Experiences Combined Lateral Microscopic / Endoscopic Approaches to Petrous Apex Lesions : Pilot Clinical

Background: Surgical treatment of lesions involving the temporal bone, petrous apex, or internal auditory canal is usually performed using the classical microscopic approach that necessitates wide external incisions and soft tissue dissection. At present, the main application of endoscopic surgery is in the surgical treatment of middle ear cholesteatoma, but with the natural evolution of the technique, there will be an increasing number of applications in lateral skull base surgery. Objective: This study aimed to describe the pilot clinical experiences of our institution with combined microscopic/ endoscopic-assisted approaches to the lateral skull base. Methods: A retrospective chart review was performed on patients undergoing an operation between July 2005 and September 2011 for lateral skull base pathology using the endoscope-assisted technique. Results: Nine patients (7 female, 2 male; mean age = 57.4 years) were reviewed and included in the present study. In all cases, the petrous apex lesion of each patient was unilateral: 6 cases had cholesteatoma of the petrous bone; 2 cases had cholesterinic granuloma of the petrous apex; and 1 case had a low-grade chondrosarcoma of the petrous apex. Overall, after a mean follow-up of 30.7 months, no residual disease has been found in our series up to the present time in the cholesteatoma group. In the cholesterinic granuloma group, only a partial success was obtained in the patient who underwent the infracochlear approach, since the most medial part of the pathology was not accessed and still persisted at neuroradiologic examinations made postoperatively. Conclusion: In our case series, lateral combined microscopic/endoscopic procedures have proved to be effective in the treatment of petrous apex lesions, allowing less destructive approaches compared to exclusive microscopic procedures.