Endolymphatic sac surgery: why we do not do it. The nonspecific effect of sac surgery

Three of the present authors described a trial in 1981 which showed that cortical mastoidectomy was as effective as an endolymphatic sac shunt in controlling vertigo in patients with Ménière's disease both on a short-term as well as a long-term basis. The hearing was not influenced by the treatment and any change was considered to be the result of time, rather than the effect of the surgery. Upon perusal of the literature only two other studies exist resembling our study, and they both reached the same conclusion, that sac surgery is at best non-specific and at worst of no value. None of the numerous other studies published have convinced the authors that sac decompression is specific in nature. We have also looked at ECoG as a means of proving the specificity of sac operations and come to the same conclusion that the existing information is conflicting and confusing, and cannot be used to prove anything about sac surgery. The present conclusion is therefore that in treating patients with Ménière's disease anything goes, even sac surgery.     

Prognostic value of electrocochleography in patients with unilateral Menière's disease undergoing saccus surgery*

Although a controversial operation, saccus surgery has continued to be used in patients with severe Menière's disease in whom hearing preservation is the objective. The aim of this study was to determine if electrocochleography (ECoG) could predict the patients who would be free of vertigo, 2 and 5 years after surgery. Seventy patients with severe Menière's syndrome underwent ECoG prior to endolymphatic sac surgery. Eighty‐four per cent of the patients had an abnormal electrocochleogram. The patients were interviewed 2 and 5 years after surgery. At 2 years, 4/10 (40%) patients with normal ECoG were relieved of dizziness compared to 38/51 (75%) with abnormal ECoG (P < 0.05). At 5 years, 5/8 (63%) patients with normal ECoG were relieved of dizziness compared to 30/30 (100%) with abnormal ECoG (P < 0.001). The patients with a normal ECoG do have less severe measurable hearing impairment (P < 0.05) although they are more likely (P < 0.05) to complain of constant tinnitus. Their history of dizziness is longer and their dizziness more disabling before surgery. In conclusion, patients with a normal ECoG will be less likely to benefit from saccus surgery in the first 5 years. These patients may represent a different nosological entity.     

Caloric function after endolymphatic sac surgery

OBJECTIVE: To evaluate the effect of endolymphatic sac surgery on vestibular functions using caloric testing on electronystagmography (ENG). STUDY DESIGN: 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. CONCLUSION: 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.     

Intratympanic gentamicin for unilateral Menière's disease: results of therapy

Intratympanic gentamicin for unilateral Menière's disease: results of therapy Patients with Menière's disease that remains refractory to conservative treatment have traditionally been subjected to ablative surgery. The purpose of this prospective study was to evaluate the use of intratympanic gentamicin in eliminating incapacitating vertigo, while preserving hearing. Over the past 8 years, 83 patients have received between 1 and 6 intratympanic injections of gentamicin in an out‐patient setting, with duration of therapy titrated to individual symptom response and effect on hearing. Using established AAO‐HNS guidelines, we present data on 50 patients who have a minimum of 2 years follow‐up. Control or significant improvement of definitive Menière's attacks was achieved in 92% of patients and hearing preserved or improved in 76%. Only one patient experienced profound sensorineural hearing loss. We feel this treatment option should be considered and offered to patients in whom medical treatment has failed.     

Summating potential-action potential waveform amplitude and width in the diagnosis of Menière's disease

OBJECTIVES: It has been suggested that analyzing the width and amplitude of the summating potential-action potential (SP-AP) waveforms can increase the sensitivity of electrocochleography. The objective of this study was to evaluate the ratio of SP to AP amplitude (SP/AP) and SP-AP waveform width, as well as the AP latency difference to condensation and rarefaction clicks, for the diagnosis of Menière's disease. STUDY DESIGN: This was a prospective, controlled study. METHODS: We used transtympanic electrocochleography to evaluate 21 patients with definite Menière's disease and 19 normal-hearing patients with other cochleovestibular disorders, comparing SP/AP, AP latency difference, and SP-AP waveform widths as well as calculating the diagnostic sensitivity of these parameters. RESULTS: Mean SP-AP waveform width was 1.89 ms in the study group and 1.58 ms in the control group. Mean SP/AP was 0.37 in the study group and 0.22 in the control group. The mean product of SP-AP waveform width and SP/AP was 75.26 ms% in the study group and 34.60 ms% in the control group. Mean AP latency difference was 0.13 ms in the study group and 0.07 ms in the control group. For the parameters evaluated, the differences between the groups were statistically significant. In the study group, the sensitivities for the width of the SP-AP waveform, the SP/AP, and the AP latency difference were 33.3%, 52.4%, and 23.8%, respectively. CONCLUSIONS: The use of the parameters evaluated did not increase the sensitivity of the electrocochleography, whether used in isolation or in conjunction with the SP/AP. Determining SP/AP presented the greatest sensitivity.     

ELECTROCOCHLEOGRAPHY IN ENDOLYMPHATIC HYDROPS USING TONE-PIP AND CLICK STIMULI

The use of electrocochleography (ECochG) in the identification of endolymphatic hydrops in Menière's disease, using either trans-tympanic or extra-tympanic recording techniques, has become very popular. The presence of an enhanced summating potential (SP) component is considered to be a diagnostic indicator of hydrops. The response evoked by a click stimulus is widely used in this investigation. The aim of this study was to assess the value of tone-pip stimuli for measurement of the SP component in patients with suspected Menière's disease. Extra-tympanic ECochG was recorded from a surface electrode positioned on the postero-inferior quadrant of the ear canal close to the tympanic annulus. Forty patients referred to the Evoked Potentials Clinic at the Queen's Medical Centre were studied. The combined summating potential and action potential waveform (SP/AP) were recorded using click and tone-pip stimuli. The pips had tone frequencies of 1 and 4 kHz and all stimuli were presented with alternating phase at a repetition rate of 10 per second. The percentage SP (%SP), width and latency characteristics of the SP/AP waveform were calculated for each stimulus condition. There were four patients (10%) with an enhanced tone-pip %SP when the click %SP was within normal limits. Width measurement of the tone-pip waveform at the onset point of the response was abnormal in 13 patients (33%) when a similar measurement of the click-evoked response was normal. There were nine of these patients identified by an abnormal width measurement at the 50% amplitude point of the SP/AP waveform. Both tone-pip frequencies were required in order to identify all these abnormal measurements. In conclusion, the tone-pip response provides valuable additional information to the click stimulus in support of the diagnosis of endolymphatic hydrops.     

Topical mitomycin C and cephalosporin in endolymphatic sac surgery

OBJECTIVE: To determine whether intraoperative topical application of the drug mitomycin C to the endolymphatic sac area in conjunction with endolymphatic sac ballooning surgery (ESBS) can safely achieve longer-lasting relief from incapacitating, medically intractable Meniere symptom-complex than ESBS alone. STUDY DESIGN/METHOD: A retrospective study is presented of 142 cases of ESBS performed by the author between May 1998 and November 1999, in which a solution of mitomycin C diluted to 1 mg/mL of physiological saline was applied to the sac area for 5 minutes followed by irrigation with a cephalosporin antibiotic solution. The results of the 103 of 142 cases diagnosed as classic Meniere's disease or endolymphatic hydrops are given special attention, comparing them with the results of an earlier-reported series of 109 cases of ESBS sharing the same diagnostic and result evaluation criteria but not using mitomycin C. RESULTS: In terms of vertigo control, the comparative short-term rates (<3 y) of complete/substantial control for the aforementioned 103-case series and earlier 109-case series are similar: respectively, 90.3% (after 1.5--3 years' follow-up) versus 91.7% (after 2.5-3 years' follow-up). In the 103-case series, to date, there has been no recurrence of incapacitating vertiginous symptoms necessitating revision surgery, whereas in the 109-case series, although there were likewise no cases necessitating revision surgery during the reported 2.5-to 3-year follow-up period, at least 8 patients in that series are known to have undergone revision surgery at later dates. Hearing results were significantly better (P =.004) in the 103-case series than the 109-case series: respectively, 30.0% versus 12.8% hearing improvement. CONCLUSIONS: Preliminarily, the superior hearing results in the present series indicate that possible adverse effects of mitomycin C on the inner ear and endolymphatic system have been averted; and no recurrence of incapacitating symptoms to date offers hope that longer-term efficacy of endolymphatic sac surgery using mitomycin C can be maintained.     

The pharmacological treatment of Menière's disease

The management of Menière's disease often provides a formidable clinical challenge largely because its precise aetiology is unknown. There is no known ‘cure’ once the condition is established, but drugs may be helpful in treating both the acute attacks of vertigo, and in more long-term management, particularly in the earlier fluctuant stage. These remedies are largely symptomatic and there are few if any properly controlled studies of their efficacy. Suppressant drugs may act centraly at neurotransmitter sites, or peripherally on the labyrinth. Conventional diuretics and osmotically acting agents have been given to reduce the endolymph fluid volume Histamine anlogues directly reduce inner ear fluid pressure mainly by increasing the cochlear blood flow. and are probably the treatment of choice. Otovestibulotoxic drugs given systemically to cause chemical labyrinthine ablation are frequently effective in abolishing attacks of vertigo but often resulted in disabling oscillopsia and ataxia. There is now evidence that local administration by intratympanic injection may well be more efficacious resulting in selective partial end organ ablation. To date innovative immune modigying regimes have not proved helpful.     

The effect of glycerol on the guinea-pig hydropic ear

The aim of this paper was to investigate the effect of glycerol on experimental endolymphatic hydrops in guinea-pigs. The right endolymphatic sac and duct were obliterated through an extradural posterior fossa approach. Some animals received a 3 g/kg dose of glycerol for a period of 7 days, whereas others received the same dose for 30 days. The activity of glycerol was studied by investigating the volumetric changes in the scala media determined with a computerized planimeter. Glycerol induced a significant reduction of the hydrops showing its effectiveness and suggesting a strial metabolic response.     

Current state of evidence for endolymphatic sac surgery in Menière’s disease: a systematic review

Abstract

Background: Endolymphatic sac surgery is an invasive procedure recommended to patients with Menière’s disease.

Aims/Objectives: To provide an overview and quality assessment of the existing evidence and to provide an updated assessment of the utility of endolymphatic sac surgery in Menière’s disease.

Material and Methods: We performed a systematic literature search for systematic reviews and randomized controlled trials (RCTs). The AMSTAR tool was used to assess the quality of systematic reviews and the Cochrane risk of bias tool for RCTs. The overall certainty of effects for the individual outcomes was evaluated using the GRADE approach.

Results: One systematic review of high quality matched the inclusion criteria, and included three RCTs. An updated literature search from the last search date of the included review provided no further relevant RCTs. The identified RCTs individually reported a positive effect of both the placebo and active treatment groups following surgery, strongly indicative of a placebo effect. The overall certainty of the effect was very low.

Conclusions and significance: There is still a lack of high-quality research suggesting that endolymphatic sac surgery provides a significant amount of symptomatic relief for Menière’s patients.     

Non-invasive perilymphatic pressure measurement in patients with Menière's disease

The MMS-10 Tympanic Displacement Analyser is a new device to measure the perilymphatic pressure in humans. This instrument was used in 25 patients with Menière's disease (28 affected ears) and a group of 50 young normal hearing subjects. No significant differences were found in perilymphatic pressure measurements between the groups. Although measurement parameters showed large inter-individual variation, the intra-individual correlation was good. In patients with Menière's disease, no relationship was found between perilymphatic pressure, hearing thresholds, blood pressure, gender or age.     

Effects of endolymphatic sac drainage with steroids for intractable Meniere's disease: a long-term follow-up and randomized controlled study

OBJECTIVE: Meniere's disease is a common inner ear disease with an incidence of 15 to 50 per 100,000 population. Since Meniere's disease is thought to be triggered by an immune insult to the inner ear, we examined intraendolymphatic sac application of steroids as a new therapeutic strategy for intractable Meniere's disease. STUDY DESIGN: Prospective randomized controlled study. METHODS: Between 1996 and 2005, we enrolled and assigned 197 intractable Meniere's patients to three groups in a randomized controlled trial: Group I (G-I)- patients who underwent endolymphatic sac drainage and steroid-instillation; Group II (G-II)-those who underwent endolymphatic sac drainage without steroid-instillation; and Group III (G-III)-those who declined endolymphatic sac drainage. Definitive spells and hearing in all three groups were determined for 2 to 7 years after treatment. RESULTS: According to the 1995 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria, 2-year results demonstrated that vertigo was completely controlled in 88.0% of patients in G-I (n = 100), 85.1% of patients in G-II (n = 47), and 8.0% in G-III (n = 50). Statistically, G-I = G-II>G-III. Hearing was improved in 49.0% of patients in G-I, 31.9% in G-II, and 6.0% in G-III (G-I>G-II>G-III). Results after 7 years showed that vertigo was completely controlled in 78.8% of patients in G-I, 79.2% in G-II, and 25.0% in G-III (G-I = G-II>G-III). Hearing improved in 36.5% of patients in G-I, 8.3% in G-II, and 0.0% in G-III (G-I>G-II = G-III). CONCLUSIONS: From non-surgical observation in G-III for at least 7 years after treatment, steroids instilled into endolymphatic sac in G-I patients significantly improved hearing in intractable Meniere's patients, more so than endolymphatic sac drainage without steroids in G-II patients.     

Electrophysiological measures of cochlear function in guinea pigs with long-term endolymphatic hydrops

Experimental endolymphatic hydrops was induced in guinea pigs by obliteration of the endolymphtic sac and duct. From 3 to 24 months after this operation, cochlear action potential (AP) audiograms and AP tuning curves were measured. The purpose of this study was to establish parallels, if any, between this supposed animal model of Menière's disease and the auditory symptoms of the disease in man. In some animals, low and middle frequency AP threshold elevations were observed whilst higher frequency regions maintained normal sensitivity. Other animals developed flat or very gradually sloping AP audiograms. These patterns are qualitatively similar to those found clinically in Menière's disease. AP tuning curves measured in frequency regions of threshold elevation indicated a deterioration of cochlear frequency selectivity; psychophysical and electrocochleographic studies demonstrate related changes in Menière's patients. One animal exhibited modifications in AP thresholds and tuning as a result of glycerol administration. These observations improve our confidence in the validity of this animal model for further studies of the pathophysiology of Menière's disease.     

Endolymphatic hydrops in asymptomatic ears in unilateral Ménière's disease

OBJECTIVES/HYPOTHESIS: The aim of our study was the objective assessment of endolymphatic hydrops in asymptomatic ears in unilateral Ménière's disease with a noninvasive electrophysiological test and investigation of significant clinical signs. The null hypothesis was that there would be no signs of endolymphatic hydrops in the asymptomatic ear. STUDY DESIGN: Prospective study using the traveling wave velocity test for endolymphatic hydrops. METHODS: The traveling wave velocity test was used in conjunction with standard audiological tests to investigate both ears of 181 Ménière's patients attending the Medical Research Council Institute of Hearing Research in Southampton, United Kingdom. The test uses derived auditory brainstem responses to estimate the velocity of the cochlear traveling wave that is altered in endolymphatic hydrops. Ménière's disease was assessed using Arenberg's five staging criteria. Significant correlations were evaluated using standard statistical methods. RESULTS: Of 100 patients with clinically unilateral Ménière's disease, 27% showed evidence of endolymphatic hydrops in their asymptomatic ear. There was a significant correlation between signs of hydrops and the mean air-conduction threshold at 500 Hz. CONCLUSIONS: We recommend that a full assessment of incipient disease in the asymptomatic ear in unilateral Ménière's disease should be undertaken before offering any treatment options to patients. Any suspicion of early disease in the asymptomatic ear in unilateral Ménière's disease should lead to full electrophysiological assessment to assess the evidence of endolymphatic hydrops in that ear.     

Medical management of Ménière's disease

Objectives: Ménière's disease (MD) is poorly understood with respect to its etiology, pathophysiology, clinical course, and treatment. Furthermore, in the absence of controlled clinical studies, empiric treatments have been used with varying degrees of success. In this paper, the authors review the current medical management of MD. Study Design: Literature review. Results: Because of a dearth of well‐controlled studies, the medical management of MD remains empirical and is largely restricted to lifestyle changes, pharmacotherapy, and office‐based procedures. The development of transtympanic therapies represents a true therapeutic advance that has largely supplanted surgical intervention. A treatment algorithm for acute and chronic medical management is reviewed. Conclusions: Despite absence of a complete understanding of MD, medical management or its natural history leads to control of vertigo in the majority of patients. Basic research is needed to understand its pathophysiology so that directed therapies can be developed and can be tested in well‐controlled clinical trials.     

The AAO–HNS Committee on Hearing and Equilibrium Guidelines for the diagnosis and evaluation of therapy in Menière's disease: have they been applied in the published literature of the last decade?

The AAO–HNS Committee on Hearing and Equilibrium Guidelines for the diagnosis and evaluation of therapy in Menière's disease: have they been applied in the published literature of the last decade? To assess how effectively the American Academy of Otolaryngology–Head and Neck Surgery Committee on Hearing and Equilibrium (AAO–HNS CHE) guidelines for the diagnosis and evaluation of therapy in Menière's disease have been applied in the last 11 years of published literature. This was a MedLine‐based review. Some 79.7% of papers attempted to use the AAO–HNS CHE guidelines. However, only 50% of these publications managed to use the AAO–HNS CHE criteria in the diagnosis and evaluation of therapy correctly. In order to advance our understanding of this condition, improved application of the AAO–HNS CHE guidelines by authors and editors alike is required in the reporting of results of the therapy of Menière's disease.