Round Window Gentamicin Absorption: An In Vivo Human Model
Article first published online: 2 JAN 2009
Copyright © 2002 The Triological Society
Volume 112, Issue 9, pages 1610–1613, September 2002
How to Cite
Becvarovski, Z., Bojrab, D. I., Michaelides, E. M., Kartush, J. M., Zappia, J. J. and LaRouere, M. J. (2002), Round Window Gentamicin Absorption: An In Vivo Human Model. The Laryngoscope, 112: 1610–1613. doi: 10.1097/00005537-200209000-00015
- Issue published online: 2 JAN 2009
- Article first published online: 2 JAN 2009
- Manuscript Accepted: 26 FEB 2002
- round window;
- human labyrinthine sampling model;
- inner ear
Objective/Hypothesis Using a novel human labyrinthine sampling model, in vivo gentamicin absorption through the round window can be measured.
Study Design A prospective study.
Methods Gentamicin was delivered either transtympanically (preoperative) or through a facial recess approach (intraoperative). The lateral semicircular canal and vestibule were opened, and by means of a microsyringe, labyrinthine fluid was aspirated. A sample of serum was also drawn. In all patients cerebrospinal fluid was also drawn. The samples were analyzed using a standard chemistry analyzer.
Results Intratympanic gentamicin diffused through the round window membrane and achieved concentrations in the labyrinthine fluid ranging from 0 to 16 mg/L. Intratympanic gentamicin was absorbed into the systemic circulation in 4 of 11 patients with serum levels ranging from 0.3 to 0.4 mg/L. No gentamicin was detected in the cerebrospinal fluid.
Conclusions Intratympanic gentamicin diffuses rapidly through the round window membrane and achieves significant levels in the inner ear. Thus, this new model can be used to assess round window permeability to clinically relevant medications such as steroids and ototopical antibiotics.