scholarly journals An aberrant venous channel mimicking the perilabyrinthine cells in the petrous bone of a patient with vestibular schwannoma: illustrative case

2021 ◽  
Vol 2 (18) ◽  
Author(s):  
Masato Ito ◽  
Yoshinori Higuchi ◽  
Kentaro Horiguchi ◽  
Shigeki Nakano ◽  
Shinichi Origuchi ◽  
...  
Keyword(s):  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Posterior Wall ◽  
Anatomical Variations ◽  
Petrous Bone ◽  
Bone Defects ◽  
Jugular Bulb ◽  
Illustrative Case ◽  
Computed Tomographic ◽  
Major Vein

BACKGROUND Anatomical variations, such as high jugular bulbs and air cell development in the petrosal bone, should be evaluated before surgery. Most bone defects in the internal auditory canal (IAC) posterior wall are observed in the perilabyrinthine cells. An aberrant vascular structure passing through the petrous bone is rare. OBSERVATIONS A 48-year-old man presented with a right ear hearing disturbance. Magnetic resonance imaging revealed a 23-mm contrast-enhancing mass in the right cerebellopontine angle extending into the IAC, consistent with a right vestibular schwannoma. Preoperative bone window computed tomographic scans showed bone defects in the IAC posterior wall, which ran farther posteroinferiorly in the petrous bone, reaching the medial part of the jugular bulb. The tumor was accessed via a lateral suboccipital approach. There was no other major vein in the cerebellomedullary cistern, except for the vein running from the brain stem to the IAC posterior wall. To avoid complications due to venous congestion, the authors did not drill out the IAC posterior wall or remove the tumor in the IAC. LESSONS Several aberrant veins in the petrous bone are primitive head sinus remnants. Although rare, their surgical implication is critical in patients with vestibular schwannomas.

High Jugular Bulb: Implications for Posterior Fossa Neurotologic and Cranial Base Surgery

1993 ◽  
Vol 102 (2) ◽  
pp. 100-107 ◽  
Author(s):  
Steven D. Rauch ◽  
Wen-Zhuang Xv ◽  
Joseph B. Nadol
Keyword(s):  
Temporal Bone ◽  
Posterior Fossa ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Petrous Bone ◽  
Jugular Bulb ◽  
Variable Position ◽  
High Jugular Bulb ◽  
Cranial Base Surgery ◽  
Bone Exposure

The suboccipital-retrosigmoid approach to the internal auditory canal and cerebellopontine angle is being used with increasing frequency for neurotologic surgery, including vestibular nerve section and resection of acoustic neuroma. It offers wide exposure of the cerebellopontine angle and the cranial nerve VII—VIII complex as it courses from the brain stem to the temporal bone. Exposure of the internal auditory canal can be achieved by removing its posterior bony wall. Safe utilization of this approach requires familiarity with the variable position of structures within the petrous bone, including the lateral venous sinus and jugular bulb. We report here a case in which bleeding resulted from injury to a high jugular bulb during surgical exposure of the internal auditory canal via the suboccipital route and discuss the regional anatomy of the jugular bulb based on study of 378 consecutive temporal bone specimens from the collection of the Massachusetts Eye and Ear Infirmary. High jugular bulb was defined as encroachment of the dome of the bulb within 2 mm of the floor of the internal auditory canal. Forty-six percent of scoreable specimens met this criterion. However, when donors less than 6 years of age were excluded, a high jugular bulb was identified in 63% of specimens. Relevance to neurotologic surgery of the posterior fossa is presented.

scholarly journals The using of neuronavigation in vestibular schwannoma surgery

2008 ◽  
Vol 7 (5-2) ◽  
pp. 475-477
Author(s):  
K. B. Yrysov
Keyword(s):  
Acoustic Neuroma ◽  
Internal Auditory Canal ◽  
Posterior Wall ◽  
Localization Error ◽  
Computed Tomographic ◽  
Corridor Method ◽  
Resection Line ◽  
Navigational System ◽  
The Relationship ◽  
Anatomic Localization

We described the experience of a microscope-based navigational system for opening of the posterior wall of the internal auditory canal (IAC) via the retrosigmoid route. Computed tomographic findings for 47 acoustic neuroma cases were divided into three groups, on the basis of the relationship between the labyrinth and the sigmoid-fundus line (medial,on the line,or lateral). The shortest distances between the most medial labyrinthine extension (MMLE) and the resection line were measured. In 20 acoustic neuroma operations, the different features and the practicality of the microscope-based navigational system for opening of the IAC were evaluated.The mean anatomic localization errors were (0,67 ± 0,2) mm for navigation to the IAC and (0,71 ± 0,37) mm for navigation to the posterior semicircular canal. The average distances between the MMLE and the resection line were 3,65; 3,36, and 2,0 mm for the lateral, on-the-line, and medial groups, respectively. Direct contouring of structures at risk does not take into account the localization error, nor does it provide reliable navigational information. A novel indirect contouring concept that takes into account the localization error (the safety corridor method) was therefore introduced.

scholarly journals Management of jugular bulb injury during retrosigmoid transmeatal resection of vestibular schwannoma

2021 ◽  
Vol 5 (2) ◽  
pp. V5
Author(s):  
Felipe Constanzo ◽  
Bernardo Correa de Almeida Teixeira ◽  
Mauricio Coelho Neto ◽  
Ricardo Ramina
Keyword(s):  
Surgical Resection ◽  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Standard Technique ◽  
Jugular Bulb ◽  
Vestibular Schwannomas ◽  
Link Type

Inadvertent laceration of the jugular bulb is a potentially serious complication of the retrosigmoid transmeatal approach to vestibular schwannomas. Here, the authors present the case of a 51-year-old woman with a right Hannover T4a vestibular schwannoma and bilateral high-riding jugular bulb, which was opened during drilling of the internal auditory canal (IAC). They highlight the immediate management of this complication, technical nuances for closing the defect without occluding the jugular bulb, and modifications of the standard technique needed to continue surgical resection. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2155

Transapical extension in difficult cerebellopontine angle tumours: preliminary report

2003 ◽  
Vol 117 (10) ◽  
pp. 788-792 ◽  
Author(s):  
Mario Sanna ◽  
Manoj Agarwal ◽  
Yogesh Jain ◽  
Alessandra Russo ◽  
Abdel Kader Taibah
Keyword(s):  
Vestibular Schwannoma ◽  
Cerebellopontine Angle ◽  
Cranial Nerves ◽  
Internal Auditory Canal ◽  
Petrous Bone ◽  
Vestibular Schwannomas ◽  
Type I ◽  
Posterior Surface ◽  
Prepontine Cistern ◽  
Anterior Extension

Difficult cerebellopontine angle (CPA) tumours namely large/giant vestibular schwannomas, vestibular schwannomas with a significant anterior extension and meningiomas of the posterior surface of the petrous bone extending anterior to the internal auditory canal (IAC) have always posed a problem for the otoneurosurgeon. Modifications of the enlarged translabyrinthine approach (ETLA) specifically aimed at dealing with these tumours are not reported. The aim of this paper is to introduce the transapical extension of ETLA which involves increased circumferential drilling around the IAC beyond 270°C. The extension allows enhanced surgical control over the tumour as well as the anterior aspect of the CPA including the prepontine cistern, the Vth and VIth cranial nerves. The extension is further classified into Type I and II depending upon the extent of drilling. Type I extension entails drilling around the IAC for 300–320° and is indicated for large/giant vestibular schwannomas (large vestibular schwannoma extrameatal diameter 3–3.9 cm, giant vestibular schwannoma extrameatal diameter [ges ]4 cm) and vestibular schwannomas with significant anterior extension. Type II extension involves complete drilling around the canal for 360° and is indicated for meningiomas of the posterior surface of the petrous bone extending anterior to the IAC.

Intrameatal thrombosed anterior inferior cerebellar artery aneurysm mimicking a vestibular schwannoma

2011 ◽  
Vol 114 (4) ◽  
pp. 1057-1060 ◽  
Author(s):  
Dennis Päsler ◽  
Jörg Baldauf ◽  
Uwe Runge ◽  
Henry W. S. Schroeder
Keyword(s):  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Artery Aneurysm ◽  
Posterior Wall ◽  
Anterior Inferior Cerebellar Artery ◽  
Indocyanine Green Videoangiography ◽  
Cerebellar Artery ◽  
Aneurysm Resection ◽  
End To End ◽  
Acute Hearing Loss

Aneurysms of the anterior inferior cerebellar artery (AICA) are a rare entity. Purely intrameatal aneurysms are even rarer. The authors report an intrameatal thrombosed AICA aneurysm mimicking a vestibular schwannoma that was treated by resection and end-to-end anastomosis. This 22-year-old man presented with acute hearing loss, vertigo, and moderate facial palsy. Magnetic resonance imaging showed an atypical intrameatal lesion with dilation of the internal auditory canal. Microsurgical inspection via a retrosigmoid approach and drilling of the posterior wall of the internal auditory canal revealed a thrombosed AICA aneurysm. The aneurysm was excised, and an end-to-end suture was performed to restore AICA continuity. Intraoperative indocyanine green videoangiography as well as postoperative digital substraction angiography showed a good revascularization. Intrameatal AICA aneurysms may present with symptoms similar to vestibular schwannomas. End-to-end reanastomosis after aneurysm resection is a treatment option when clipping is impossible.

Petrous Bone Pneumatization Is a Risk Factor for Cerebrospinal Fluid Fistula Following Vestibular Schwannoma Surgery

2010 ◽  
Vol 67 (suppl_2) ◽  
pp. ons509-ons515 ◽  
Author(s):  
Lennart Henning Stieglitz ◽  
Mario Giordano ◽  
Venelin Gerganov ◽  
Andreas Raabe ◽  
Amir Samii ◽  
...  
Keyword(s):  
Risk Factor ◽  
Cell Volume ◽  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Tumor Grade ◽  
Petrous Bone ◽  
Control Group ◽  
Surgical Removal ◽  
Csf Fistula ◽  
The Mean

ABSTRACT BACKGROUND: For the prevention of postoperative CSF fistula a better understanding of origins and risk factors is necessary. OBJECTIVE: To identify the petrous bone air cell volume as a risk factor for developing CSF fistula, we performed a retrospective analysis. METHODS: From 2000 to 2007 519 patients had a retrosigmoidal surgical removal of a vestibular schwannoma. The 22 who had a postoperative CSF fistula were chosen for evaluation in addition to 78 patients who were randomly selected in 4 equally sized cohorts: male/female with small/large tumors. Preoperative CT scans were analyzed regarding petrous bone air cell volume, area of visible pneumatization at the level of the internal auditory canal (IAC), tumor grade, and sex. RESULTS: Women developed nearly half as many CSF fistulas (2.7%) as men (5.2%). The mean volume of the petrous bone air cells was 10.97 mL (SD, 4.9; range, 1.38-27.25). It was significantly lower for women (mean, 9.23 mL; SD, 3.8) than for men (mean, 12.5 mL; SD, 5.28; P = .0008). The mean air cell volume of CSF-fistula patients was 13.72 mL (SD, 5.22). The difference concerning the air cell volume between patients who developed CSF fistulas and patients from the control group was significant (P = .0042). There was a significant positive correlation between the air cell volume and the area of pneumatization in one CT slide at the level of the IAC. CONCLUSION: The higher incidence of CSF fistulas in men compared with women can be explained by means of differently pneumatized petrous bones. A high amount of petrous bone pneumatization has to be considered as a risk factor for the development of postoperative CSF fistula after vestibular schwannoma surgery.

Image-Guided, Endoscopic-Assisted Drilling and Exposure of the Whole Length of the Internal Auditory Canal and Its Fundus With Preservation of the Integrity of the Labyrinth Using a Retrosigmoid Approach: A Laboratory Investigation

2009 ◽  
Vol 65 (suppl_6) ◽  
pp. ons53-ons59 ◽  
Author(s):  
Promod Pillai ◽  
Steffen Sammet ◽  
Mario Ammirati
Keyword(s):  
High Resolution ◽  
Semicircular Canal ◽  
Image Guidance ◽  
Internal Auditory Canal ◽  
Posterior Wall ◽  
Retrosigmoid Approach ◽  
Slice Thickness ◽  
Posterior Semicircular Canal ◽  
Computed Tomographic ◽  
Reference Markers

Abstract Objective: Hearing loss after removal of vestibular schwannomas with preservation of the cochlear nerve can result from labyrinthine injury of the posterior semicircular canal and/or common crus during drilling of the posterior wall of the internal auditory meatus. Indeed, there are no anatomic landmarks that intraoperatively identify the position of the posterior semicircular canal or of the common crus. We investigated the usefulness of image guidance and endoscopy for exposure of the internal auditory canal (IAC) and its fundus without labyrinthine injury during a retrosigmoid approach. Methods: A retrosigmoid approach to the IAC was performed on 10 whole fresh cadaveric heads after acquiring high-resolution computed tomographic scans (120 kV; slice thickness, 1 mm; field of vision, 40 cm; matrix, 512 × 512) with permanent boneimplanted reference markers. Drilling of the posterior wall of the IAC was executed with image guidance. Its most lateral area was visualized using endoscopy. Results: Target registration error for the procedure was 0.28 to 0.82 mm (mean, 0.46 mm; standard deviation, 0.16 mm). The measured length of the IAC along its posterior wall was 9.7 ± 1.6 mm. The angle of drilling (angle between the direction of drill and the posterior petrous surface) was 43.3 ± 6.0 degrees, and the length of the posterior wall of the IAC drilled without violating the integrity of the labyrinth was 7.2 ± 0.9 mm. The surgical maneuvers in the remaining part of the IAC, including the fundus, were performed using an angled endoscope. Conclusion: Frameless navigation using high-resolution computed tomographic scans and bone-implanted reference markers can provide a “roadmap” to maximize safe surgical exposure of the IAC without violating the labyrinth and leaving a small segment of the lateral IAC unexposed. Further exposure and surgical manipulation of this segment, including the fundus without additional cerebellar retraction and labyrinthine injury, can be achieved using an endoscope. Use of image guidance and an endoscope can help in exposing the entire posterior aspect of the IAC including its fundus without violating the labyrinth through a retrosigmoid approach. This technique could improve hearing preservation in vestibular schwannoma surgery.

scholarly journals Use of Neuroanatomic Knowledge and Neuronavigation System for a Safe Anterior Petrosectomy

2021 ◽  
Vol 11 (4) ◽  
pp. 488
Author(s):  
Ana Flores-Justa ◽  
Sabino Luzzi ◽  
Alice Giotta Lucifero ◽  
Juan F. Villalonga ◽  
Amparo Saenz ◽  
...  
Keyword(s):  
Anterior Part ◽  
Internal Auditory Canal ◽  
Petrous Bone ◽  
Surgical Approaches ◽  
Illustrative Case ◽  
Petroclival Region ◽  
Anterior Transpetrosal Approach ◽  
Neuronavigation System ◽  
Anterior Petrosectomy ◽  
Key Aspects

Introduction: The petroclival region is among the most challenging anatomical areas to deal with in skull base surgery. Drilling of the anterior part of the petrous bone during the anterior transpetrosal approach involves the risk of injury of the cochlea, superior semicircular canal, internal carotid artery, and internal auditory canal. A thorough understanding of the microneurosurgical anatomy of this region is mandatory to execute the transpetrosal approaches, decreasing the risk of complications. The aim of this study is to describe the anatomical structures of the petroclival region, highlighting the importance of neuronavigation for safe performance of the anterior transpetrosal approach. Methods: Three adult cadaveric human heads were formalin-fixed and injected with colored silicone. They underwent an axial 1 mm slab CT scan, which was used for neuronavigation during the surgical approaches. The anterior petrosectomy was performed with the aid of neuronavigation during the drilling of the petrous bone. The surgical management of a patient harboring a petroclival meningioma, operated on using an anterior transpetrosal approach, was reported as an illustrative case. Results: The anterior petrosectomy was completed accurately with wide exposure of the surgical target without injuring the cochlea and other structures in all three cadaveric specimens. In the surgical case, no approach-related complications occurred, and a gross total resection of the tumor was achieved. Conclusions: Deep knowledge of the location and relationships of the vital elements located within the temporal bone, along with the use of neuronavigation, are the key aspects to perform the anterior transpetrosal approach safely, reducing the risk of complications.

Cerebrospinal fluid (CSF) otorhinorrhoea following vestibular schwannoma surgery treated by extended subtotal petrosectomy with obliteration

1993 ◽  
Vol 107 (12) ◽  
pp. 1122-1124 ◽  
Author(s):  
Jona Kronenberg ◽  
Erez Bendet ◽  
Gideon Findler ◽  
Yehudah Roth
Keyword(s):  
Cerebrospinal Fluid ◽  
Facial Nerve ◽  
Vestibular Schwannoma ◽  
Internal Auditory Canal ◽  
Semicircular Canals ◽  
Jugular Bulb ◽  
Sigmoid Sinus ◽  
Mastoid Cell ◽  
Csf Leakage ◽  
Subtotal Petrosectomy

Extended subtotal petrosectomy as a treatment for persistent cerebrospinal fluid (CSF) otorhinorrhoea is presented. Four patients were successfully operated on by this technique, all previously having undergone suboccipital removal of vestibular schwannoma: other interventions used had failed to seal the fistulae. The internal auditory canal was the usual pathway for CSF leakage as well as retrosigmoid, retrolabyrinthine, retro- or perifacial cells. Total exenteration of middle ear and mastoid cell tracts, skeletonization of sigmoid sinus, jugular bulb and facial nerve, drilling out of semicircular canals, vestibule, and cochlea, and skeletonization of the internal auditory canal, followed by obliteration, are the main steps of this approach.

scholarly journals Endoscopic-assisted resection of vestibular schwannomas in high-riding jugular bulb

2021 ◽  
Vol 5 (2) ◽  
pp. V4
Author(s):  
Florian Roser ◽  
Tanmoy Maiti ◽  
Mohamed Samy Elhammady
Keyword(s):  
Vestibular Schwannoma ◽  
Posterior Margin ◽  
Internal Auditory Canal ◽  
Progression Free Survival ◽  
Jugular Bulb ◽  
Retrosigmoid Approach ◽  
Vestibular Schwannomas ◽  
Sitting Position ◽  
Free Survival ◽  
Dural Opening

The present surgical video demonstrates safe opening of the internal auditory canal (IAC) during vestibular schwannoma surgery via a retrosigmoid approach in the sitting position. Resection of the intrameatal portion of a tumor is important for progression-free survival. Preoperative thin-sliced CT revealed a high-riding jugular bulb obscuring the trajectory. After dural opening, the IAC was approached anteriorly and superiorly. The posterior margin of IAC drilling was above the Tubingen line. Drilling was performed under continuous jugular compression. The vein was pushed down to augment visibility. An angled endoscope was helpful. IAC can be drilled safely in a high-riding jugular bulb with the technique mentioned in the video. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2198

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