Michele Bailo

The role of CXCR4 in highly malignant human gliomas biology: current knowledge and future directions.

Given the extensive histomorphological heterogeneity of high‐grade gliomas, in terms of extent of invasiveness, angiogenesis, and necrosis and the poor prognosis for patients despite the advancements made in therapeutic management. The identification of genes associated with these phenotypes will permit a better definition of glioma heterogeneity, which may ultimately lead to better treatment strategies. CXCR4, a cell surface chemokine receptor, is implicated in the growth, invasion, angiogenesis and metastasis in a wide range of malignant tumors, including gliomas. It is overexpressed in glioma cells according to tumor grade and in glioma tumor initiating cells. There have been various reports suggesting that CXCR4 is required for tumor proliferation, invasion, angiogenesis, and modulation of the immune response. It may also serve as a prognostic factor in characterizing subsets of glioblastoma multiforme, as patients with CXCR4‐positive gliomas seem to have poorer prognosis after surgery. Aim of this review was to analyze the current literature on biological effects of CXCR4 activity and its role in glioma pathogenesis. A better understanding of CXCR4 pathway in glioma will lead to further investigation of CXCR4 as a novel putative therapeutic target. GLIA 2014;62:1015–1023

Management of spheno-orbital en plaque meningiomas: clinical outcome in a consecutive series of 40 patients

Abstract Objective. The clinical results of combined surgical–radiosurgical treatment of the spheno-orbital en plaque meningiomas in a consecutive series of 40 patients are presented. The clinical outcome is evaluated in terms of surgical morbidity, tumour control, visual function and cosmetic result. Methods. Forty patients harbouring spheno-orbital en plaque meningiomas were treated. Forty-two surgical procedures were performed through a fronto-temporal craniotomy. The reconstruction of the orbital walls was performed using a titanium mesh. In case of sub-total resection, the patients underwent Gamma-Knife radiosurgery on residual tumour. Visual function was evaluated considering visual acuity tested with a Snellen chart, funduscopy and Goldmann perimetry for visual field defects. Proptosis was quantified on CT scans. Results. Total or gross-total tumour resection was achieved in 56.1% of cases. Permanent morbidity was recorded in three patients after surgery. Visual acuity and visual field defect both improved in 66.7% of patients; improvement of proptosis was recorded in 92.7% of cases. Eighteen patients were treated with Gamma-Knife radiosurgery for residual tumour after surgery and four patients for tumour relapse at follow-up. The mean follow-up period was 72.6 months. Conclusions. Surgical treatment of spheno-orbital en plaque meningiomas is safe and effective: a low morbidity rate was recorded and visual function improved in about two-thirds of patients. Reconstruction of the orbital walls with titanium mesh provides for good functional and cosmetic results. In case of superior orbital fissure and cavernous sinus invasion, the combined surgical–radiosurgical treatment allows to minimise surgical morbidity and to achieve tumour control.

The suprameatal dural flap for superior petrosal vein protection during the retrosigmoid intradural suprameatal approach.

OBJECT The drilling of the suprameatal bone during the retrosigmoid intradural suprameatal approach (RISA) puts the superior petrosal vein complex at risk of heating and mechanical injury, which may lead to cerebellar swelling and infarction. We present a new technique to protect the superior petrosal venous complex during suprameatal bone drilling. MATERIAL AND METHODS A microanatomical laboratory investigation on cadaver was conducted. The surgical technique is described and intraoperative schematic pictures are provided. RESULTS The surgical steps of this technique and the related intraoperative images are reported. One case illustration regarding the removal of a large petrous apex meningioma with Meckel cave extension is described to demonstrate the application of the technique in a clinical setting. CONCLUSIONS Reflecting a dural flap onto the posterior trigeminal nerve root and the superior petrosal vein complex can be a simple way to protect the nerve and the vein during the suprameatal bone drilling during the RISA.

Bilateral Temporal Myofascial Flap for the Reconstruction of Frontal Sinus Defects

BACKGROUND A frontal sinus infection, following a transsinus skull base procedure, portends potentially life-threatening complications, making surgical revision mandatory in refractory infections. The authors describe the application of the bilateral temporal myofascial flap (BTMF) as a valuable option for frontal sinus reconstruction, when pericranial or galeal-frontalis myofascial flap (GFMF) is no longer available. METHODS A microanatomic laboratory cadaver investigation was conducted to obtain anthropometric measurements. Surgical technique is described, and intraoperative images are provided. RESULTS The surgical steps of this technique and the related intraoperative images are reported. One case illustration regarding frontal sinus reconstruction following a postoperative infection, as a complication after a transsinus procedure, is reported. CONCLUSION The BTMF should be considered as a valuable option for frontal sinus reconstruction after transsinus skull base procedures when GFMF is not available.

Resection of tumors of the third ventricle involving the hypothalamus: effects on body mass index using a dedicated surgical approach

Resection of large lesions growing into the third ventricle is considered nowadays still a demanding surgery, due to the high risk of severe endocrine and neurological complications. Some neurosurgical approaches were considered in the past the procedures of choice to access the third ventricle, however they were burden by endocrine and neurological consequences, like memory loss and epilepsy. We report here the endocrine and functional results in a series of patients operated with a recently developed approach specifically tailored for the resection of large lesions growing into the third ventricle. Authors conducted a retrospective analysis on 10 patients, operated between 2011 and 2012, for the resection of large tumors growing into the third ventricle. Total resection was achieved in all patients. No perioperative deaths were recorded and all patients were alive after the follow-up. One year after surgery 8/10 patients had an excellent outcome with a Karnofsky Performance Status of 100 and a Glasgow Outcome score of 5, with 8 patients experiencing an improvement of the Body Mass Index. Modern neurosurgery allows a safe and effective treatment of large lesions growing into the third ventricle with a postoperative good functional status.

Comparative Anatomical Study on Operability in Surgical Approaches to the Anterior Part of the Third Ventricle

BACKGROUND Surgery of the third ventricle still represents a challenge in modern neurosurgery. To optimize the surgical planning, some aspects, related to ventricular anatomy, have to be taken into consideration. An operability score could represent a preoperative tool to evaluate these variables to choose a tailored surgical approach. METHODS We compared the transcallosal transforaminal approach and the combined interhemispheric subcommissural translamina terminalis approach (CISTA) to the anterior part of the third ventricle, applying the operability score. RESULTS Compared with the transcallosal transforaminal approach, the CISTA provides a statistically significant improvement in terms of depth of surgical field, surgical angle of attack, and maneuverability arc considering as 4 approach-related critical structures: the optic chiasm (P value: <0.0001, <0.0001, <0.0001, respectively), the anterior commissure (P value: <0.0001, <0.0001, <0.0001 respectively), the tuber cinereum (P value: <0.0001, 0.0224, 0.0173), and the interthalamic adhesion (P value: 0.2917, <0.0001, <0.0001 respectively). CONCLUSIONS Tumors originating from the anterosuperior part of the third ventricle can be easily approached through a transcallosal transforaminal route, whereas lesions arising from the anteroinferior portion of the third ventricle might be safely and effectively approached through the CISTA.

Endoscope-Assisted Trans-Maxillo-Sphenoidal Approach to Sellar and Parasellar Regions: Anatomic Study.

BACKGROUND Anterolateral skull base surgery in the sellar and parasellar regions has always represented a technical challenge for neurosurgeons. The microscopic endoscope-assisted transmaxillosphenoidal approach (MEMSA) affords a direct surgical corridor free from critical skull base structures. Here we describe and critically evaluate the use of MEMSA to access the sellar and parasellar areas, in terms of surgical exposure and operability. METHODS Six cadaveric heads were examined. A stepwise dissection using MEMSA was performed. Relevant anatomy and surgical technique were critically described and comparatively reviewed. The operability score was applied for quantitative analysis of surgical operability. RESULTS MEMSA provides wide bilateral surgical exposure and vascular control of the sellar, suprasellar, and parasellar regions, achieving the highest operability on the midline and in the parasellar region. The approach can be tailored to the lesion, with the surgical corridor easily widened toward the contralateral pterygopalatine fossa. Anatomic knowledge of maxillary sinus landmarks is key to the use of this approach. Favorable sphenoidal anatomy is the main limiting factor, making MEMSA a surgical alternative to endoscopic endonasal routes in situations where those routes are not feasible, and the approach of choice in selected cases of primarily sellar lesions widely extending contralaterally to the approached maxillary sinus. CONCLUSIONS MEMSA is a safe and effective technique that provides access to the sellar, suprasellar, and contralateral parasellar areas via a direct, minimally disruptive surgical corridor. The preservation of nasal anatomy ensures the availability of mucosal flaps for use in further reconstruction.

Endoscope-Assisted Transmaxillosphenoidal Approach to the Sellar and Parasellar Regions: An Anatomic Study

BACKGROUND Anterolateral skull base surgery in the sellar and parasellar regions has always represented a technical challenge for neurosurgeons. The microscopic endoscope-assisted transmaxillosphenoidal approach (MEMSA) affords a direct surgical corridor free from critical skull base structures. Here we describe and critically evaluate the use of MEMSA to access the sellar and parasellar areas, in terms of surgical exposure and operability. METHODS Six cadaveric heads were examined. A stepwise dissection using MEMSA was performed. Relevant anatomy and surgical technique were critically described and comparatively reviewed. The operability score was applied for quantitative analysis of surgical operability. RESULTS MEMSA provides wide bilateral surgical exposure and vascular control of the sellar, suprasellar, and parasellar regions, achieving the highest operability on the midline and in the parasellar region. The approach can be tailored to the lesion, with the surgical corridor easily widened toward the contralateral pterygopalatine fossa. Anatomic knowledge of maxillary sinus landmarks is key to the use of this approach. Favorable sphenoidal anatomy is the main limiting factor, making MEMSA a surgical alternative to endoscopic endonasal routes in situations where those routes are not feasible, and the approach of choice in selected cases of primarily sellar lesions widely extending contralaterally to the approached maxillary sinus. CONCLUSIONS MEMSA is a safe and effective technique that provides access to the sellar, suprasellar, and contralateral parasellar areas via a direct, minimally disruptive surgical corridor. The preservation of nasal anatomy ensures the availability of mucosal flaps for use in further reconstruction.

Gamma Knife Radiosurgery for Residual and Recurrent Vestibular Schwannomas After Previous Surgery: Clinical Results in a Series of 90 Patients and Review of the Literature

OBJECTIVE Complete removal of vestibular schwannomas (VS) is not always achievable without any risk of disabling postoperative complications, especially in terms of facial nerve function. Moreover, even after gross total removal, a relevant rate of recurrence has been reported. The aim of this study is to validate Gamma Knife radiosurgery (GKRS) as an effective strategy to treat tumor regrowth after previous surgery. METHODS Ninety patients treated with GKRS for VS after previous microsurgery were included in the present study. GKRS was performed at a median of 31 months (range, 4-174 months) postoperatively. Mean tumor volume was 3.35 cm3 (median, 2.5 cm3; range, 0.027-13 cm3) and median marginal dose was 13 Gy. RESULTS At a mean follow-up of 77.2 months, tumor control was achieved in 90% of patients: 2 patients underwent repeated GKRS, and 7 patients underwent further microsurgery. Tumor shrinkage at last follow-up was recorded in 80.3% of cases. The complication rate was low and many consisted of a transient worsening of preexisting symptoms. The overall incidence of persisting facial nerve deficit and trigeminal nerve impairment was, in both cases, 3.3%. Two of 5 patients (40%) preserved functional hearing at last follow-up. One patient (1.1%) underwent ventriculoperitoneal shunting 12 months after GKRS. CONCLUSIONS GKRS is a safe and effective treatment for growing residual and recurrent VSs, with tumor control obtained in 90% of cases and a low morbidity rate. Moreover, the possibility of treating patients with major medical comorbidities constitutes a significant advantage over repeated surgery.

The emerging role of gamma knife radiosurgery in the management of glossopharyngeal neuralgia

Glossopharyngeal neuralgia (GPN) represents a rare craniofacial disorder accounting for about 1% of all craniofacial pain syndromes. GPN shares several pathophysiologic and clinical features with the more common trigeminal neuralgia. Medical therapy and microvascular decompression, in case of vascular nerve compression, represented the mainstay of GPN management. Other ablative therapies have been reported to date; however, few data are available because of the rarity of this pain syndrome. Among the ablative procedures, gamma knife radiosurgery (GKRS) has been recently introduced in the management of GPN with good pain control and low complication rates. Authors performed a systematic review of the published literature about GKRS in the management of GPN. Radiosurgical treatment data, pain control and recurrence rate have been analysed and compared. GKRS represented a valuable and effective treatment option for the management of GPN. Pain control and complication rates are better than those reported by other ablative procedures and microvascular decompression; however, future studies should be focused on the long-term efficacy of GKRS.