Piezosurgery for safe and efficient petrous bone cutting in cerebellopontine angle and petroclival meningioma surgery.

Intradural petrous bone drilling has become a widespread practice, providing extended exposure in the removal of cerebellopontine angle (CPA) or petroclival tumors. Adjacent neurovascular structures are at risk, however, when drilling is performed in this deep and narrow area. Hence, this study evaluates the use of Piezosurgery (PS) as a non-rotating tool for selective bone cutting in CPA surgery. A Piezosurgery® device was used in 36 patients who underwent microsurgery for extra-axial CPA or petroclival tumors in our Neurosurgical Department between 2013 and 2019. The clinical and radiological data were retrospectively analyzed. The use of PS was evaluated with respect to the intraoperative applicability and limitations as well as efficacy and safety of the procedure. Piezosurgical petrous bone cutting was successfully performed in the removal of meningiomas or extra-axial metastases arising from the dura of the petroclival region (21 patients) or petrous bone (15 patients). PS proved to be very helpful in the deep and narrow CPA region, considerably reducing the surgeon's distress toward bone removal in close proximity to cranial nerves and vessels in comparison to common rotating drills. The use of PS was safe without injuries to neurovascular structures. Gross total resection was achieved in 67% of petroclival and 100% of petrous bone tumors. Piezosurgery proved to be an effective and safe method for selective petrous bone cutting in CPA surgery avoiding rotating power and associated risks. This technique can particularly be recommended for bone cutting in close vicinity to critical neurovascular structures.

Piezosurgical lateral suboccipital craniectomy and opening of the internal auditory canal in the rat.

AIM: Rotating burs (RB), routinely used in skull base and cerebellopontine angle (CPA) surgery for craniotomy and opening of the internal auditory canal (IAC) carry some risks for neurovascular tissue due to their rotating power. This paper describes the use of piezosurgery (PS), which selectively cuts bone with preservation of soft tissue, in lateral suboccipital craniectomy and opening of the IAC in the rat. METHODS: A lateral suboccipital craniectomy and opening of the bony IAC were performed with the Mectron® piezosurgical device under microsurgical conditions in the anesthezised rat. The piezosurgical device was evaluated with respect to practicability, safety, preciseness of craniectomy and IAC opening, and preservation of adjacent neurovascular tissue. The operation procedure is described in detail. RESULTS: The present work shows that PS allows easy, safe and precise bone cutting with no injury to neurovascular tissue, such as dura, transverse or sigmoid sinus, brain, and cranial nerves. No complications were noted during the procedure. Due to the absence of rotating power near neurovascular structures the drilling process was easy and comfortable for the surgeon. CONCLUSION: PS proved to be a safe, precise and easy to handle tool to perform suboccipital craniectomy and opening of IAC in the rat. Since PS makes the drilling process safer and more comfortable compared to a rotating bur it may be used instead of rotating burs in all scientific applications in animal models where a safe removal of bone near delicate nervous or soft tissue structures is essential.

[Value of different strategies in the treatment of vestibular schwannoma: therapeutic aspects and literature analysis]. / Wertigkeit unterschiedlicher Methoden zur Behandlung von Akustikusneurinomen: Differenzialtherapeutische Aspekte und Literaturauswertung.

Treatment strategies for vestibular schwannoma have been extended and become more differentiated. An analysis of the international literature with the help of a PubMed search shows that otological and neurosurgical procedures as well as radiation therapies do not only compete but also complement each other. Standardized protocols for the classification of hearing, facial nerve function and quality of life enable a better comparison of functional results. Recent publications discuss - in addition to the standard of preserving facial nerve function and hearing - aspects of vestibular function as well as quality of life, especially in long-term follow up. In addition to effective tumour control, major focus is put on minimizing morbidity. The choice of therapy in patients with neurofibromatosis 2 and recurrent tumours is particularly challenging. The complex topic requires a profound knowledge of differential therapeutic aspects from consulting and treating physicians. Therefore, the individual treatment recommendation should be given in a specialized center.