Microsurgical resection of a large petroclival meningioma through an extended retrosigmoid approach: how I do it.

BACKGROUND: Petroclival meningiomas are challenging tumors. Several skull base approaches have been proposed in the last decades, with variable rates of postoperative morbidity and extent of resection. METHODS: We herein reported the step-by-step microsurgical resection of a large petroclival meningioma through an extended retrosigmoid approach. Detailed surgical technique has been accompanied by a 2D operative video. CONCLUSION: The extended retrosigmoid approach allowed for a safe gross total resection of the tumor, as confirmed by the postoperative MRI. The patient did not experience any new postoperative deficit, despite a transient diplopia, and was discharged on postoperative day 7.

The role of preoperative [11C]methionine PET in defining tumor-related epilepsy and predicting short-term postoperative seizure control in temporal lobe low-grade gliomas.

OBJECTIVE: Surgery is the mainstay of treatment for low-grade glioma (LGG)-related epilepsy. However, the goal of achieving both oncological radical resection and seizure freedom can be challenging. PET with [11C]methionine (MET) has been recently introduced in clinical practice for the management of patients with LGGs, not only to monitor the response to treatments, but also as a preoperative tool to define the metabolic tumor extent and to predict tumor grading, type, and prognosis. Still, its role in defining tumor-related epilepsy and postoperative seizure outcomes is limited. The aim of this preliminary study was to investigate the role of MET PET in defining preoperative seizure characteristics and short-term postoperative seizure control in a cohort of patients with newly diagnosed temporal lobe low-grade gliomas (tLGGs). METHODS: Patients with newly diagnosed and histologically proven temporal lobe grade 2/3 gliomas (2021 WHO CNS tumor classification) who underwent resection at the authors' institution between July 2011 and March 2021 were included in this retrospective study. MET PET images were acquired, fused with MRI scans, and qualitatively and semiquantitatively analyzed. Any eventual PET/MRI involvement of the temporomesial area, seizure characteristics, and 1-year seizure outcomes were reported. RESULTS: A total of 52 patients with tLGGs met the inclusion criteria. MET PET was positive in 41 (79%) patients, with a median metabolic tumor volume of 14.56 cm3 (interquartile range [IQR] 6.5-28.2 cm3). The median maximum and mean tumor-to-background ratio (TBRmax, TBRmean) were 2.24 (IQR 1.58-2.86) and 1.53 (IQR 1.37-1.70), respectively. The metabolic tumor volume was found to be related to the presence of seizures at disease onset, but only in noncodeleted tumors (p = 0.014). Regarding patients with uncontrolled seizures at surgery, only the temporomesial area PET involvement showed a statistical correlation both in the univariate (p = 0.058) and in the multivariate analysis (p = 0.030). At 1-year follow-up, seizure control was correlated with MET PET-derived semiquantitative data. Particularly, higher TBRmax (p = 0.0192) and TBRmean (p = 0.0128) values were statistically related to uncontrolled seizures 1 year after surgery. CONCLUSIONS: This preliminary study suggests that MET PET may be used as a preoperative tool to define seizure characteristics and outcomes in patients with tLGGs. These findings need to be further validated in larger series with longer epileptological follow-ups.

A randomized prospective comparative study on sinonasal morbidity and quality of life of transsphenoidal endoscopic surgery for pituitary adenomas: endonasal versus trans-septal approach.

PURPOSE: Endoscopic endonasal transsphenoidal approach (Endonasal approach) is commonly used to treat pituitary adenomas. The extent of dissection possibly changes the anatomy and the physiology of the nasal cavities and could give rise to post-operative morbidity and the quality of life (QoL). The purpose of this study was to investigate sinonasal morbidity and general QoL in patients who underwent surgery for treatment of pituitary adenoma, comparing Endonasal and endoscopic trans-septal transsphenoidal approach (Trans-septal approach). METHODS: A prospective observational study, recruiting 40 patients undergoing surgery for pituitary adenoma, 20 via Endonasal approach and 20 via Trans-septal approach at our institution. Surveys with Sinonasal Outcome Test-22 (SNOT-22), Chronic Sinusitis Survey (CSS), and Short Form Health Survey 36 version 2 (SF-36v2) were obtained to collect QoL data pre- and postoperatively. RESULTS: All the 40 patients completed the questionnaires. At 6 months postoperatively, the SNOT-22 and CSS score shows significant improvements both in Endonasal approach (p = 0.01) and in Trans-septal approach (p = 0.02). No significant difference in sinonasal morbidity is observed between the two groups for SNOT-22 (p = 0.13) and CSS scores, except for sinus headache (p = 0.49), with a better score in Endonasal approach. The mean SF-36v2 scores remain the same in pre- and post-operative periods, but an improvement in time is seen in general health (p = 0.027), and general health compared to one year ago (p < 0.001). CONCLUSIONS: Endoscopic transsphenoidal surgery has negligible morbidity and does not negatively affect the nasal function in the long term. Endonasal approach and Trans-septal approach are comparable in terms of morbidity outcomes and general QoL, leaving the choice of the approach to the surgeon preference.

Combined telovelar posterolateral (far lateral) approach for the resection of a large posterior fossa ependymoma: how I do it.

BACKGROUND: Ependymomas are glial cell tumors whose recommended treatment, according to the recent European guidelines, is surgical. Patient outcomes, in terms of progression-free survival and overall survival, are strongly related to the extent of resection. However, in some cases, critical locations and/or large dimensions could make a gross total resection challenging. In this article, we describe the surgical anatomy and technique of a combined telovelar-posterolateral approach for the resection of a giant posterior fossa ependymoma. METHODS: A 24-year-old patient who presented to our institution complaining of a 3-month history of headache, vertigo, and imbalance. Preoperative MRI scans showed a large mass within the fourth ventricle, extending towards the left cerebellopontine angle and perimedullary space through the homolateral Luschka foramen. Surgical treatment was proposed with the aims of releasing the preoperative symptoms, obtaining the tumor's histopathological and molecular definition, and preventing any future neurological deterioration. The patient gave his written consent for surgery and consented to the publication of his images. A combined telovelar-posterolateral approach was then performed to maximize the tumor's exposure and resection. Surgical technique and anatomical exposure have been extensively described, and a 2-dimensional operative video has been included. RESULTS: The postoperative MRI scan demonstrated an almost complete resection of the lesion, with only a millimetric tumor remnant infiltrating the uppermost portion of the inferior medullary velum. Histo-molecular analysis revealed a grade 2 ependymoma. The patient was discharged home neurologically intact. CONCLUSIONS: The combined telovelar-posterolateral approach allowed to achieve a near total resection of a giant multicompartimental mass within the posterior fossa in a single surgical stage.

Cerebellar Ischemic Stroke Secondary to Rotational Non-Dominant Vertebral Artery Occlusion (RVAO): A Rare Complication Following Supratentorial Surgery.

Non-traumatic vertebrobasilar stroke syndrome is rare. Many etiological mechanisms have been described over the years, with the dynamic occlusion of one vertebral artery following head rotation (RVAO) being one of them. We report the case of a patient undergoing surgery for supratentorial metastasis, who postoperatively developed a cerebellar ischemic stroke secondary to RVAO. Postoperative imaging showed a right hypoplastic VA; so, a transient occlusive mechanism was thought to be responsible for the postoperative cerebellar stroke. Although rare, RVAO can occur following head rotation during patient positioning for neurosurgical procedures.

Minimally invasive microsurgical decompression of the lumbar spine using a novel robotised digital microscope: A preliminary experience.

BACKGROUND: The operative microscope (OM) represents, to date, the standard for neurosurgical procedures. However, new technologies have been proposed during the latest years to overcome its limitations, from high-quality exoscopes to complex robotised visualisation systems. We report our preliminary experience with a novel digital robotised microscope, the BHS RoboticScope (RS), for minimally invasive spinal surgery. METHODS: We employed the RS in five consecutive patients who underwent bilateral lumbar spine decompression through a monolateral approach. Patient outcomes, device technical characteristics and the surgeon's personal perspectives have been evaluated. RESULTS: No complications occurred. All procedures were concluded without switching to the microscope. Image quality, lightning, depth perception and freedom of movement were judged satisfactory as compared to the standard microscope. CONCLUSION: The easy maneuverability and the high quality of pictures provided by the RS device improve the surgeon's comfort in deep fields, representing an effective option for minimally invasive spinal procedures.