A medical vacuum aspiration apparatus (100) includes: a vacuum cylinder (110) closed at a first end by a valve (140), and closed at a second end by a plunger (120) moveable along the cylinder (110), the valve (140) being formed from a flexible nozzle (130) and a releasable nozzle clamp (142), the nozzle (130) having also an aperture (136) in fluid communication with a vacuum chamber formed by the cylinder (110), characterised in that the aperture (136) is stepped in diameter or tapered in size to accept cannulae (10) of different sizes in use. Disclosed also is a plunger locking mechanism which requires the twisting of a plunger handle (124).
