Sigmoid Sinus Research Articles

Morphological remodeling of the repaired sigmoid sinus bone wall in patients with pulsatile tinnitus after successful surgical reconstruction: an ultra-high-resolution CT study.

Sigmoid sinus wall reconstruction (SSWR) is an effective treatment for pulsatile tinnitus (PT). However, follow-up postoperative imaging manifestations have not been extensively reported. To evaluate the morphological changes in patients with PT after successful SSWR using ultra-high-resolution computed tomography (U-HRCT). Data were retrospectively analyzed from 10 patients with PT who underwent successful SSWR primarily with autologous bone powder. U-HRCT scans were performed within 3 days of surgery and repeated 6 months later. The integrity, relative density, extent, and shape of the repaired wall were analyzed. The chi-square test was used to compare the categorical variables and the Phi (φ) coefficient was used to represent the magnitude of the correlation. Among the 10 patients with PT, 1 (10%) achieved complete coverage of the defect with the residual bone, 8 (80%) had partial coverage, and 1 (10%) showed complete separation. A gap between the repaired wall and residual bone in the initial U-HRCT was linked to incomplete defect coverage in the subsequent U-HRCT scan (P < 0.001, φ = 0.903). The repaired wall shrank from the periphery to the center and the density increased. The repaired wall compressed into the sigmoid sinus retracts over time, reshaping into a naturally curved sigmoid sinus sulcus. Morphological remodeling is a typical characteristic of the repaired sigmoid sinus wall in patients with PT. Short-term incomplete repair may imply incomplete coverage of the defect in the future, but this is not correlated with recurrence.

Unilateral papilledema: illustrative case.

Idiopathic intracranial hypertension is caused by an elevation of intracranial pressure and can present with slowly progressive visual deterioration from bilateral papilledema. Unilateral papilledema is an exceedingly rare phenomenon, and the mechanisms underlying asymmetric optic nerve involvement remain unknown. A 42-year-old woman presented with acute left-eye blurred vision and extraocular pain. Examination revealed unilateral left optic disc edema with an enlarged blind spot, while the right optic disc appeared flat. Neuroimaging examination was suggestive of intracranial hypertension, characterized by flattening of the posterior globes and narrowing of bilateral distal transverse sinuses. Increased intracranial pressure was confirmed by lumbar puncture. Acetazolamide and weight loss yielded initial improvement, but recurrence prompted cerebral arteriography, revealing a transstenotic gradient in the right distal transverse sinus and hypoplastic left sigmoid and transverse sinuses with extensive collateralization to the left cavernous sinus. Stenting of the right transverse sinus successfully alleviated the optic disc swelling. This case highlights the intricate interplay between venous sinus dynamics and unilateral papilledema, underscoring the importance of tailored interventions. https://thejns.org/doi/10.3171/CASE24385.

Retrolabyrinthine approach to the lateral skull base: The value of preoperative temporal bone CT analysis

PurposeThe most used neurosurgical approach to reach cerebellar-pontine angle is the retrosigmoid route. This article describes the presigmoid approach which requires excellent knowledge of the labyrinthine block together with quantitative analysis of temporal bone CT. MethodsCT-based quantitative measurements were obtained in patients undergoing vestibular neurectomy with a presigmoid approach. Eighteen patients were enrolled, and five measures were taken: Trautmann’s area, the petro-clival angle, presigmoid dura length and its angle. The relationship between these measurements and hospitalization days, operating times, and complications was explored. ResultsThe posterior semicircilar canal (PSC)-sigmoid sinus (SS) distance, presigmoid dura- internal auditory canal (IAC)-PSC angle, and duration of surgery are predictors of complications. Specifically, a PSC-sigmoid sinus distance <11 mm, a dura presig-IAC-PSC angle <14 are associated with the highest risk of complications. ConclusionPreoperative temporal bone CT scan can guide the surgeon through the narrowest areas of the surgical approach. Trautmann’s triangle area and petro-clival angle reduction are challenging and can be faced with combined microscopic-endoscopic technique, and with optics angulation-rotation. The retrolabyrinthine approach can enable hearing preservation and minimal cerebellar retraction.

Clinical characteristics and outcomes of cerebral venous sinus thrombosis in patients with antiphospholipid syndrome.

Cerebral venous sinus thrombosis (CVST) is a rare but serious manifestation of venous thrombosis in patients with antiphospholipid syndrome (APS). This study investigated the risk factors, clinical characteristics and prognosis of CVST in APS patients. This retrospective cohort study included all thrombotic APS (tAPS) patients from Peking Union Medical College Hospital (PUMCH) from April 2005 to August 2023. Demographic characteristics, laboratory data and thrombotic risk factors were compared between tAPS-CVST group and tAPS-non-CVST group. Kaplan-Meier survival analysis was utilized to compare the recanalization rate and the recurrence rate. A total of 453 APS patients were enrolled, and 40 (8.8%) APS patients were with CVST. The median age of the APS-CVST patients was 27 (21.25, 32.75) years, and 72.5% were females. In 50% of these patients, CVST was the initial symptom of APS, with headache being the most prevalent clinical symptom (95%). Involvement of more than two venous sinuses were observed in 79.5% of patients, with the transverse sinus (79.5%) and sigmoid sinus (74.4%) being the most commonly affected sites. Oral contraceptives, intracranial infections and malignancy were identified as risk factors of APS-CVST. There were no statistically significant differences in baseline characteristics or the distribution of antiphospholipid antibodies profiles between the two groups. After a median follow-up of 24 (12, 52) months, 21 patients (52.5%) experienced recanalization, and 13 patients (32.5%) had a thrombotic recurrence. Survival analysis indicated that adequate anticoagulant therapy significantly contributed to recanalization (HR 6.27, 95% CI 2.616-15.02, P = 0.003), while continuous anticoagulant therapy was highly effective in reducing the recurrence of thrombotic events (HR 0.14, 95% CI 0.0447-0.4328, P = 0.0007). CVST should be considered in APS patients who experience sudden onset headaches, particularly those with thrombotic risk factors, such as the use of oral contraceptives, intracranial infections and malignancy. Continuous and adequate anticoagulant therapy is pivotal and beneficial for achieving recanalization and prevention of recurrence. Key Points • The prevalence of CVST in patients with APS may be underestimated. • APS-CVST is associated with special risk factors, including pregnancy, intracranial infection, oral contraceptives and tumors. • Long-term and adequate anticoagulation therapy can increase the vascular recanalization rate and reduce thrombosis recurrence.

Optimization of image shoot timing for cerebral veins 3D-digital subtraction angiography by interventional angiography systems

Abstract3D-digital subtraction angiography (3D-DSA) is essential for understanding the anatomical structure of cerebral veins, crucial in brain tumor surgery. 3D-DSA produces three-dimensional images of veins by adjusting the X-ray delay time after contrast agent injection, but the delineation of veins varies with the delay in X-ray timing. Our study aimed to refine the delay time using time-enhancement curve (TEC) analysis from 2D-DSA conducted before 3D-DSA imaging. We retrospectively reviewed 26 meningioma patients who underwent cerebral angiography from March 2020 to August 2021. Using 2D-DSA, we analyzed arterial and venous TECs to determine the contrast agent’s peak time and estimated the optimal imaging timing. Cases performed near this optimal time were in Group A, and others in Group B, with cerebral venous pixel values compared between them. TEC analysis identified peak times: internal carotid artery: 2.8 ± 0.7 s, middle cerebral artery (M4): 4.1 ± 0.9 s, superior sagittal sinus: 8.3 ± 1.1 s, sigmoid sinus: 9.5 ± 1.3 s, and venous structures near tumors: 7.3 ± 1.0 s. We observed several veins peaking immediately after arterial contrast passage, suggesting the optimal X-ray delay should incorporate the arterial contrast agent’s transit time. Statistical analysis revealed that Group A, with imaging timed to reflect the contrast agent transit time, demonstrated significantly better contrast effects than Group B. The X-ray delay time for 3D-DSA imaging of cerebral veins can be optimized in angiography systems by incorporating the contrast agent transit time, calculated from TEC analysis of cerebral 2D-DSA images.

Long-Term Outcomes of Sigmoid Sinus Wall Reconstruction for Pulsatile Tinnitus Due to Sigmoid Sinus Wall Anomalies.

To assess the long-term outcomes of sigmoid sinus wall reconstruction (SSWR) in patients with pulsatile tinnitus (PT) with sigmoid sinus wall anomalies (SSWAs). Single-center retrospective review. Tertiary referral center. Patients who underwent SSWR for PT with SSWAs more than 5 years prior to study initiation. Therapeutic-all patients underwent sinus wall reconstruction for pulsatile tinnitus with sigmoid sinus anomalies. The primary outcomes were complete or partial resolution of PT lasting at least 5 years postoperatively and short-term relief from PT after surgery with long-term recurrence as determined by a self-assessment questionnaire and corroborated by the medical record. Thirty-five patients (37 ears) out of 58 eligible patients 5 years postoperatively from SSWR completed the survey. Short-term and long-term success rates of SSWR are 97.3% (36/37 ears) and 83.8% (31/37 ears), respectively. Of the patients, 13.5% (5/37 ears) experienced recurrence of PT on the same side following initial resolution. Of our patients, 8.6% had a confirmed diagnosis of idiopathic intracranial hypertension (IIH) after a follow-up period of more than 5 years. Sinus wall reconstruction is an effective procedure for long-term control of PT in patients with SSWAs, with an acceptable safety profile and very low additional risk of exacerbating or provoking complications associated with IIH.

Primary jugular foramen fibrous dysplasia: surgically nuanced video of extradural infratemporal transjugular approach. Illustrative case.

Fibrous dysplasia of the bone is a disease caused by a somatic GNAS mutation that affects craniofacial bones and can have a mass effect on different neurovascular structures. The authors present the first case of primary jugular foramen fibrous dysplasia with occlusion of the transverse and sigmoid sinuses. A 33-year-old man presented with a history of dizziness and occasional dysphagia over the past year. Magnetic resonance imaging showed a uniform enhanced mass in the left jugular foramen, with complete blockage of the adjacent transverse and sigmoid sinuses. The computed tomography scan revealed a cystic bone lesion of the jugular foramen. The patient underwent a gross-total removal of the tumor through an infratemporal transjugular approach with complete preservation of the lower cranial nerves. This first reported case of primary jugular foramen fibrous dysplasia highlights the importance of considering this diagnosis when evaluating jugular fossa lesions. Understanding the anatomy of the infratemporal and jugular fossae, along with proficiency in microsurgical techniques, is essential for removing such tumors while preserving cranial nerve functions and the patient's quality of life. https://thejns.org/doi/10.3171/CASE24396.

The use of balloon guide catheters during venous sinus stenting: A case series.

Venous sinus stenting (VSS) is a safe and effective treatment strategy for pulsatile tinnitus (PT) and idiopathic intracranial hypertension (IIH). Although complications are rare, the morbidity associated with the complications is high. Navigating through the venous sinuses poses unique challenges to the interventionalist. There is limited literature regarding device selection to maximize safety and efficiency. We report on the safety and advantages of using a balloon guide catheter (BGC) for venous access in VSS. Retrospective analysis of all patients undergoing VSS using a BGC over a three-month period. A total of 22 patients were included in the analysis (median age 35; 21 female). The indication for treatment was PT in 10 patients and IIH in 12 patients. The BGC was navigated into the sigmoid and transverse sinuses, enabling successful delivery of the stent in all cases. The BGC balloon was inflated 23 times for navigating past tortuosity or obstructions, and for anchoring. There were no intraprocedural complications. The use of BGC in VSS is safe and feasible. BGCs have features that can be utilized to overcome the unique challenges encountered during VSS.

Endoluminal Sigmoid Sinus Occlusion During Jugular Foramen Tumor Surgery: Novel Technique, Operative Nuances, and Clinical Experience With 33 Patients.

Surgery of jugular foramen tumors (JFTs) often requires vascular control by means of ligating the internal jugular vein and sigmoid sinus (SS) to allow intrabulbar access. Occlusion of the SS traditionally involves presigmoid and retrosigmoid durotomies allowing introduction of ligature devices, predisposing to cerebrospinal fluid (CSF) leakage and pseudomeningoceles. We describe a simple and novel endoluminal sigmoid sinus occlusion (ESSO) technique with Gelfoam that is entirely extradural. An extended anterolateral infralabyrinthine approach with ESSO was performed in 33 patients with JFTs. After ligating the internal jugular vein, the SS is opened and Gelfoam is placed endoluminally into the proximal SS. Care is taken to avoid occlusion of the venous outflow of the vein of Labbe to avoid temporal lobe venous infarction. Hemostatic gelatin matrix is injected distally to stop venous backflow from the inferior petrosal sinus. The jugular venous system is isolated, and the outer jugular wall can be opened to expose the JFT for resection. There were no complications of temporal lobe venous infarction or postoperative hematoma observed. Four patients with intradural tumor extension developed pseudomeningoceles. For patients with purely extradural JFTs, none developed postoperative incisional CSF leaks and one had pseudomeningocele. This ESSO technique is fast and effective, permitting occlusion of the SS during JFT surgery. It has the advantage of being entirely extradural, avoiding durotomy which can result in postoperative CSF leak. It is important to keep the Gelfoam distal to the transverse-sigmoid junction to avoid occlusion of the vein of Labbe inlet and temporal lobe venous infarction.

Cerebral venous thrombosis in children an 18-year review of a Portuguese hospital

IntroductionCerebral venous thrombosis (CVT) is an uncommon and clinically heterogeneous cerebrovascular particularly in children, only a few published case series focused in the pediatric population. Patients and methodsRetrospective single-center observational and analytical study of consecutive pediatric patients admitted in a level II Portuguese hospital with a confirmed diagnosis of CVT, from 2003 to 2021. Clinical presentation, neuroimaging findings, prothrombotic factors, treatment strategies, outcome and recanalization were documented. ResultsTwelve children were included (58% female). Mean age was 7.3 years. The most frequent symptoms were vomiting, headache and behavioral alterations. Infection was the triggering factor in 50% of the cases. The diagnosis of CVT was made based on imaging evidence of thrombosis through magnetic imaging resonance (MRI) with venography and/or computed tomography (CT) with venography. In 67% of cases there were multiples sinuses involved; the transverse sinus was the most affected, followed by the sigmoid sinus. In 83% of cases anticoagulant therapy was initiated with low molecular weight heparin (LMWH) and associated prothrombotic factors were investigated, with no major prothrombotic factors identified. No deaths occurred, but 30% had long-term neurological sequelae. One patient recurred 18 years later. ConclusionThe results of this study are consistent with data from other published studies. MRI is the preferred imaging method for diagnosis in children by avoiding ionizing radiation and allowing identification of subjacent causes. Anticoagulation with LMWH is recommended and important to reduce mortality and sequelae. Infectious diseases are the most common trigger for CVT and can also be the cause for high morbidity and poor outcomes.

Treatment of Cholesteatoma-associated Sigmoid Sinus Thrombosis should be Performed Preoperatively

Treatment of Cholesteatoma-associated Sigmoid Sinus Thrombosis should be Performed Preoperatively

Pipeline embolization device as a standalone curative approach for recurrent sigmoid sinus DAVF.

Dural arteriovenous fistulas (dAVFs) can occur as complications after surgical procedures, especially following the resection of meningiomas near the dural sinus. This case report presents a 74-year-old male who developed a recurrent sigmoid dAVF following meningioma resection. Initially treated with transvenous embolization and middle meningeal artery embolization, the dAVF recurred with worsening clinical symptoms. Conventional treatment options, including sinus sacrifice and transarterial embolization, were unsuitable due to the critical role of the patient's dominant right sigmoid sinus in cerebral venous drainage. Consequently, a reconstructive approach was employed using a pipeline embolization device (PED) construct. The PED successfully occluded the dAVF while preserving the function of the sigmoid sinus. A follow-up angiogram confirmed stable occlusion and normalization of intracranial venous drainage. This case underscores the potential of flow diversion as a viable treatment option for dAVFs, particularly in scenarios where preserving venous sinus function is paramount.

Novel technique utilizing polymethylmethacrylate cement for the treatment of pulsatile tinnitus caused by different sigmoid sinus pathologies

Novel technique utilizing polymethylmethacrylate cement for the treatment of pulsatile tinnitus caused by different sigmoid sinus pathologies

Sigmoid Sinus Thrombosis In A Child With Unsafe Type Of Chronic Otitis Media

Introduction: Sigmoid sinus thrombosis, an uncommon condition, is described as a possible intra-cranial complication of both acute &amp; chronic otitis media in standard texts. However, current medical literature mostly describes this condition in relation to acute otitis media. We are reporting a case of sigmoid sinus thrombosis as a complication of chronic otitis media. Case Report: A 10-year-old male child presented with history of long-standing right sided ear discharge and deafness. His immediate presenting complaints were swelling in the postaural region along with severe ipsilateral headache &amp; fever for the past seven days. On clinical examination, ear findings were suggestive of chronic otitis media with cholesteatoma with mastoiditis. CT scan showed loss of architecture of the mastoid antrum and air cells with destruction of bone of mastoid cortex and complete erosion of sinus plate. MRI with contrast confirmed the presence of sigmoid sinus thrombosis. Patient was initially administered iv antibiotics and then operated. Modified radical mastoidectomy was done along with evacuation of the thrombus from the sigmoid sinus. Patient had a quick and uneventful postoperative recovery. Conclusion: Sigmoid sinus thrombosis, a rare intra-cranial complication of otitis media, can lead to several other complications including death if left untreated. Early detection and management are crucial for favourable outcome.

Impact of Sigmoid Sinus Anatomy on Assessing the Feasibility of the Retrofacial Access to the Entire Jugular Fossa Before Surgery.

The jugular fossa (JF) is a challenging area for surgical approaches because of its complex anatomy and proximity to neurovascular structures. The study evaluates the feasibility of the neuronavigated microsurgical transmastoid extended infralabyrinthine extradural retrofacial approach (mTEIER-A) in human head specimens for accessing the entire intraosseous JF in relation to the position of the sigmoid sinus (SS), horizontal angle of attack, and size of the SS. The mTEIER-A was performed on human head specimens. Before dissection, the position of the SS, horizontal angle of attack, and size of the SS were measured on tilted axial high resolution computed tomography scans; after dissection, access to the lateral aspect of the JF on dissected human head specimens and on postoperative high-resolution computed tomography scans was examined. The position of the SS was classified relative to a predefined reference line, and the feasibility of retrofacial access was documented. SS positions located medial to the reference line (P1) and horizontal angles >12.5° significantly enhance retrofacial access to the lateral aspect of the JF, whereas the size of the SS has a limited impact. Depending on the position of the SS and the horizontal angle of access, mTEIER-A provides sufficient retrofacial access to the lateral aspect of the JF. These findings emphasize the need for precise preoperative planning and suggest that mTEIER-A could minimize the need for more invasive approaches, potentially reducing related morbidity. Further clinical studies are recommended to validate these findings.

Transverse sinus blood flow characteristics of pulsatile tinnitus with dehiscent sigmoid plate based on 4D flow MRI

Objective: To investigate the hemodynamic characteristics of transverse sinus with sigmoid sinus wall dehiscence (SSWD) of pulsatile tinnitus (PT) based on 4D flow MRI. Methods: Retrospective analysis was performed on all patients admitted to Beijing Friendship Hospital, Capital Medical University from January 2019 to January 2021 for dehiscent sigmoid plate pulsatile tinnitus. A total of 26 patients (sides) who met the criteria and underwent 4D flow MRI were included. A total of 26 subjects (46 sides), matched 1∶1 according to gender and age, were included in the normal healthy control group. Nonparametric rank sum test, Student's t test, and ANOVA were performed by SPSS 19.0 software. Binary Logistic regression was applied to the data with statistical significance. Results: There were more patients with dominant drainage on the affected side in PT group than in control group (73.1% vs. 42.3%). The incidence of transverse with a focal intraluminal filling defect and tapered stenosis was higher than that in control group (21.7% vs. 69.2%; 17.4% vs. 42.3%). Average through-plane velocity and maximum through-plane velocity in PT group were higher than those in control group [(33.75±13.88) cm/s vs. (15.84±7.21) cm/s; (93.19±33.55) cm/s vs. (40.40±14.40) cm/s]. The middle part and proximal end of Flowavg (ml/s) in PT group were larger than those in control group [4.69 (2.87; 5.62) ml/s vs. 2.76 (1.67; 4.99) ml/s; 3.41 (2.16; 5.47) ml/s vs. 2.67 (1.68; 4.41) ml/s]. In control group, the velocity of transverse sinus changed relatively gently, while in PT group, the velocity of proximal sinus increased significantly. Binary Logistic regression showed that SSWD PT was independently correlated with proximal maximum flow velocity [OR=1.086(1.029-1.146),P=0.003]. Conclusion: 4D flow MRI showed that the dominant drainage and higher velocity at the proximal end of the transverse sinus might be an important hemodynamic characteristics of dehiscent sigmoid plate pulsatile tinnitus.

Toward a Diagnostic Imaging Algorithm for Undifferentiated Pulsatile Tinnitus.

Decisions around the diagnostic evaluation for pulsatile tinnitus (PT) remain challenging. We describe the usage patterns and diagnostic accuracy of imaging modalities and propose an evidence-based diagnostic approach for undifferentiated PT. Retrospective. Single otology/neurotology clinic. Patients with PT presenting between 2009 and 2020. Sensitivity, specificity, diagnostic yield, and diagnostic accuracy. A total of 315 subjects met inclusion criteria (74% female, mean ± SD age = 52 ± 17 years). Subjects were divided into four cohorts based on exam findings: normal (n = 229), venous cohort (n = 34), arterial cohort (n = 16), and outer/middle ear pathology cohort (n = 40). In total, 53% of patients received a nonidiopathic diagnosis for PT. The most common identifiable cause was sigmoid sinus dehiscence (78%) in the venous cohort, carotid stenosis (36%) in the arterial cohort, and glomus tumor (56%) in the outer/middle ear pathology cohort. There was a higher diagnostic rate among patients with positive exam findings compared to those with unrevealing exams ( p = 0.04). Imaging studies with the highest diagnostic yield were computed tomography (CT) venography (44%), formal angiography (42%), and magnetic resonance venography (40%); studies with the highest specificity were formal angiography (0.82), CT angiography (0.67), and CT venography (0.67). A diagnostic algorithm is proposed. Reaching a diagnosis in patients with PT requires a systematic approach, taking into account both clinical and radiographic information. Physical examination is a key first step for differentiating patients into venous, arterial, and other cohorts to narrow down the likely pathology and determine which radiographic studies have the highest yield and accuracy.

Anatomical Variations of the Jugular Bulb: A Critical and Comprehensive Review.

Background and Objectives: The jugular bulb (JB) is the uppermost part of the internal jugular vein receiving the sigmoid sinus. The aim of the present research is to aid the comprehension of the JB, its abnormalities, and surrounding structures for improving both academic and surgical awareness. Materials and Methods: Various studies on this topic were critically reviewed. Cone-beam CT scans and CT and MR angiograms were used to demonstrate each type of the discussed variations. Results: Variations in the JB anatomy were thoroughly documented: high JB, dehiscent JB, hypoplasia and hyperplasia, and diverticula of the JB, as they have significant clinical implications, particularly in the context of otological and neuro-otological surgery, skull base pathology, and diagnostic imaging. Definitions and critical arguments were also specified to clarify existing literature. Additionally, we present a case report illustrating a high and dehiscent JB, an anatomical variation of clinical interest due to its potential for misdiagnosis as a glomus tumor. Another case describes a dehiscent JB with a hypotympanic air cell protruding into it, further highlighting the variability of this condition. Conclusions: It is necessary to proceed with caution when observing abnormal morphological characteristics of the JB. Preoperative assessment of each case is essential for optimal outcomes.

Endovascular management of pediatric pial arteriovenous fistulas with hereditary GDF2 mutation: illustrative case.

Intracranial pial arteriovenous fistulas (PAVFs) are uncommon neurovascular anomalies that primarily affect the pediatric population. PAVFs are often linked to hereditary hemorrhagic telangiectasia, yet the specific genetic mutations remain unidentified. While endovascular embolization is the preferred treatment for PAVFs, complications like hydrocephalus and sinus thrombosis pose challenges in management. The authors present a rare case of PAVF in a 6-month-old male neonate with a hereditary GDF2 mutation, where the fistula was supplied by the posterior inferior cerebellar artery and drained directly into the sigmoid sinus. The PAVF was effectively treated with endovascular embolization using coils and Onyx. Furthermore, the authors describe the successful use of rivaroxaban in managing subsequent sinus thrombosis after the embolization of PAVFs. Additionally, the authors review treatment strategies and complications following fistula disconnection. Endovascular embolization is the primary treatment choice for the majority of pediatric PAVFs, while a hereditary GDF2 mutation is considered a potential contributing factor to the formation of these malformations in children. Rivaroxaban has shown promise as an effective therapeutic option for pediatric sinus thrombosis, supported by its established safety profile. https://thejns.org/doi/10.3171/CASE24182.

Deskeletonizing the Sigmoid Sinus Is Noncompulsory in Skull Base Surgery: 3D Modeling of the Translabyrinthine Approach

Abstract Objectives Sigmoid sinus (SS) compression and injury is associated with postoperative SS occlusion and corresponding morbidity. Leaving the SS skeletonized with a thin boney protection during surgery might be favorable. This study quantifies the effect of the SS position on the operative exposure in the translabyrinthine approach and assesses the feasibility of retracting a skeletonized SS. Methods Twelve translabyrinthine approaches were performed on cadaveric heads with varying SS retraction: skeletonized stationary (TL-S), skeletonized posterior retraction (TL-R), and deskeletonized collapsing of the sinus (TL-C). High-definition three-dimensional reconstruction of the resection cavity was obtained. The primary outcome, “surgical freedom” (mm2), was the area at the level of the craniotomy from which the internal acoustic porus could be reached in an unobstructed straight line. Secondary outcomes include the “exposure angle,” “angle of attack,” and presigmoid depth. Results During TL-R, surgical freedom increased by a mean of 41% (range: 9–92%, standard deviation [SD]: 28) when compared to no retraction (TL-S). Collapsing the SS in TL-C provided a mean increase of 52% (range: 19–95%, SD: 22) compared to TL-S. In most cases, the exposure is the greatest when the SS is collapsed. In 40% of the specimens, the provided exposure while retracting (TL-R) instead of collapsing (TL-S) the sinus is equal or greater than 50% of other specimens in which the sinus is collapsed. Conclusion In cases with favorable anatomy, a translabyrinthine resection in which the skeletonized SS is retracted provides comparably sufficient exposure for adequate and safe tumor resection.