Blood flow to the promontory in cochlear otosclerosis

Vertigo Associated with Otosclerosis and Stapes Surgery-A Narrative Review

Otosclerosis is a pathological condition affecting the temporal bone, and is characterized by remodelling of the labyrinthine bone tissue through a dynamic process of osteolysis and osteogenesis. This condition progressively leads to hearing loss, tinnitus, and vertigo. Stapedotomy, a surgical procedure involving the removal of the stapes superstructure and its replacement with a prosthesis, is the treatment of choice to improve hearing in individuals with otosclerosis. However, vestibular dysfunction is a significant complication associated with this procedure, which can occur intraoperatively or postoperatively, ranging from the immediate postoperative period to weeks, months, or even years after surgery. This paper aims to provide a comprehensive review of the most important causes of vertigo associated with otosclerosis and stapes surgery with the goal of minimizing the incidence of this complication. Understanding the underlying factors contributing to vertigo in this context is crucial for the prevention and effective management of vertigo in patients undergoing stapedotomy.

Labral Reconstruction via Capsular Augmentation Maintains Perfusion to the Acetabular Labrum and Locally Transferred Autograft: An in Vivo Laser Doppler Flowmetry Analysis

Background

The purpose of the present study was to examine the effects of arthroscopic labral repair with capsular augmentation on blood flow in vivo with use of laser Doppler flowmetry (LDF) to measure microvascular perfusion of the labrum and autograft tissue.

Methods

The present prospective case series included patients ≥18 years old who underwent arthroscopic acetabular labral repair with capsular augmentation; all procedures were performed by a single surgeon between 2018 and 2022. The LDF probe measured microvascular blood flow flux within 1 mm3 of the surrounding labral and capsular tissue of interest. Mean baseline measurements of flux were compared with readings immediately following capsular elevation and after completing labral augmentation. Blood flux changes were expressed as the percent change from the baseline measurements.

Results

The present study included 41 patients (24 men [58.5%] and 17 women [41.5%]) with a mean age (and standard deviation) of 31.3 ± 8.4 years, a mean BMI of 24.6 ± 3.4 kg/m2, a mean lateral center-edge of angle 35.3° ± 4.9°, a mean Tönnis angle of 5.8° ± 5.8°, and a mean arterial pressure of 93.7 ± 10.9 mm Hg. Following capsular elevation, the mean percent change in capsular blood flow flux was significantly different from baseline (-9.24% [95% confidence interval (CI), -18.1% to -0.04%]; p < 0.001). Following labral augmentation, the mean percent change in labral blood flow flux was significantly different from baseline both medially (-22.3% [95% CI, -32.7% to -11.9%]; p < 0.001) and laterally (-32.5% [95% CI, -41.5% to -23.6%]; p = 0.041). There was no significant difference between the changes in medial and lateral perfusion following repair (p = 0.136).

Conclusions

Labral repair with capsular augmentation sustains a reduced blood flow to the native labrum and capsular tissue at the time of fixation. The biological importance of this reduction is unknown, but these findings may serve as a benchmark for other labral preservation techniques and support future correlations with clinical outcomes.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Association Between the Duration of Hearing Loss and Hearing Outcomes in Surgery for Otosclerosis

INTRODUCTION

Hearing loss due to otosclerosis is effectively treated with surgery. The association between duration of hearing loss and surgical outcomes is unknown.

STUDY DESIGN

Retrospective review.

SETTING

Large otology referral center.

METHODS

Patients undergoing primary stapes surgery for otosclerosis from 2005 to 2017 were evaluated according to their self-reported duration of hearing loss. Closure of the air-bone gap (ABG) was the primary outcome measure.

RESULTS

A total of 580 stapes operations were included. Sixteen percent of patients reported hearing loss for ≤1 year; 25%, >1 to ≤5 years; 24%, >5 to ≤10 years; 24%, >10 to ≤20 years; and 12%, >20 years, respectively. Average pre- and postoperative ABGs were 26.1 and 9.6 dB (P < .0005). Patients with longer duration of hearing loss had worse preoperative ABGs (P < .0005). After surgery, patients with longer duration of hearing loss had a greater reduction in their ABGs (P < .0005) such that the remaining ABG was not associated with duration of hearing loss (P > .05). There were no significant associations between the duration of hearing loss and complication rates or the need for revision surgery.

CONCLUSION

Otosclerosis is effectively treated with surgery even after a long duration of hearing loss, provided that sensorineural hearing and word recognition are favorable. Although far-advanced otosclerosis has known poorer hearing outcomes after stapes surgery, a long duration of hearing loss is an unreliable surrogate for this.

Use of near-infrared systems for investigations of hemodynamics in human in vivo bone tissue: A systematic review

A range of technologies using near infrared (NIR) light have shown promise at providing real time measurements of hemodynamic markers in bone tissue in vivo, an exciting prospect given existing difficulties in measuring hemodynamics in bone tissue. This systematic review aimed to evaluate the evidence for this potential use of NIR systems, establishing their potential as a research tool in this field. Major electronic databases including MEDLINE and EMBASE were searched using pre-planned search strategies with broad scope for any in vivo use of NIR technologies in human bone tissue. Following identification of studies by title and abstract screening, full text inclusion was determined by double blind assessment using predefined criteria. Full text studies for inclusion were data extracted using a predesigned proforma and quality assessed. Narrative synthesis was appropriate given the wide heterogeneity of included studies. Eighty-eight full text studies fulfilled the inclusion criteria, 57 addressing laser Doppler flowmetry (56 intra-operatively), 21 near infrared spectroscopy, and 10 photoplethysmography. The heterogeneity of the methodologies included differing hemodynamic markers, measurement protocols, anatomical locations, and research applications, making meaningful direct comparisons impossible. Further, studies were often limited by small sample sizes with potential selection biases, detection biases, and wide variability in results between participants. Despite promising potential in the use of NIR light to interrogate bone circulation, the application of NIR systems in bone requires rigorous assessment of the reproducibility of potential hemodynamic markers and further validation of these markers against alternative physiologically relevant reference standards. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2595-2603, 2018.

Ear and Temporal Bone: Cartilaginous and Osseous Pathologies

Although the majority of conditions involving the ear and temporal bone are inflammatory or epithelial based, cartilage and osseous entities will also be encountered. The pathologic examination of these underlying cartilaginous and osseous structures and their histologic findings and associated differential diagnoses will be discussed. Correlation with clinical and imaging findings are also critical for accurate determination of the pathologic entity.

Monitoring blood-flow in the mouse cochlea using an endoscopic laser speckle contrast imaging system

Laser speckle contrast imaging (LSCI) enables continuous high-resolution assessment of microcirculation in real-time. We applied an endoscope to LSCI to measure cochlear blood-flow in an ischemia–reperfusion mouse model. We also explored whether using xenon light in combination with LSCI facilitates visualization of anatomical position. Based on a previous preliminary study, the appropriate wavelength for penetrating the thin bony cochlea was 830 nm. A 2.7-mm-diameter endoscope was used, as appropriate for the size of the mouse cochlea. Our endoscopic LSCI system was used to illuminate the right cochlea after dissection of the mouse. We observed changes in the speckle signals when we applied the endoscopic LSCI system to the ischemia-reperfusion mouse model. The anatomical structure of the mouse cochlea and surrounding structures were clearly visible using the xenon light. The speckle signal of the cochlea was scattered, with an intensity that varied between that of the stapes (with the lowest signal), the negative control, and the stapedial artery (with the highest signal), the positive control. In the cochlear ischemia–reperfusion mouse model, the speckle signal of the cochlea decreased during the ischemic phase, and increased during the reperfusion phase, clearly reflecting cochlear blood-flow. The endoscopic LSCI system generates high-resolution images in real-time, allowing visualization of blood-flow and its changes in the mouse cochlea. Anatomical structures were clearly matched using LSCI along with visible light.

Cochlear Lymph Fluid Signal Increase in Patients with Otosclerosis after Intravenous Administration of Gadodiamide

Purpose:

Increased cochlear lymph fluid signals on three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) images obtained several minutes after intravenous administration of a single dose of gadolinium-based contrast agent (IV-SD-GBCA) in a patient with severe retrofenestral type otosclerosis had been reported. This increase was thought to represent breakdown of the blood-labyrinthine barrier. The purpose of this study was to evaluate cochlear lymph signal on heavily T₂-weighted 3D-FLAIR (HF) images obtained 4 hours after IV-SD-GBCA in patients with otosclerosis, Ménière’s disease, and healthy subjects.

Materials and Methods:

Twenty-two ears from 12 patients with otosclerotic plaques determined by computed tomography (CT), 16 ears from 8 healthy volunteers, and 10 ears from 9 Ménière’s disease patients with significant endolymphatic hydrops on magnetic resonance (MR) images were retrospectively analyzed. Images were obtained 4 hours after IV-SD-GBCA. Patients and healthy volunteers underwent MR cisternography (MRC) for anatomical reference of the fluid space and HF at 3T. The region of interest (ROI) was manually drawn on MRC images around the scala tympani in the basal cochlear turn. The reference ROI was set in the cerebellum. ROIs were copied onto HF images and the signal intensity ratio (SIR) of cochlear perilymph to cerebellum was measured. Differences in the SIR on HF images among the three groups were tested by one-way analysis of variance (ANOVA).

Results:

The mean SIR was 24.0 ± 10.1 in otosclerosis patients, 7.9 ± 1.5 in volunteers, and 11.6 ± 3.9 in Ménière’s disease patients. The mean SIR was significantly higher in the otosclerosis group than in the other groups (P < 0.001). In the otosclerosis group, there was a significant difference in the SIR between the retrofenestral type and the fenestral type (P = 0.033).

Conclusions:

In patients with otosclerosis, the SIR was higher than in Ménière’s disease patients or in healthy volunteers. The SIR was higher in the retrofenestral type than in the fenestral type.

Imaging Review of the Temporal Bone: Part II. Traumatic, Postoperative, and Noninflammatory Nonneoplastic Conditions

The first part of this review of the temporal bone discussed anatomy of the temporal bone as well as inflammatory and neoplastic processes in the temporal bone region (1). This second part will first discuss trauma to the temporal bone and posttraumatic complications. The indications for common surgical procedures performed in the temporal bone and their postoperative imaging appearance are then presented. Finally, a few noninflammatory nonneoplastic entities involving the temporal bone are reviewed. They are relatively uncommon diagnoses compared with infectious or inflammatory diseases. However, because patients present with symptoms that are either common (hearing loss) or distinctive (sensorineural hearing loss in a child), they are important for the radiologist to be aware of and recognize.

Revision surgery for otosclerosis: An overview

Stapes surgery for otosclerosis has been proved to be a very satisfying procedure. However, the condition is difficult for the patients with no or little hearing gain after surgery and for those who had sudden or gradual hearing loss after a successful air-bone gap closure in the follow-up period. The issue of re-exploring the middle ear is challenging. A general review of this subject from several points of view remains lacking. In this study, articles related with the revision surgery for otosclerosis have been reviewed after a PubMed research and common and/or contradictory points were documented. The aim of this study is to give an insight to diagnostic and therapeutic approaches for the clinicians in patients who need a revision surgery. In conclusion, prosthesis problems, loose prosthesis in stapedotomy and migrated prosthesis in stapedectomy are the most common causes for revision surgery. Most important indicators which effect better hearing outcome following revision surgery are those ears with the presence of incus, with no obliteration of oval window, with small fenestra stapedotomy and the experience of surgeon. The risk of neurosensorial hearing loss in revision cases is not high but the hearing gain is limited as compared to primary cases. The rate of 10 dB air-bone gap closure is around 60%-70% at most and even less promising results have been reported. Patient’s demands and expectations have to be clarified in a realistic way.

Free flap blood flow evaluated using two-dimensional laser speckle flowgraphy

Objective. We investigated the efficiency of laser speckle flowgraphy for evaluating blood flow in free flaps used for plastic surgery. Methods. We measured blood flow using a visual laser meter capable of providing two-dimensional color graphic representations of flow distribution for a given area using a dynamic laser speckle effect. Using laser speckle flowgraphy, we examined the blood flow of 20 free flaps applied following the excision of head and neck tumors. Results. After anastomosis of the feeding and draining blood vessels and sewing the flap, musculocutaneous (MC) flaps showed significantly lower blood flow than jejunal or omental flaps (P < .05). The ratio of blood flow decrease from the edge to the center was significantly greater in MC flaps than in jejunal or omental flaps (P < .001). Conclusion. Laser speckle flowgraphy is useful for the perioperative measurement of blood flow in free flaps used in plastic surgery. This method is a highly useful, practical, and reliable tool for assessing cutaneous blood flow and is expected to be applicable to several clinical fields.

Evaluation of the usefulness of skin blood flow measurements by laser speckle flowgraphy in pressure-induced ischemic wounds in rats

Assessment of blood circulation in pressure ulcers can be beneficial for predicting the severity of tissue damage and making the prognosis. Here, we evaluated the usefulness of laser speckle flowgraphy (LSFG) for assessing skin blood flow in pressure-induced ischemic wounds in rats in comparison with skin temperature measurements by thermography, which is commonly used in clinical settings. The blood flow was assessed in 3 groups (control, 1 kg loading, and 10 kg loading for 3 hours), before, immediately after, and on days 1, 2, and 3 after loading. The 10 kg loading induced more severe tissue damage but did not show any distinguishable gross manifestations immediately after releasing the indenter. LSFG detected a significantly reduced blood flow velocity after 10 kg loading compared with 1 kg loading, whereas thermography did not. These results indicate the usefulness of LSFG measurements for assessing tissue circulation in an early phase after tissue damage onset.

Measurement of blood flow in the rotator cuff using laser Doppler flowmetry

The aim of this study was to define the microcirculation of the normal rotator cuff during arthroscopic surgery and investigate whether it is altered in diseased cuff tissue. Blood flow was measured intra-operatively by laser Doppler flowmetry. We investigated six different zones of each rotator cuff during the arthroscopic examination of 56 consecutive patients undergoing investigation for impingement, cuff tears or instability; there were 336 measurements overall. The mean laser Doppler flowmetry flux was significantly higher at the edges of the tear in torn cuffs (43.1, 95% confidence interval (CI) 37.8 to 48.4) compared with normal cuffs (32.8, 95% CI 27.4 to 38.1; p = 0.0089). It was significantly lower across all anatomical locations in cuffs with impingement (25.4, 95% CI 22.4 to 28.5) compared with normal cuffs (p = 0.0196), and significantly lower in cuffs with impingement compared with torn cuffs (p < 0.0001). Laser Doppler flowmetry analysis of the rotator cuff blood supply indicated a significant difference between the vascularity of the normal and the pathological rotator cuff. We were unable to demonstrate a functional hypoperfusion area or so-called 'critical zone' in the normal cuff. The measured flux decreases with advancing impingement, but there is a substantial increase at the edges of rotator cuff tears. This might reflect an attempt at repair.

Three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging findings in a patient with cochlear otosclerosis

A 51-year-old man had progressive hearing loss over more than 15 years. He had bilateral sensorineural hearing loss (SNHL). Computed tomography (CT) showed extensive bilateral demineralization of the cochlear capsule, which is characteristic of diffuse cochlear otosclerosis. Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) of magnetic resonance imaging before enhancement revealed high signals in the cochlea and vestibule. Postcontrast 3D-FLAIR revealed enhancement of the basal turn of the left cochlea. This is the first published case of the breakdown of the blood-labyrinth barrier in a patient with cochlear otosclerosis. Our findings suggest that the breakdown of the blood-labyrinth barrier is associated with a part of SNHL in cochlear otosclerosis.

Current research in otosclerosis

PURPOSE OF REVIEW

The aim of this article is to summarize and put into historical perspective current advances in research in otosclerosis, a disorder of the human temporal bone with a hereditary predisposition that is among the most common causes of acquired hearing loss.

RECENT FINDINGS

Genetic studies have revealed that otosclerosis is heterogeneous, with evidence for defects in at least seven genes associated with six distinct chromosomal loci. Measurements of high levels of osteoprotegerin expression in the normal otic capsule and soft tissues of the cochlea provide the first molecular insight as to why the normal otic capsule remodels minimally, if at all. Osteoprotegerin knockout mice provide the best available animal model to date to study abnormal otic capsule remodeling that closely resembles otosclerosis. There is mounting evidence that the measles virus plays an important role in pathogenesis of otosclerosis although the mechanisms by which the virus results in otosclerosis remain unknown. Quantitative measures of angiogenesis can reliably distinguish between clinical and histological otosclerosis. Advances in the emerging field of osteoimmunology will likely impact and benefit from the research in otosclerosis.

SUMMARY

Insights into molecular mechanisms that inhibit extensive remodeling in the normal otic capsule, and understanding of how these mechanisms are dysregulated in otosclerosis will allow future design of rational treatment strategies for otosclerosis.