The quantification of endolymphatic hydrops in an experimental animal model with guinea pigs.

To better quantify endolymphatic hydrops in experimental guinea pigs, endolymphatic hydrops was induced by endolymphatic sac obliteration through an extradural posterior cranial fossa approach in the right ear. The area of the scala vestibuli and scala media of each turn on both cochlear midmodiolar sections was measured, using an automated computer-aided design (AutoCAD R14) software combined with a digital camera. No endolymphatic hydrops was observed in all nonoperated ears; however, various degrees of hydrops were present in all operated ears. The average maximum SMA (scala media area) ratio in the 4-week group (2.22 +/- 0.20) was greater than that in the control group (1.10 +/- 0.06). The average maximum SMA ratio of the 8-week group (4.04 +/- 0.52) was greater than that of the 4-week group (p < 0.05). This study provides a reliable methodologic base for the experimental study of Ménière's disease.