The Keyhole Retrosigmoid Endoscopic Approach to the CPA: Techniques and Results

Objective: To establish the versatility and usefulness of the keyhole retrosigmoid approach to the cerebellopontine angle (CPA) in various pathologies. Study Design: Prospective clinical study. Setting: Tertiary referral university hospital. Methods: A total of 121 patients with various pathologies of the CPA underwent the relevant investigations and were operated upon by the retrosigmoid microendoscopic approach. The technical modifications and progression of our technique are described. Results: This group consisted of 121 patients (103 men and 28 women). The pathologies included were 60 acoustic neuromas, 28 vestibular neurectomies, 9 meningiomas, and 4 arachnoid cysts. For nonmass lesions, no additional facial nerve injury or deterioration of hearing occurred. Total excision of mass lesions was achieved in 94.5% of cases. Facial nerve integrity was preserved in 92.3% of cases with mass lesions and permanent facial paralysis occurred in 8.3%. There were no mortalities, and the most frequent complication was a delayed cerebrospinal fluid leak from the site of the wound (15%), which was managed conservatively in all cases. Conclusions: The keyhole retrosigmoid approach is a versatile one. It can be used to deal with different pathologies through a unified access, and with the increasing exclusive use of endoscopes, a truly minimally invasive surgery can be achieved.