LII Experimental Blockage of the Endolymphatic DUCT and SAC and ITS Effect on the Inner Ear of the Guinea Pig

Abstract

In all 61 guinea pigs in which the endolymphatic duct and sac were obliterated surgically, endolymphatic hydrops was observed up to 14 months postoperatively; all controls remained normal. Additional experiments, involving electrocautery, incision and opening of the sac at the operculum rim, splitting open of the duct, insertion of foreign substances and tissue masses into the sac were performed on 27 other guinea pigs and resulted in 5 instances of cochlear hydrops. Evidence in the present study favors blockage of this site as a cause for the production of hydrops. Distention of Reissner''s membrane and histopathological change continues slowly for many months. Changes in the organ of Corti, stria vascularis and spiral ganglia are often seen at the apical turns. Possible explanations for cellular atrophy and etiology of experimental hydrops are discussed. Electron microscopic findings from similar hydrops cases are presented with particular emphasis on the pathological alteration of the sensory cell and Reissner''s membrane.