Endolymphatic Sac Research Articles

Imaging of Temporal Bone Mass Lesions: A Pictorial Review.

Tumoral lesions of the temporal bone include benign or malignant tumors and congenital or inflammatory lesions. Temporal bone lesions are difficult to approach. Therefore, making a preoperative diagnosis and considering whether the lesions require treatment are necessary; if they require treatment, then the type of treatment requires consideration. These tumors cannot be observed directly and must be diagnosed based on symptoms and imaging findings. However, the differentiation of temporal bone lesions is difficult because they are rare and large in variety. In this pictorial review, we divided temporal bone lesions by location such as along the facial nerve, along the internal jugular vein, around the endolymphatic sac, in the internal auditory canal/cerebellopontine angle, petrous apex, middle ear, and mastoid, focusing on the imaging findings of temporal bone lesions. Then, we created a diagnostic flowchart that suggested that the systematic separation of imaging findings is useful for differentiation. Although it is necessary to make comprehensive judgments based on the clinical symptoms, patient background, and imaging findings to diagnose temporal bone mass lesions, capturing imaging features can be a useful differentiation method.

Feasibility Analysis and Surgical Details of Vestibular Schwannoma Resection via Retrolabyrinthine Approach With Preservation of Endolymphatic Sac.

Objectives: To study the feasibility of reserving the endolymphatic sac in the cerebellopontine angle (CPA) and the fundus of the internal auditory canal (IAC) by the retrolabyrinthine approach. Design: Single-center retrospective study. Methods: Through 3-dimensional preoperative computed tomography reconstruction, vestibular schwannoma (VS) resection was performed using a retrolabyrinthine approach with preservation of the endolymphatic sac in selected patients, and hearing and facial nerve functions were followed to assess the feasibility of this operation and the effectiveness of function preservation. Results: VS was completely removed in all cases and the postoperative detectable hearing retention rate (AAO-HNS hearing rating grade A, B, and C) was 80% (4/5). Postoperative facial nerve function was well preserved (HB grade I), no leakage of cerebrospinal fluid or other cranial complications was observed in all patients, and no recurrence was observed during follow-up. Conclusions: With less trauma and a promising route for hearing preservation and facial nerve functions, the retrolabyrinthine approach is a potential choice for the treatment of VS located in the IAC-CPA.

Significance of endolymphatic sac surgery with and/or without simultaneous cochlea implant surgery in respect of vertigo control and speech perception in patients with Menière’s disease

PurposeThe focus on treating patients with Menière’s Disease (MD) lies on the reduction of vertigo attacks and the preservation of sensory function. Endolympathic hydrops is considered as an epiphenomenon in MD, which can potentially be altered by endolymphatic sac surgery (ESS). Purpose of the study was to investigate the influences on vertigo control through manipulation of the perilymphatic system with or without ESS.MethodsRetrospective data analysis of 86 consecutive patients with MD according to current diagnostic criteria after endolymphatic sac surgery alone (ESSalone; n = 45), cochlear implantation (CI) alone (CIalone; n = 12), and ESS with CI (ESS + CI; n = 29), treated at a tertiary referral center. Main Outcome Measures: vertigo control, speech perception pre- and postoperatively.ResultsGender, side, and preoperative treatment were similar in all groups. Age was younger in the ESSalone-group with 56.2 ± 13.0 years (CIalone = 64.2 ± 11.4 years; ESS + CI = 63.1 ± 9.7 years). Definitive MD was present in all the CIalone, in 79.3% of the ESS + CI and in 59.6% of the ESSalone-patients. Likewise, vertigo control rate was 100% in the CIalone, 89.7% in the ESS + CI and 66.0% in the ESSalone-group.ConclusionsVertigo control was improved in all three groups, however, superior in groups treated with CI, potentially contributed by the manipulation of both the endo- and perilymphatic systems. A more systematic characterization of the patients with larger case numbers and documentation of follow up data would be needed to evaluate a clinical effect more properly.

Live Imaging of the Dehydration Effect of Isosorbide on the Normal and Hydropic Guinea Pig Cochleae Using Optical Coherence Tomography.

To investigate the isosorbide-induced dehydration effect on the endolymphatic space by intratympanic administration of isosorbide. Isosorbide, an osmotic diuretic, is used orally as a typical conservative therapy for Menière's disease (MD) in Japan. The dehydration effect occurs 6 hours after isosorbide ingestion. Intratympanic administration of isosorbide resolves endolymphatic hydrops faster than oral ingestion. In addition, the dehydration effect has never been shown directly. Therefore, we investigated the dehydration effect of intratympanic administration of isosorbide on endolymphatic hydrops using optical coherence tomography. We used eight Hartley guinea pigs, divided into normal and hydrops groups. In the hydrops group, the animals underwent endolymphatic sac obliteration to create endolymphatic hydrops. We obtained midmodiolar section images of the cochleae using optical coherence tomography. Then, 50 to 70% isosorbide was sequentially administered intratympanically for 5 minutes, and the apical turn of the cochlea was observed. The relative midmodiolar cross-sectional area of the scala media was calculated for quantitative assessment of the endolymphatic space. In the normal group, 50% isosorbide had a slight but significant dehydration effect on the scala media; at 55 to 70%, Reissner's membrane became flat. In the hydrops group, 50% isosorbide slightly reduced endolymphatic hydrops; 65% flattened Reissner's membrane, and 70% slightly concaved it toward the basilar membrane. The results suggest that we could select the concentration of isosorbide according to the stage or severity of MD and relief from acute attack. Intratympanic administration of isosorbide may be a promising treatment for patients with MD.

Iatrogenic inner ear dehiscence associated with lateral skull base surgery: a systematic analysis of drilling injuries and their causal factors.

Drilling injuries of the inner ear are an underreported complication of lateral skull base (LSB) surgery. Inner ear breaches can cause hearing loss, vestibular dysfunction, and third window phenomenon. This study aims to elucidate primary factors causing iatrogenic inner ear dehiscences (IED) in 9 patients who presented to a tertiary care center with postoperative symptoms of IED following LSB surgery for vestibular schwannoma, endolymphatic sac tumor, Meniere's disease, paraganglioma jugulare, and vagal schwannoma. Utilizing 3D Slicer image processing software, geometric and volumetric analysis was applied to both preoperative and postoperative imaging to identify causal factors iatrogenic inner ear breaches. Segmentation analyses, craniotomy analyses, and drilling trajectory analyses were performed. Cases of retrosigmoid approaches for vestibular schwannoma resection were compared to matched controls. Excessive lateral drilling and breach of a single inner ear structure occurred in 3 cases undergoing transjugular (n=2) and transmastoid (n=1) approaches. Inadequate drilling trajectory breaching ≥1 inner ear structure occurred in 6 cases undergoing retrosigmoid (n=4), transmastoid (n=1), and middle cranial fossa approaches (n=1). In retrosigmoid approaches the 2-cm visualization window and craniotomy limits did not provide drilling angles to the entire tumor without causing IED in comparison to matched controls. Inappropriate drill depth, errant lateral drilling, inadequate drill trajectory, or a combination of these led to iatrogenic IED. Image-based segmentation, individualized 3D anatomical model generation, and geometric and volumetric analyses can optimize operative plans and possibly reduce inner ear breaches from lateral skull base surgery.

Radiological feature heterogeneity supports etiological diversity among patient groups in Meniere’s disease

We aimed to determine the prevalence of radiological temporal bone features that in previous studies showed only a weak or an inconsistent association with the clinical diagnosis of Meniere’s disease (MD), in two groups of MD patients (n = 71) with previously established distinct endolymphatic sac pathologies; i.e. the group MD-dg (ES degeneration) and the group MD-hp (ES hypoplasia). Delayed gadolinium-enhanced MRI and high-resolution CT data were used to determine and compare between and within (affected vs. non-affected side) groups geometric temporal bone features (lengths, widths, contours), air cell tract volume, height of the jugular bulb, sigmoid sinus width, and MRI signal intensity alterations of the ES. Temporal bone features with significant intergroup differences were the retrolabyrinthine bone thickness (1.04 ± 0.69 mm, MD-hp; 3.1 ± 1.9 mm, MD-dg; p < 0.0001); posterior contour tortuosity (mean arch-to-chord ratio 1.019 ± 0.013, MD-hp; 1.096 ± 0.038, MD-dg; p < 0.0001); and the pneumatized volume (1.37 [0.86] cm3, MD-hp; 5.25 [3.45] cm3, MD-dg; p = 0.03). Features with differences between the affected and non-affected sides within the MD-dg group were the sigmoid sinus width (6.5 ± 1.7 mm, affected; 7.6 ± 2.1 mm, non-affected; p = 0.04) and the MRI signal intensity of the endolymphatic sac (median signal intensity, affected vs. unaffected side, 0.59 [IQR 0.31–0.89]). Radiological temporal bone features known to be only weakly or inconsistently associated with the clinical diagnosis MD, are highly prevalent in either of two MD patient groups. These results support the existence of diverse—developmental and degenerative—disease etiologies manifesting with distinct radiological temporal bone abnormalities.

Hearing Outcomes Following Endolymphatic Duct Blockage Surgery and Factors Associated with Improved Audition at Two Years Follow-Up.

Objective: To evaluate hearing outcomes at 2 years post endolymphatic duct blockage (EDB) surgery, with an analysis of factors that may predict hearing improvement. Study Design: Retrospective comparative study. Setting: Tertiary care center. Subjects: Definite Ménière's Disease (MD) patients undergoing EDB for refractory disease. Methods: Chart review was conducted to assign cases to one of the three hearing outcome groups (deteriorated, stable, and improved). All cases that met our inclusion criteria were selected. Preoperative data collected were audiograms, bithermal caloric tests, preoperative vertigo episodes, history of previous ear surgery for Ménière, intratympanic steroid injections (ITS) and intraoperative endolymphatic sac (ELS) tear or opening. Postoperative data collected at 24 months were audiograms, vertigo episodes and bithermal caloric testing. Results: Preoperative vertigo episodes, caloric paresis and history of surgery, ITS injections or ELS integrity, as well as postoperative vertigo class distribution and caloric paresis changes were not different between our groups. Preoperative word recognition score (WRS) was lowest in the improved hearing group (p = 0.032). The persistence of tinnitus at 2 years postoperatively was associated with deteriorated hearing (p = 0.033). Conclusions: There are no strong predictors of hearing improvement on presentation pre-EDB, but low preoperative WRS may be the best estimator available. Therefore, ablative interventions should be considered very carefully in patients presenting with low WRS, as they may benefit more from EDB; there is a fair chance of a good hearing outcome with EDB surgery. Persistence of tinnitus can reflect deteriorating audition. Vertigo control and hearing preservation are independent outcomes of EDB surgery, making it desirable as an early intervention for refractory MD cases.

What a Neurosurgeon Should Know About the Endolymphatic Sac: Part 2 – Diagnosis and Management of the Endolymphatic Sac Tumors

Abstract Objective This article is divided into three parts. In the second part of this review, the authors focus on describing the endolymphatic sac tumor and presenting illustrative cases. Methods A review of previous studies, from 1957 to 2021, from basic and translational research using human and animal endolymphatic sac (ES) tissue or cells, as well as other reviews on this theme. Results The ES is an inner ear structure, which is responsible for the homeostatic regulation, as well as endolymphatic fluid volume control, immune response etc. One of the possible alterations of the ES is the ELST, a low-grade malign neoplasm that originates from the epithelium of the endolymphatic duct and sac. The clinical presentation of the ELST includes hearing loss, tinnitus, headache, and vertigo. The diagnosis in the early stages is rare, given that this group of symptoms is very similar to other, more common, diseases such as the Meniere syndrome. Its diagnosis is made by computed tomography (CT), magnetic resonance imaging (MRI), immunohistochemistry, and confirmed by histopathology. However, none of these examinations are part of the pathological guidelines for ELST. The treatment for ELST in the early stages has a high rate of success. Conclusion The ELST is a very difficult diagnosis due to its presentation. Furthermore, the interactions between ELST and the Von Hippel-Lindau disease usually result in a more aggressive condition. Despite the difficulty of the diagnosis, doing it early increases the chances of successful treatment.

What a Neurosurgeon Should Know About the Endolymphatic Sac: Part 3 – Ménière Disease

Abstract Objective To elucidate all the aspects that neurosurgeons should know about the Ménière disease (MD). Methods Review of guidelines, books, and studies from 1933 to 2021, from basic to translational research, using human and animal endolymphatic sac (ES) tissue or cells, as well as reviews, case reports, and papers about surgical experience. This article is divided into three parts. In this last part, we review the MD. Results The MD is one of the most common pathologies in the ES. It was first described by Prosper Ménière in 1861 with its clinical triad: dizziness, tinnitus, and hearing loss. A lot of theories relating ES to the MD have been proposed. Some of them postulate that it is caused by a narrowing and shortening in the endolymphatic duct, and others relate it to severe inflammation on the ES. Mostly due to the lack of understanding of this pathology, the diagnosis is mainly clinical, despite histopathology being helpful to confirm the diagnosis. The treatment of the MD can be done in 3 different ways: pharmacological, nonpharmacological, and surgical. Conclusion The MD is one of the most common pathologies in the inner ear and has been largely studied over the years. The latest diagnosis guidelines must help in the classification and give better basis for diagnosis and treatment, which, despite not being curative yet, has improved over the years. Pharmacological treatment based on the possible etiologies, allied with proper diet and routine exercise, is showing promising results.

Surgical Management of Endolymphatic Sac Tumor: A Systematic Review and Meta-Analysis.

The aim of our study was to report rates of facial nerve palsy and residual tumor following surgical intervention and subsequent tumor recurrence in patients with endolymphatic sac tumors. A systematic literature review of preoperative assessment and surgical management is also included. Studies including patient/s affected by sporadic or von Hippel-Lindau disease related endolymphatic sac tumors, reporting levels of facial nerve function, residual and recurrence pathology following a surgical procedure, were considered. Data were combined for proportional meta-analysis, and the selected studies' methodological quality was also evaluated. Overall 34 papers, including 202 subjects (209 cases of endolymphatic sac tumors) were analyzed. Pooled proportion rate (95% CI) of overall facial nerve palsy was 39.7% (28.2-51.9) and residual tumor was 16.5% (10.3-23.7) after surgical procedure. Pooled proportion rate (95% CI) of tumor recurrence was 14.0% (9.7-19.3) during a mean follow-up period of 49.7 months (8-136). Our results showed that preoperative facial nerve function is impaired in almost 30% of patients with endolymphatic sac tumors. Surgical management of endolymphatic sac tumor may cause a worsening of facial nerve function in a low percentage of treated subjects. Residual and/or recurrence of endolymphatic sac tumors are not rare events, and follow-up strategies should be designed accordingly.

전정수도관 확장 증후군 환자에서 발견된 내림프낭 종양 1예

An endolymphatic sac tumor (ELST) is a tumor of neuroectodermal origin. Although several cases have been reported in Korea, it is known to be very rare. Clinically, it grows slowly but shows an aggressive pattern accompanied by bone destruction pathologically. As the tumor grows, it shows symptoms due to endolymphatic hydrops such as hearing loss, tinnitus, and dizziness. In this paper, we report a case in which an ELST was found in a patient suffering from profound sensorineural hearing loss, tinnitus, and dizziness, who turned out to be an enlarged vestibular aqueduct syn-drome.

The effect of vascular risk factors on the efficacy of endolymphatic sac decompression surgery for Meniere's disease: a retrospective cohort study.

This study aimed to investigate the effect of vascular risk factors on the outcomes of endolymphatic sac decompression (ESD) surgery in patients with Meniere's disease. The study included 56 patients with Meniere's disease, who had undergone unilateral ESD surgery. The patients' vascular risk factors were assessed based on the preoperative 10-year atherosclerotic cardiovascular diseases risk classification. Those with no or low risk were defined as the low-risk group, while those with medium, high, or very high risk were defined as the high-risk group. The correlation between the vascular risk factors and ESD efficacy was evaluated by the comparison of vertigo control grade between the two groups. The functional disability score was also assessed to investigate whether ESD improved the quality of life in Meniere's disease patients with vascular risk factors. After ESD, 78.95 and 81.08% of patients from the low-risk and high-risk groups, respectively, demonstrated at least grade B vertigo control; no statistically significant difference was observed (p = 0.96). The postoperative functional disability scores in both groups were significantly lower compared with those before surgery (p < 0.01), with a median decrease of two (1, 2) points in both groups. No statistically significant difference between the two groups was observed (p = 0.65). Vascular risk factors have little effect on the efficacy of ESD in patients with Meniere's disease. Patients with one or more vascular risk factors can still experience a not poor vertigo control and improved quality of life after ESD.

Can MRI biomarkers for hearing loss in enlarged vestibular aqueduct be measured reproducibly?

Morphological features of an enlarged endolymphatic duct (ED) and sac (ES) are imaging biomarkers for genotype and hearing loss phenotype. We determine which biomarkers can be measured in a reproducible manner, facilitating further clinical prediction studies in enlarged vestibular aqueduct hearing loss. A rater reproducibility study. Three consultant radiologists independently measured previously reported MRI ED & ES biomarkers (ED midpoint width, maximal ED diameter closest to the vestibule, ES length, ES width and presence of ES signal heterogeneity) and presence of incomplete partition Type 2 from 80 ears (T2 weighted axial MRI). Interclass correlation coefficients (ICC) and Gwet's Agreement Coefficients (AC) were generated to give a measure of reproducibility for both continuous and categorical feature measures respectively. ES length, width and sac signal heterogeneity showed adequate reproducibility (ICC 95% confidence intervals 0.77-0.95, Gwet's AC for sac heterogeneity 0.64). When determining ED midpoint width, measurements from multiple raters are required for "good" reliability (ICC 95% CI 0.75-0.89). Agreement on the presence of incomplete partition Type 2 ranged from "moderate" to "substantial". Regarding MR imaging, the opinion of multiple expert raters should be sought when determining the presence of an enlarged ED defined by midpoint width. ED midpoint, ES length, width and signal heterogeneity have adequate reproducibility to be further explored as clinical predictors for audiological phenotype. We report which ED & ES biomarkers are reproducibly measured. Researchers can confidently utilise these specific biomarkers when modelling progressive hearing loss associated with enlarged vestibular aqueduct.

Menière's Syndrome Associated With Fibrous Dysplasia of the Temporal Bone.

Menière's Syndrome Associated With Fibrous Dysplasia of the Temporal Bone.

Endolymphatic Duct Blockage as a Surgical Treatment Option for M&amp;#233;ni&amp;#232;re's Disease

Endolymphatic duct blockage is a relatively new treatment option for Ménière's disease, aiming to reduce vertigo attacks while sparing hearing and equilibrium. After a regular mastoidectomy, the posterior semicircular canal is identified, and Donaldson's line is determined. This is a line through the horizontal semicircular canal, crossing the posterior semicircular canal. The endolymphatic sac is usually found at this site under the posterior semicircular canal. The bone of the endolymphatic sac and the dura are thinned until the sac is skeletonized, after which the endolymphatic duct is identified. The duct is then blocked with a titanium clip. Using a computerized tomography (CT) scan, the position is confirmed. Follow-up visits take place 1 week, 6 weeks and 1 year after surgery. To this day, only one prospective trial assessing this method has been conducted, comparing this new method to endolymphatic sac decompression. Results of the duct blockage are promising, with 96.5% of the patients free of vertigo after 2 years. However, further research is required.

Endolymphatic Sac Decompression

The endolymphatic sac (ELS) decompression can be performed for patients with Meniere’s disease that have failed conservative treatment such as dietary changes and medical therapy. The full pathophysiological mechanisms that result in Meniere’s disease are not entirely understood. The variation in techniques for performing ELS decompression support this; there is no concrete data to justify one approach over another. Regardless, in the correct patient, ELS decompression can significantly alleviate the patient’s symptoms. To do so, a mastoidectomy is performed to expose the bony labyrinth as well as the bone overlying the sigmoid sinus. Decompression of the sac can be accomplished by removing overlying bone, incising the dura, or stenting the dura open.

Evaluation of changes in endolymphatic volume after middle ear pressure therapy for intractable meniere’s disease using 3D magnetic resonance imaging

Background Nowadays, the endolymphatic space size can be evaluated by 3D-analysis of 3 T-MRI after intravenous injection of gadolinium enhancement. Aims/objectives In the present study, to elucidate the relationships between vertigo and endolymphatic hydrops (EH) volume after middle ear pressure therapy (MEPT), we investigated changes in EH volume after MEPT for intractable Meniere’s disease (MD) by means of the inner ear MRI (ieMRI) in relation to clinical results. Materials and methods We enrolled 202 successive definite MD cases with intractable vertiginous symptoms from 2015 to 2020, assigning Group-I of MEPT, and Group-II of endolymphatic sac drainage (ELSD). Ninety patients completed the planned 2-year-follow-up, which included assessment of vertigo frequency and changes in EH volume using ieMRI (Group-I/MEPT: n = 40; Group-II/ELSD: n = 50). Results Two years after surgery, vertigo was completely controlled in 77.5% of patients in Group-I and 90.0% in Group-II. Hearing improved by >10 dB in 7.5% of patients in Group-I and 24.0% in Group-II. ELS ratios were significantly reduced after treatments of Group-I and Group-II only in the vestibule. Conclusions The obtained results indicate that MEPT as well as ELSD could be a good treatment option for patients with intractable MD.

The Diagnosis and Management of Advanced Endolymphatic Sac Tumor.

Endolymphatic sac tumor (ELST) is a group of low-grade malignant tumors originating from the endolymphatic sac of the inner ear. It is rare in the clinic and has the biological characteristics of slow growth and local aggression. Due to the lack of specificity in the clinical manifestations of patients with ELST, many cases have entered the advanced stage at the time of diagnosis. However, there are still great challenges in the treatment of advanced ELSTs. Here, the authors describe a case of advanced ELST, which relapsed after 2 operations. This time, the authors chose the transotic approach for tumor resection, which achieved the goal of complete resection of the tumor, and the patient recovered smoothly after surgery. There were no surgical complications and no tumor recurrence after the follow-up. Through literature review and our own experience, the authors suggest that complete surgical resection is the first choice for both primary and recurrent advanced ELSTs. The choice of a reasonable surgical approach is the key to ensuring complete resection of the tumor, while preoperative angiography and embolization, fine treatment of important structures during surgery, and postoperative long-term follow-up are equally important for patients with advanced ELST to obtain a good prognosis.

Symptom: Vertigo After Labyrinthectomy

Symptom: Vertigo After Labyrinthectomy

VON HIPPEL-LINDAU DISEASE, DESCRIPTION, GENETICS, MOLECULAR BASIS, CLASSIFICATION AND MANIFESTATIONS OF THE DISEASE

Introduction: Von Hippel-Lindau disease (VHL) is autosomal dominant tumor syndrome that debuts mostly in young adults , patients with this disease are linked to the triggering of various types of benign and malignant neoplasms in multiple locations, systems and organs, in particular affecting more the nervous system and other internal organs. Approximately this tumor syndrome shows an incidence rate of 1 in 36,000 live births with a penetrance greater than 90%. The molecular basis of VHL disease is the impairment of VHL protein function and the consequent clustering of hypoxia-inducible factors with subsequent consequences on cell differentiation and metabolism. Objective: to present current information related to Von Hippel-Lindau disease, description, genetics, molecular basis, classification and manifestations of the disease. Methodology: a total of 33 articles were analyzed in this review, including review and original articles, as well as clinical cases, of which 26 bibliographies were used because the other articles were not relevant to this study. The sources of information were PubMed, Google Scholar and Cochrane; the terms used to search for information in Spanish, Portuguese and English were: Von Hippel-Lindau, VHL, tumor suppressor gene, pheochromocytoma, hemangioblastomas. Results: VHL has an incidence of approximately 1 in 36,000 live births, with a penetrance of over 90%. These present tumors are initiated by inactivation of biallelic VHL and are related to pathologic activation of hypoxic gene response pathways. Conclusions: Von Hippel-Lindau disease is an autosomal dominant disorder that is generated by mutations in the VHL tumor suppressor gene. Within the field intrafamilial variation may evidence correctly shaped genotype-phenotype connections for renal cancer and pheochromocytoma risks. Visceral cysts (renal, pancreatic and epididymal) are frequent, however organ function involvement is rare. They usually occur with hemangioblastomas of the central nervous system and retina, as well as renal cancers. Unusually it includes non-functioning pancreatic endocrine cancers, adrenal and extra-adrenal pheochromocytomas, endolymphatic sac tumors, as well as head and neck paragangliomas. KEYWORDS: Von Hippel-Lindau, VHL, gene, suppressor, tumor, pheochromocytoma, hemangioblastomas