Surgical approaches to the petrous apex

Combined microscope-endoscopy resection of petrous bone cholesteatoma with temporary facial nerve transposition versus nontransposition

PURPOSE

The narrow supralabyrinthine space affects surgical procedures. To study the effect of temporary transposition of geniculate ganglion of facial nerve versus nontransposition on lesion recurrence and facial nerve function in patients with petrous bone cholesteatoma.

METHODS

A total of 18 patients with petrous bone cholesteatoma involving the facial nerve were treated in our hospital from November 2016 to March 2023. The main surgical method is the extended supralabyrinthine approach assisted by a microscope and an endoscope. We collected and retrospectively analyzed their medical records.

RESULTS

Temporary facial nerve transposition was performed in five patients, and nontransposition was performed in 13 patients. Cholesteatoma recurred in three patients with facial nerve nontransposition, whereas none in patients with facial nerve transposition. In this study, except for one case with a second operation, postoperative facial paralysis in other cases was improved to varying degrees, and there was no significant difference between the two groups.

CONCLUSION

Temporary transposition of geniculate ganglion of facial nerve will not affect the postoperative nerve function of patients and can reduce the possibility of cholesteatoma recurrence of the petrous bone.

Fusobacterium necrophorum an Underrecognized Cause of Petrous Apicitis Presenting with Gradenigo Syndrome: A Case Report

BACKGROUND With the advent of antibiotics, petrous apicitis (PA), inflammation of the petrous temporal bone, has become a rare complication of otitis media. Even more uncommon is Gradenigo syndrome (GS), a result of PA, characterized by a triad of otitis media or purulent otorrhea, pain within the regions innervated by the first and second division of the trigeminal nerve, and ipsilateral abducens nerve palsy. Recent literature has demonstrated increasing reports of Fusobacterium necrophorum isolated in cases of GS. CASE REPORT A 21-year-old man presented with otalgia, reduced hearing, and severe headache. Examination revealed right-sided purulent otorrhea, anesthesia within the trigeminal nerve distribution, and an ipsilateral abducens nerve palsy. F. necrophorum was isolated from an ear swab and a blood culture. Computed tomography and magnetic resonance imaging (MRI) demonstrated otomastoiditis, PA, cavernous sinus thrombosis, and severe stenosis of the petrous internal carotid artery. He was treated with intravenous benzylpenicillin, underwent a mastoidectomy and insertion of a ventilation tube, and was started on a 3-month course of dabigatran. Interval MRI showed improved internal carotid artery caliber, persistent petrous apex inflammation, and normal appearance of both cavernous sinuses. Follow-up clinical review noted persistent abducens and trigeminal nerve dysfunction. CONCLUSIONS We identified 190 cases of PA; of these, 80 presented with the classic Gradenigo triad. Fusobacterium sp. were cultured in 10% of GS cases, making them the most frequent isolates. Due to the fastidious nature of F. necrophorum, it may be underrepresented in the historical literature, and we recommend that empiric antibiotics cover anaerobic organisms.

Incidental Petrous Apex Cephalocele Presenting With Transient Global Amnesia: A Case Report and Rapid Literature Review

Transient global amnesia (TGA) constitutes a rare clinical entity that manifests with temporary memory without any other neurological manifestation. Several pathogenetic mechanisms have been implicated, including temporal hypoperfusion, venous congestion, and cortical spreading potentials. Accordingly, the only relevant imaging findings are hippocampal CA1 areas of restricted diffusion on diffusion-weighted images. In the current case report, we present the rare case of a patient with TGA associated with bilateral petrous apex cephalocele (PAC). A 63-year-old female presented with a single episode of transient memory. The brain MRI showed a bilateral PAC and an empty sella. The patient was neurologically intact upon examination and was conservatively managed. There was no symptom recurrence during the six months of follow-up. We hypothesize that the presence of the meningocele could be associated with the pathogenesis of TGA. To the best of our knowledge, this is the first case of a petrous apex meningocele presenting with TGA. Most previously reported patients were females in their fourth decade of life, usually presenting with headaches or incidentally. Almost half of the cases were bilateral, with an empty sella. Surgical treatment was reserved for symptomatic patients with cerebrospinal fluid leaks and excruciating trigeminal neuralgia. Patients with TGA may be associated with temporal lesions, including PAC. Likewise, PAC is an extremely rare clinical entity that could occasionally present with TGA.

Nasopharyngeal Approach to a Cholesterol Granuloma of the Petrous Apex

Cholesterol granulomas are rare cystic inflammatory lesions characterized by the formation of cholesterol crystals. They are the most prevalent lesions of the petrous apex and when symptomatic, hearing loss, vertigo, tinnitus, headache, and facial pathology can be present. Surgical management is recommended in symptomatic patients. There are different surgical approaches to cholesterol granulomas. The aim of this article is to present and describe an endoscopic endonasal nasopharyngeal approach to a cholesterol granuloma and explain the advantages and disadvantages.

Neurosurgical Intervention in the Treatment of Gradenigo Syndrome: A Case Report

Gradenigo syndrome comprises a clinical triad: retro-orbital pain, sixth cranial nerve palsy, and purulent otorrhea. This clinical syndrome often arises secondary to petrous apicitis, which is an infection of the petrous apex that may result from the contiguous spread of infection from the ear or mastoid. This syndrome is very rare, and based on the existing literature, the initial approach for treatment involves long-term administration of IV antibiotics, which may resolve the underlying infection related to petrous apicitis, mastoiditis, and/or otitis media. In this case, the patient, a 69-year-old male, had a progression of several symptoms, including recurrent headaches, diplopia, hearing loss, and dysphagia, despite long-term antibiotic therapy and a prior mastoidectomy. Thus, the neurosurgical team decided to intervene via anterior petrous bone resection via the Kawase approach, which unfortunately did not result in the resolution of the patient's symptoms. The patient continued to have symptoms of Gradenigo syndrome, including sixth cranial nerve palsy and was subsequently referred to outpatient follow-up for further management. In this report, we present the patient's case and a brief review of the literature concerning various treatment modalities for Gradenigo syndrome.

Cyst-to-Mastoid Antrum Diversion as an Alternate Pathway for Management of Small Symptomatic Petrous Apex Cholesterol Granuloma Without Anteromedial Expansion Using an Extradural Middle Fossa Approach: A Technical Case Report

BACKGROUND AND IMPORTANCE

Cholesterol granuloma (CG) is the most common petrous apex (PA) cystic lesion. Posterolateral expansion of a PA CG (PACG) compresses the internal auditory canal (IAC), leading to vestibulocochlear (VC) and facial nerve dysfunction. Even small, symptomatic PACGs are managed surgically. The preferred strategy is not complete removal, but drainage and aeration. PACG with anteromedial expansion using an endoscopic endonasal approach provides natural drainage into the nasal sinus without risking VC and facial dysfunction. Endoscopic endonasal approach is inappropriate for small PACGs without anteromedial expansion because of potential damage to the petrous internal carotid artery. Small PACGs without anteromedial expansion are managed using extradural middle fossa (EMF) approach, which lacks a natural drainage pathway, thus necessitating an artificial drainage pathway for PACG aeration to prevent recurrence. We introduced EMF approach for CG decompression and cyst-to-mastoid antrum (MA) diversion for managing small, symptomatic PACGs without anteromedial expansion.

CLINICAL PRESENTATION

A 48-year-old woman presented with headache, vertigo, tinnitus, and left hemifacial spasm with preserved hearing because of IAC compression caused by a small PACG without anteromedial expansion. Using the EMF approach, the CG and IAC were safely decompressed. Effective and long-standing artificial drainage for CG aeration was established by anterior petrosectomy and silicone tubing from the CG into the MA. Surgery resolved the symptoms, which have not recurred in 3 years.

CONCLUSION

Granuloma decompression and cyst-to-MA diversion using silicone tubing using the EMF approach is a safe and effective surgical management for small, symptomatic PACG without anteromedial expansion.

Surgical management of petrous apex cholesteatomas in the pediatric population: A systematic review

Background:

Cholesteatomas are growths of squamous epithelium that can form inside the middle ear and mastoid cavity and damage nearby structures causing hearing loss when located at the petrous apex. The primary goal of petrous apex cholesteatoma resection is gross total removal with tympanoplasty and canal-wall up or canal-wall down tympanomastoidectomy. At present, there is no definitive surgical approach supported by greater than level 4 evidence in the literature to date.

Methods:

A systematic review was conducted utilizing PubMed, Embase, and Scopus databases. Articles were screened and selected to be reviewed in full text. The articles that met inclusion criteria were reviewed for relevant data. Data analysis, means, and standard deviations were calculated using Microsoft Excel.

Results:

After screening, five articles were included in the systematic review. There were a total of eight pediatric patients with nine total cholesteatomas removed. Conductive hearing loss was the most common (77%) presenting symptom. Perforations were noted in seven ears (86%). Recurrence was noted in 50% of patients with an average recurrence rate of 3.5 years (SD = 1.73). Average length of follow-up was 32.6 months (SD = 21.7). Canal-wall up was the most utilized technique (60%) and there were zero noted surgical complications. Five of the seven (71%) patients that experienced hearing loss from perforation noted improved hearing.

Conclusion:

Due to its rarity, diagnostic evaluation and treatment can vary. Further, multi-institutional investigation is necessary to develop population-level management protocols for pediatric patients affected by petrous apex cholesteatomas.

Imaging of Petrous Apex Lesions

The petrous apex may be affected by a range of lesions, commonly encountered as incidental and asymptomatic findings on imaging performed for other clinical reasons. Symptoms associated with petrous apex lesions commonly relate to mass effect and/or direct involvement of closely adjacent structures. Petrous apex lesions are optimally assessed using a combination of high-resolution CT and MRI of the skull base. Management of petrous apex lesions varies widely, reflecting the range of possible pathologies, with imaging playing a key role, including lesion characterization, surveillance, surgical planning, and oncological contouring.

Patient-specific virtual and mixed reality for immersive, experiential anatomy education and for surgical planning in temporal bone surgery

OBJECTIVE

The recent development of extended reality technology has attracted interest in medicine. We explored the use of patient-specific virtual reality (VR) and mixed reality (MR) temporal bone models in anatomical teaching, pre-operative surgical planning and intra-operative surgical referencing.

METHODS

VR and MR temporal bone models were created and visualized on head-mounted display (HMD) and MR headset respectively, by a novel webservice that allows users to convert computed tomography images to VR and MR images without specific knowledge of programming. Eleven otorhinolaryngology trainees and specialists were asked to manipulate the healthy VR temporal bone model and to assess its validity by filling out a questionnaire. Additionally, VR and MR pathological models of petrous apex cholesteatoma were utilized for surgical planning pre-operatively and for referring to the anatomy during the surgery.

RESULTS

Most participants were favorable about the VR model and considered HMD as superior to a flat computer screen. 91% of the participants agreed or somewhat agreed that VR through HMD is cost effective. In addition, the VR pathological model was used for planning and sharing the surgical approach during a pre-operative surgical conference. The MR headset was worn intra-operatively to clarify the relationship between the pathological lesion and vital anatomical structures.

CONCLUSION

Regardless of the participants' training level in otorhinolaryngology or VR experience, all participants agreed that the VR temporal bone model is useful for anatomical education. Furthermore, the creation of patient-specific VR and MR models using the webservice and their pre- and intra-operative usages indicated the potential of innovative adjunctive surgical instrument.