Feres Chaddad-Neto

The pterional craniotomy: tips and tricks

This review intended to describe in a didactic and practical manner the frontotemporosphenoidal craniotomy, which is usually known as pterional craniotomy and constitute the cranial approach mostly utilized in the modern neurosurgery. This is, then, basically a descriptive text, divided according to the main stages involved in this procedure, and describes with details how the authors currently perform this craniotomy.

Microsurgical techniques using human placenta.

Dr. Flavio Ramalho Romero – Praca Amadeu Amaral 27 / 5o andar 01327-010 Sao Paulo SP Brasil. E-mail: romerocnr@gmail.com / icne@icne.com.br Training in microsurgical techniques is the first step to allow procedures in the central nervous system. One of them is the dissection of human placenta. Others include mannequin head, virtual reality environment, animal and cadaver dissections. The human placenta is a maternalfetal structure constituted of a bigger fetal portion and a smaller maternal portion. The fetal membranes and the placenta are responsible for protection, nutrition, breath, excretion and hormone production. The placenta usually shows an ovoid shape with a 16–20 cm diameter and a 2–3 cm thickness. It weighs between 500 and 600 gr. The umbilical cord is usually composed of a vein and two arteries. The fetal surface has a fetal corion – amniotic membrane which is very similar to the cerebral arachnoid and a rich vascular component with 1–6 mm diameter vessels. The anterior cerebral artery has 1–3 mm diameter and the medium cerebral artery one is between 2.4 and 4.6 mm. On the other hand, the vertebral artery has 0.92–4.09 mm diameter, the posterior cerebral and the lower posterior cerebelar arteries ones are between 0.65 and 1.78 mm. Therefore, the human placenta is an excellent material for microsurgical technique training.

Head positioning for anterior circulation aneurysms microsurgery

OBJECTIVE To study the ideal patients head positioning for the anterior circulation aneurysms microsurgery. METHOD We divided the study in two parts. Firstly, 10 fresh cadaveric heads were positioned and dissected in order to ideally expose the anterior circulation aneurysm sites. Afterwards, 110 patients were submitted to anterior circulation aneurysms microsurgery. During the surgery, the patients head was positioned accordingly to the aneurysm location and the results from the cadaveric study. The effectiveness of the position was noted. RESULTS We could determine mainly two patterns for head positioning for the anterior circulation aneurysms. CONCLUSION The best surgical exposure is related to specific head positions. The proper angle of microscopic view may minimize neurovascular injury and brain retraction.

Melanotic Schwannoma of the Cervical Spine Progressing With Pulmonary Metastasis: Case Report

Melanotic schwannoma (MS) is an unusual variant of nerve sheath neoplasm. Only 10% of these tumors will undergo malignant degeneration, with exceedingly rare reported metastasis. We present a 32-year-old woman with a 6-month history of cervical pain and left arm progressive weakness. Neurological examination showed a left upper limb radicular pain, with pyramidal syndrome at C5 level. The magnetic resonance imaging (MRI) study highlighted an intradural extramedullary heterogeneous mass along the spinal cord at the C4–C5 level, slightly hyperintense with T1 and hypointense with T2-weighted sequences, invading the left neural foramen. The patient underwent C3–C5 laminectomy with total resection of a black tumor. In the postoperative period, a patent deficit of shoulder abduction ensued related to the nervous section. Microscopically, compactly fascicles of spindle-shaped cells with pleomorphic and hypercromatic nuclei, dark brown intracellular pigments, as well as some mitotic figures were seen. Immunohistochemical stains for S-100, Human Melanoma Black-45 (HMB-45), and vimentin were positive, with Ki-67 labelling index (LI) of 15% compatible with MS. Six months after radiotherapy she presents local recurrence and lung metastatic dissemination of the MS. She underwent left pulmonary segmentectomy, followed by chemotherapy and radiosurgery. The patient developed a febrile neutropenia and worsening of general status, and died after 3 months due to respiratory complications. MS are rare tumors with potential for local recurrence and distal metastasis. Complete surgical resection remains as the treatment of choice, once the uncommon cases with malignant progression shows low response to chemo and radiotherapy.

Is the omega sign a reliable landmark for the neurosurgical team? An anatomical study about the central sulcus region.

The central sulcus region is an eloquent area situated between the frontal and parietal lobes. During neurosurgical procedures, it is sometimes difficult to understand the cortical anatomy of this region.Objective Find alternative ways to anatomically navigate in this region during neurosurgical procedures.Method We analyzed eighty two human hemispheres using a surgical microscope and completed a review of the literature about central sulcus region.Results In 68/82 hemispheres, the central sulcus did not reach the posterior ramus of the lateral sulcus. A knob on the second curve of the precentral gyrus was reliably identified in only 64/82 hemispheres.Conclusion The morphometric data presented in this article can be useful as supplementary method to identify the central sulcus region landmarks.

Head Positioning For Anterior Circulation Aneurysms Microsurgery [posicionamento Da Cabeça Para Microcirurgias De Aneurismas Da Circulação Anterior]

OBJECTIVE To study the ideal patients head positioning for the anterior circulation aneurysms microsurgery. METHOD We divided the study in two parts. Firstly, 10 fresh cadaveric heads were positioned and dissected in order to ideally expose the anterior circulation aneurysm sites. Afterwards, 110 patients were submitted to anterior circulation aneurysms microsurgery. During the surgery, the patients head was positioned accordingly to the aneurysm location and the results from the cadaveric study. The effectiveness of the position was noted. RESULTS We could determine mainly two patterns for head positioning for the anterior circulation aneurysms. CONCLUSION The best surgical exposure is related to specific head positions. The proper angle of microscopic view may minimize neurovascular injury and brain retraction.

Microsurgical approach of arteriovenous malformations in the central lobule

Arteriovenous malformations (AVM) are neurovascular disorders that occur mainly in young adults. Their clinical presentation is variable and depends on its location, size and occurrence of bleeding. They can represent incidental findings in neuro radiological exams. The treatment of these lesions when located in eloquent areas, namely around the central sulcus, is controversial, with different therapeutical approaches presented in the literature. We consider that surgical extirpation of many of these lesions is feasible in selected cases , when supported by profound anatomical knowledge and refined microsurgical technique, achieving cure with minimal additional deficit. In the present article, we elaborate a surgical technique for the approach of AVMs located in the central sulcus, specially in finding the topographic lesion location and craniotomy.

Transcortical selective amygdalohippocampectomy technique through the middle temporal gyrus revisited: An anatomical study laboratory investigation

The anterior temporal lobectomy (ATL) and selective amygdalohippocampectomy (SelAH) have been used for surgical treatment of mesial temporal lobe epilepsy. We examined the comprehensive white matter tract anatomy of the temporal lobe to gain an insight into the trans-middle temporal gyrus, a lateral approach which has been commonly used. The transmiddle temporal gyrus approach was performed in a stepwise manner on cadaveric human heads to examine the traversing white matter pathways through it and the structures located in the temporal horn. We reviewed the literature to compare the trans-middle temporal gyrus approach with other SelAH techniques based on surgical outcomes. There does not appear to be a significant difference in seizure outcome between SelAH and ATL. However, the SelAH provides a better neuropsychological outcomes than the ATL in selected patients. Each SelAH approach has individual advantages and disadvantages. Based on our anatomical study, in the transcortical amygdalohippocampectomy technique through the middle temporal gyrus the white matter pathways to be encountered. In the temporal horn, the collateral eminence, hippocampus, lateral ventricular sulcus, choroidal fissure, inferior choroidal point, choroid plexus, fimbria of the fornix, and amygdala are exposed. The subpial dissection is performed along the lateral ventricular sulcus from the collateral eminence on lateral side and from the choroidal fissure on medial side by microdissector for en bloc resection of the hippocampus proper. The trans-middle temporal gyrus approach is commonly used in treatment of mesial temporal lobe epilepsy patients. A better anatomical and functional understanding of the structures of the temporal lobe is crucial for safer and more accurate surgery.

Craniotomia pré temporal

This paper aims to describe the performance of the pretemporal craniotomy performed didactically from 2002 to 2012 in eighty patients. It is therefore a fundamentally descriptive text, organized in the sequence of the main stages in which such a craniotomy is performed, and describing in detail the technique with which this group of evolutionarily authors came to accomplish the task.

Dissection technique for the study of the cerebral sulci, gyri and ventricles

Neuroanatomy in addition to neurophysiology, are the basic areas for the proper formation from health students to specialized professionals in neuroscience. A step by step guide for practical studies of neuroanatomy is required for this kind of knowledge to become more acceptable among medical students, neurosurgeons, neurologists, neuropediatricians and psychiatric physicians. Based on the well known courses of sulci, gyri and ventricles offered by Beneficência Portuguesa Hospital in São Paulo, Brazil, two times a year, since 1994, totalizing more than 20 complete courses, and answering the request of many neuroscience students and professionals whose asked for a practical guide to the neuroanatomy study, the authors suggest a protocol for the study of superficial and deep brain structures showing how to approach the more structures as possible with minimum damage to the anatomic piece and with the smaller number of brains.