Federico Landriel

Sternberg's canal as a cause of encephalocele within the lateral recess of the sphenoid sinus: A report of two cases

Background: Intrasphenoidal encephaloceles are extremely rare findings. Sternbergs canal is a lateral craniopharyngeal canal resulting from incomplete fusion of the greater wings of the sphenoid bone with the basisphenoid. It acts as a weak spot of the skull base, which may lead to develop a temporal lobe encephalocele protruding into the lateral recess of the sphenoid sinus (SS). Case Description: We present two cases of intrasphenoidal encephalocele due to persistence of the lateral craniopharyngeal canal. The first case presented with cerebrospinal fluid (CSF) rhinorrhea and the second one was referred to the neurosurgical department with CSF rhinorrhea and meningitis. Radiological investigations consisted of computed tomography (CT) scan, CT cisternography and magnetic resonance images in both cases. These imaging studies identified a herniated temporal lobe through a bony defect which communicates the middle cranial fossa with the lateral recess of the SS. Both patients underwent a transcranial repair of the encephalocele because of the previous failure of the endoscopic surgery. There was no complication related to the surgical procedure and no recurrence of CSF leakage occurred 2 and 3 years after surgery, respectively. Conclusion: Encephalocele within the lateral recess of the SS is a rare entity which must be suspected in patients who present with spontaneous CSF rhinorrhea. Congenital intrasphenoidal encephaloceles, which are located medial to the foramen rotundum, seem to be due to persistence of the Sternbergs canal. Transcranial approach is a good option when a transnasal approach had failed previously.

Polyetheretherketone interbody cages versus autogenous iliac crest bone grafts with anterior fixation for cervical disc disease.

Objective: The aim of this study was to compare the fusion rate, operation time, recovery of disc space height, clinical duration and improvement, return to activities of daily living, and complication rate associated with anterior cervical discectomy with interbody fusion by using polyetheretherketone cages or autogenous iliac crest bone grafts as disc replacement in a series of 60 patients. Materials and Methods: Between November 2006 and February 2010 a retrospective analytical observational cohort study was carried out in 60 consecutive patients surgically treated with anterior cervical discectomy with interbody fusion for degenerative disc desease at the Neurosurgical Department of the Hospital Italiano de Buenos Aires. The patients were divided into 2 groups for the assessment of clinical characteristics, demographics, fusion rates, duration of surgical procedure, neurological and functional outcomes, imaging results, and complications. Group A included patients treated with autogenous iliac crest bone grafts, and group B included patients treated with polyetheretherketone cages. Results: The mean age of the patients was 50.8 years. Female patients comprised the majority in both groups (63.3%). Cervicobrachialgia was the most common presentation. Clinical improvement, fusion rates, and recovery of disc space height were similar in both groups. The operation time was significantly shorter in the polyetheretherketone group (P<0.001). Twenty percent (n=6) of the patients in group A suffered complications, >80% of which were associated with iliac crest bone graft harvesting. Patients in group B had no complications (P<0.05). Conclusions: Although outcomes were very successful in both groups in terms of fixation stability, recovery of disc space, return to activities of daily living and work, and remission of symptoms, operation time was considerably shorter for patients in the polyetheretherketone group, who had none of the complications associated with iliac crest bone graft harvesting, both differences being statistically significant.

Identifying the trigeminal nerve branches for transovale radiofrequency thermolesion: "no pain, no stress".

BACKGROUND: Radiofrequency thermorhizotomy of the trigeminal nerve is a known treatment of trigeminal neuralgia. Analysis of verbal responses to electric stimulation of the trigeminal rootlets has been the only method available to localize the affected branch, but patient discomfort may lead to unreliable verbal responses, resulting in increased morbidity or even therapeutic failure. Orthodromically elicited evoked potentials of the trigeminal nerve have also been used, but their application is tedious and results may vary. OBJECTIVE: To develop an electrophysiological method for intraoperative localization of the trigeminal nerve branches. METHODS: A series of 55 patients under general anesthesia during radiofrequency thermorhizotomy were studied. The trigeminal nerve root was stimulated through the foramen ovale with the RF electrode. Antidromic responses were recorded from the 3 divisions of the trigeminal nerve in the face. Effectiveness rate, pain relief, recurrence, complications, and patient comfort after the procedure were analyzed. RESULTS: Reproducible and easily obtained antidromic responses were clearly recorded in every subdivision of the trigeminal nerve in all patients. Ninety-four percent of patients experienced immediate pain relief after the procedure. The recurrence rate was 12.72%, and the surgical morbidity was 20%. CONCLUSION: This method proved to be useful to determine the exact localization of individual subdivisions of the trigeminal nerve in anesthetized patients, making this procedure safer and more comfortable for them. ABBREVIATION: RF-TL, radiofrequency thermolesioning

Multicentric extramedullary myxopapillary ependymomas: Two case reports and literature review.

Background: Ependymoma has been described typically as an intramedullary tumor derived from ependymal cells. Intradural extramedullary presentation is rarely described and almost always as a unique lesion. Myxopapillary ependymoma is a histological variant that distinguishes from the ordinary type of ependymoma because of its generally better prognosis. We present two cases of multicentric extramedullary myxopapillary ependymomas. Case Description: Case 1 was a 30-year-old man with progressive paresthesia and paresis in the lower limbs, urinary sphincter disturbances, gait instability, ataxia, and chronic low back pain with multiple intradural extramedullary lesions at C2-C3, D2-D4-D5, and D12-L1. Case 2 was a 32-year-old man, presented with low back pain and mild paresthesia in the right lower limb. Magnetic resonance imaging (MRI) showed multiple intradural extramedullary lesions with homogeneous enhancement after gadolinium injection at C7, D2, D4, D5, D8, D10, D11, L1, L3, L5, S1, and S2. Complete tumor resection of the approached tumors was archived in both cases. Histological studies confirm myxopapillary ependymomas. Patients neurologic outcome was good and no residual tumor was present at MRI control at 10 years in case 1 and 12 months in case 2. Conclusions: We report the first two cases of multicentric extramedullary myxopapillary ependymomas, this etiology must be taken into account in the differential diagnosis of intradural extramedullary tumors.

Atypical hemorrhagic presentation of a fourth ventricle subependymoma: case report.

To present a case of a fourth ventricle subependymoma (SE) with a spontaneous acute subarachnoid intra-cisternal bleeding. A 33-year-old man was admitted with 5 days history of oppressive occipital headache and neck pain without additional neurological focus. Unenhanced computed tomography (CT) scan demonstrated an isointense mass located in the fourth ventricle with a spontaneously hyperdense acute extratumoral hemorrhage in the cisterna magna. Contrast-enhanced magnetic resonance imaging (MRI) revealed a well-delimitated non-enhanced tumor, hypointense on T1-weighted and hyperintense on T2-weighted images, involving the floor of the fourth ventricle and extending caudally into the cervical spinal canal via foramen magnum. Intraoperative, a large blood clot was removed and a macroscopically hypovascularlesion was completely excised from the right lateral recess and the floor of the fourth ventricle. Intra and postoperative immuno-histopathological examination revealed a SE. The patient has a normal postoperative course and was discharged in the fifth postoperative day. A 10-month postoperative MRI study confirmed a complete tumor resection. Symptomatic SEs should be surgically treated emphasizing the urgency in the presence of hemorrhage. The interest of this case is to demonstrate that infratentorial SEs although extremely rare, might present with acute subarachnoid bleeding.

Massive subarachnoid pneumocephalus after a stereotactic brain biopsy

Sir, Image-guided stereotactic brain biopsy (SBB) is a common and generally safe procedure with a morbidity of 3-5% and a mortality of 0-7%.[1] The most frequent complications include hemorrhage and infection. Pneumocephalus is a common consequence of craniotomies in neurosurgical practice[2] but not following SBB. We could not find a case of tension pneumocephalus (TP) following SBB in the review of English literature.

Cirugía transnasal endoscópica para tumores de hipófisis

Introducción: Exponer la técnica utilizada y los resultados obtenidos en los primeros 52 pacientes portadores de tumores hipofisarios tratados por la vía endoscópica transnasal en el Hospital Italiano de Buenos Aires Métodos: Se llevó a cabo un análisis retrospectivo de 52 cirugías endoscópicas transnasales utilizadas en el tratamiento de tumores hipofisários. Las mismas fueron realizadas en el Hospital Italiano de Buenos Aires durante el período junio del 2011 a junio del 2012. Se analizaron las características demográficas de los pacientes, la patología de base y la morbimortalidad asociada a la cirugía. Resultados: La edad media de los pacientes fue de 41,52 años con un rango de 18-79. La distribución fue similar entre hombres y mujeres. Las patologías más frecuentes fueron: adenomas no funcionantes (40.4%), tumores productores de GH/Acromegalia (25%) y tumores productores de ACTH/Enfermedad de Cushing (23.1%). Aproximadamente el 70 % correspondieron a macroadenomas. Sólo un paciente presentó complicaciones. No se registro ningún óbito. Conclusión: Si bien podremos objetivar fehacientemente resultados más concluyentes en futuros trabajos, podemos decir a priori que, en la endoscopía el detalle anatómico es claramente superior al microscópico y que la posibilidad de la introducción del endoscopio en la silla turca permite la visualización directa de remanentes tumorales, de sitios de fístula y como así también de la glándula normal, ventajas que potencialmente podrían permitir obtener mejores resultados quirúrgicos, en términos de control de la enfermedad y tasa de complicaciones.

Curva de aprendizaje en la colocación de tornillos pediculares percutáneos mínimamente invasivosLearning curve of minimally invasive pedicle screw placement

Resumen Objetivo: El objetivo de este estudio fue estimar la curva de aprendizaje necesaria para la correcta colocación de tornillos transpediculares percutáneos (TTP). Introducción: Los TTP son la forma de instrumentación más utilizada en el tratamiento quirúrgico de lesiones espinales que requieren estabilización. Métodos: Evaluamos retrospectivamente la inserción de 422 TTP (T5 a S1) en 75 pacientes operados entre 2013–2016, bajo guía fluoroscópica bidimensional. El cirujano 1 colocó siempre los tornillos del lado derecho y el cirujano 2, la totalidad del lado izquierdo. El posicionamiento y ruptura pedicular fue determinando con la clasificación tomográfica de Gertzbein. Se comparó la precisión en la colocación de TTP de nuestra serie con una tasa de ruptura de 8,08% (rango de 0,67-20,83%), valor de referencia obtenido de un meta-análisis propio. Resultados: De los 422 TTP, 395 fueron insertados en el pedículo sin violación de su cortical (Grado 1 = 93,6%), 27 (6,4%) rompieron la pared pedicular, de los cuales el 3,8% fue Grado 2, el 1,65% Grado 3 y sólo el 0,9% Grado 4. El Cirujano 1, presentó una tasa se ruptura global de 6,6%, alcanzando valores estándares de precisión al colocar 74 TTP; el Cirujano 2 presentó una tasa de ruptura de 6,1%, alcanzando valores de referencia a los 64 TTP; la diferencia entre ambos no fue estadísticamente significativa (P = 0,9009). Conclusión: En la serie evaluada se evidenció que se necesitan colocar aproximadamente 70 TTP para lograr resultados en términos de exactitud intrapedicular comparables con lo reportado por cirujanos experimentados en esta técnica mínimamente invasiva.Objective The aim of this study was to estimate the learning curve needed for correct placement of minimally invasive percutaneous pedicle screws (PPS). Introduction PPS are the most common system used for instrumentation of spinal lesions that require stabilization. Methods We retrospectively assessed the insertion of 422 PPS (T5 to S1) in 75 patients operated between 2013-2016 under two-dimensional fluoroscopic guidance. The surgeon 1 always placed the PPS on the right side and the surgeon 2 on the left side. Screw positioning and pedicle rupture was determined with the Gertzbein tomographic classification. We compared the accuracy of PPS placement in our series with a reference rupture rate of 8.08%, value obtained from a meta-analysis. Results Of the 422 TTP, 395 were inserted into the pedicle without violation of its cortical wall (Grade 1 = 93.6%), 27 (6.4%) disrupted the pedicle, of which 3.8% were Grade 2, 1.65% Grade 3 and only 0.9% Grade 4. The Surgeon 1, presented an overall break rate of 6.6% reaching standard values of accuracy by placing 74 PPS, Surgeon 2 showed a disruption rate of 6.1%, reaching baseline values at 64 PPS; the difference between them was not statistically significant (P = 0.9009). Conclusion In our series, it was necessary to place approximately 70 PPS to achieve intrapedicular accuracy comparable to results reported by experienced surgeons in this minimally invasive technique.

Lateral Transpsoas Approach for Lumbar Indirect Lateral Recess Decompression: 2-Dimensional Operative Video

Neurogenic claudication is a common symptom of lumbar spinal stenosis; its pathophysiology is thought to be ischemia of the nerve roots secondary to compression from surrounding structures. The stenosis of the lateral recesses and neuroforamen can cause these symptoms and its surgical treatment is decompression. The placement of interbody cages that restore the disc space height may indirectly decompress the neuroforamen and alleviate the nerve impingement symptoms. In case of concomitant low-grade spondylolisthesis, interbody devices might also reduce the slippage. We present a technical surgical video of a minimally invasive lateral transpsoas fusion, relying on indirect decompression to treat a patient with neurogenic claudication secondary to grade 1 spondylolisthesis. The patient signed a written consent to publish a video, recording, photograph, image, illustration, and/or information about him.

Minimally Invasive Resection of a Cervical Anterolateral Meningioma: 2-Dimensional Operative Video

Intradural extramedullary spinal tumors were historically managed through traditional midline approaches. Although conventional laminectomy or laminoplasty provides a wide tumor and spinal cord exposure, they may cause prolonged postoperative neck pain and late kyphosis deformity. Minimally invasive ipsilateral hemilaminectomy preserves midline structures, reduces the paraspinal muscle disruption, and could avoid postoperative kyphosis deformity. A safe tumor resection through this approach could be complicated in large sized or anteromedullary located lesions. We present a surgical video of C3 antero located meningioma removed en bloc through a minimally invasive approach. The patient signed a written consent to publish video, recording, photograph, image, illustration, and/or information about him.