Intraoperative endoscopy of the anterior epitympanum recess through the posterior tympanotomy.

INTRODUCTION: The anterior epitympanum recess (AER) is a common place of the development of the cholesteatoma, which is why removal of the matrix from this area plays a key role in the surgical treatment of chronic otitis media. AIM: To evaluate the intraoperative visibility of AER in endoscopic optics in comparison to microscopic optics and to determine the prevalence of cholesteatoma in various types of construction of the AER. Study design: retrospective analysis of intraoperative search. MATERIAL AND METHODS: The study included 55 patients treated in the Department of Otolaryngology, Medical University of Warsaw within the years 2009-2011, who underwent endoscopy-assisted canal wall up tympanoplasty with posterior tympanotomy. The type of construction of the AER - cellular or dome-shaped - was determined. RESULTS: Cellular type of recess was found intraoperatively in 32% of ears and dome-shaped in 68% of the study group. The population with chronic otitis media does not differ significantly compared to the general population in terms of the construction of the anterior epitympanum recess (p = 0.668108; χ2 = 0.1838235, df = 1). Among the ears with cholesteatoma a cellular AER was found in 48.3% of cases and a dome-shaped AER was found in 51.7%. CONCLUSIONS: The cellular type of AER was significantly more frequent in ears with cholesteatoma (p < 0.01, χ2 = 29.86492, df = 1). Level of evidence: 1b.

Intraoperative monitoring of hearing during cerebellopontine angle tumor surgery using transtympanic electrocochleography.

OBJECTIVE: To investigate the use of transtympanic electrocochleography (TT-ECochG) analyzed on-line by a detector strategy software that made possible automatic extraction of TT-ECochG components intraoperatively in real-time domain. PATIENTS: Fifteen patients with cerebellopontine angle tumor among 50 patients were included in this study. INTERVENTION: All subjects were operated on via middle fossa or retrosigmoid approach. Pure-tone average (PTA) was measured at 0.5, 1.0, and 2.0 kHz, and calculations were performed before and after surgery. Auditory function was monitored intraoperatively via TT-ECochG, and analyzed data were displayed on-line. MAIN OUTCOME MEASURES: TT-ECochG changes in morphology were described. Postoperative PTA elevation level correlated with TT-ECochG morphology changes occurring intraoperatively. RESULTS: Analyzed on-line, TT-ECochG data were displayed as first negative peak of compound action potential amplitude and latency in time domain every 3 to 5 seconds. A good correlation between postoperative PTA elevation and TT-ECochG morphology changes was showed (Spearman rank test, R = +0.93; t(N-2) = 9.00; p < 0.0001). CONCLUSION: TT-EcochG seemed to effectively mirror even minimal changes in auditory function during intraoperative monitoring in real-time domain. Developed strategy of on-line analysis makes the intraoperative hearing status assessment faster and easier.