Extracapsular dissection in peripheral nerve schwannoma surgery using bright light and fluorescein sodium visualization: case series Abstract Background Schwannomas are the most frequent peripheral nerve sheath tumors and are treated by surgical resection when symptomatic. Tumor removal is performed by intraneural dissection and enucleation. In order to safely remove the tumor from the nerve, the use of sodium fluorescein has recently been proposed to distinguish the tumor from the adjacent normal nerve fibers, before incision of the tumor pseudocapsule and during intraneural tumor dissection. Methods We report a consecutive case series of 5 peripheral nerve schwannomas operated in 4 patients, in which we evaluate the usefulness of sodium fluorescein compared to usual visual landmarks, at each step of the surgical procedure. Results After exposition of the schwannoma, sodium fluorescein helped with the localization of intracapsular en passant nerve fascicles in only one case. Hence, the definition of a safe entry zone for capsular incision relied mainly on nerve monitoring and direct visualization of en passant nerve fascicles under microscope. During intraneural dissection, there was a sharp contrast between the fluorescent tumor and the non-fluorescent adjacent pseudocapsule in most cases but the colorimetric variation between tumor and normal tissue induced by fluorescence did not outperform the natural contrast between the yellow true capsule and the gray-red layers of the pseudocapsule. Conclusion Based on these results, we consider that the limited additional value of sodium fluorescein in primary peripheral nerve schwannoma surgery does not warrant its use in daily clinical practice. Additional studies are needed to assess its usefulness during the surgery of recurrences and tumors which are intertwined with several fascicles of origin such as neurofibromas.

Advances in Vestibular schwannoma microneurosurgery: Improving Results with New Technologies (2019) Editors: L. Mastronardi, T. Fukushima A. Campione 174 pages, illustrated ISBN: 9783030031671 Springer Publishers

Minimally invasive resection of a lumbar extradural schwannoma: how I do it Abstract Background Complete surgical resection of a foraminal lumbar schwannoma may require an extended surgical exposure and facetectomy and thus secondary instrumentation. The minimally invasive technique through the use of tubular retractors may represent a valid surgical alternative. Method We describe the resection of a foraminal lumbar schwannoma through the use of tubular retractors, along with its advantages and limitations. A limited medial facetectomy was performed and no stabilization was needed. Conclusion Minimally invasive surgery is suitable for an efficient and safe resection of foraminal schwannomas and may help in avoiding stabilization when a limited facetectomy is performed.

The transcallosal transchoroidal approach to the diencephalic-mesencephalic junction: how I do it Abstract Background Different approaches have to be considered for lesions of the diencephalic-mesencephalic junction based on the localization, extension of the lesion, and relationship to the ventricular system. Method We present the case of a young lady who presented with a cavernoma of the junction of midbrain and diencephalon after an episode of hemorrhage. The microsurgical anatomy of the trans-callosal trans-choroidal approach for this lesion is described along with its advantages and limitations. Conclusion The trans-choroidal approach allows adequate access to lesions of the diencephalic-mesencephalic junction that project into the third ventricle.

A new technique of endoscopic decompression of suprasellar craniopharyngioma cyst Abstract Introduction Craniopharyngiomas represent a unique management challenge. Aggressive surgical management has traditionally been associated with high rates of morbidity. Modern surgical techniques, and increasing practice of subtotal resection followed by radiosurgery, have reduced morbidity and mortality rates. One cause of postoperative morbidity, and indeed mortality, is aseptic meningitis from spill-out of craniopharyngioma cyst contents. We have developed a surgical technique for the management of large craniopharygngioma cysts extending into the third ventricle, to reduce this risk. Methods We describe a technique of using an epidural catheter, inserted into the working channel of a neuroendoscope, to decompress the cystic portion of a craniopharyngioma cyst before opening the cyst wall widely, preventing spill-out of large volumes of cyst content into the ventricular system. Results We have had no cases of aseptic meningitis, nor any complications, from use of the described technique. Discussion We believe that this is a safe and effective technique of decompression and fenestration of large suprasellar craniopharyngioma cysts that reduces rates of aseptic meningitis and the associated morbidity and mortality from this.

Interfascial approach for pterional craniotomy: technique and adjustments to prevent cosmetic complications Abstract Background Interfascial dissection for pterional craniotomy is one of the main techniques to expose the pterional region. Method A step-by-step optimized method of interfascial dissection to avoid three main esthetic complications of the pterional approach—upper facial nerve palsy, temporal muscle atrophy, and retro-orbital depression. A video of the interfascial dissection and three artistic drawings are provided in support of this technique. Conclusion A safe method of interfascial dissection, respecting anatomy, and avoiding cosmetic complications has been proposed.

How I do it: combined petrosectomy Abstract Background Petroclival lesions are among the most complex to address in skull base surgery, being closely related to critical neurovascular structures and brainstem. The combined petrosectomy allows a wide exposure of large petroclival lesions with short working distance and provides multiple angles of attack, while limiting brain retraction. Method We describe in a step-wise fashion the surgical steps of the combined petrosectomy. Conclusion Combined petrosectomy with posterior transposition of the transverse-sigmoid sinus provides a wide surgical corridor to the ventral brainstem, middle and upper clivus, and infra-retrochiasmatic region.

Extra-intradural extracavernous subtemporal approach for chondrosarcomas: technical note and case report Abstract Background Skull base chondrosarcomas are rare tumors often invading the petrous apex and cavernous sinus, and many surgical approaches have been described. For most of them, these tumors grow slowly and their partial removal can be a first option before complementary radiotherapy. We described herein a minimally invasive approach that could be useful for soft non-calcified chondrosarcomas. Method and results We report a case of right parasellar chondrosarcoma, for which an extra-intradural extracavernous subtemporal approach allowed a safe effective partial removal. Conclusion This surgical approach is indicated in selected cases to obtain good decompression or partial removal of lesions involving the parasellar space and the petrous apex.

Hearing preservation in vestibular schwannoma surgery via retrosigmoid transmeatal approach Abstract Background Advances in various diagnostic and/or treatment modalities, including radiological imaging, neuromonitoring, and microsurgical techniques, have resulted in treatments of vestibular schwannomas being aimed at preserving facial and hearing functions while achieving optimal tumor control. Method We describe our surgical technique for hearing preservation in vestibular schwannoma surgery. Conclusion The retrosigmoid transmeatal approach under continuous neuromonitoring (auditory brainstem response, cochlear nerve action potentials, and continuous facial nerve monitoring) enables gross-total resection of vestibular schwannomas, while preserving hearing and facial functions. Radiological assessment and microsurgical techniques, such as meticulous tumor dissection, are also essential for functional preservation with sufficient tumor removal.

How I do it? Endoscopic discectomy using a new trocar “Endospine Plus” for lumbar prolapsed intervertebral disc Abstract Background Endoscopic spine surgery is a promising minimally invasive technique and use of trocars like Metrx (Neurosurgery 51(5):S129–36, 2002), Destandau (Neurol Res 21:39–42, 1999), and Easy go (Acta Neurochir (Wien) 151:1027‑33, 2009) has revolutionized this field. However, the steep learning curve makes this procedure elusive to many parts of the world. Methods The authors describe the technique of pure endoscopic discectomy using a specialized trocar devised by the senior author “Endospine Plus” which makes the technique easy to learn along with the advantages and complications of the procedure. Conclusions Endoscopic lumbar discectomy is a safe and effective technique for the treatment of prolapsed intervertebral disc.