Cerebellopontine Angle Epidermoids: Comparative Results of Microscopic and Endoscopic Excision Using the Retromastoid Approach”

Abstract

Background Densely packed neurovascular structures, often times inseparable capsular adhesions and sometimes a multicompartmental tumor extension, make surgical excision of cerebellopontine angle epidermoids (CPEs) a challenging task. A simultaneous or an exclusive endoscopic visualization has added a new dimension to the classical microscopic approaches to these tumors recently.

Methods Eighty-six patients (age: 31.6 ± 11.7 years, M:F = 1:1) were included. Nineteen patients (22.1%) had a multicompartmental tumor. Tumor extension was classified into five subtypes. Sixty-two patients underwent a pure microscopic approach (72%) out of which 10 patients (16%) underwent an endoscope-assisted surgery (11.6%) and 24 patients (28%) underwent an endoscope-controlled excision. Surgical outcomes were retrospectively analyzed.

Results Headache (53.4%), hearing loss (46.5%), and trigeminal neuralgia (41.8%) were the leading symptoms. Interestingly, 21% of the patients had at least one preexisting cranial nerve deficit. Endoscopic assistance helped in removing an unseen tumor lobule in 3 of 10 patients (30%). Pure endoscopic approach significantly reduced the hospital stay from 9.2 to 7.3 days (p = 0.012), and had a statistically insignificant yet a clearly noticeable lesser incidence of subtotal tumor excision (0 vs. 10%, p = 0.18) with comparable cranial nerve deficits but with a higher postoperative cerebrospinal fluid (CSF) leak rate (29% vs. 4.8%, p = 0.004).

Conclusion Endoscope assistance in CPE surgery is a useful addition to conventional microscopic retromastoid approach. Pure endoscopic excision in CPE is feasible, associated with a lesser duration of hospital stay, better extent of excision in selected cases, and it has a comparable cranial nerve morbidity profile albeit with a higher rate of CSF leak.

Keywords

cerebellopontine angle - epidermoid - endoscopy - multicompartmental - cisterns - classification - microsurgery - complications

Publication History

Received: 03 May 2020

Accepted: 05 November 2020

Article published online:
22 February 2021

• References

• 1 Safain MG, Dent WC, Heilman CB. An endoscopic assisted retrosigmoid approach to the cerebello-pontine angle for resection of an epidermoid cyst. Neurosurg Focus 2014; 36 (1, Suppl): 1
• 2 Hasegawa M, Nouri M, Nagahisa S. et al. Cerebellopontine angle epidermoid cysts: clinical presentations and surgical outcome. Neurosurg Rev 2016; 39 (02) 259-266 , discussion 266–267
• 3 Son DW, Choi CH, Cha SH. Epidermoid tumors in the cerebellopontine angle presenting with trigeminal neuralgia. J Korean Neurosurg Soc 2010; 47 (04) 271-277
• 4 Kunigelis K, Yang A, Youssef AS. Endoscopic assisted retrosigmoid approach for cerebellopontine angle epidermoid tumor. J Neurol Surg B Skull Base 2018; 79 (5, Suppl 5): S413-S414
• 5 Abolfotoh M, Bi WL, Hong CK. et al. The combined microscopic-endoscopic technique for radical resection of cerebellopontine angle tumors. J Neurosurg 2015; 123 (05) 1301-1311
• 6 Yaşargil MG, Abernathey CD, Sarioglu AC. Microneurosurgical treatment of intracranial dermoid and epidermoid tumors. Neurosurgery 1989; 24 (04) 561-567
• 7 Farhoud A, Khedr W, Aboul-Enein H. Surgical resection of cerebellopontine epidermoid cysts: limitations and outcome. J Neurol Surg B Skull Base 2018; 79 (02) 167-172
• 8 Chowdhury FH, Haque MR, Sarker MH. Intracranial epidermoid tumor; microneurosurgical management: an experience of 23 cases. Asian J Neurosurg 2013; 8 (01) 21-28
• 9 deSouza CE, deSouza R, da Costa S. et al. Cerebellopontine angle epidermoid cysts: a report on 30 cases. J Neurol Neurosurg Psychiatry 1989; 52 (08) 986-990
• 10 Balasundaram P, Garg A, Prabhakar A, Joseph Devarajan LS, Gaikwad SB, Khanna G. Evolution of epidermoid cyst into dermoid cyst: embryological explanation and radiological-pathological correlation. Neuroradiol J 2019; 32 (02) 92-97
• 11 Samii M, Tatagiba M, Piquer J, Carvalho GA. Surgical treatment of epidermoid cysts of the cerebellopontine angle. J Neurosurg 1996; 84 (01) 14-19
• 12 Matsushima K, Kohno M, Nakajima N, Ichimasu N. Combined transpetrosal approach with preservation of superior petrosal vein drainage for a cerebellopontine angle epidermoid cyst extending into Meckel's cave: 3-dimensional operative video. Oper Neurosurg (Hagerstown) 2019; 16 (06) E172-E173
• 13 Shimamoto Y, Kawase T, Sasaki H, Shiobara R, Yamada F. Anterior transpetrosal approach to the prepontine epidermoids. Skull Base Surg 1999; 9 (02) 75-80
• 14 Tummala RP, Coscarella E, Morcos JJ. Transpetrosal approaches to the posterior fossa. Neurosurg Focus 2005; 19 (02) E6
• 15 Peng Y, Yu L, Li Y, Fan J, Qiu M, Qi S. Pure endoscopic removal of epidermoid tumors of the cerebellopontine angle. Childs Nerv Syst 2014; 30 (07) 1261-1267
• 16 Hu Z, Guan F, Kang T. et al. Whole course neuroendoscopic resection of cerebellopontine angle epidermoid cysts. J Neurol Surg A Cent Eur Neurosurg 2016; 77 (05) 381-388
• 17 Safavi-Abbasi S, Di Rocco F, Bambakidis N. et al. Has management of epidermoid tumors of the cerebellopontine angle improved? A surgical synopsis of the past and present. Skull Base 2008; 18 (02) 85-98
• 18 Schroeder HW, Oertel J, Gaab MR. Endoscope-assisted microsurgical resection of epidermoid tumors of the cerebellopontine angle. J Neurosurg 2004; 101 (02) 227-232
• 19 Aboud E, Abolfotoh M, Pravdenkova S, Gokoglu A, Gokden M, Al-Mefty O. Giant intracranial epidermoids: is total removal feasible?. J Neurosurg 2015; 122 (04) 743-756
• 20 Czernicki T, Kunert P, Nowak A, Wojciechowski J, Marchel A. Epidermoid cysts of the cerebellopontine angle: clinical features and treatment outcomes. Neurol Neurochir Pol 2016; 50 (02) 75-82
• 21 Li J, Qian M, Huang X, Zhao L, Yang X, Xiao J. Repeated recurrent epidermoid cyst with atypical hyperplasia: a case report and literature review. Medicine (Baltimore) 2017; 96 (49) e8950
• 22 Rutherford SA, Leach PA, King AT. Early recurrence of an intracranial epidermoid cyst due to low-grade infection: case report. Skull Base 2006; 16 (02) 109-116
• 23 Kobata H, Kondo A, Iwasaki K. Cerebellopontine angle epidermoids presenting with cranial nerve hyperactive dysfunction: pathogenesis and long-term surgical results in 30 patients. Neurosurgery 2002; 50 (02) 276-285 , discussion 285–286