RESUMO
ABSTRACT Objective: To define whether the electroneurophysiological stimulation would be a safe method for reducing injuries in nerve roots during surgery of lumbar spine arthrodesis, as well as verify whether there is a direct correlation between the intraoperative impedance values and the distance from the medial cortical pedicle screw. Methods: Randomized retrospective multicenter study of 10 patients who underwent arthrodesis of lumbar spine after conservative treatment failure, with a total of 50 pedicle screws instrumented. Reliable and safe impedance values were measured in order to reduce the risk of injury to nerve roots in the perioperative period, and these values were compared with the distance between the screw and the medial cortical of the pedicle by CT scan, measured in the immediate post-operative period. Results: There is no direct correlation between the intraoperative impedance values and the distance from the screw to the medial cortical of the pedicle. Conclusion: The electroneurostimulation proved to be a reliable quantitative method to reduce the risk of injury to nerve roots during surgery of lumbar spine arthrodesis when the measured values are greater than 10mA.
RESUMO Objetivo: Definir se a estimulação eletroneurofisiológica seria um método seguro para redução de lesões em raízes nervosas no intraoperatório de artrodese de coluna lombar, bem como verificar se há correlação direta entre os valores de impedância transoperatória e a distância do parafuso e a cortical medial do pedículo. Métodos: Estudo retrospectivo, multicêntrico com seleção randômica consecutiva de 10 pacientes que realizaram artrodese de coluna lombossacra após falha de tratamento conservador, com um total de 50 parafusos pediculares instrumentados. Os valores confiáveis e seguros de impedância para diminuir os riscos de lesão em raízes nervosas foram aferidos no período perioperatório, sendo esses valores comparados com os da distância entre o parafuso e a cortical medial do pedículo na tomografia computadorizada, aferida no pós-operatório imediato. Resultados: Não há correlação direta entre os valores de impedância transoperatória e a distância do parafuso até a cortical medial do pedículo. Conclusão: A eletroneuroestimulação mostrou ser um método quantitativo seguro para diminuir os riscos de lesões em raízes nervosas no intraoperatório de artrodese de coluna lombar quando os valores aferidos são maiores que 10mA.
RESUMEN Objetivo: Definir si la estimulación electroneurofisiológica sería un método seguro para reducir las lesiones en las raíces nerviosas durante la cirugía de artrodesis de columna lumbar, así como verificar si hay correlación directa entre los valores de impedancia perioperatoria y la distancia entre tornillo y la cortical medial del pedículo. Métodos: Estudio retrospectivo, multicéntrico, con selección aleatoria consecutiva de 10 pacientes que fueron sometidos a la artrodesis de columna lumbosacra después de falla del tratamiento conservador, con un total de 50 tornillos pediculares instrumentados. Valores fiables y seguros de impedancia para reducir el riesgo de lesiones a las raíces nerviosas se midieron en el periodo perioperatorio, y estos valores se compararon con la distancia entre el tornillo y la cortical medial del pedículo en la tomografía computarizada, medida en el período postoperatorio inmediato. Resultados: No existe una correlación directa entre los valores de impedancia perioperatoria y la distancia desde el tornillo hasta la cortical medial del pedículo. Conclusión: La electroneuroestimulación mostró ser un método cuantitativo fiable para reducir el riesgo de lesiones a raíces nerviosas durante la cirugía de artrodesis de columna lumbar cuando los valores medidos son mayores que 10mA.
Assuntos
Humanos , Vértebras Lombares , Artrodese , Impedância Elétrica , Estimulação Elétrica , Raízes Nervosas EspinhaisRESUMO
BACKGROUND: Despite possible advantages, few surgical series report specifically on awake craniotomy for intrinsic brain tumors in eloquent brain areas. OBJECTIVES: Primary: To evaluate the safety and efficacy of fully awake craniotomy (FAC) for the resection of primary supratentorial brain tumors (PSBT) near or in eloquent brain areas (EBA) in a developing country. Secondary: To evaluate the impact of previous surgical history and different treatment modalities on outcome. PATIENTS AND METHODS: From 1998 to 2007, 79 consecutive FACs for resection PSBT near or in EBA, performed by a single surgeon, were prospectively followed. Two groups were defined based on time period and surgical team: group A operated on from March 1998 to July 2004 without a multidisciplinary team and group B operated on from August 2004 to October 2007 in a multidisciplinary setting. For both time periods, two groups were defined: group I had no previous history of craniotomy, while group II had undergone a previous craniotomy for a PSBT. Forty-six patients were operated on in group A, 46 in group B, 49 in group I and 30 in group II. Psychological assessment and selection were obligatory. The preferred anesthetic procedure was an intravenous high-dose opioid infusion (Fentanil 50 microg, bolus infusion until a minimum dose of 10 microg/kg). Generous scalp and periosteous infiltrations were performed. Functional cortical mapping was performed in every case. Continuous somato-sensory evoked potentials (SSEPs) and phase reversal localization were available in 48 cases. Standard microsurgical techniques were performed and monitored by continuous clinical evaluation. RESULTS: Clinical data showed differences in time since clinical onset (p < 0.001), slowness of thought (p = 0.02) and memory deficits (p < 0.001) between study periods and also time since recent seizure onset for groups I and II (p = 0.001). Mean tumor volume was 51.2 +/- 48.7 cm3 and was not different among the four groups. The mean extent of tumor reduction was 90.0 +/- 12.7% and was similar for the whole series. A trend toward a larger incidence of glioblastoma multiforme occurred in group B (p = 0.05) and I (p = 0.04). Recovery of previous motor deficits was observed in 75.0% of patients, while motor worsening in 8.9% of cases. Recovery of semantic language deficits, control of refractory seizures and motor worsening were statistically more frequent in group B (p = 0.01). Satisfaction with the procedure was reported by 89.9% of patients, which was similar for all groups. Clinical complications were minimal, and surgical mortality was 1.3%. CONCLUSIONS: These data suggest that FAC is safe and effective for the resection of PSBT in EBA as the main technique, and in a multidisciplinary context is associated with greater clinical and physiological monitoring. The previous history of craniotomy for PSBT did not seem to influence the outcome.