Otoneurological management of petrous apex cholesterol granuloma

Radiological Classification and Management Algorithm of Petrous Apex Cholesterol Granuloma

Background: Petrous apex cholesterol granulomas (PACGs) are benign inflammatory cystic lesions of the temporal bone. Usually, asymptomatic patients may develop symptoms as the lesions expand. The diagnosis is based on both CT and MRI scans and the management relies on "wait and scan" or surgery. This paper aims at evaluating surgical outcomes and proposing a CT-based classification and a management algorithm. Methods: Patients with PACGs who were surgically treated between 2014 and 2024 were included. Symptoms, imaging, approach type and complications were considered. CT scans were classified as Type A (preserved apex cellularity), Type B (erosion of the apex cellularity), and Type C (involvement of the noble structures bone boundaries). The possible connection of the lesion with the infracochlear, perilabyrinthine and sphenoidal cellularity was assessed. Results: Nineteen patients with symptoms like diplopia, headache and sensorineural hearing loss were included. According to our classification, 1/19 patients was Type A, 4/19 were Type B and 14/19 were Type C. Five patients underwent a total resection, seven a subtotal and seven a surgical drainage. Only two complications were recorded, and 17/19 patients showed symptom regression and stability during follow-up. Conclusions: While the management of PACGs is still controversial, according to our classification and surgical outcomes, Type A, being mostly asymptomatic, should be managed with "wait and scan", Type B should undergo surgery when symptoms are present, while Type C should always undergo surgery because of their invasiveness and potential complications. When possible, a drainage should be attempted; otherwise, a surgical resection is chosen, and its completeness depends on the preoperative general and hearing status.

Surgical Approaches to Petrous Apex Cholesterol Granulomas: A Systematic Review and Network Meta-analysis

OBJECTIVE

To compare the outcomes of different surgical approaches to petrous apex cholesterol granulomas (PACG).

DATA SOURCES

PubMed, Embase, Google Scholar, Cochrane, and Web of Science.

REVIEW METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses-Network Meta-analyses guidelines, databases were searched from inception to November 31, 2022. Studies comparing two or more approaches were included. Reviews and population studies were excluded. The main outcome measures were the resolution of symptoms, serviceable hearing, complication, and revision rates.

RESULTS

The search yielded 2132 studies. After applying inclusion and exclusion criteria, 15 studies remained, consisting of 214 patients treated with lateral approaches (n = 182) or anterior endonasal approaches (n = 32). The efficacy of lateral and anterior endonasal approaches in achieving symptom resolution was comparable (73% vs. 68%, p = 0.5). Both exhibited similar rates of complications (33% vs. 37%, p = 0.3), albeit with distinct profiles. Lateral approaches were associated with higher rates of facial palsy and sensorineural hearing loss (44% vs. 18%, p = 0.03). Anterior endonasal approaches demonstrated higher rates of epistaxis and cerebrospinal fluid leak (15% vs. 1%, p = 0.001). Anterior endonasal approaches exhibited lower revision rates (OR: 0.35, 95% CI: 0.14-0.88). The placement of a stent in both approaches was associated with higher symptom resolution (OR: 5.12, 95% CI: 1.05-9.97) and lower revision rates (OR: 0.71, 95% CI: 0.33-0.92).

CONCLUSIONS

Anterior endonasal approaches yield lower revision rates compared to lateral approaches for PACG. Both approaches demonstrate similar effectiveness in symptom resolution and comparable rates of complications, with distinct profiles. Facial nerve and hearing status are important factors that should be addressed when selecting the approach. Stenting is beneficial.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:1540-1550, 2024.

Quantitative Evaluations of Vestibular Function in Patients With Petrous Apex Cholesterol Granulomas Treated With an Endoscopic Transsphenoidal Approach: A Report of Two Cases

OBJECTIVE

We report two cases of petrous apex cholesterol granuloma (PACG) treated with an endoscopic transsphenoidal approach. Vestibular functions of the two patients were evaluated quantitatively by video Head Impulse Test (vHIT) and/or vestibular evoked myogenic potentials (VEMPs).

PATIENTS

Two patients with PACG who experienced episodes of dizziness are presented.

INTERVENTION

An endoscopic transsphenoidal approach to PACG.

MAIN OUTCOME MEASURE

The preoperative and postoperative vestibular functions as evaluated by vHIT and VEMP.

RESULTS

Two cases of PACG were treated by a transsphenoidal approach. The internal auditory canal was compressed by the PACG in both cases. The patients both experienced episodes of dizziness before surgery and preoperative vestibular testing including vHIT and VEMP indicated dysfunction of vestibular nerves. After surgery, their symptoms were completely resolved, and the vestibular testing results were improved.

CONCLUSIONS

This article is noteworthy for being the first to publish quantitative vestibular function testing for patients with PACG with vestibular dysfunction. PACG may show various symptoms, with dizziness being one of the most common symptoms. In cases in which the internal auditory canal is compressed by the PACG, vestibular functions should be evaluated by vHIT and VEMP. In the present cases, dizziness was found to be resolved by surgery to release the compression on internal auditory canal. Based on the present cases, the transsphenoidal approach is considered to be both safe and effective.

Characteristics and Clinical Management Strategy of Petrous Apex Cholesterol Granulomas

Purpose: To evaluate the clinical characteristics of petrous apex cholesterol granulomas (PACG) and assess outcomes after different treatment strategies. Method: A consecutive case series of 34 patients with a PACG. Main outcomes were PACG growth, symptoms, and the outcomes of different treatment strategies: wait-and-scan (WS) and surgical drainage. Results: Thirty-four patients were analyzed; mean follow-up time was 7.1 years. Twenty-one patients (61.7%) showed symptoms, mostly more than one. Most symptoms reported were cranial nerve palsy (58.8%) and headache (35.3%). Twenty-one patients (61.8%) received solely wait-and-scan (WS), and thirteen patients (38.2%) underwent surgery, five of whom (38.5%) after an initial WS period. In the solely WS group, one (4.8%) developed new symptoms, and two (9.5%) reported symptom progression despite a stable granuloma size. Two (9.5%) showed granuloma growth on follow-up scans without symptom progression. Surgery consisted of drainage. Eleven (84.6%) of these thirteen patients reported partial recovery; one (7.7%) reported no recovery; and one (7.7%) reported full recovery of reported symptoms related to PACG. Among the patients with cranial nerve involvement, 7.7% showed full recovery after surgery; 84.6% showed partial recovery; and 7.7% did not recover. Adverse events occurred in five out of 13 patients who underwent surgery, all with full recovery. Conclusions: This study confirms that PACG are slow-growing lesions with a low risk of adverse events. Solely using wait-and-scan strategy is a safe option for patients without symptoms, with acceptable symptoms without symptom progression, and with asymptomatic growth. Surgical treatment can be considered in patients with symptom progression or symptomatic growth.

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.

[Pathology of the apex of the temporal bone pyramid: cholesterol granuloma and congenital cholesteatoma]

The report presents modern views on the origin and pathomorphological characteristics of the cholesterol granuloma of the petrous apex of temporal bone, its clinical comparison with congenital cholesteatoma of the same localization. The differential diagnostic features in CT and MRI scans are analyzed in detail, and the principles of surgical treatment, indications and contraindications are discussed. Also the case of atypical course of cholesterol granuloma is presented, which was difficult in the diagnostics but with a successful treatment result.

Management of Intractable Petrous Bone Cholesteatoma With a Combined Translabyrinthine-Transsphenoidal Approach

OBJECTIVE

To evaluate whether a combined translabyrinthine-transsphenoidal approach can be used to achieve adequate surgical resection of an extensive petrous bone cholesteatoma and create a debris drainage route for the residual cholesteatoma that is maintained long-term.

PATIENT

A 71-year-old man with residual petrous temporal bone cholesteatoma that had spread extensively to the internal carotid artery and posterior cranial fossa.

INTERVENTION

Surgical resection of the cholesteatoma via a translabyrinthine approach and creation of a debris drainage route into the nasopharynx via a transsphenoidal approach.

MAIN OUTCOME MEASURES

Control of unresectable petrous temporal bone cholesteatoma and occurrence of cholesteatoma- or surgery-related complications.

RESULTS

Although complete removal of the cholesteatoma was attempted via a translabyrinthine approach, this was not possible because the epithelium of the cholesteatoma was strongly attached to the internal carotid artery and posterior cranial fossa. A debris drainage route leading to the nasopharynx was created by drilling the clivus on the side of the lesion via a transsphenoidal approach. The patient has had no complications since surgery. The drainage route remains open, and the cholesteatoma has been controlled for 57 months.

CONCLUSIONS

A markedly advanced petrous temporal bone cholesteatoma can be managed safety and reliably by combining a translabyrinthine approach with a transsphenoidal approach. Creation of a debris drainage route into the nasopharynx can prevent isolation of the cholesteatoma and mastoid cavity problems after surgery. This one-stage surgery may be a suitable method for keeping cholesteatoma under control in patients with unresectable petrous bone cholesteatoma.

Rare Diseases of the Middle Ear and Lateral Skull Base

Otalgia, otorrhea and hearing loss are the most common ear-related symptoms that lead to the consultation of an otolaryngologist. Furthermore, balance disorders and affections of the cranial nerve function may play a role in the consultation. In large academic centres, but also in primary care, the identification of rare diseases of the middle ear and the lateral skull base is essential, as these diseases often require interdisciplinary approaches to establish the correct diagnosis and to initiate safe and adequate treatments. This review provides an overview of rare bone, neoplastic, haematological, autoimmunological and infectious disorders as well as malformations that may manifest in the middle ear and the lateral skull base. Knowledge of rare disorders is an essential factor ensuring the quality of patient care, in particular surgical procedures. Notably, in untypical, complicated, and prolonged disease courses, rare differential diagnoses need to be considered.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Cholesterol Granulomas: A Comparative Meta-Analysis of Endonasal Endoscopic versus Open Approaches to the Petrous Apex

Petrous apex cholesterol granulomas (PACG) are rare disorders that can lead to patient morbidity and must, occasionally, be drained by either endoscopic endonasal (EN) or open procedures (OP). The objective of our study was to complete a review of the literature to compare the EN and OP approaches on multiple levels, notably on safety and effectiveness. Ovid MEDLINE and Embase were used to perform a thorough literature review of all cases of PACG treated by either EN or OP dating from January 1948 to August 2017. In total, 49 articles were selected including 23 for EN (n=76) and 26 for OP (n=210). Differences were found in the incidence of preoperative hearing loss (HL) (EN 18.4%, OP 57.3%; p<0.001), headache (EN 48.7%, OP 31.2%; p=0.007), and disequilibrium (EN: 14.5%, OP 26.1%; p=0.04). Differences in lesion proximity to the sphenoid sinus (EN 23.6%, OP: 1.0%; p<0.001), clivus (EN 11.8%, OP 4.7%; p=0.03), otic capsule (EN 0.0%, OP 5.2%; p=0.03), internal auditory canal (EN 2.6%, OP 10.9%; p=0.01), and internal carotid artery (ICA) (EN 9.2%, OP 2.8%; p=0.02) were found on preoperative imaging. The EN procedure had better hearing improvement rates (EN 85.7%, OP 23.4%; p<0.001), lower complication rates (EN 7.9%, OP 17.6%; p=0.04), shorter median follow-up (EN:13.5 months, OP:37.2 months; p<0.001), and shorter time to recurrence (EN 3 months, OP 22.6 months; p=0.002) than the known OP. No differences were found in age, preoperative size, recurrence rate, operative time, stent placement, or improvement of other symptoms. Endoscopic nasal approaches, when feasible, should be favored to open procedures for PACG drainage given their better hearing improvement and less complication rates.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Indications and endonasal treatment of petrous apex cholesterol granulomas

PURPOSE OF REVIEW

Lesions of the petrous apex of the temporal bone can be challenging to access and approaches laterally through the mastoid as well as medially through an endonasal approach are utilized to access this region while preserving function of adjacent structures. Cholesterol granulomas of the petrous apex requiring surgery are marsupialized to prevent expansion of the inflamed cyst and relieve associated clinical symptoms. The endonasal approach to the petrous apex has in the past been limited to lesions medial to the internal carotid artery.

RECENT FINDINGS

Endoscopic approaches have been developed to expand the range of petrous apex lesions that are accessible endonasally. These endonasal corridors include a nasopharyngeal/transclival corridor, lateralization of the internal carotid artery to create an expanded medial window, a pterygopalatine infrapetrosal approach, and a contralateral maxillary approach, which allow improved access to the inferior and lateral petrous apex. Nasoseptal flaps may reduce the risk of postoperative stenosis of the drainage tract.

SUMMARY

Endoscopic endonasal approaches can be used safely to address both medial and lateral/inferior petrous apex lesions. Morbidity of these procedures is low and use of a nasoseptal flap may limit restenosis of the drainage pathway.

Petrous Apex Cholesterol Granulomas: Outcomes, Complications, and Hearing Results From Surgical and Wait-and-Scan Management

OBJECTIVE

1. To analyze the surgical outcomes in the management of petrous apex cholesterol granulomas (PACG) with a brief literature review.2. To evaluate the importance of wait-and-scan management option.

STUDY DESIGN

Retrospective review.

SETTING

Quaternary referral center for otology and skull base surgery.

SUBJECTS AND METHODS

Charts of 55 patients with at least 12 months of follow-up were analyzed for demographic, clinical, audiometric, and radiological features. Patients were divided into surgical group (SG) (n = 31) and wait-and-scan (n = 24) (WS) group. Surgical approach was chosen as per hearing status and PACG extension and relation to nearby neurovascular structures and included either drainage by transmastoid-infralabyrinthine approach (TM-IL)/transcanal-infracochlear approach (TC-IC) or resection by infratemporal fossa type B approach (ITF-B). The combination of ITF-B with trans-otic (TO) approach or TO approach solely was used in unserviceable hearing cases. Postoperative outcomes and complications were evaluated in SG.

RESULTS

Postoperative symptom relief was observed in 24 patients (77.4%). Diplopia and paresthesia recovered in each case and improvement in headache, dizziness, tinnitus, and hearing loss was observed in 87.1% cases. Serviceable hearing was preserved in 24 of 26 cases. Postoperative complication rate was 32.2% including incidences of profound hearing loss, facial nerve paresis, carotid artery injury and intraoperative CSF leaks. Revision surgery was required in 3 (9.6%) cases, after TM-IL approach.

CONCLUSION

Surgical drainage is preferable to more aggressive resection procedures, with the latter reserved for recurrent lesions or lesions with severe hearing loss/involvement of critical neurovascular structures. ITF-B approach provides adequate cyst and neurovascular control for resection, while avoiding brain retraction. An initial wait-and-scan approach can be used in most patients where symptoms and imaging justify so.

Long-term Symptom-specific Outcomes for Patients With Petrous Apex Cholesterol Granulomas: Surgery Versus Observation

OBJECTIVE

Review long-term symptom-specific outcomes for petrous apex cholesterol granulomas (PACG).

STUDY DESIGN

Retrospective review.

SETTING

Tertiary center.

PATIENTS

Adults with PACG were assessed from 1998 to 2015.

INTERVENTION(S)

Symptomatic patients were stratified into surgical and observation subgroups.

MAIN OUTCOME MEASURE(S)

Resolution rates of individual symptoms and chief complaints were assessed as was the impact of surgical approach and stent usage on symptom-specific outcomes. Symptom recurrence rates were tabulated.

RESULTS

Twenty-seven patients were included whose mean age was 44.8 ± 3.3 years. Fourteen and 13 patients stratified into the surgical and observation subgroups respectively. The surgical subgroup trended toward a longer follow-up period (mean 68.5 vs. 33.8 mo; p = 0.06). Overall, the most frequent symptoms encountered were headache (52%), aural fullness, tinnitus, and vestibular complaints (41% each). Visual complaints, retro-orbital pain, and cranial neuropathies were less common (18%, 15%, 11%). The overall symptom resolution rate was significantly higher in the surgical subgroup (48% vs. 26%, p = 0.03). In both subgroups, headache, retro-orbital pain, and visual complaints had the highest resolution rates. Vestibular complaints and tinnitus were very unlikely to resolve. Significantly more patients in the surgical group resolved their chief complaints (70% vs. 25%, p = 0.02). While approach type and stent usage did not significantly influence symptom outcomes, all patients with symptom recurrence (11%) were initially managed without stents.

CONCLUSION

Symptom-specific outcomes were better in patients managed surgically for PACG. Individual symptom resolution rates were highly variable. Some symptoms were refractory regardless of management strategy. Surgical approach and stent usage did not significantly influence symptom outcomes.

Cranial Nerve Disorders in Children: MR Imaging Findings

Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. If cranial nerve involvement is suspected, careful evaluation of the cranial nerves should include specific MR imaging protocols. Localization is an important consideration in cranial nerve imaging, and should cover entire pathways and target organs as much as possible. Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016.

Sixth Nerve Palsy from Cholesterol Granuloma of the Petrous Apex

Herein, we report a patient who had an isolated sixth nerve palsy due to a petrous apex cholesterol granuloma. The sixth nerve palsy appeared acutely and then spontaneously resolved over several months, initially suggesting a microvascular origin of the palsy. Subsequent recurrences of the palsy indicated a different pathophysiologic etiology and MRI revealed the lesion at the petrous apex. Surgical resection improved the compressive effect of the lesion at Dorello’s canal and clinical improvement was observed. A relapsing–remitting sixth nerve palsy is an unusual presentation of this rare lesion.

Endoscopic transsphenoidal surgery using pedicle vascularized nasoseptal flap for cholesterol granuloma in petrous apex: A technical note

BACKGROUND

Compared with surgical resection, endoscopic transsphenoidal surgery (TSS) for cholesterol granuloma (CG) in the petrous apex (PA) is associated with local recurrence due to obstruction of the drainage route. We present a detailed procedure of an endoscopic TSS using pedicle vascularized nasoseptal flap (PVNF).

METHODS

A 40-year-old woman with a history of repeated surgery for left tympanitis was referred to our institution. Neurological examination revealed severe hearing loss in the left ear. Radiologic examination presented a round mass in the left PA and significant fluid collection in the mastoid air cells of the left temporal bone. CG was strongly suspected, and endoscopic TSS using PVNF was performed. Prior to endoscopic drainage, a PVNF was harvested from the mucosa of the ipsilateral nasal septum, with an attempt to preserve the sphenopalatine artery in the flap. Following this, puncture and adequate irrigation of the lesion was performed by endoscopic TSS, with neuro-navigation system assistance; the apex of PVNF was then placed into the lesion to prevent the obstruction of the drainage route. An absorbable polyglycolic acid sheet and fibrin glue were applied on the flap to prevent spontaneous deviation from the lesion.

RESULTS

The patient was discharged without any further neurological complications. Eight-month postoperative computed tomography images showed no recurrence; the drainage route was patent and the fluid collection in the left mastoid air cells was resolved. Moreover, hearing loss was improved.

CONCLUSIONS

Endoscopic TSS using PVNF may be one of available surgical options for PACG.

The Natural History and Management of Petrous Apex Cholesterol Granulomas

OBJECTIVE

To evaluate the clinical and radiographic characteristics of cholesterol granulomas of the petrous apex, as well as the outcomes of operative and conservative management.

STUDY DESIGN

Retrospective chart review.

SETTING

Two independent tertiary academic referral centers.

PATIENTS

Adult and pediatric patients with cholesterol granulomas of the petrous apex were identified from the experience of two separate centers. Patients were included after radiographic diagnosis and clinical evaluation. All patients with less than 6 months of follow-up and those with iatrogenic postoperative cholesterol granulomas were excluded.

INTERVENTION

Demographic information, presenting symptoms, imaging characteristics, treatment strategies, and outcomes were recorded.

MAIN OUTCOME MEASURES

Patients were evaluated on the basis of symptom and radiographic evolution during time, with or without operative intervention.

RESULTS

Ninety petrous apex cholesterol granulomas were analyzed (57.8% females, 55.6% right-sided). The average age at presentation was 43.1 years (median 42.0, range 8.0-77.0 years). The most common presenting symptom was headache (56.7%), and the average lesion size in the greatest dimension was 2.1 cm (median 1.7, range 0.7-5.0 cm). During a mean follow-up of 46.0 months, no cases of spontaneous rupture or carotid injury occurred. Twenty-three patients (25.6%) ultimately underwent surgical management, most commonly for intractable headache, and only 47.8% of these patients experienced durable symptom improvement by their last postoperative follow-up.

CONCLUSION

Many cholesterol granulomas of the petrous apex remain stable during time and can be safely managed with primary observation. Surgery should be reserved for lesions that are causing, or threatening, neurologic dysfunction because of mass effect or erosion of critical structures such as the otic capsule. Cranial neuropathy associated with cholesterol granuloma may improve after operative management; however, symptoms such as headache and dizziness are less likely to benefit from surgery. As a general guideline, in the presence of a radiologically stable cholesterol granuloma in the petrous apex, alternative etiologies for headache and dizziness should be considered and treated before offering surgical intervention.

Surgical outcomes after endoscopic management of cholesterol granulomas of the petrous apex: a systematic review

OBJECT

Endoscopic endonasal treatment of petrous apex cholesterol granulomas allows for a natural drainage pathway into the nasopharynx. Because of the limited number of case series in the literature, there is limited evidence of recurrence rates and outcomes following endoscopic endonasal management. The purpose of this study was to determine the surgical outcomes of endoscopic endonasal approaches in the treatment of cholesterol granulomas of the petrous apex.

METHODS

A systematic literature review was performed using PubMed for articles published from January 1980 to April 2014 to identify all studies reporting outcomes for endoscopic endonasal surgical management of cholesterol granulomas of the petrous apex. Operative approach, use of a stent, symptom outcome, restenosis, cyst recurrence, reoperation, and complications were extracted from included studies.

RESULTS

A total of 53 patient cases were included from 22 relevant studies. The mean age was 41 years, and 26 patients (49%) were female. Stents were used in 45.1% of cases. Symptom resolution or improvement was seen in 98.6% of cases at follow-up (mean follow-up 20 months). Complications were reported in 13.2% of cases, with the most common complication being epistaxis. Restenosis on follow-up office endoscopic examination occurred in 9 of 45 cases (20.0%). Only 4 of these restenosis cases resulted in symptomatic cyst recurrence, resulting in an overall recurrence rate of 7.5%. The mean time from surgery to cyst recurrence was 13.5 months. The rate of symptomatic cyst recurrence was 10.7% in cases without the use of a stent compared with 4.3% in cases with stent placement (p = 0.6).

CONCLUSIONS

Based on current literature, endoscopic endonasal approaches result in a high rate of symptom improvement or resolution. Complication rates are lower than prior case series that have utilized open approaches. Asymptomatic restenosis can be managed conservatively, since it is associated with symptomatic cyst recurrence less than half of the time. This study revealed a nonsignificant trend toward a decrease in symptomatic cyst recurrence when a stent was used, but further work is needed to clarify its impact.

Use of the pedicled nasoseptal flap in the endoscopic management of cholesterol granulomas of the petrous apex

BACKGROUND

Nowadays the endoscopic approach represents a useful alternative to traditional surgical approaches in the treatment of cholesterol granulomas (CGs) of the petrous apex (PA). Recently the nasoseptal flap (NSF) has been employed to permit long-term patency of drainage site. The purpose of this study is to report our experience with the NSF in the endoscopic management of CG and to analyze the advantages, limitations, and outcomes of the technique.

METHODS

A retrospective analysis was carried out on 10 patients affected by CG of the PA who had been treated endoscopically, using the NSF.

RESULTS

An endoscopic transpterygoid approach was used for 6 patients and the remaining 4 were treated using the transclival approach. A NSF was used in all 10 cases. In 6 cases the flap was ipsilateral to the lesion whereas in 4 it was contralateral. In 90% of our patients no evidence of disease was observed after a mean follow-up period of 35.7 months, with resolution of their symptoms. One patient presented a recurrence because of a technical error (inadequate placement of the flap in the cavity), and has been retreated endoscopically.

CONCLUSION

The pedicled NSF seems to be helpful in avoiding the concentric growth of the granulomatous cyst epithelium while assuring ventilation and drainage of the cyst. However, bigger studies with longer-term follow-up are needed to confirm these findings. Correct and meticulous placement of the flap inside the cystic cavity is the most critical issue for the success of the procedure.

Cholesterol Granuloma of the Petrous Apex: A 5-Year Review of Radiology Reports with Follow-Up of Progression and Treatment

Objectives To assess the stability and outcomes of patients with cholesterol granulomas at Brigham and Women's Hospital. Design A retrospective review of neuroradiology magnetic resonance imaging (MRI) studies was performed. The number of newly diagnosed cases of cholesterol granuloma per year was determined. Additional data included age and gender, clinical presentation if applicable, growth on imaging follow-up, and recurrence on postoperative follow-up if applicable. Participants Inclusion criteria included patients who underwent MRI studies between January 1, 2009 and July 1, 2013. Upon review of imaging of these patients, 18 patients had findings compatible with cholesterol granuloma. Results During the study period, an average of three cases of cholesterol granuloma were diagnosed on MRI per year. Three of 18 patients underwent treatment. Two underwent surgery, both of whom demonstrated recurrence on postoperative follow-up imaging. One patient who underwent computed tomography-guided percutaneous aspiration and Gelfoam (Pfizer, New York, United States) embolization had no recurrence on imaging follow-up of up to 23 months. Among the patients who were observed without intervention, growth was identified in only one patient. Conclusions Cholesterol granulomas are a rare entity; however, their appearance on imaging may be greater than previously reported. Most of the lesions demonstrate stability and can be observed.

Surgical Anatomy of the Infralabyrinthine Approach

Objective

The objective of this study is to demonstrate the surgical anatomy of the infralabyrinthine approach (ILA) and ways to prevent complications based on the complex anatomy.

Study Design

Cadaveric study.

Setting

Ankara University Faculty of Medicine, Department of Anatomy.

Subjects and Methods

Temporal bones were selected from 30 sides of 20 fixed human cadaver heads. Computed tomography (CT) scans of the heads were performed and, afterward, the cadavers were dissected using a surgical microscope and electric drill.

Results

An appropriate tract could be achieved in 73.3% of the dissections by applying slight pressure to the jugular bulb (JB). The narrowest portion of the ILA was defined as the inner window, which was located superior-inferiorly between the inferior border of the cochlea and the inferior wall of the petrous apex and anterior-posteriorly between the posterior wall of the carotid canal and the cochlear opening of the cochlear aqueduct. The ILA could not be performed when the distances between the facial nerve-JB and JB-cochlea were less than 2.9 mm and 2.6 mm, respectively, on CT scan.

Conclusion

Close attention should be paid to the access and inner window during preoperative temporal bone imaging to assess for ILA. The detailed anatomy of the route, measurements of the topography of the cochlea from the mastoid view, and angles of the route are defined to prevent complications.

Image-guided percutaneous aspiration and gelfoam treatment of petrous apex cholesterol granuloma: a new theory and method for diagnosis and treatment

Although diagnosis of cholesterol granulomas of the skull base can be straightforward with computed tomography (CT) and magnetic resonance imaging (MRI) appearance, treatment is controversial with various skull base approaches described in the literature. This report describes a 35-year-old man who presented with a symptomatic, enlarging cystic lesion in the left petrous apex and clivus that had imaging features of a cholesterol granuloma (cholesterol cyst). Due to a prior history of treated mediastinal germ cell tumor, pathologic confirmation of the lesion was requested. A CT-guided percutaneous aspiration revealed dark used motor oil-like fluid. Continued aspiration yielded a change in the character of the fluid to marrow red. Injection of contrast revealed no communication with cerebrospinal fluid. Gelfoam (Pfizer, New York, New York, USA) was subsequently injected percutaneously into the residual cavity. Histopathology showed no evidence of malignancy and follow-up MRI at 1 month, 3 months, 6 months, and 1 year demonstrated continued decrease in size and signal of the lesion.

Usefulness of image guidance in the surgical treatment of petrous apex cholesterol granuloma

The petrous apex is a pyramid-shaped structure, located medial to the inner ear and the intrapetrous segment of the internal carotid artery. Lesions of the petrous apex can be surgically treated through different surgical routes. Because of the important neurovascular structures located inside the temporal bone, anatomical 3D knowledge is paramount. For this reason, image-guided surgery could represent a useful tool. We report the case of a young woman who came to our observation for a trigeminal neuralgia due to a petrous apex cholesterol granuloma. The lesion was treated through the placement of a drainage tube via an infracochlear approach, with the aid of neuronavigation and intraoperative MRI. Preoperative CT scan images and intraoperative MRI images were fused for surgical planning. The accuracy of the neuronavigation system has proved to be good, and the safety of the procedure was enhanced. Therefore, neuronavigation and intraoperative MRI, though not available in all neurootological centres, should be considered useful tools in these challenging procedures.

Middle fossa approach for total resection of petrous apex cholesterol granulomas: use of vascularized galeofascial flap preventing recurrence

BACKGROUND

Cholesterol granulomas (CGs) of the petrous apex (PA) are rare, benign, expanding lesions. Surgical treatment is recommended for patients with symptomatic disease; however, the optimal surgical procedure is still controversial due to high recurrence rates. The main treatment strategy is divided into drainage and complete resection.

OBJECTIVE

We advocate radical resection of the lesion by the middle fossa approach and reconstruction with a vascularized galeofascial flap.

METHODS

A 10-year retrospective case review of 17 patients undergoing surgical treatment of PA CGs between 2000 and 2010 was undertaken. Operative outcomes and surgical complications were analyzed. In addition, our operative method and the related anatomy are described from cadaveric dissections.

RESULTS

All but 1 patient was operated on via a middle fossa approach. Using the middle fossa approach, radical resection of all PA CGs was achieved with obliteration of the cyst cavity using a vascularized flap. Important surrounding structures included the internal auditory canal, cochlea, petrous carotid artery, and abducens nerve. There was 1 death caused by internal carotid artery occlusion. No other major complications or cranial nerve deficits occurred postoperatively. Clinical recurrence occurred in 1 patient (5.9%).

CONCLUSION

Our technique of radical resection and reconstruction with a vascularized flap has the advantage of being less invasive with less cosmetic deformity and allows preservation of cranial nerve function with a low recurrence rate. Knowledge of the surgical anatomy and the characteristics of CG is prudent because important neurovascular structures may be exposed behind the CG wall due to bony erosion.

Petrous apex cholesterol granuloma: pictorial review of radiological considerations in diagnosis and surgical histopathology

BACKGROUND

Petrous apex cholesterol granulomas are expansile, cystic lesions containing cholesterol crystals surrounded by foreign body giant cells, fibrous tissue reaction and chronic inflammation. Appropriate treatment relies on an accurate radiological diagnosis and an understanding of the distinguishing radiological features of relevant entities in the differential diagnosis of this condition.

METHODS

Firstly, this paper presents a pictorial review of the relevant radiological features of petrous apex cholesterol granuloma, and highlights unique features relevant to the differential diagnosis. Secondly, it reviews the histopathological and radiological findings associated with surgical drainage of these lesions.

RESULTS

Radiological features relevant to the differential diagnosis of petrous apex cholesterol granuloma are reviewed, together with radiological and histopathological features relevant to surgical management. Following surgical management, histopathological and radiological evidence demonstrates that the patency of the surgical drainage pathway is maintained.

CONCLUSION

Accurate diagnosis of petrous apex cholesterol granuloma is essential in order to instigate appropriate treatment. Placement of a stent in the drainage pathway may help to maintain patency and decrease the likelihood of symptomatic recurrence.

Petrous apex cholesterol granuloma: maintenance of drainage pathway, the histopathology of surgical management and histopathologic evidence for the exposed marrow theory

OBJECTIVES

(1) To assess the maintenance of drainage pathway patency in patients who undergo surgical management of cholesterol granulomas, (2) to review the histopathologic and radiologic changes associated with surgical drainage of petrous apex (PA) cholesterol granulomas, and (3) to provide histopathologic evidence regarding the exposed marrow theory of PA cholesterol granulomas.

STUDY DESIGN

Retrospective case review and histopathologic analysis.

SETTING

Tertiary referral center.

PATIENTS

Records of 17 patients with surgically managed PA cholesterol granulomas were reviewed. Histopathologic analysis was performed on temporal bones of 11 patients with PA cholesterol granulomas from the Temporal Bone repository at the House Research Institute.

INTERVENTIONS

Surgical drainage of PA cholesterol granulomas; follow-up radiologic imaging (computed tomography or magnetic resonance imaging), when available.

MAIN OUTCOME MEASURES

Primary outcome is demonstrated maintenance of a PA outflow drainage pathway after the surgical drainage procedure as assessed by radiologic imaging, available histopathology, and/or recurrence of symptoms indicating failure of maintenance. Other measures include need for revision surgery and histopathology findings.

RESULTS

A majority (65%) of patients exhibited maintenance of their PA drainage pathway. Histopathologic evidence suggests that the PA drainage pathway can be maintained for many years after surgical drainage. Recurrence of symptoms was related to obstruction of the drainage pathway by fibrous tissue and/or granulomatous tissue. Placement of a stent improved the patient's chance of remaining symptom-free, with recurrence of symptoms and revision surgery required in only 2 stent cases (18%) as compared with 83% of those with no stent (p ≤ 0.035). Histopathologic evidence for the exposed marrow theory of PA cholesterol granulomas was found.

CONCLUSION

The majority of patients who undergo surgical drainage of PA cholesterol granulomas remain symptom-free after surgical drainage. Histopathologic analysis of temporal bone specimens provides evidence supporting the exposed marrow theory of PA cholesterol granuloma formation. Loss of patency of the PA drainage pathway may be an important predictor for symptomatic recurrence of PA cholesterol granulomas. Placement of a stent may decrease the likelihood of symptomatic recurrence.

Petrous apex cholesterol granulomas: endonasal versus infracochlear approach

OBJECTIVES/HYPOTHESIS

The aim of this study was to investigate and compare the surgical anatomy of two different routes to access and drain petrous apex (PA) cholesterol granulomas: the expanded endonasal approach (EEA) and the transcanal infracochlear approach (TICA).

STUDY DESIGN

Anatomic and radiologic study.

METHODS

The EEA and TICA to the PA were performed in 11 anatomic specimens with the assistance of imaging guidance. The PA was categorized into three zones: superior PA, anterior-inferior PA, and posterior-inferior PA. The maximum drainage window achieved by each approach was calculated using the imaging studies of each anatomic specimen.

RESULTS

The EEA was able to reach superior PA and anterior-inferior PA in all specimens and posterior-inferior PA in 90%. The TICA did not provide access to superior PA in any case. The TICA was suitable to reach anterior-inferior PA in 80% of specimens and posterior-inferior PA in 60%. Based on the radiologic study, the EEA provided a drainage window three times larger than the TICA.

CONCLUSIONS

The transnasal approach provides reliable access to the PA when combined with internal carotid artery exposure and allows for large drainage window. The transcanal approach is less versatile and more limited than the transnasal approach but provides access to the most posterior and inferior portion of the PA without Eustachian tube transection. Here we propose a new surgical classification that may help to decide the most suitable approach to the PA according to the location and extension of the lesion.

Endoscopic endonasal approach to cholesterol granulomas of the petrous apex: a series of 17 patients

Object

The aim of this study was to report the results in a consecutive series of patients who had undergone an endoscopic endonasal approach (EEA) for drainage of a petrous apex cholesterol granuloma (CG).

Methods

Seventeen cases with a confirmed diagnosis of petrous apex CG were identified from a database of more than 1600 patients who had undergone an EEA to skull base lesions at the authors' institution in the period from 1998 to 2011. Clinical outcomes were reviewed and compared with those in previous studies of open approaches.

Results

Nine patients underwent a transclival approach and 8 patients underwent a combined transclival and infrapetrous approach. A Silastic stent was used in 11 patients (65%), a miniflap in 4 (24%), and a simple marsupialization of the cyst in 3 (18%). All symptomatic patients had partial or complete improvement of their symptoms postoperatively and at the follow-up (mean follow-up 20 months, range 3–67 months). Complications developed in 3 patients (18%) including epistaxis, chronic serous otitis media, eye dryness, and a transient sixth cranial nerve palsy. Two patients (12%) had a symptomatic recurrence of the cyst requiring repeat endoscopic endonasal drainage. There were no instances of internal carotid artery injuries, CSF leaks, or new hearing loss. The mean postoperative hospital stay was 2 days (range 0.7–4.6 days). These results were comparable with those in previous studies of open approaches to petrous apex CGs.

There was a strong correlation between the size of the cyst and the type of approach chosen (Rpb [point biserial correlation coefficient] = +0.67, p = 0.003359) and a very strong correlation between the degree of medial extension (defined by the V-angle) and the choice of approach (Rpb = +0.81, p < 0.0001). Based on these observations, the authors developed an algorithm for guiding the choice of the most appropriate route of drainage.

Conclusions

The EEA is a safe and effective alternative to traditional open approaches to petrous apex CGs.

Endoscopic balloon dilation as an adjunct to extended endoscopic approaches to the skull base

Cholesterol granulomas (CGs) are benign, expanding cystic lesions surrounded by a thick fibrous capsule and filled with fluid, formed by the degradation of blood elements. The goal of surgery is to open the granuloma widely, creating a well-drained cavity. The endonasal endoscopic approach for this extradural lesion is a minimal access method for surgical removal or fenestration. The role of balloon dilation in creating a wide fenestration has not been previously described. The authors describe a patient with a recurrent petrous apex CG who underwent an endoscopic, endonasal, transmaxillary transpterygoid approach to the petrous apex. A balloon sinuplasty catheter was used to dilate the surgical fenestration to maintain continued patency. The authors report on their first experience using balloon dilation combined with endoscopic drainage of the petrous apex. The excellent surgical outcome of this minimally invasive technique holds promise for future endonasal approaches to the middle cranial fossa.

Minimally invasive endoscopic endonasal management of skull base cholesterol granulomas

BACKGROUND

Skull base cholesterol granulomas (SBCGs) are rare lesions that have traditionally been managed via middle fossa or transtemporal approaches. Despite the relative paucity in the literature, the endoscopic endonasal approach may serve as a potential alternative surgical route. In this study, we report our experience with the management of SBCG using this minimally invasive approach.

METHODS

The charts and imaging studies of three patients were reviewed retrospectively. The mean age was 36 years (range 30-42). The male/female ratio was 2:1. The epicenter of the lesion was petrous apex in two patients and clivus in one. One patient had undergone surgery via a middle fossa approach 3 years before the endoscopic procedure. The SBCG was drained using an endoscopic endonasal approach in all patients. A stent was left in place in 2 cases.

RESULTS

All patients presented with headaches and ipsilateral retroorbital pain. One patient also had diplopia, ipsilateral blepharospasm, and hearing loss. Average lesion size was 31 mm (22-37 mm). Pain and associated neurologic symptoms completely resolved in one patient, and the headache significantly improved in the other two. These two patients underwent revision surgeries for symptomatic reaccumulation and stenosis of cavity opening at 5 and 7 months, respectively. Both patients improved subsequently, and have been stable since that time. One patient developed chronic sphenoid sinusitis. Average hospital stay was 1 day per procedure. All patients had functional patency of the SBCG with average follow-up of 25 months (10-36 months).

CONCLUSIONS

Endoscopic endonasal approach may serve as a technically feasible and minimally invasive alternative to traditional surgical approaches for the management of SBCG in carefully selected patients.