Endoscopic trans-sphenoidal removal of cholesterol granuloma of the petrous apex: case report and literature review

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 the petrous apex

The petrous apex is a difficult to reach surgical area due to its deep position in the skull base and many vital surrounding structures. Petrous apex pathology ranges from extradural cholesterol granulomas, cholesteatomas, asymmetric pneumatization, and osteomyelitis to intradural meningiomas and schwannomas. Certain lesions, such as cholesterol granulomas, can be managed with drainage while neoplastic lesions must be completely resected. Surgical options use open, endoscopic, and combined techniques and are categorized into anterior, lateral, and posterior approaches. The choice of approach is determined by the nature of the pathology and location relative to vital structures and extension into surrounding structures and requires thorough preoperative evaluation and discussion of surgical goals with the patient. The purpose of this state-of-the-art review is to discuss the most commonly used surgical approaches to the petrous apex, and the anatomy on which these approaches are based.

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.

[The extended endoscopic endonasal transsphenoidal approach in surgery for epidermoid cysts of the chiasmatic region]

Surgical treatment for epidermoid cysts of the chiasmatic region is a challenge because of the tendency to a massive spread of epidermoid masses through the cerebrospinal fluid pathways and a significant lesion deviation from the midline.

PURPOSE

To analyze capabilities of the extended endoscopic endonasal transsphenoidal approach in surgery for epidermoid cysts.

MATERIAL AND METHODS

The study included 6 patients with epidermoid cysts of the chiasmatic region who were operated on using the extended anterior endoscopic endonasal transsphenoidal approach at the Burdenko Neurosurgical Institute in the past 5 years.

RESULTS

Epidermoid masses were completely removed in 5 patients; in none of the cases, complete removal of the epidermoid cyst capsule was achieved. There were no cases of vision deterioration and the development of new focal neurological symptoms. One female patient developed hypopituitary disorders in the postoperative period. There was no recurrence of epidermoid cysts during follow-up.

CONCLUSION

Removal of epidermoid cysts of the chiasmatic region using the extended anterior endoscopic transsphenoidal approach may be an alternative to transcranial microsurgery.

Endoscopic Endonasal Surgery of Epidermoid Cysts of the Chiasmatic Region

BACKGROUND

Despite the rarity of epidermoid cysts in the chiasmatic region, their surgical treatment is particularly complicated because of the tendency toward massive dissemination of the epidermoid masses along cerebrospinal fluid pathways and significant deviation of the tumor from the midline.

OBJECTIVE

The purpose of the present work is evaluation of the role of extended transsphenoidal endoscopic endonasal approaches in the surgery of epidermoid cysts.

METHODS

The study included 6 patients with epidermoid cysts in the chiasmatic region who were operated on at the Burdenko Neurosurgery Institute in the last 5 years using an anterior extended transsphenoidal endoscopic endonasal approach.

RESULTS

The epidermoid masses were totally removed in 5 patients, but in no patient was it possible to completely remove the epidermoid cyst capsule. Visual deterioration was not noted in any patient, nor did new focal neurologic symptoms appear. One of the patients developed hypopituitary disorders in the postoperative period. No recurrence of the epidermoid cysts was observed during the follow-up period.

CONCLUSIONS

Removal of epidermoid cysts in the chiasmatic region using an anterior extended transsphenoidal endoscopic approach may be an alternative to transcranial microsurgery operations. This technique is widely accepted as an approach to this area.

Upper Nasopharyngeal Corridor for Transnasal Endoscopic Drainage of Petroclival Cholesterol Granulomas: Alternative Access in Conchal Sphenoid Patients

Background Cholesterol granulomas arising at the petrous apex can be treated via traditional open surgical, endoscopic, and endoscopic-assisted approaches. Endoscopic approaches require access to the sphenoid sinus, which is technically challenging in patients with conchal sphenoidal anatomy.

Clinical Presentation A 55-year-old woman presented with intermittent headaches and tinnitus. Formal audiometry demonstrated moderately severe bilateral hearing loss. CT of the temporal bones and sella revealed a well-demarcated expansile lytic mass. MRI of the face, orbit, and neck showed a right petrous apex mass measuring 22 × 18 × 19 mm that was hyperintense on T1- and T2-weighted images without enhancement, consistent with a cholesterol granuloma. The patient had a conchal sphenoidal anatomy.

Operative Technique Herein, we present an illustrative case of a low-lying petroclival cholesterol granuloma in a patient with conchal sphenoidal anatomy to describe an alternative high nasopharyngeal corridor for endoscopic transnasal transclival access.

Postoperative Course Postoperatively, the patient's symptoms recovered and no complications occurred. Follow-up imaging demonstrated a patent drainage tract without evidence of recurrence.

Conclusion In patients with a conchal sphenoid sinus, endoscopic transnasal transclival access can be gained using a high nasopharyngeal approach. This corridor facilitates safe access to these lesions and others in this location.

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.

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.

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 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.