gms | German Medical Science

Objective: The piezosurgical technique is based on microvibrations, which are generated by the piezoelectrical effect. Thus the piezosurgical device selectively cuts bone while preserving adjacent soft tissue. The present study examined the applicability of piezosurgery as well as advantages and disadvantages of the piezosurgical device compared to the use of conventional rotating burs for opening the posterior wall of the internal auditory canal (IAC) in acoustic neuroma surgery.

Methods: MECTRON^® piezosurgery was used in 8 patients, who underwent microsurgical resection of acoustic neuroma under neurophysiological monitoring. After suboccipital craniectomy, opening the cerebellomedullary cistern, and retracting the cerebellum, the IAC and the tumor were exposed. The piezosurgical device was then used to cut the posterior wall of the IAC instead of a conventional rotating bur. Piezosurgery was evaluated with respect to practicability, safety, preciseness of bone cutting, preservation of cranial nerves and influences on neurophysiological monitoring.

Results: The piezosurgical device cut bone selectively and preserved cranial nerves, which could be measured by means of neuromonitoring. The handling of the instrument was very safe and the cut precise since the effect of bone drilling is caused by microvibrations instead of rotating power. Bone could be cut carefully layer by layer by the angled disc-dissector-shaped tip. There was no influence on neurophysiological monitoring that was attributable to piezosurgery. The possibility of hearing preservation surgery using piezosurgery seemed to be at least as good as with the conventional technique in the few studied cases. Due to the construction of the tip, the device showed better handling in right-sided than in left-sided tumors in the hands of a right-handed surgeon. A further disadvantage is the slightly inconvenient handling of the device attributable to the short, thick handpiece with which the surgeon has to work in the narrow space of the cerebellopontine angle.

Conclusions: The piezosurgical device proved to be a useful tool for selective opening of the posterior wall of the IAC with preservation of cranial nerves in acoustic neuroma surgery. The technique showed no major disadvantages or negative influence on neuromonitoring and hearing and facial nerve preservation rates. We conclude that piezosurgery has the potential to replace rotating burs for this indication due to its safe and precise bone drilling properties.