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Effect of Cochleostomy Size on CSF Perilymph Fistula Control
Author(s) -
Craig Catherine A.,
Robey Ashley B.,
Lyden Elizabeth R.,
Lusk Rodney P.
Publication year - 2009
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1002/lary.21540
Subject(s) - citation , perilymph , medicine , library science , computer science , anatomy , inner ear
University of Nebraska Medical Center Email: ccraiga@unmc.edu Phone: (402)559-7777 Website: www.unmc.edu/ent Introduction: Although the overall incidence of perilymphatic gushers is approximately 1%1,2, patients with inner ear anomalies are at an increased risk for development of perilymphatic gushers. As cochlear implantation becomes more common in patients with inner ear anomalies (such as Mondini defect or common cavity defect), the ability to successfully seal such leaks becomes of paramount importance to reduce the risk of subsequent meningitis. Methods and Materials: Two cadaveric temporal bones were drilled out utilizing a facial recess approach to expose the promontory. A 1.0 mm cochleostomy and a 1.5 mm cochleostomy were made in the respective temporal bones. Cochlear implants with silastic electrodes (Cochlear®, Medical Electronics® and Advanced Bionics®) were placed in the cochleostomy in standard fashion, and porcine periosteum was used to pack around the cochleostomy site. A fixed 23gauge needle was inserted into the oval window to apply a fixed amount of pressure to the inner ear. The presence or absence of a leak was recorded for 10 different packings of each cochleostomy diameter at 0, 10, 15, 20 and 30 cm H20. Results: For the Cochlear®, Medical Electronics® and Advanced Bionics® electrode, no statistically significant difference was noted between the 1.0 mm and the 1.5 mm cochleostomy at 0-5, 10, 15, and 20 cm H20. With the Cochlear® implant at 30 cm H20, 6/10 1.0 mm cochleostomies showed evidence of a leak whereas 0/10 of the 1.5 mm cochleostomies showed leakage (p= 0.004). 2/10 of the 1.0 mm Med-El® implants leaked at 30 cm H20 whereas 0/10 leaked at this pressure with the 1.5 mm cochleostomy (p=0.24). With the Advanced Bionics® electrode, 5/10 of the 1.0 mm cochleostomies vs. 0/10 of the 1.5 mm cochleostomies leaked at 30 cm H20 (p= 0.03). Conclusions: 1.5 mm cochleostomies are associated with a decreased risk of perilymphatic fistula as compared to 1.0 mm cochleostomies at 30 cmH20; this likely represents a phenomenon of packing adequacy. Effect of Cochleostomy Size on CSF Perilymph Fistula Control