Cholesterol Granulomas of the Petrous Apex: Review of 30 Cases and Results of Endoscopic Endonasal Surgery at Long-Term Follow-up

Introduction: Cholesterol granulomas (CGs) are an infrequent entity of uncertain etiology. Surgery allows control of symptoms and modifies the progression of the lesion. The authors’ preliminary experience has showed that endoscopic endonasal drainage of petrous apex CGs is a safe and efficient procedure. The purpose of this review was to evaluate the long-term outcomes of this approach.

Material and Methods: We retrospectively analyzed 30 patients (19 men) with histologically proven CGs who underwent an endoscopic endonasal approach (EEA) between January 2003 and December 2016. Six patients were excluded because of lack of follow-up. The approaches were pure transclival, transclival with internal carotid artery (ICA) mobilization or infrapetrous transclival EEA, depending on the extension of the lesion and its relationship with the petrosal and paraclival ICA. The granulomas were partially resected, drained and marsupialized into the sinus by placing a stent or miniflap.

We reviewed the clinical and neuroimaging (CT and MRI) records to determine recurrence.

Results: The mean age was 44.5 (19.8–70.0) years. Sixteen patients (66.6%) presented with headache, 10 (41.6%) diplopia, 5 (20.8%) decreased hearing, 5 (20.8%) vertigo and 2 (7.4%) were incidental findings. Four (16.7%) were recurrent tumors operated via transcranial or endonasal routes at other institutions. In 12 cases (50%), a stent was placed into the cavity and in the other half an external communication was created with miniflap, whose patency was confirmed with the control images.

The mean time of clinical follow-up was 88.4 months (13.4–185.94) and imaging follow-up was 53.7 (0.02–153.2) months. Twenty-two patients (91.6%) had more than 24 months of follow-up, with a mean time of 95.1 (30.5–185.94). Twenty-three cases (95.8%) had symptomatic improvement: 16 patients (66.7%) had complete resolution and 7 (29.2%) had improvement. There were 2 radiological and symptomatic recurrences (8.3%) after surgery in our institution, 1 of them without improvement of the symptoms after repeated drainage. The mean time of relapse was 11 and 41.6 months after surgery.

Three cases (12.5%) had intraoperative CSF leak; 2 without sequelae but 1 developed aseptic meningitis with a postoperative leak requiring surgical repair. One case developed postoperative epistaxis requiring bilateral internal maxillary artery embolization. Two patients (8.3%) required general anesthesia for stent removal. Two patients had transient abducens palsies and 2 complained of dry eye related to vidian nerve transection. Finally, 2 patients required minor surgeries due to complications associated with the EEA, such as Eustachian tube dysfunction requiring tympanostomy, and chronic sinusitis with debridement.

Conclusion: Endoscopic endonasal drainage and marsupialization of petrous apex CGs are effective, low morbidity procedures to control this disease with excellent relief of symptoms and a low rate of recurrence.