Neurocirugía en época de COVID-19. Protocolo de actuación / Neurosurgery in the time of COVID-19. Action protocol

El manejo de pacientes debido a la aparición del nuevo coronavirus 2019 (COVID-19) representa un desafío para los equipos médicos y quirúrgicos, ya que modificó el funcionamiento de los sistemas de salud en casi todo el mundo. Para contribuir a la re organización del sistema de salud, el Servicio de Neurocirugía del Hospital Italiano de Buenos Aires trabajó en adoptar distintas medidas en concordancia con las tomadas a nivel institucional y nacional; por lo que se analizó la bibliografia publicada, asi como las normas dictadas por el comité de crisis de nuestra institucion. A su vez realizamos una breve encuesta dirigida a neurocirujanos de america latina para conocer como se manejaban actualmente en relación a niveles de protección y realización de cirugias. La actual pandemia de COVID-19 es el mayor desafío que enfrentan los sistemas nacionales de salud en los últimos tiempos. Los neurocirujanos podemos contribuir a la reducción del riesgo de infección nosocomial de los trabajadores de la salud al adaptar distintos protocolos en pacientes con COVID-19.

Patient's management due to the appearance of new coronavirus 2019 (COVID-19) represents a challenge for medical and surgical departments, since it modified the running of health systems in almost all the world. In order to help in this new situation, the Neurosurgical Department of our institution has adopted different measures in accordance with those taken at institutional and national level. In order to do this, we made a literature review and we added to this, the norms dictated by the crisis committee of our hospital. We also carried out a brief survey among neurosurgeons from Latin America to find out how they managed protection levels in relation to surgery. COVID-19 pandemic is certainly one of the greatest challenge national health systems face in a century. Adapting different protocols in neurosurgical patients with COVID-19 can contribute in reducing the risk of nosocomial infection of health workers.

[Relevance of Simpson's grades in the resection of grade I meningiomas]. / Relevancia de los grados de Simpson en la resección de meningiomas grado I.

OBJECTIVE: Compare the number of recurrences in patients with WHO Grade I meningiomas that underwent microsurgical resection. INTRODUCTION: In 1957 Simpson established five grades for surgical resection for intracranial meningiomas and recurrence rate. He thought that an aggressive removal of these tumors with dura and bone was necessary to cure them. Development of new diagnostic methods, advances in anatomopathology and microsurgical technique lead us to question if this scale has a value nowadays. METHODS: A retrospective analysis was performed. All patients operated from grade I meningiomas between February 2006 to December 2015 were included. Pre and postoperative MRI as well as histology were analyzed. A multivariate analysis was performed, a P < 0.05 was considered statistically significant. RESULTS: There was no statistical significant difference between patients undergoing Simpson Grade I, II, III or IV resection (P = 0,3117). This could be best stated for Simpson Grade I and II resection, where the number of patients included in the study was higher. When we analyze tumor location there was not significant difference in recurrence between groups (P = 0,2203). CONCLUSION: For grade I meningiomas there is no significant difference in the recurrence between patients with a Simpson Grade I or II resection, thus increasing morbidity of the surgery is not justified. A new resection scale should be designed taking into account the WHO classification.

Meningioma cordoide: reporte de dos casos y revisión de la literatura / Cordoid meningioma: report of two cases and review of the literature

El meningioma cordoide es un subtipo infrecuente de meningioma. La mayoría es de gran tamaño y de localización supratentorial. Suelen presentarse clínicamente con síntomas inespecíficos. La Resonancia Magnética de Cerebro muestra una lesión extraaxial compatible con meningioma, siendo la histología y las pruebas de inmunohistoquímica necesarias para realizar el diagnóstico definitivo. La anatomía patológica remeda a la del cordoma ya que se encuentran constituidos por células vacuoladas, epiteloides o fusiformes, dispuestas en cordones o islas dentro de una matriz mixoide. La importancia de conocer esta variante de meningioma radica en su alta tasa de recurrencia, principalmente si la exéresis es incompleta, por lo que son considerados como tumores de mayor agresividad y peor pronóstico. Se presentan dos casos de meningioma cordoide operados en nuestro centro.

Chordoid meningiomas are a rare form of meningioma that, as with most meningiomas, typically present as a bulky, supratentorial tumor. Otherwise, their clinical presentation is non-specific. Brain MRI shows an extra-axial lesion compatible with a meningioma; however, the diagnosis must be confirmed by histopathology and immunohistochemistry. Microscopically, these tumors are composed of spindle or epithelioid, partly-vacuolated cells arranged in nests or cords in a myxoid matrix, resembling a chordoma. Recurrence rates are high following subtotal resection. As such, these tumors are considered a more aggressive variant associated with poorer outcomes. Two patients with a chordoid meningioma treated surgically at our centre, using microsurgical techniques, are presented.

Potentiation of adrenaline vasoconstrictor response by sub-threshold concentrations of U-46619 in human umbilical vein: involvement of smooth muscle prostanoid TP(alpha) receptor isoform.

Considering the potential physiological, pharmacological and therapeutic relevance of synergistic interaction of thromboxane A(2) with adrenaline at postjunctional receptor sites, we examined whether sub-threshold concentrations of thromboxane A(2) mimetic U-46619 (9,11-dideoxy-9alpha, 11alpha-methanoepoxy prostaglandin F(2alpha)) could amplify adrenaline-induced contraction in human umbilical vein. The receptor involved in U-46619-induced potentiation of adrenaline contractility was also investigated. Umbilical cords (n=125) from healthy patients after full-term vaginal or caesarean deliveries were employed. The vein was dissected out of cords and rings used for isolated organ bath experiments or reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Presence of endothelium did not modify U-46619-induced contraction in human umbilical vein. Prostanoid TP-selective receptor antagonist, SQ-29548 (7-[3-[[2-[(phenylamino)carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1]hept-2-yl]-[1S(1alpha,2alpha(Z),3alpha,4alpha)]-5-Heptenoic acid), inhibited U-46619-induced contraction (pA(2)=8.22+/-0.11). U-46619 sub-threshold concentrations (0.1-0.3 nM) potentiated adrenaline-vasoconstriction response in a concentration-dependent manner. SQ-29548 (0.1 microM) abolished this potentiation. Using RT-PCR, we found that human umbilical vein rings with or without endothelium express the prostanoid TP(alpha), but not the prostanoid TP(beta) receptor isoform. Western blot allowed the identification of proteins with an electrophoretic mobility (47- and 55-kDa) indistinguishable from human platelet prostanoid TP receptor, a rich source of prostanoid TP(alpha) receptor isoform. Collectively, present results demonstrate that prostanoid TP(alpha) is the major receptor isoform localized on smooth muscle cells which participate in both direct vasoconstriction and potentiating effects of U-46619 on adrenaline contractions in human umbilical vein. These results suggest that thromboxane A(2) may interact synergistically with adrenaline in pathophysiological situations that lead to an increase of its umbilical venous levels (e.g. preeclampsia associated with fetal distress) raising the possibility of vasoconstriction affecting fetal blood flow.

Human umbilical vein vasoconstriction induced by epinephrine acting on alpha1B-adrenoceptor subtype.

OBJECTIVE: Our purpose was to determine the presence of alpha(1)-adrenoceptor messenger RNA subtypes and extend the pharmacologic characterization of alpha(1)-adrenoceptors involved in human umbilical vein (HUV) contraction. STUDY DESIGN: Cords (n=124) from healthy patients after term vaginal or cesarean deliveries were used. The vein was carefully dissected out of cords and used for reverse transcription combined with polymerase chain reaction (RT-PCR) to amplify alpha(1)-adrenoceptor transcripts. In isolated organ baths, HUV rings were mounted and cumulative concentration-response curves were constructed either for epinephrine or the selective alpha(1A)-adrenoceptor agonist, A-61603. In other series of experiments, the effects of the selective alpha(1A)- and alpha(1B)-adrenoceptor antagonists (RS-100329 or B8805-033 or spiperone, AH11110A and cyclazosin, respectively) were evaluated to estimate its blocking potencies on epinephrine concentration-response curves. RESULTS: By means of RT-PCR technique alpha(1a)- and alpha(1b)-adrenoceptor transcripts were detected in the HUV. The blocking potency values of RS-100329 or B8805-033 against responses mediated by epinephrine were not consistent with the activation of an alpha(1A)-adrenoceptor population. Moreover, the low potency of the agonist A-61603 was not in accordance with an alpha(1A)-adrenoceptor interaction. On the other hand, the antagonist potencies of spiperone, AH11110A and cyclazosin were in agreement with an interaction on alpha(1B)-adrenoceptor subtype. CONCLUSION: Although alpha(1a)- and alpha(1b)-adrenoceptor messenger RNAs are detected in the HUV, only alpha(1B)-adrenoceptors are involved in epinephrine vasoconstrictor action.