Cryosurgical destruction of the sensory epithelium of the lateral ampulla provides an opportunity to study the response of the endolymphatic sac to aseptic labyrinthine trauma. The lateral ampullae of ten young guinea pigs were cryosurgically injured one to four days prior to sacrifice, and the ampullar morphology was correlated with that of the endolymphatic sac. The maximum extent of the ampullar lesion was noted two days after surgery, and the endolymphatic sac demonstrated histological signs of an increased activity with evidence of fluid reabsorption and phagocytosis of endolymphatic debris. Four days after cryosurgery, the epithelial surface of the ampulla had healed, the endolymph had cleared, and the activity of the endolymphatic sac had diminished. These experiments confirm the important role of the endolymphatic sac in response to labyrinthine trauma.
