foerster clamp foerster clamp a foerster clamp is a surgical clamp with a round eyelet. also known as a sponge clamp, or sponge stick. used for atraumatically grasping lung tissue in thoracic surgery. when grasping a surgical sponge in the jaws, foerster clamps are commonly used for removing small amounts of fluids from the operative area and applying pressure to sites of bleeding. may also be used for tissue dissection. invented by david william foerster of oklahoma city, oklahoma, who pioneered sex change operations in the united states. slotted foerster forceps non-medical uses it is commonly used in body piercing, particularly for tongue piercings.