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Midbrain cavernous malformations (MCMs) are rare and dangerous taken the important structures and tracts located in this segment of the brainstem. MCM treatment is still controversial, and surgical resection is basically indicated in cases of recurrent hemorrhage and progressive neurologic deterioration. The optimal moment to operate ruptured MCM is in the subacute stage. Once indicated for surgical resection, preoperative planning needs to be individualized. There are various ways to access midbrain lesions, depending on the extension and predominant location: lateral subtemporal, posterior transtentorial, interhemispheric transcallosal, and anterior temporopolar approaches, or some of the alternatives. The aim of this Video 1 case is to review the surrounding anatomic structures and demonstrate the advantages of the semisitting position and the viability of the supracerebellar infratentorial approach for a tegmental midbrain lesion.1-10 In this 2-dimensional video, we present an 18-year-old man with a 4-year history of diplopia and third nerve palsy, which worsened 10 days before admission. He underwent microsurgical total resection of this MCM via extreme lateral supracerebellar infratentorial approach in a semisitting position. At the end, the surgical site and surrounding structures were reviewed microscopically and endoscopically. The patient tolerated the surgery well, and the perioperative course was uneventful. His recovery was smooth but he maintained the previous oculomotor nerve palsy. We discuss important steps of the surgical approach, local neuroanatomy, and the microsurgical techniques for the resection of these challenging MCM. The goal is total resection of the MCM with the preservation of the developmental venous anomaly and the surrounding white fiber tracts.
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OBJECTIVE: The lateral aspect of the cerebellomesencephalic fissure frequently harbors vascular pathology and is a common surgical corridor used to access the pons tegmentum, as well as the cerebellum and its superior and middle peduncles. The quadrangular lobule of the cerebellum (QLC) represents an obstacle to reach these structures. The authors sought to analyze and compare exposure of the cerebellar interpeduncular region (CIPR) before and after QLC resection and provide a case series to evaluate its clinical applicability. METHODS: Forty-two sides of human brainstems were prepared with Klingler's method and dissected. The exposure area before and after resection of the QLC was measured and statistically studied. A case series of 59 patients who underwent QLC resection for the treatment of CIPR lesions was presented and clinical outcomes were evaluated at 1-year follow-up. RESULTS: The anteroposterior surgical corridor of the CIPR increased by 10.3 mm after resection of the QLC. The mean exposure areas were 42 mm2 before resection of the QLC and 159.6 mm2 after resection. In this series, ataxia, extrapyramidal syndrome, and akinetic mutism were found after surgery. However, all these cases resolved within 1 year of follow-up. Modified Rankin Scale score improved by 1 grade, on average. CONCLUSIONS: QLC resection significantly increased the exposure area, mainly in the anteroposterior axis. This surgical strategy appears to be safe and may help the neurosurgeon when operating on the lateral aspect of the cerebellomesencephalic fissure.
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Cerebelo , Procedimentos Neurocirúrgicos , Humanos , Cerebelo/cirurgia , Procedimentos Neurocirúrgicos/métodos , Tronco Encefálico/cirurgia , Microcirurgia/métodos , Craniotomia/métodosRESUMO
Introducción: Los meningiomas de la región pineal son lesiones poco frecuentes, representando el 2 al 8% de los tumores localizados en esta área. Estos tumores son lesiones con comportamiento biológicamente benigno y potencialmente curables con la resección quirúrgica radical. A su vez representan un desafío quirúrgico debido a su profunda localización y la cercanía de estructuras anatómicas vitales. El abordaje supracerebeloso infratentorial, en posición semisentado (cuando las condiciones generales del paciente lo permiten), provee un corredor natural a la región pineal mediante la retracción cerebelosa gravitatoria. Objetivo: Presentación de la exéresis microquirúrgica completa de un meningioma de la región pineal. Descripción del caso: Paciente de 52 años que consulta por inestabilidad de la marcha y diplopía de 2 semanas de evolución. La resonancia magnética cerebral mostró una lesión expansiva, que realza con contraste, de 43 x 30 mm en la región pineal, con hidrocefalia obstructiva acompañante. Se realiza la exéresis microquirúrgica mediante abordaje supracerebeloso infratentorial con el paciente en posición semisentado. Resultado: Se realizó la exéresis completa de la lesión. La paciente cursó el primer día postoperatorio en Unidad de Terapia Intensiva y luego pasó a sala de internación general. Fue dada de alta al tercer día, sin déficit neurológico. La anatomía patológica de la lesión informó meningioma transicional (OMS grado I). El control imagenológico postquirúrgico mostró la resección de la lesión sin remanente tumoral. Conclusión: Los meningiomas de la región pineal presentan un desafío quirúrgico debido a la relación con estructuras anatómicas vitales. El abordaje supracerebeloso infratentorial ofrece un corredor anatómico natural mediante la retracción cerebelosa por la gravedad.
Background: Meningiomas of the pineal region are rare lesions representing 2 to 8% of the tumors located in this area. These tumors are lesions with biologically benign behavior and potentially curable by radical surgical resection. As well, they are a surgical challenge due to their deep location and the proximity to vital anatomical structures. The supracerebellar infratentorial approach, in a semisitting position (when the patient's general conditions allow it), provides a natural corridor to the pineal region through gravitational cerebellar retraction. Objetive: Presentation of a complete microsurgical resection of a meningioma of the pineal region. Case description: A 52-year-old patient who consulted due to gait instability and diplopia of 2 weeks of evolution. Brain magnetic resonance showed an expansive lesion, with contrast enhancement, 43 x 30 mm in the pineal region, with obstructive hydrocephalus. The microsurgical resection was performed by supracerebellar infratentorial approach with the patient in a semisitting position. Result: The complete microsurgical resection was achieved. The patient spent the first postoperative day in Intensive Care Unit, and then went to general room. He was discharged on the third postoperative day, without neurological deficit. The histopathology assessment of the lesion reported transitional meningioma (WHO grade I). Post-surgical imaging showed the resection of the lesion without remaining tumor. Conclusion: Meningiomas of the pineal region present a surgical challenge due to the relationship with vital anatomical structures. The supracerebellar infratentorial approach offers a natural anatomical corridor through cerebellar retraction by gravity.
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Meningioma , Encéfalo , Espectroscopia de Ressonância Magnética , Hidrocefalia , NeoplasiasRESUMO
OBJECTIVE: The brainstem is a compact, delicate structure. The surgeon must have good anatomical knowledge of the safe entry points to safely resect intrinsic lesions. Lesions located at the lateral midbrain surface are better approached through the lateral mesencephalic sulcus (LMS). The goal of this study was to compare the surgical exposure to the LMS provided by the subtemporal (ST) approach and the paramedian and extreme-lateral variants of the supracerebellar infratentorial (SCIT) approach. METHODS: These 3 approaches were used in 10 cadaveric heads. The authors performed measurements of predetermined points by using a neuronavigation system. Areas of microsurgical exposure and angles of the approaches were determined. Statistical analysis was performed to identify significant differences in the respective exposures. RESULTS: The surgical exposure was similar for the different approaches-369.8 ± 70.1 mm2 for the ST; 341.2 ± 71.2 mm2 for the SCIT paramedian variant; and 312.0 ± 79.3 mm2 for the SCIT extreme-lateral variant (p = 0.13). However, the vertical angular exposure was 16.3° ± 3.6° for the ST, 19.4° ± 3.4° for the SCIT paramedian variant, and 25.1° ± 3.3° for the SCIT extreme-lateral variant craniotomy (p < 0.001). The horizontal angular exposure was 45.2° ± 6.3° for the ST, 35.6° ± 2.9° for the SCIT paramedian variant, and 45.5° ± 6.6° for the SCIT extreme-lateral variant opening, presenting no difference between the ST and extreme-lateral variant (p = 0.92), but both were superior to the paramedian variant (p < 0.001). Data are expressed as the mean ± SD. CONCLUSIONS: The extreme-lateral SCIT approach had the smaller area of surgical exposure; however, these differences were not statistically significant. The extreme-lateral SCIT approach presented a wider vertical and horizontal angle to the LMS compared to the other craniotomies. Also, it provides a 90° trajectory to the sulcus that facilitates the intraoperative microsurgical technique.
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BACKGROUND: The epidermoid cyst as a pineal region tumor is an infrequent pathology and with few descriptions in literature. Its prevalence in the third ventricle is 0,0042% of all intracranial tumors. To achieve a complete exéresis we used an endoscopic supracerebellar-infratentorial approach, surgical technique for pineal region approach. OBJECTIVES: The purpose of this work is to show the surgical technique of this novel approach for the treatment of a very infrequent disease. METHODS: 16 years old male patient with history of diabetes insipidus and chronic headaches (m-RS 1). Brain MRI showed a lesion with hyperintensity in T2WI and hypointensity in T1WI. It presents peripheral enhancement with gadolinium and restricted diffusion pattern in DWI. The pituitary stalk also showed enhancement with contrast. Germ cell tumor was a possible diagnosis but tumor cell markers were negative in CSF samples. We decided to make the purely endoscopic approach to the region to make a biopsy and a possible resection. Intraoperative pathology result informed an epidermoid tumor, so we continued with the complete exeresis of the tumor. RESULTS: We achieved a complete resection of a third ventricle epidermoid cyst with a purely endoscopic supracerebellar-infratentorial approach and a skull base rigid endoscope in a 16 years old male patient. The patient has recovered without any sequelae, headaches free but persistence of diabetes insipidus (m-RS 1).Conclusion: The purely endoscopic supracerebellar-infratentorial approach is a safe option to the surgical management of third ventricle pathologies, in this case, an epydermoid cyst.
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OBJECTIVE: To describe and compare surgical exposure through microsurgical cadaveric dissection of the intercollicular region afforded by the median, paramedian, and extreme-lateral supracerebellar infratentorial (SCIT) approaches. METHODS: Ten cadaveric heads were dissected using SCIT variant approaches. A neuronavigation system was used to determine tridimensional coordinates for the intercollicular zone in each route. The areas of surgical and angular exposure were evaluated and determined by software analysis for each specimen. RESULTS: The median surgical exposure was similar for the different craniotomies: 282.9 ± 72.4 mm2 for the median, 341.2 ± 71.2 mm2 for the paramedian, and 312.0 ± 79.3 mm2 for the extreme-lateral (P = 0.33). The vertical angular exposure to the center of the intercollicular safe entry zone was also similar between the approaches (P = 0.92). On the other hand, the horizontal angular exposure was significantly wider for the median approach (P < 0.001). CONCLUSIONS: All the SCIT approaches warrant a safe route to the quadrigeminal plate. Among the different variants, the median approach had the smallest median surgical area exposure but presented superior results to access the intercollicular safe entry zone.
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Cerebelo/cirurgia , Craniotomia , Neuronavegação , Procedimentos Neurocirúrgicos , Cadáver , Craniotomia/métodos , Dissecação/métodos , Humanos , Microcirurgia/efeitos adversos , Microcirurgia/métodos , Neuronavegação/efeitos adversos , Neuronavegação/métodos , Procedimentos Neurocirúrgicos/métodosRESUMO
INTRODUCCIÓN: el abordaje supracerebeloso infratentorial fue descripto originalmente por Sir Victor Horsley, siendo posteriormente adaptado por Stein quien aplica la técnica microquirúrgica mejorando los resultados de las cirugías de la región pineal. OBJETIVOS: resaltar y sistematizar las indicaciones, detalles técnicos-anatómicos en el abordaje supracerebeloso infratentorial en base a nuestra experiencia quirúrgica y la revisión de la anatomía microquirúrgica de la región Pineal. MATERIAL Y MÉTODOS: se realizó un estudio descriptivo retrospectivo analizando las historias clínicas de 7 pacientes intervenidos quirúrgicamente a través de un abordaje supracerebeloso infratentorial, entre septiembre 2010 hasta septiembre 2013 en nuestro servicio. Las imágenes intraquirúrgicas y de preparados anatómicos fueron adquiridas en 3D. La revisión bibliográfica se realizó en Pub Med utilizando las palabras claves: Abordaje Supracerebeloso Infratentorial; Región Pineal; Craniectomía Suboccipital. RESULTADOS: durante el período 2010-2013 fueron intervenidos 7 pacientes. A todos se le practicó un abordaje supracerebeloso infratentorial. Fueron tratados 5 tumores de la región pineal, 1 glioma del culmen cerebeloso y 1 MAV de la fisura cerebelo mesencefálica. Se estandarizaron los siguientes pasos para la realización del abordaje supracerebeloso infratentorial de Stein: preparación prequirúrgica, posición sentado, posición de la cabeza, marcación y antisepsia cutánea, colocación de campos estériles, incisión de piel y tejido celular subcutáneo, disección de plano muscular, craneotomía, apertura dural, preparación del corredor supracerebeloso, disección intradural y anatomía microquirúrgica de la región pineal y consideraciones sobre elcierre. CONCLUSIONES: se sistematizó el abordaje supracerebeloso infratentorial con el que pudimos acceder a tumores pineales y también a lesiones vasculares en la región. En todos los casos la exposición anatómica fue suficiente para tratar en forma adecuada las patologías mencionadas, con mínima retracción de las estructuras del SNC
INTRODUCTION: even though Horsley was the first one to describe the supracerebellar infratentorial approach, it was Stein who adapted it to microsurgical techniques in an attempt to improve the results of surgical procedures on the pineal gland. OBJECTIVES: to enhance the indications and technical details of the supracerebellar infratentorial approach, based upon our experiences, we review the microsurgical anatomy of the pineal region that is exposed via this approach. MATERIALS AND METHODS: a retrospective descriptive study was conducted by analyzing the records of seven patients who had been operated on using this approach at our institution between September 2010 and September 2013. The images shown were obtained in 3D. RESULTS: the indications for surgery in these seven patients were a pineal gland tumor in five patients, and a culmen glioma and mesencephalic-fissure AVM in one patient each. The following steps were standardized according to Stein's description of the supracerebellar infratentorial approach: pre-surgical preparation, sitting position, head position, incision drawing and anti-sepsis, surgical field, collocation, skin and hypodermis incision, muscular dissection, hemostatic control, craniotomy, dural opening, supracerebellar corridor preparation, intradural dissection, microsurgical anatomy study, and considerations regarding closure. CONCLUSIONS: via this approach, we not only have been able to access pineal gland tumors but also vascular lesions in this region. The anatomical exposure achieved was enough to treat these lesions successfully, with minimal manipulation of the CNS