unité folliculaire qui comprend une pièce à main destinée à maintenir un poinçon à follicule au niveau de son extrémité distale qui s'étend depuis la pièce à main et se termine distalement dans un bord de découpe. Le poinçon est relié de manière amovible à un axe d'entraînement à moteur dans la pièce à main, afin de pouvoir tourner avec ce dernier. Une partie de l'axe d'entraînement est tubulaire, et renferme un piston qui peut