Caloric function after endolymphatic sac surgery.
OBJECTIVE
To evaluate the effect of endolymphatic sac surgery on vestibular functions using caloric testing on electronystagmography (ENG).


METHODS
Retrospective chart review.


METHODS
The medical records of 21 adult patients with unilateral Ménière's disease who underwent endolymphatic sac surgery between 1998 and 2004 were reviewed. With use of ENG, the absolute value of the caloric response of the operated ear (i.e., the cool + warm irrigation response) and the degree of reduced vestibular response (RVR) rates as indicators of caloric functions were compared before and after surgery. Average follow-up was 17 (6-52) months.


RESULTS
The mean change in RVR after surgery was found to be 2.9%. In total, there were six (28.5%) patients who had an RVR increase more than 10%. Of those, there were three (14.2%) patients who demonstrated an RVR increase more than 20%. Only one (4.8%) patient had an RVR increase more than 30%. Total loss of vestibular function was not observed in any of the patients. There were three (14.2%) patients who exhibited a decrease of more than 10% in their RVR. In two (9%) patients, the contralateral ear was shown to have less vestibular function than the operated side on ENG postoperatively (in one case, the absolute caloric nystagmus response remained the same in the operated ear, and in the other case, the response increased on the surgical side). When we evaluated the absolute caloric responses of the operated ear only, we found no statistical difference between the pre- and postoperative values (P = .219). Early results of vertigo control and hearing outcomes were comparable with those in the literature.


CONCLUSIONS
Endolymphatic sac surgery does not appear to be a vestibular destructive procedure, and it is a therapeutic alternative for patients with Ménière's disease who have failed medical treatment. This is important given the possibility of bilateral disease in some patients.
Ulubil
S Arif
SA
Department of Otolaryngology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey.
Eshraghi
Adrien A
AA
Telischi
Fred F
FF
Angeli
Simon I
SI
Balkany
Thomas J
TJ
Joy
Jennifer J
JJ
D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D002150:Caloric Tests; D004584:Electronystagmography; D004712:Endolymphatic Sac / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000601:surgery*; D008875:Middle Aged; D009760:Nystagmus, Physiologic; D011182:Postoperative Care; D011300:Preoperative Care; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014724:Vestibular Function Tests