Prevalence, Location, and Variations of the Posterior Superior Alveolar Canal With Age and Gender in the Indian Population: A Cone Beam Computed Tomography (CBCT)-Based Retrospective Study.

BACKGROUND: Enhancing the availability of bone in the vertical dimension for implant insertion is thought to be possible through implant site preparation using direct or indirect sinus lift. The posterior superior alveolar (PSA) canal is extremely vulnerable to trauma during this procedure. The anatomy of this region should be thoroughly evaluated to prevent traumatizing this artery and eventual perioperative bleeding. Due to a lack of relevant knowledge and the clinical importance of this problem, the position, diameter, detectability, and proximity of this canal to the alveolar ridge were assessed on cone beam computed tomography (CBCT) scans which were the main objectives of this study. METHODOLOGY: A total of 240 CBCT scans were examined, and the position of the PSA canal, its diameter, the perpendicular distance from the inferior border of the PSA canal to the alveolar crest, and the perpendicular distance from the inferior border of the canal to the maxillary sinus floor was measured. RESULTS: Intraosseous PSA canals were the most prevalent, followed by intrasinusal and extraosseous canals. Males had larger canal diameters and greater distances between the maxillary sinus floor and alveolar crest and the canal (P < 0.05). CONCLUSION: CBCT was proven to be a useful method for assessing and localizing the PSA artery to prevent intraoperative bleeding and further complications.

Sigmoid Sinus Wall Anomalies Can Progress and May Not Be Congenital.

OBJECTIVE: Sigmoid sinus wall anomalies (SSWA) are closely linked to venous pulsatile tinnitus (PT). This study aims to demonstrate that SSWA develops progressively rather than being congenital. METHODS: We retrospectively analyzed 42 PT patients with SSWA who had at least two non-operative CT scans at our clinic. CT images were longitudinally assessed to track SSWA progression, while MRI and Doppler ultrasound evaluated transverse sinus stenosis and venous hemodynamics. Changes in PT perception were tracked using the tinnitus handicap inventory (THI) questionnaire. RESULTS: Among the 42 SSWA patients, 12 (28.6%) exhibited progression. Anastomosis between diploic vein and diverticulum was significantly higher compared to the dehiscence cohort (p < 0.01). Within the diverticulum group, seven individuals (30.4%) experienced enlargement, with a mean diverticular wall expansion of 5.9% ± 11.4%. Progressive erosion was observed in two cases (12.5%) in the dehiscence cohort, with a mean sigmoid plate erosion of 3.8% ± 10.1%. In cases progressing from dehiscence to diverticulum, three subjects transitioned, with a mean sigmoid sinus wall length expansion of 43.8% ± 31.9%. SSWA progression showed a significant negative correlation with QBILATERAL (r = -0.857, p = 0.014), and there was a significant difference between initial and revisit THI scores (p < 0.01). CONCLUSION: SSWA can undergo morphological progression, indicating it is a progressive clinical condition rather than congenital. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:4707-4715, 2024.

Fluid-structure interaction study on the causes of mending material damage after sigmoid sinus wall reconstruction.

BACKGROUND AND OBJECTIVE: Sigmoid Sinus (SS) Wall Reconstruction (SSWR) is the mainstream treatment for pulsatile tinnitus (PT), but it has a high risk of recurrence. The damage of mending material is the key cause of recurrence, and its hemodynamic mechanism is still unclear. The purpose of this study was to investigate the hemodynamic causes of mending material breakage. METHODS: In this study, six patient-specific geometric models were reconstructed based on the data of the computed tomography angiography (CTA). The transient fluid-structure coupling method was performed to clarify the hemodynamic state of sigmoid sinus and the biomechanical state of the mending material. The distribution of stress and displacement and the flow pattern were calculated to evaluate the hemodynamic and biomechanics difference at the mending material area. RESULTS: The area of blood flow impact in some patients (2/6) was consistent with the damaged location of the mending material. The average stress (6/6) and average displacement (6/6) of damaged mending material were higher than those of complete mending material. All (6/6) patients showed that the high-stress and high-displacement proportion of the DMM region was higher than that of the CMM region. Moreover, the average stress fluctuation (6/6) and average displacement (6/6) fluctuation degree of damaged mending material is larger than that of complete mending material. CONCLUSIONS: The impact of blood and the uneven stress and displacement fluctuation of the mending material may be the causes of mending material damage. High stress and high displacement might be the key causes of the mending material damage.

Endoscopic ultrasound guided resection of a Cushing's adenoma invading the medial cavernous sinus wall using the "interdural peeling" technique.

Cushing's adenoma invading the cavernous sinus requires aggressive resection to be cured. MRI is frequently inconclusive for identifying microadenomas, and visualizing the involvement of the medial cavernous sinus is even more challenging. In this video, the authors present a patient with an adrenocorticotropic hormone (ACTH)-producing microadenoma with doubtful left medial cavernous sinus involvement on MRI. She underwent an endoscopic endonasal exploration of the medial compartment of the cavernous sinus. The abnormally thickened wall, confirmed by intraoperative endoscopic endonasal ultrasound, was safely excised using the "interdural peeling" technique. Complete resection of the tumor resulted in normalization of her postoperative cortisol levels and disease remission with no complications. The video can be found here: https://stream.cadmore.media/r10.3171/2023.4.FOCVID22150.

Endoscopic endonasal approach for MRI-Negative Cushing's microadenoma.

A 54-year-old male with a history of diabetes mellitus type 2 for 12 years and hypertension was seen in the clinic due to poorly controlled diabetes. Inferior petrosal sinus sampling (IPSS) confirmed Cushing's disease with primary adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma on the right. However, 3T and subsequent 7T MRI showed no visible tumor. An endoscopic transsphenoidal approach was selected to explore the pituitary gland and resect the presumed microadenoma. Tumor was identified in the lateral recess along the right medial cavernous sinus wall and gross-total resection (GTR) was performed. The normal pituitary gland was preserved, and the patient went into remission. The video can be found here: https://stream.cadmore.media/r10.3171/2023.4.FOCVID2324.

Multiphysics Interaction Analysis of the Therapeutic Effects of the Sigmoid Sinus Wall Reconstruction in Patients with Venous Pulsatile Tinnitus.

Sigmoid sinus wall dehiscence (SSWD) is an important etiology of venous pulsatile tinnitus (VPT) and is treated by sigmoid sinus wall reconstruction (SSWR). This study aimed to investigate the therapeutic effects of the different degrees of SSWR and the prognostic effect in patients with VPT. Personalized models of three patients with SSWD (control), 3/4SSWD, 1/2SSWD, 1/4SSWD, and 0SSWD were reconstructed. A multiphysics interaction approach was applied to elucidate the biomechanical and acoustic changes. Results revealed that after SSWR, the average pressure of venous vessel on the SSWD region reduced by 33.70 ± 12.53%, 35.86 ± 12.39%, and 39.70 ± 12.45% (mean ± SD) in three patients with 3/4SSWD, 1/2SSWD, and 1/4SSWD. The maximum displacement of the SSWR region reduced by 25.91 ± 30.20%, 37.20 ± 31.47%, 52.60 ± 34.66%, and 79.35 ± 18.13% (mean ± SD) in three patients with 3/4SSWD, 1/2SSWD, 1/4SSWD, and 0SSWD, with a magnitude approximately 10-3 times that of the venous vessel in the SSWD region. The sound pressure level at the tympanum reduced by 23.72 ± 1.91%, 31.03 ± 14.40%, 45.62 ± 19.11%, and 128.46 ± 15.46% (mean ± SD). The SSWR region was still loaded with high stress in comparison to the surrounding region. The SSWR region of the temporal bone effectively shielded the high wall pressure and blocked the transmission of venous vessel vibration to the inner ear. Patients with inadequate SSWR still had residual VPT symptoms despite the remission of VPT symptoms. Complete SSWR could completely solve VPT issues. High-stress distribution of the SSWR region may be the cause of the recurrence of VPT symptoms.

Surgical treatment of pulsatile tinnitus related to the sigmoid sinus.

Objective: Tinnitus-a common clinical symptom-can be categorized into pulsatile tinnitus (PT) and non-PT. Among these, PT is usually associated with sigmoid sinus symptoms, such as sigmoid sinus wall defect or diverticulum, for which various surgical treatments are available. We have discussed the clinical efficacy of surgery for sigmoid sinus-associated PT via the transmastoid approach in this study. Methods: We conducted a retrospective review of 4 patients who underwent surgery for sigmoid sinus-associated PT via the transmastoid approach at Nanjing Drum Tower Hospital from January to December 2020. Of these, 2 patients had sigmoid sinus wall defect and 2 had sigmoid sinus diverticulum. Post-operative tinnitus grading and surgical efficacy were determined. Results: After surgery, PT dissolved in 3 patients, while tinnitus significantly decreased in 1 patient. During the follow-up period of 12-18 months, none of the 4 patients showed complications related to increased intracranial pressure or venous sinus thrombosis, and tinnitus symptoms disappeared in 3 patients without recurrence, although 1 patient occasionally developed tinnitus. Postoperative thin-slice CTA of the temporal bone indicated that the sigmoid sinus bone wall defect or diverticulum was completely repaired with a thick soft tissue coverage. Conclusion: Surgical repair of sigmoid sinus-associated PT via the transmastoid approach deserves clinical promotion as it exhibited better efficiency while being relatively less invasive.

Binswanger and the carotid sinus (Historical Note) / Binswanger e o seio carotídeo (Nota Histórica)

The 'carotid sinus' is an arterial dilatation placed usually at the beginning of the internal carotid artery. The medial wall of this dilatation appears modified, with a reduction of the media, and an increase of the adventitia, besides containing nervous terminations, forming thus a sensorial structure. This dilatation was possibly first observed by John Bell (1808), and clearly described and named by Cruveilhier (1834). However, many authors credited the initial finding to Burns (1811), followed by a number of researchers, as Luschka (1862), Manson (1866), Meyer (1876), Schäfer (1878), most with a view related to aneurysm formation, but some seeing the formation as a normal trait. Finally, Binswanger (1879) reaffirmed that the dilatation meant a normal feature of the region, based on his own observations, and on the opinion of some forerunners. Besides, he was the first to classify this dilatation regarding the variability of its localization. The thinning of this region was initially identified by Meyer (1876) and detailed by Binswanger (1879), at bare eye visual inspection and on microscopic examination, observing there an important reduction of the width of the tunica media. Despite Meyer's effort, and mostly Binswanger's, the microscopic findings are incipient, what can be explained by the limitations of the histological techniques at the time. However, there is no doubt that Binswanger and his forerunners provided important information for the upcoming research, comprising the structure, innervation, and function of this formation.

O 'seio carotídeo' é uma dilatação arterial situada geralmente no início da artéria carótida interna. A parede medial dessa dilatação apresenta-se modificada, com redução da média e aumento da adventícia, além de conter terminações nervosas, constituindo assim uma estrutura sensorial. Essa dilatação foi possivelmente observada primeiro por John Bell (1808) e claramente descrita e denominada por Cruveilhier (1834). Entretanto, muitos autores creditam o achado inicial a Burns (1811), seguido por numerosos pesquisadores, como Luschka (1862), Manson (1866), Meyer (1876), Schäfer (1878), a maioria com olhar relacionada à formação de aneurisma, mas alguns vendo a formação como uma característica normal. Finalmente, Binswanger (1879) reafirmou que a dilatação representava um aspecto normal da região, baseado em observações próprias e na opinião de alguns de seus antecessores. Além disso, foi o primeiro a classificar essa dilatação quanto a variabilidade de sua localização. O adelgaçamento dessa região foi identificado inicialmente por Meyer (1876) e detalhado por Binswanger (1879), à inspeção visual a olho nu e ao exame microscópico, observando lá uma importante redução da espessura da túnica média. Apesar do esforço de Meyer e sobretudo de Binswanger, os achados microscópicos são incipientes, o que pode ser explicado pelas limitações das técnicas histológicas daquele tempo. Todavia, não há dúvida que Binswanger e seus precursores proveram importante informação para as pesquisas que se sucederam, compreendendo a estrutura, inervação e função dessa formação.

Retroauricular/Transcranial Color-Coded Doppler Ultrasound Approach in Junction With Ipsilateral Neck Compression on Real-Time Hydroacoustic Variation of Venous Pulsatile Tinnitus.

Alterations in dural venous sinus hemodynamics have recently been suggested as the major contributing factors in venous pulsatile tinnitus (PT). Nevertheless, little is known about the association between real-time alterations in hemodynamics and the subjective perception of venous PT. This study aimed to investigate the hydroacoustic correlations among diverticular vortices, mainstream sinus flow, and PT using various Doppler ultrasound techniques. Nineteen venous PT patients with protrusive diverticulum were recruited. The mainstream sinus and diverticular hemodynamics before and after ipsilateral internal jugular vein (IJV) compression were investigated using an innovative retroauricular color-coded Doppler (RCCD) method to examine the correlation between the disappearance of PT and hemodynamic alterations. To reveal the hydroacoustic characteristics of disparate segments of venous return, a computational fluid dynamics (CFD) technique combined with the transcranial color-coded Doppler method was performed. When the ipsilateral IJV was compressed, PT disappeared, as the mean velocity of mainstream sinus flow and diverticular vortex decreased by 51.2 and 50.6%, respectively. The vortex inside the diverticulum persisted in 18 of 19 subjects. The CFD simulation showed that the flow amplitude generated inside the transverse-sigmoid sinus was segmental, and the largest flow amplitude difference was 20.5 dB. The difference in flow amplitude between the mainstream sinus flow and the diverticular flow was less than 1 dB. In conclusion, the sensation of PT is closely associated with the flow of kinetic energy rather than the formation of a vortex, whereby the amplitude of PT is correlated to the magnitude of the flow velocity and pressure gradient. Additionally, the range of velocity reduction revealed by the RCCD method may serve as a presurgical individual baseline curative marker that may potentially optimize the surgical outcomes.

Hemodynamics study on the relationship between the sigmoid sinus wall dehiscence and the blood flow pattern of the transverse sinus and sigmoid sinus junction.

Sigmoid sinus wall dehiscence (SSWD) is a common pathophysiology of patients with pulsatile tinnitus (PT). However, the pathological mechanism of SSWD is unclear. This study aimed to investigate the relationship between the position of the SSWD and blood flow pattern of the transverse sinus and sigmoid sinus (TS-SS) junction. The impact of the blood flow was hypothesized to be the pathological mechanism of SSWD. Twenty patients and two healthy volunteers were analyzed retrospectively, and transient computer fluid dynamics was used to verify this hypothesis. A 4D flow magnetic resonance imaging experiment was performed to validate the numerical simulation. The position of high-velocity blood flow impacting the vessel wall (17/20) was consistent with SSWD. In healthy volunteers, the temporal bone was thin where the blood flow impacted the blood vessel wall. The average wall shear stress (20/20) and pressure (18/20) of the SSWD area (peak) were higher than those of sigmoid sinus wall anomalies (the contact area between the vessel wall and the temporal bone at the TS-SS junction). The average wall pressure percentage differences of 16/20, 11/20, and 4/20 patients were more than 5%, 10%, and 20%, respectively. The average wall shear stress percentage differences of 20/20, 18/20, and 16/20 patients were more than 5%, 10%, and 20%, respectively. In brief, the blood flow of the TS-SS junction impacted the vessel wall and increased wall pressure, which might be an important pathological mechanism of SSWD. This study could serve as a basis for the diagnosis and SSWD resurfacing surgery of patients with PT induced by SSWD.

Study on the correlation between hemodynamic status of the transverse sinus-sigmoid sinus and the clinical efficacy of sigmoid sinus wall reconstruction.

BACKGROUND AND PURPOSE: For patients with pulsatile tinnitus who have both transverse sinus stenosis and sigmoid sinus wall anomalies, sigmoid sinus wall reconstruction surgery is the first-choice treatment when the trans-stenotic pressure gradient less than 10 mmHg. However, not all patients are cured by surgery. We hypothesized the abnormal hemodynamics caused by transverse sinus stenosis is associated with the clinical efficacy of surgery. METHODS: Eight pulsatile tinnitus patients treated with surgery were retrospectively reviewed (4 rehabilitated, 4 nonrehabilitated). All patients had radiologically diagnosed transverse sinus stenosis and sigmoid sinus wall anomalies. A numerical simulation of the hemodynamics of the transverse sinus-sigmoid sinus was performed using computational fluid dynamics technology. Changes in the blood flow patterns before and after surgery were observed. The blood flow velocity at the stenosis, vorticity of blood flow in the sigmoid sinus and wall pressure distribution in the sigmoid sinus wall anomalies area were compared. RESULTS: The blood flow velocity in the stenosis (preoperative P = 0.04, postoperative P = 0.004) and vorticity in the sigmoid sinus (preoperative P = 0.02, postoperative P = 0.007) pre- and post-surgery were significantly higher in the non-rehabilitation group than in the rehabilitation group. No significant difference was found in the wall pressure distribution in the sigmoid sinus wall anomalies area (preoperative P = 0.12, postoperative P = 0.24). CONCLUSIONS: There is a clear correlation between the abnormal hemodynamic status caused by transverse sinus stenosis and the clinical efficacy of surgery. The blood flow velocity at the stenosis and vorticity of blood flow in the sigmoid sinus are factors influencing the clinical efficacy of surgery.

Long-Term Outcomes of Nasoseptal Perforation Repair Using Anterior Maxillary Sinus Wall as an Interpositional Graft.

BACKGROUND: Various graft materials have been used to repair nasoseptal perforation, but there is no standardized treatment method. The anterior maxillary sinus wall is flattened in appearance and can be easily obtained in a sufficient amount for a large-sized nasoseptal perforation. OBJECTIVES: The aim of this study is to determine whether the anterior maxillary sinus wall is suitable as an interpositional graft in the surgical repair of septal or nasoseptal perforation. METHODS: This is a retrospective review of 21 patients who underwent repair of nasoseptal perforation using anterior maxillary sinus wall as an interpositional graft. The etiology, pre- and post-operative NOSE and GBI score, and perforation size were reviewed. The surgical outcome was considered successful if total closure was achieved after postoperative follow-up. RESULTS: 19 of the 21 perforations were successfully repaired with anterior maxillary sinus wall. Failure of the repair was found in 2 patients. Causal etiology of perforation was previous septoplasty in 10 patients, and electrocautery in 1 case, but not identified in 10 cases. The largest size was 2.7 × 2.2 cm. The most common symptoms were epistaxis, crusting, and nasal obstruction. Closure of septal perforation resulted in improved subjective symptoms and quality of life which were evaluated with NOSE and GBI score. CONCLUSION: Anterior maxillary sinus wall as interpositional graft between mucoperichondrial flaps can be used to reliably repair nasoseptal perforations.

Imaging of the Postoperative Temporal Bone.

Evaluation of the postoperative temporal bone can be difficult given the complex anatomy of this region and the myriad surgical approaches for management of a variety of conditions. This article provides an understanding of common postsurgical changes of the temporal bone and their typical imaging appearances. Ultimately, greater radiologist knowledge of postoperative temporal bone imaging findings will help to serve patients and referring clinicians with prompt diagnosis and recognition of expected postintervention changes compared with postoperative complications and/or disease recurrence.

Associations among Audiometric, Doppler Hydroacoustic, and Subjective Outcomes of Venous Pulsatile Tinnitus.

OBJECTIVE: Venous pulsatile tinnitus (PT) has received increasing attention recently. As analyses of psychophysical and neuropsychological dimensions of venous PT are lacking, this study aimed to quantitatively and qualitatively investigate the correlation among audiometric, hydroacoustic, and subjective outcomes in patients with PT. METHODS: Fifty-five venous PT patients, with or without sigmoid sinus wall anomalies (SSWAs), were subdivided into SSWAs (n = 30) and non-SSWAs (n = 25) groups. Audiometric and hemodynamic evaluations were assessed. Questionnaires including the Tinnitus Handicap Inventory, Hospital Anxiety and Depression Scale (HADS), and Athens Insomnia Scale (AIS) were deployed to evaluate the psychological impacts of PT. RESULTS: Among 55 subjects, PT frequency-related pure-tone audiometry (PTA) was significantly different between ipsilesional non-PT frequency-related PTA (p < 0.01), ipsilateral jugular vein compression PTA (p < 0.01), and contralesional ear PTA (p < 0.01). In contrast with the pulsatility index and flow velocity, bilateral EOET and flow volume were significantly different (p < 0.01). Of the 3 questionnaire types, there was a strong correlation between HADS anxiety and AIS scores (r = 0.658, p < 0.01). The duration of PT was not correlated with subjective outcomes, and there was no statistical significance found among audiometric, hemodynamic, and subjective outcomes between SSWAs and non-SSWAs groups. CONCLUSIONS: (1) The duration of PT was irrelevant to the increase of PTA. (2) Venous PT is the perception of vascular flow sound, in which hydroacoustic characteristics can be highly independent. (3) Anxiety, depression, and sleep disorders commonly prevail among PT patients.

Evidence of air-conduction transmission pathway and strategized transtemporal operative techniques for venous pulsatile tinnitus: Combining water occlusion test and operative sensing applications.

OBJECTIVES: (1) To establish evidence of the transmission pathway of venous pulsatile tinnitus (PT) associated with sigmoid sinus wall anomalies (SSWAs) and (2) quantify the efficacy of transtemporal surgery. METHODS: This retrospective study included 33 surgical cases of PT associated with SSWAs and 15 controls with venous PT without SSWAs. Quantitative water occlusion test (q-WOT) and imaging data were acquired for preoperative evaluation prior to strategized transtemporal osteovascular reconstruction surgery. A condenser microphone and hydrophone were intraoperatively deployed to assess and monitor in vivo amplitude variations of the PT in eight participants. RESULTS: A total of 23 (69.6%) participants with SSWA responded to the q-WOT with a median solution volume of 1.3 (1.1/1.6), which significantly differed from that observed in controls (p < 0.01). The change in the operative peak amplitude of the acoustic data was statistically significant (p < 0.01), from a median of 57.6 (55.5/57.9) dB SPL to 34.3 (33.4/38.8) dB SPL. CONCLUSION: Intraoperative application of acoustic sensors revealed that PT associated with SSWAs is predominantly transmitted via the air-conduction pathway. If objective findings such as q-WOT and sensing applications suggest that the transmission of venous PT is involved in middle ear air conduction, the reconstruction technique should be prioritized; if less involvement of middle ear air-conduction is indicated, addressing flow pathologies may be imperative for resolving venous PT. LEVEL OF EVIDENCE: 4.

Transmastoid Hydroxyapatite Resurfacing for Sigmoid Sinus Wall Anomalies Causing Pulsatile Tinnitus.

OBJECTIVE: Comprising 4% of tinnitus, pulsatile tinnitus (PT) can be particularly difficult for affected patients as well as surgeons looking to address their symptoms. Often the cause is not identified but can be secondary to turbulent flow in or near the sigmoid sinus, particularly if there is an identifiable sigmoid sinus dehiscence (SSDe) and/or diverticulum (SSDi). These sigmoid sinus wall anomalies (SSWA) may be treated with transmastoid sigmoid sinus resurfacing; however, this intervention remains relatively novel and its technique, materials used, resolution success, and complications need to be continuously reviewed. METHODS: A retrospective case series of patients with PT due to SSWA at a tertiary referral center was reviewed. A total of 6 patients (7 ears) treated by transmastoid resurfacing using hydroxyapatite (HA) were retrospectively assessed. Pre-operative demographics and symptoms, pre- and post-operative hearing results, and post-operative outcomes were reviewed. RESULTS: All patients were female with an average BMI of 32.9 (±5.4) and a mean age of 45.5 years (±15.3). Mean follow-up was 648 days. Objective tinnitus was noted in all ears with SSDi (100%); however, no objective tinnitus was noted with purely SSDe. In 100% of ears, PT was diminished with ipsilateral jugular compression and was amplified with contralateral head turn. Pre-operative symptoms of PT resolved in all patients, but delayed recurrence (>1 year) occurred in 1 ear (14%). No patient had pre- or post-operative hearing loss. No major complications were encountered. CONCLUSIONS: Transmastoid resurfacing for SSWA with HA bone cement is a safe, reliable intervention in properly identified PT patients.

Hydroacoustic analysis and extraluminal compression surgical insights of venous pulsatile tinnitus.

OBJECTIVE: This study aimed to quantitatively and qualitatively evaluate the hydroacoustic changes from "presence" to "disappearance" of pulsatile tinnitus (PT) with the extraluminal compression surgical technique. The recent issues of concern pertaining to the hydroacoustic characteristics of sigmoid sinus wall anomalies and distal transverse sinus stenosis (dTSS) were discussed. METHODS: This study was based on a retrospective case series. Seventy-seven patients with PT and transverse-sigmoid sinus enlargement with or without transverse-sigmoid sinus junction anomalies and transverse sinus stenosis (TSS) who had undergone extraluminal compression surgery under local anesthesia were included. Management of intractable intraoperative challenges and techniques for reversal extraluminal compression were introduced. Anatomical measurements, intraoperative color-coded Doppler ultrasonography, spectro-temporal analysis, and computational fluid dynamics were employed to analyze the hydroacoustic characteristics of PT. RESULTS: The efficacy of the extraluminal compression technique was evident with the significant reduction in peak turbulent kinetic energy, vorticity, and mean pressure gradient at the transverse-sigmoid junction, resulting in over 20% reduction in PT amplitude. dTSS is a common finding in patients with PT exhibiting transverse-sigmoid sinus enlargement. Patients with dTSS presented with significant differences in hemodynamic characteristics as compared to those without. Linear regression analysis showed that the flow disturbance (turbulent kinetic energy and vorticity) was closely associated with the degree of dTSS, whereas the flow amplitude was not related to the degree or location of TSS. Low-pulsatory vortex flow at the transverse-sigmoid junction was visualized during an intraoperative color-coded Doppler examination, and the displayed low-frequency PT sound corresponded to the patients' subjective perception of PT. CONCLUSION: (1) A reduction of over 20% of the flow-induced noise is the therapeutic goal of extraluminal compression technique. Since reductions in the magnitude of hemodynamic parameters, including turbulent kinetic energy, vorticity, and mean pressure gradient, render the flow-induced noise inaudible, besides sigmoid sinus wall anomalies, it is likely that PT develops from the aggregation of flow-based pathologies. (2) Although dTSS and diverticulum may greatly affect the hemodynamics at the transverse-sigmoid junction, in contrast to dehiscence, dTSS and diverticulum may not be the limiting factors for PT development.

Association of pulse synchronous tinnitus and sigmoid sinus wall abnormalities in patients with idiopathic intracranial hypertension.

PURPOSE: Pulse synchronous tinnitus (PT) is common in patients with idiopathic intracranial hypertension (IIH) and in those with sigmoid sinus wall abnormalities (SSWAs). Although patients with SSWAs and IIH share many clinical features, the incidence of SSWAs in patients with IIH and its relationship to PT in this cohort is less well established. The purpose of this study is to assess the incidence of SSWAs in patients with IIH and PT, and to determine if there is an association between SSWAs and PT in this population. MATERIALS AND METHODS: Prospective computed tomography (CT) study of adults with IIH. Subjective PT was correlated with presence or absence of SSWAs on CT. RESULTS: 22 subjects were enrolled and 14 subsequently underwent CT. The incidence of SSWAs was significantly higher in subjects with PT than without (70% vs. 0%, p = 0.02). Mean age, BMI and opening pressures did not differ between those with and without SSWAs or PT. CONCLUSIONS: There is a high incidence of SSWAs in subjects with IIH and PT. These findings support an association between SSWAs and PT, and implicate SSWAs as a possible cause of, or contributing factor to, PT in patients with IIH. Patients with IIH and PT that does not resolve with reducing intracranial pressure should undergo diagnostic CT and consider treatment of a SSWA if present.

Patterns of audiometric threshold shifts from pulsatile tinnitus due to sigmoid sinus wall anomalies.

PURPOSE: To determine the severity and nature of audiometric threshold shifts for patients with pulsatile tinnitus (PT) due to sigmoid sinus wall anomalies (SSWA). MATERIALS AND METHODS: 38 patients with SSWAs and available pre-operative audiograms were examined. Low- and high-frequency pure tone averages (LF-PTA, HF-PTA) were calculated. Audiometric data were compared between affected and unaffected ears, with the interaural difference (affected-unaffected PTA) representing the change in hearing due to PT. Additionally, post-operative change was examined in 14 patients with available data. RESULTS: The average pre-operative air conduction (AC) LF-PTA was 17.04 dB on the affected side and 11.38 dB on the unaffected side (p < 0.001). The mean AC HF-PTA was significantly higher on the affected side as well (16.45 dB vs. 14.08 dB, p = 0.008). All shifts were sensorineural, with no significant air-bone gaps, and most subjects still had low-frequency thresholds in the normal range. Though the post-op change was not significant due to attrition, 5/14 patients (35.7%) had complete resolution of their pre-op interaural difference. A similar number developed a HF-PTA post-op threshold elevation in the surgical ear. CONCLUSIONS: PT due to SSWAs causes a mean 6 dB low-frequency bone-conduction threshold elevation, and smaller high-frequency threshold shifts, due to masking. Patients with larger threshold shifts should have other potential causes of hearing loss explored. LEVEL OF EVIDENCE: Level IV.

Treatment of pulsatile tinnitus caused by anomalies of the sigmoid sinus wall via combined internal and external sigmoid sinus wall reconstruction with 3D temporal bone CT guidance.

PURPOSE: The present analysis aims to describe a surgical approach wherein pulsatile tinnitus (PT) arising due to sigmoid sinus wall anomalies (SSWA) can be treated via combination internal and external sigmoid sinus wall reconstruction. We further evaluated the utility of temporal bone 3D-CT imaging during both the pre- and post-operative assessments of all treated patients. METHODS: Data pertaining to 11 patients that had undergone sigmoid sinus wall reconstruction were retrospectively analyzed. All of these patients underwent preoperative 3D-CT imaging assessment. These patients were additionally subjected to sigmoid sinus wall reconstruction via a combined internal and external layer approach. Postoperatively, all patients underwent a radiological assessment of auricular cartilage and autologous bone powered displacement. Patients were additionally asked about any subjective changes in PT or associated symptoms at follow-up time points. RESULTS: SSWA in the 3D-CT imaging from these patients were all distinct. In 10/11 patients, PT fully resolved following reconstruction of the sinus wall. The remaining patients exhibited significant improvements in symptoms postoperatively, with PT fully resolving within a 1-month follow-up period. No patients suffered any major complications. CONCLUSIONS: Temporal bone 3D-CT imaging allow for effective visualization of SSWA, enabling effective pre- and post-operative assessments of treated patients. A combined internal and external layer approach to sigmoid sinus wall reconstruction can be implemented safely and effectively, yielding high rates of satisfactory outcomes and achieving rigid reconstruction of this surface. As such, there is clear value in the consideration of this approach when treating individuals suffering from PT as a result of SSWA.