One-Step Posterior and Anterior Combined Approach for L5 Retroperitoneal Schwannoma Eroding a Lumbar Vertebra.

We report the case of a large lumbar schwannoma eroding the vertebra and originating from spinal canal with invasion of the retroperitoneal space. We also review all the cases in literature reporting lumbar schwannomas eroding the vertebral bodies and invading the retroperitoneal space focusing on the surgical strategies to manage them. Spinal CT-scan revealed a 44 mm × 55 mm inhomogeneous soft-tissue mass arising from the right L5-S1 neural foramen and its most anterior portion had a clear colliquative aspect. Magnetic resonance image showed a neoplastic lesion with homogeneous low signal in T1WI, heterogeneous signal in T2WI, and strong enhancement in postgadolinium examination. It developed as well in the retroperitoneal space, posteriorly to the iliac vein, up to the psoas muscle with wide erosion of the omolateral conjugate foramen. We performed a one-step combined approach together with the vascular surgeon because the lesion was too huge to allow a complete resection via a posterior approach and furthermore its tight relationship with the psoas muscle and the iliac vessels in the retroperitoneal space should be more safely managed via a retroperitoneal approach. We strongly suggest a 1-step surgery first approaching the dumbbell and the intraspinal schwannomas posteriorly achieving the decompression of the spinal canal and the cleavage of the tumor cutting the root of origin and the vascular supply and valuating the stability of the spine for potential artrodesis procedure. The patient must be then operated on via a retroperitoneal approach achieving the complete en bloc resection of the tumor.

Safe Resection of Gliomas of the Dominant Angular Gyrus Availing of Preoperative FMRI and Intraoperative DTI: Preliminary Series and Surgical Technique.

OBJECTIVE: Language dysfunction, visual deficit, numeracy impairment, and Gerstmann syndrome often occur in the cortical area; furthermore, the subcortical white matter is the inviolable limit of "functional neurosurgery." Preoperative functional magnetic resonance imaging (fMRI) and tractography are capable of providing the data required for safe "surgical planning" at both the cortical and subcortical levels. METHODS: We report our experience regarding high-grade gliomas affecting the dominant angular gyrus (AG), supramarginal gyrus (SMG), intraparietal sulcus (IPS), and their respective subcortical areas using intraoperative MRI and diffusion tensor imaging (DTI). Retrospectively, we reviewed a consecutive series of 27 patients operated in a BrainSuite for high-grade intraparenchymal tumors of the left posterior temporoparietal junction. We included tumors involving the dominant AG, SMG, and/or IPS and the subcortical course of arcuate fasciculus (AF) and all the patients who underwent preoperative fMRI and DTI to localize the AF and the eloquent cortical areas. Just after craniotomy, new volumetric MRI and DTI verified and corrected possible brain shift. After the gross total resection was carried out, and before approaching the residual mass close to the white matter tract, an intraoperative MRI was again performed. RESULTS: We operated on 27 patients, 15 males and 12 females, whose diagnosis was always high-grade glioma. During the preoperative neurologic examination, 6 patients were asymptomatic; 3 presented a Gerstmann syndrome; 16 showed dysphasic disturbances, 6 of which were associated with visual field deficits; and 2 showed weakness of the right limb. CONCLUSIONS: Our results suggest that this approach is completely safe and effective as an alternative to awake surgery.

Intraoperative DTI and brain mapping for surgery of neoplasm of the motor cortex and the corticospinal tract: our protocol and series in BrainSUITE.

We report our preliminary series of patients treated for lesions involving the motor cortex and the corticospinal tract in BrainSuite, with intraoperative MRI, tractography and "neuronavigated" electrophysiological cortical and subcortical mapping. An exact localization of the cortical and subcortical functional areas is mandatory for executing surgery of intra-parenchymal neoplasm involving the motor cortex and the corticospinal tract. Nowadays modern technology offers a variety of tools to reduce as much as possible postoperative deficits during surgery of cerebral eloquent areas. From December 2008 and June 2010, 18 patients underwent functional surgery, for neoplasm involving the motor cortex and/or the subcortical pathway, in BrainSuite. Our preliminary series include 14 gliomas and 4 metastases; Table 1 summarizes all of the data. We included in this series patients with complete removal of lesions of eloquent areas with an average distance from the corticospinal tract of 4 mm. Six neoplasms were considered in contact and/or involving the motor cortex, while in 18 cases (100%) the tumour involved eloquent areas concerning the corticospinal tract. All of the patients underwent complete removal of the lesion as subsequently demonstrated by intraoperative postsurgical MRI. Our series highlights the good integration and the high compatibility between BrainSUITE with 1.5 T intraoperative magnetic field and neurophysiological monitoring. We strongly believe that intraoperative MRI with DTI allows us to treat complex surgery tumours that without its auxilium we would not be able to deal with.