Petrous Bone Cholesteatoma: Facial and Hearing Preservation.

Abstract

Objectives: Petrous bone cholesteatoma (PBC) is a rare condition of the petrous portion of the temporal bone. Treatment of choice consists of radical surgical removal, paying attention to protect the facial nerve and inner ear as far as possible. The aim of the present study was to evaluate the efficacy of modified translabyrinthine techniques in preserving hearing function and the use of the adjuvant endoscopic techniques in a group of PBC patients. Methods: This study comprised 16 cases of PBCs surgically treated in our Department. Pre- and post-operative hearing status was assessed with pure tone audiometry and speech discrimination and graded according to the Gardner- Robertson classification system. Facial function was based on the House Brackman (HB) classification. PBCs were grouped using Sanna's classification. The choice of surgical technique was based on the above findings together with preoperative evidence. Post-operative follow-up ranged from 1 to 10 years and also included Computed Tomography and Magnetic Resonance Imaging assessment. Results: PBCs were classified as follows: 37.5% infralabyrinthine; 43.75% supralabyrinthine; and 18.75% massive. Preservation of the bone conduction threshold was feasible in 62.5% of patients. For supralabyrinthine PBCs a subtotal petrosetomy was performed in all cases and hearing preservation was possible in 57% of them: an adjuvant endoscopic approach was performed in 43%. Infralabyrinthine PBCs were treated using a modified translabyrinthine approach with preservation of bone conduction in 83% of patients; an adjuvant endoscopic approach was performed in 50% cases. One patient with a massive cholesteatoma was treated by modified translabyrinthine approach, preserving a serviceable level of hearing. In all massive cases, an adjuvant endoscopic approach was performed. In 2 patients with preoperative palsy, facial nerve function showed an improvement. The follow-up period revealed evidence of limited recurrence at CT imaging in 2 patients. Conclusions: The introduction of modified surgical approaches, able to preserve the anatomical-functional structures, have shown an improvement of post-operative hearing outcomes.