RESUMO
Intraoperative imaging during skull-base surgery allows the operator to control surgical dissection and to tailor the approach, reducing morbidity due to inadequate resection or reintervention. The O-arm® (Medtronic, Fridley, MN, USA) navigation system is an intraoperative cone-beam CT device that was first designed for spinal surgery but now has applications in lateral skull-base surgery. In this technical note, we present a patient with petrous apex cholesterol granuloma located medial to the intrapetrous internal carotid artery and in the infralabyrinthine compartment. We report the possibility of natural drainage, using intraoperative imaging to guide resection, through a rapid, safe and minimally invasive approach.
RESUMO
INTRODUCTION: The aim of this study was to evaluate the feasibility of ossiculoplasty via a minimally invasive endoscopic transtympanic approach (ETTA). CASE SERIES: We investigated the exposure of target structures (incus and stapes) on 4 human temporal bones by placing an endoscope into the middle ear cleft through the 4 tympanic quadrants. Then, on 3 additional specimens, we performed an incudostapedial disjunction and repaired it with a drop of hydroxyapatite cement via ETTA. We measured the size of tympanic perforation, and the acoustic transfer function of the middle ear (125-8000Hz) before and after repair by placing an insert in the external auditory canal and recording the acoustic signal in the utricle by a microphone. The acoustic signal gain was estimated in dB µV. Exposure was similar in all four quadrants but ergonomics was better with a posteroinferior myringotomy. Ossicular chain repair was conducted successfully in all cases and the acoustic transfer function of the middle ear was significantly improved. Residual tympanic perforation (n=3) was 2±0.3mm in diameter. CONCLUSION: ETTA to reconstruct incudostapedial joint with bone cement was feasible and effective. It opens perspectives for robot-based procedures guided by augmented reality.
