Lesión del nervio ciático mayor por proyectil de escopeta / Lesion of the major sciatic nerve due to a shotgun projectile

Se describe el caso clínico de un paciente de 26 años de edad, atendido en la consulta de Ortopedia y Traumatología del Centro de Diagnóstico Integral Salvador Allende de Caracas, en la República Bolivariana de Venezuela, quien desde hacía 6 meses había recibido un disparo de escopeta en la cara posterior de ambos muslos. Esta vez acudió a consulta con dolor intenso en el miembro inferior izquierdo, sobre todo por debajo de la rodilla, acompañado de parestesias en la zona de inervación de ambas ramas de bifurcación del nervio ciático. Se pudo comprobar que el joven presentaba múltiples impactos de proyectiles en la cara posterior de ambos muslos y marcha claudicante. Los estudios radiográficos confirmaron la presencia de 8 proyectiles, 2 en el muslo derecho y 6 en el izquierdo. En la vista lateral se observó que uno de ellos se encontraba a una profundidad que se correspondía con la región anatómica del nervio ciático izquierdo. Para la intervención quirúrgica se utilizó anestesia local, sedación y un intensificador de imágenes. Con la cooperación del paciente se pudo extraer el proyectil alojado en el epineuro del ciático sin complicaciones. A los 3 meses habían desaparecido las molestias y pudo reincorporarse a sus actividades habituales.

The case report of a 26 years patient is described. He was assisted in the Orthopedics and Traumatology Service of Salvador Allende Integral Diagnostic Center from Caracas, in the Bolivian Republic of Venezuela who had received a shotgun shot in the posterior face of both thighs 6 months ago. This time he went to visit the doctor with intense pain in the left inferior member, mainly below the knee, accompanied by paresthesias in the innervation area of both bifurcation branches of the sciatic nerve. It could be demonstrated that the young man presented multiple projectile impacts in the posterior face of both thighs and hesitating gait. The radiographic studies confirmed the presence of 8 projectiles, two in the right thigh and 6 in the left one. In the lateral view it was observed that one of them was at a depth that matched with the anatomical region of the left sciatic nerve. Local anesthesia, sedation and an images intensifier were used for the operation. The projectile located in the epineurium of the sciatic nerve could be removed with the patient cooperation without complications. After 3 months the discomfort had disappeared and he could return to his usual activities.

Morphometric study of rat sciatic nerve recovery after three nerve repair techniques: epineural suture, polyethylene glycol hydrogel and fibrin sealant / Estudio morfométrico de la recuperación del nervio ciático de rata después de tres técnicas de reparación nerviosa: sutura epineural, hidrogel de polietilenglicol y sellante de fibrina

SUMMARY: The effectiveness of microsurgical technique has a direct impact on the recovery of the injured peripheral nerve. The aim of our study was to investigate the result of sciatic nerve regeneration in rats after complete neurotomy and after nerve repair techniques including: 1) epineural suture; 2) polyethylene glycol hydrogel (PEG) (DuraSeal); 3) fibrin sealant (Tisseel). The cross-section of distal sciatic nerve was studied at 14th, 30th and 60th days after nerve repair. Morphometry of myelinated nerve fibers in the distal stump of the sciatic nerve was performed. A significant increase in the number of myelinated nerve fibers was found, especially between 14 and 30 days. The density of myelinated nerve fibers in the distal stump at day 60 was significantly higher after using nerve repair technique including PEG and fibrin versus epineural suture (29.2 % and 32.1 % versus 21.5 %, P <0.05), and a higher level of remyelination of nerve fibers observed in the group with PEG. On day 60, complete elimination of PEG and fibrin sealant was not observed, encapsulation was found around the clusters of hydrogel. Thereby, three peripheral nerve repair techniques were equally effective, only with the use of PEG remyelination of nerve fibers was increasing.

RESUMEN: La efectividad de la técnica microquirúrgica tiene un impacto directo en la recuperación del nervio periférico lesionado. El objetivo de nuestro estudio fue investigar el resultado de la regeneración del nervio ciático en ratas después de una neurotomía completa y después de técnicas de reparación nerviosa que incluyeron: 1) sutura epineural; 2) hidrogel de polietilenglicol (PEG) (DuraSeal); 3) sellante de fibrina (Tisseel). La sección transversal del nervio ciático distal se estudió a los 14, 30 y 60 días después de la reparación del nervio. Se realizó la morfometría de fibras nerviosas mielinizadas en el muñón distal del nervio ciático. Se observó un aumento significativo en el número de fibras nerviosas mielinizadas, especialmente entre los 14 y 30 días. La densidad de las fibras nerviosas mielinizadas en el muñón distal en el día 60 fue significativamente mayor después de usar una técnica de reparación nerviosa que incluye PEG y fibrina en comparación con la sutura epineural (29,2 % y 32,1 % versus 21,5 %, P <0,05), y un mayor nivel de remielinización del nervio en fibras observadas en el grupo con PEG. El día 60, no se observó la eliminación completa de PEG y sellador de fibrina, se encontró encapsulación alrededor de los grupos de hidrogel. Por lo tanto, tres técnicas de reparación de nervios periféricos fueron igualmente efectivas, solo que aumentaba la remielinización de fibras nerviosas con PEG.

Effect of creatine and sildenafil citrate on the physical performance of mice / Efecto de la creatina y del citrato de sildenafil sobre el desempeño físico de ratones / Efeito da creatina e do citrato de sildenafila sobre o desempenho físico de camundongos

ABSTRACT Introduction: The use of substances to enhance sports performance among professional and amateur athletes is increasing. Such substances may either be included in the group of dietary supplements or fall into pharmacological classes. Every substance used for this purpose is called an ergogenic agent. The number of ergogenic options available increases every day, favoring overuse and use without proper guidance. Among the dietary supplements, we highlight the use of creatine, a substance widespread in sports. Among the pharmacological groups, many drugs are used. Recently the use of sildenafil citrate by professional athletes from various predominantly aerobic sports modalities was reported in the media. Objective: To compare and demonstrate the responses caused by physical training associated with the use of creatine and sildenafil citrate in mice. Methods: A swim training protocol was applied and then an electrophysiograph was used in order to obtain parameters related to contraction intensity, the area under the curve and the percentage drop. Results: The responses obtained demonstrated the ergogenic action of creatine because it altered the parameters used for measurement. The use of sildenafil citrate did not yield satisfactory results to frame the drug as an ergogenic agent. Conclusion: Creatine has an ergogenic effect, reducing the percentage drop after 10 seconds, while sildenafil demonstrated no ergogenic potential and, interestingly, resulted in weaker responses when compared to the exercise groups. Evidence level II; Comparative prospective study .

RESUMEN Introducción: El uso de sustancias con el objetivo de aumentar el rendimiento deportivo entre atletas profesionales y amateurs es creciente. Tales sustancias pueden formar parte del grupo de suplementos alimentarios o integrar clases farmacológicas. Toda sustancia empleada para ese fin es denominada agente ergogénico. El número de opciones entre los agentes ergogénicos aumenta cada día, favoreciendo así su uso excesivo y sin la debida orientación. Entre los suplementos alimentarios, se destaca el uso de creatina, sustancia muy difundida en el medio deportivo. Ya entre los grupos farmacológicos, muchas sustancias son usadas. Recientemente, fue divulgado entre los medios de comunicación el uso de citrato de sildenafil por atletas profesionales, de varias modalidades deportivas, predominantemente las aeróbicas. Objetivos: Comparar y demostrar las respuestas ocasionadas por el entrenamiento físico, asociadas al uso de creatina y citrato de sildenafil en ratones. Métodos: Se aplicó un protocolo de entrenamiento de natación y, a continuación, se usó un electrofisiógrafo con el objetivo de obtener parámetros referentes a la intensidad de contracción, al área bajo la curva y a la caída porcentual. Resultados: Las respuestas obtenidas demuestran acción ergogénica de la creatina, visto que alteraron los parámetros empleados para la medición. Ya el uso de citrato de sildenafil no presentó resultados satisfactorios para encuadrar al fármaco como agente ergogénico. Conclusión: La creatina presenta efecto ergogénico porque reduce la caída porcentual después de 10 segundos, mientras que el sildenafil no presentó potencial ergogénico y, curiosamente, demostró respuestas inferiores cuando comparado a los grupos de ejercicio. Nivel de evidencia II; Estudio prospectivo comparativo .

RESUMO Introdução: O uso de substâncias com o objetivo de aumentar o rendimento esportivo entre atletas profissionais e amadores é crescente. Tais substâncias podem fazer parte do grupo de suplementos alimentares ou integrar classes farmacológicas. Toda substância empregada para esse fim é denominada de agente ergogênico. O número de opções entre os agentes ergogênicos aumenta a cada dia, favorecendo assim o uso em demasia e sem a devida orientação. Entre os suplementos alimentares, salientamos a utilização de creatina, substância muito difundida no meio esportivo. Já entre os grupos farmacológicos, muitas substâncias são utilizadas. Recentemente, foi divulgado entre os meios de comunicação o uso de citrato de sildenafila por atletas profissionais de várias modalidades esportivas, predominantemente as aeróbicas. Objetivos: Comparar e demonstrar as repostas ocasionadas pelo treinamento físico, associadas ao uso de creatina e citrato de sildenafila em camundongos. Métodos: Aplicou-se um protocolo de treinamento de natação e, a seguir, empregou-se um eletrofisiógrafo com objetivo de obter parâmetros referentes à intensidade de contração, à área sob a curva e à queda percentual. Resultados: As respostas obtidas demonstram ação ergogênica da creatina, visto que alteraram os parâmetros empregados para a mensuração. Já a utilização de citrato de sildenafila não apresentou resultados satisfatórios para enquadrar o fármaco como agente ergogênico. Conclusão: A creatina apresenta efeito ergogênico porque reduz a queda percentual após 10 segundos, já a sildenafila não apresentou potencial ergogênico e, curiosamente, demonstrou respostas inferiores quando comparado aos grupos de exercício. Nível de evidência II; Estudo prospectivo comparativo .

Endometriosis con infiltración aislada del nervio ciático, una forma de presentación atípica: reporte de un caso clínico / Isolated infiltrative endometriosis of the sciatic nerve, an atypical presentation: clinical case report

INTRODUCCIÓN: La endometriosis afecta hasta un 10-15% de las mujeres jóvenes. Se define como tejido endometrial funcional fuera de la cavidad uterina y su presentación clásica es la dismenorrea. La variedad profunda afecta a un 1-2% y las localizaciones más frecuentes son el peritoneo pélvico, ovarios, ligamentos útero-sacros y septum recto-vaginal; sin embargo, puede presentarse de forma muy infrecuente como implantes aislados localizados en relación al nervio ciático. El diagnóstico habitualmente es complejo y tardío, dado que los síntomas son inespecíficos y el examen físico puede ser indistinguible de otras etiologías. El estudio imagenológico de elección para la endometriosis profunda es la resonancia magnética (RM) de pelvis ya que una adecuada localización pre-quirúrgica de las lesiones es fundamental. CASO CLÍNICO: Paciente de sexo femenino de 46 años, con tres años de dolor pélvico, dismenorrea y dispareunia. El síntoma cardinal fue dolor ciático progresivo, con déficit motor y alteraciones sensitivas, los cuales se exacerbaban durante la menstruación y no presentaban respuesta al tratamiento farmacológico. En la RM se identifica nódulo sólido sospechoso de endometriosis en relación al nervio ciático derecho. El caso es evaluado por un comité multidisciplinario y se realiza cirugía laparoscópica. El diagnóstico de sospecha es confirmado histológicamente. La paciente presenta buena recuperación post-quirúrgica y cese completo de los síntomas descritos. DISCUSIÓN: La endometriosis profunda presenta un reto diagnóstico y habitualmente es tardío. Este caso presenta el resultado exitoso de una buena sospecha clínica, un estudio imagenológico completo y la resolución con una técnica quirúrgica compleja.

INTRODUCTION: Endometriosis is a disease that affects 10-15% of young women. It is characterized as functional endometrial tissue outside the uterine cavity. The most common form of presentation is dysmenorrhea. Deep endometriosis affects 1-2% of the patients, and is frequently located in the pelvic peritoneum, ovaries, utero-sacral ligaments and recto-vaginal septum. The isolated endometriosis of the sciatic nerve is a very uncommon presentation of this disease. Late diagnosis is frequent, mainly because the symptoms are non-specific, and the physical examination may be indistinguishable from other etiologies. The imaging study of choice is the pelvic magnetic resonance imaging (MRI) and an accurate pre-surgical location of the lesions is critical for a successful surgical outcome. CLINICAL CASE: 46-year-old female patient with 3 years of pelvic pain, dysmenorrhea and dyspareunia. The cardinal symptom was progressive sciatic pain, with motor deficit and sensory alterations. The pain was persistent despite pharmacological treatment and exacerbated during menstruation. MRI identifies a nodule located in the pelvic portion of the right sciatic nerve, suggestive of an endometriosis implant. The case was discussed by a multidisciplinary committee and laparoscopic surgery was performed. The diagnosis was confirmed with histology. The patient recovered well from surgery with significant improvement of the previously described symptoms. DISCUSSION: The diagnosis of deep endometriosis is challenging and usually delayed. This rare disease had a successful outcome, due to an early clinical suspicion, a thorough imaging study and an effective resolution with a complex surgical technique.

Mechanical properties of the sciatic nerve following combined transplantation of analytically extracted acellular allogeneic nerve and adipose-derived mesenchymal stem cells

Abstract Purpose To investigate the effects of Chemically Extracted Acellular Nerves (CEANs) when combined with Adipose-Derived mesenchymal Stem Cell (ADSC) transplantation on the repair of sciatic nerve defects in rabbits. Methods A total of 71 six-month-old Japanese rabbit were used in this study. Twenty rabbits served as sciatic nerve donors, while the other 51 rabbits were randomly divided into Autologous Nerve Transplantation Group (ANT, n=17), CEAN group (n=17) and CEAN-ADSCs group (n=17). In all these groups, the rabbit's left sciatic nerves were injured before the experiment, and the uninjured sciatic nerves on their right side were used as the control (CON). Electrophysiological tests were carried out and sciatic nerves were prepared for histomorphology and stretch testing at 24 weeks post-transplant. Results There were significant differences between ANT and Con groups in amplitude (AMP): P=0.031; motor nerve conduction velocity (MNCV): P=0.029; Maximum stress: P=0.029; and Maximum strain P=0.027. There were also differences between the CEAN and CEAN+ADSCs groups in AMP: P=0.026, MNCV: P=0.024; Maximum stress: P=0.025 and Maximum strain: P=0.030. No significant differences in these parameters were observed when comparing the ANT and CEAN+SACN groups (MNCV: P=0.071) or the CEAN and ANT groups (Maximum stress: P=0.069; Maximum strain P=0.077). Conclusion Addition of ADSCs has a significant impact on the recovery of nerve function, morphology, and tensile mechanical properties following sciatic nerve injury.

Sugarcane biopolymer as a guide tube in the regeneration of peripheral nerves in rats / Biopolímero de caña de azúcar como tubo guía en la regeneración de nervios periféricos en ratones

SUMMARY: Peripheral nerve regeneration is a serious clinical problem. The goal of this work was to evaluate comparatively a biopolymer tube of sugarcane with an expanded polyethylene tube as a tube guide in peripheral nerve regeneration. Fourteen male albino Wistar rats were used, separated into three different groups: control (CG), lesion + polyethylene tube (PG) and lesion + sugarcane biopolymer (SBG). At 60 days old, animals from the PG and SBG underwent surgery for tubulization of the sciatic nerve, and 60 days after the injury they were sacrificed for collection of the nerve. In the analysis of the number of nerve fibers, a smaller number was seen in the PG and SBG groups compared to the CG, no difference was seen between the PG and SBG groups (p<0.05). With regard to the number of blood vessels, the SBG group had a larger number than the CG and PG groups (p<0.05). The SBG also presented increase on axonal diameter and G -ratio compared to PG (p<0.05). Taken together these data revealed that biopolymer tube favors a suitable environment for peripheral nerve regeneration.

RESUMEN: La regeneración nerviosa periférica es un problema clínico grave. El objetivo de este trabajo fue evaluar comparativamente un tubo de biopolímero de caña de azúcar con un tubo de polietileno expandido, como guía de tubo en la regeneración de nervios periféricos. Se utilizaron dieciocho ratas Wistar albinas macho, separadas en tres grupos: control (CG), lesión + tubo de polietileno (PG) y lesión + biopolímero de caña de azúcar (SBG). A los 60 días de edad, los animales del PG y SBG fueron sometidos a una cirugía para la tubulización del nervio ciático, y 60 días después de la lesión fueron sacrificados para la recolección del nervio. En el análisis del número de fibras nerviosas, se observó un número menor en los grupos PG y SBG en comparación con el CG; no se observaron diferencias entre los grupos PG y SBG (p <0,05). Con respecto al número de vasos sanguíneos, el grupo SBG tuvo un número mayor que los grupos CG y PG (p <0,05). El SBG también presentó un aumento en el diámetro axonal y la proporción G en comparación con PG (p <0,05). En conjunto, estos datos revelaron que el tubo de biopolímero favorece un entorno adecuado para la regeneración de nervios periféricos.

Analysis of the muscle tissue of Wistar rats submitted to the sciatic nerve compression model and cryotherapy / Análise do tecido muscular de ratos Wistar submetidos ao modelo de compressão do nervo isquiático e à crioterapia

ABSTRACT Objective: To evaluate the effects of right sciatic nerve compression and cryotherapy on muscle tissue. Methods: We used 42 male Wistar rats, subdivided in the following Groups Control, Injury 3, Injury 8 and Injury 15 submitted to nerve compression and euthanized in the 3rd, 8th and 15th day after surgery. The Cryotherapy Injury 3 was entailed treatment with cryotherapy by immersion of the animal in recipient for 20 minutes during 1 day, then animals were euthanized at the 3rd day after surgery, and the Cryotherapy Injury 8 and the Cryotherapy Injury 15 was treated for 6 days, and euthanized at the 8th and 15th day after surgery. Functional evaluation was performed by the grasping strength of the right pelvic limb. The right tibialis anterior muscles were evaluated for mass, smaller diameter and cross-sectional area. In the Cryotherapy Injury 8 and the Cryotherapy Injury 15 groups, the hydroxyproline was dosed in the right soles. Results: In the compression there was a significant difference in the Injury Groups compared with the Control Group (p<0.05). In the smaller diameter, the compression in Control Group was higher than Injury 8 (p=0.0094), Injury 15 (p=0.002) and Cryotherapy Injury 15 (p<0.001) groups. The comparison between groups with euthanasia in the same post-operative period, a significant difference (p=0.0363) was seen in day 8th after surgery, and this result in Cryotherapy Injury Group was greater than Injury Group. In the fiber area, Control Group was also higher than the Injury 8 (p=0.0018), the Injury 15 (p<0.001) and the Cryotherapy Injury 15 (p<0.001). In hydroxyproline, no significant difference was seen between groups. Conclusion: Nerve damage resulted in decreased muscle strength and trophism, the cryotherapy delayed hypotrophy, but this effect did not persist after cessation of treatment.

RESUMO Objetivo: Avaliar os efeitos da compressão nervosa do isquiático direito e da crioterapia no tecido muscular. Métodos: Foram utilizados 42 ratos Wistar machos, subdivididos nos Grupos Controle, Lesão 3, Lesão 8 e Lesão 15, submetidos a compressão nervosa e eutanasiados, respectivamente, no 3°, 8° e 15° dias pós-operatório; Lesão Crioterapia 3, tratado com crioterapia, por imersão durante 20 minutos, por 1 dia, e eutanasiados no 3° dia pós-operatório; e Lesão Crioterapia 8 e Lesão Crioterapia 15, tratados durante 6 dias e eutanasiados no 8° e 15° dias pós-operatório. A avaliação funcional foi realizada pela força de preensão do membro pélvico direito. Os músculos tibiais anteriores direitos foram avaliados quanto a massa, menor diâmetro e área de secção transversa. Em Lesão Crioterapia 8 e Lesão Crioterapia 15, foi dosada a hidroxiprolina nos sóleos direitos. Resultados: Na preensão, houve diferença significativa nos Grupos Lesão quando comparados ao Grupo Controle (p<0,05). No menor diâmetro, o Grupo Controle foi maior que Lesão 8 (p=0,0094), Lesão 15 (p = 0,002) e Lesão Crioterapia 15 (p<0,001). Na comparação entre os grupos com eutanásia no mesmo pós-operatório, houve diferença significativa (p=0,0363) no 8° pós-operatório, sendo Lesão Crioterapia maior que Lesão. Na área das fibras, o Grupo Controle também foi maior que Lesão 8 (p=0,0018), Lesão 15 (p<0,001) e Lesão Crioterapia 15 (p<0,001). Na hidroxiprolina, não houve diferença significativa entre os grupos. Conclusão: A lesão nervosa resultou na diminuição da força e em trofismo muscular, e a crioterapia retardou a hipotrofia, porém este efeito não se manteve após o tratamento cessar.

Inside-out and standard vein grafts associated with platelet-rich plasma (PRP) in sciatic nerve repair. A histomorphometric study

Abstract Purpose: To evaluated the tubulization technique with standard and inside-out vein, filled or not with platelet-rich plasma (PRP), in sciatic nerve repair. Methods: Seventy male Wistar rats were randomly divided into five groups: IOVNF (Inside-Out Vein with No Filling); IOVPRP (Inside-Out Vein filled with PRP); SVNF (Standard Vein with No Filling); SVPRP (Standard Vein filled with PRP); Sham (Control). The left external jugular vein was used as graft in a 10 mm nervous gap. Results: In the morphological analysis of all groups, myelinated nerve fibers with evident myelin sheath, neoformation of the epineurium and perineurium, organization of intraneural fascicles and blood vessels were observed. In the morphometry of the distal stump fibers, SVPRP group had the highest means regarding fiber diameter (3.63±0.42 μm), axon diameter (2.37±0.31 μm) and myelin sheath area (11.70±0.84 μm2). IOVPRP group had the highest means regarding axon area (4.39±1.16 μm2) and myelin sheath thickness (0.80±0.19 μm). As for values of the fiber area, IOVNF group shows highest means (15.54±0.67 μm2), but are still lower than the values of the Sham group. Conclusion: The graft filled with platelet-rich plasma, with use standard (SVPRP) or inside-out vein (IOVPRP), promoted the improvement in axonal regeneration on sciatic nerve injury.

Comparative study between standard and inside-out vein graft techniques on sciatic nerve repair of rats. Muscular and functional analysis

Abstract Purpose: To compare the functional result of standart vein grafts and inside-out vein graft technique on sciatic nerve repair. Methods: We used 24 male Wistar rats divided into 4 groups: control group (CG), standard vein graft group (SVG), Inside-out vein graft group (IOVG) and denervated Group (DG). SVG, IOVG and DG underwent total section of the sciatic nerve, SVG and IOVG however underwent nerve repair surgery using a graft with normal jugular vein and inside-out jugular vein, respectively. Histological analysis of the soleus and Extensor Digitorum Longus (EDL), and Sciatic Functional Index were used to compare the results after 6 weeks. Results: Both grafts acted favorably in muscle recovery and improved functionality; They were similar in all parameters, however, in more points SVG achieved similar to the CG, in the other hand IOVG more times was similar to DG. Fact that makes the graft with normal vein the most viable option between the two options. Conclusion: Both types of grafts acted beneficially wherein the graft normal vein has proved to be the best option

PPE tube filled with autologous fat in the repair of peripheral nerve: a new proposal / Tubo PPE relleno con grasa autóloga en la reparación de los nervios periféricos: una nueva propuesta

This study proposes the use of a porous polyethylene (PPE) tube as the conductive element in the regeneration in the sciatic nerve sectioning and evaluates the use of fill with autologous fat. The subject was divided randomly into five groups, 3 control and 2 experimental (PPE tube graft with/ without autologous fat). Each group was selected for functional, histological and morphometric evaluation of the sciatic nerve. Functional analysis of the sciatic nerve occurred through the "footprint" values near -100 refer sectioned sciatic nerve, near 0 (zero) refer to control group. On histological analysis of the experimental groups lots of dense connective tissue replacing nerve tissue was observed. In morphometric analysis the group EGPGf got higher performance in all of variables. The use of PPE has shown promise in nerve regeneration with favorable results when associate with fat as a trophic factor in the regeneration.

Este estudio propone el uso de un tubo de polietileno poroso (PPE) como elemento conductor en la regeneración del nervio ciático seccionado y evaluar el uso de relleno con grasa autóloga. Al azar se formaron cinco grupos, 3 y 2 de control experimental (PPE prótesis tubular con / sin grasa autóloga). Cada grupo fue seleccionado para estudiar la forma funcional, histológica y evaluación morfométrica del nervio ciático. Un análisis funcional del nervio ciático se produjo a través de los valores de "huella", cerca de -100 se refiere al nervio ciático seccionado; cerca de 0 (cero) se refiere al grupo control. En el análisis histológico de los grupos experimentales se observó una gran cantidad de tejido conjuntivo denso que sustituye el tejido nervioso. En el análisis morfométrico, el grupo experimental de injerto de polietileno lleno de grasa (EGPGf) obtuvo un mayor rendimiento en todas las variables. El uso de PPE ha mostrado ser prometedor en la regeneración del nervio, con resultados favorables cuando se asocia con la grasa como un factor trófico en la regeneración.

Osseointegration of hydroxyapatite implants in rat tibial defects with sciatic nerve injury / Oseointegración de implantes de hidroxiapatita en defectos tibiales de ratas con lesión del nervio ciático

Bone metabolism is influenced by different factors and muscle activity acts as a stimulator of bone plasticity. Conditions such as nerve injuries can compromise bone physiology due to muscle inactivity. Preview studies have shown that nerve damage reduces P substance and calcitonin gene-related peptides, also known as neuropeptides that may have a key role on bone healing. Therefore, this study evaluated the osseointegration of hydroxyapatite implants in tibial defects of rats submitted to unilateral sciatic nerve section. Twelve Wistar rats were divided into two groups (G1 and G2). In G1, the sciatic nerve was left intact and in G2 the left sciatic nerve was completely sectioned. An experimental tibial bone defect was then created in both groups and filled with hydroxyapatite granules. The animals were sacrificed 2 months after implantation and samples were submitted to macroscopic inspection and histological analysis. Good radiopacity of the hydroxyapatite granules and radiographic definition of the bone defect were noted. Histologic analysis revealed formation of new bone adjacent to the hydroxyapatite granules in G1 and, to a lesser extent, in G2 in which the proliferation of connective tissue predominated at the implant site. The formation of new bone stimulated by hydroxyapatite in bone defects can be expected even in animals with limb paralysis due to nerve injury; however, bone formation occurs at a slower speed in these animals and the volume of newly formed bone is lower.

El metabolismo óseo está influenciado por diferentes factores y la actividad muscular como un estimulador de la plasticidad ósea. Condiciones tales como lesiones nerviosas pueden comprometer la fisiología ósea debido a la inactividad muscular. Estudios previos han demostrado que el daño nervioso reduce la sustancia P y el péptido relacionado con el gen de la calcitonina, también conocidos como neuropéptidos que pueden tener un papel clave en la cicatrización ósea. Este estudio evaluó la oseointegración de los implantes de hidroxiapatita en defectos tibiales de ratas sometidas a la sección del nervio ciático unilateralmente. Doce ratas Wistar se dividieron en dos grupos (G1 y G2). En G1, el nervio ciático se dejó intacto y en el G2 el nervio ciático izquierdo fue completamente seccionado. Un defecto óseo tibial fue creado experimentalmente en ambos grupos y se rellenó con gránulos de hidroxiapatita. Los animales se sacrificaron 2 meses después de la implantación y las muestras fueron sometidas a inspección macroscópica y el análisis histológico. Se observó buena radiopacidad de los gránulos de hidroxiapatita y definición radiográfica del defecto óseo. El análisis histológico reveló neoformación ósea adyacente a los gránulos de hidroxiapatita en G1 y, en menor medida en G2, donde la proliferación de tejido conectivo predominó en el sitio de implante. La neoformación ósea estimulada por hidroxiapatita en defectos óseos se puede esperar incluso en animales con parálisis de los miembros producto de una lesión nerviosa; sin embargo, la formación de hueso se produce a menor velocidad en estos animales y su volumen es menor.

Effects of sciatic nerve transection on glucose uptake in the presence and absence of lactate in the frog dorsal root ganglia and spinal cord / Efeito da secção do nervo isquiático sobre a captação de glicose na presença e ausência de lactato em gânglio da raiz dorsal e medula espinhal de rãs

Frogs have been used as an alternative model to study pain mechanisms because the simplicity of their nervous tissue and the phylogenetic aspect of this question. One of these models is the sciatic nerve transection (SNT), which mimics the clinical symptoms of “phantom limb”, a condition that arises in humans after amputation or transverse spinal lesions. In mammals, the SNT increases glucose metabolism in the central nervous system, and the lactate generated appears to serve as an energy source for nerve cells. An answerable question is whether there is elevated glucose uptake in the dorsal root ganglia (DRG) after peripheral axotomy. As glucose is the major energy substrate for frog nervous tissue, and these animals accumulate lactic acid under some conditions, bullfrogs Lithobates catesbeianus were used to demonstrate the effect of SNT on DRG and spinal cord 1-[14C] 2-deoxy-D-glucose (14C-2-DG) uptake in the presence and absence of lactate. We also investigated the effect of this condition on the formation of 14CO2 from 14C-glucose and 14C-L-lactate, and plasmatic glucose and lactate levels. The 3-O-[14C] methyl-D-glucose (14C-3-OMG) uptake was used to demonstrate the steady-state tissue/medium glucose distribution ratio under these conditions. Three days after SNT, 14C-2-DG uptake increased, but 14C-3-OMG uptake remained steady. The increase in 14C-2-DG uptake was lower when lactate was added to the incubation medium. No change was found in glucose and lactate oxidation after SNT, but lactate and glucose levels in the blood were reduced. Thus, our results showed that SNT increased the glucose metabolism in the frog DRG and spinal cord. The effect of lactate on this uptake suggests that glucose is used in glycolytic pathways after SNT.

As rãs são usadas como modelos experimentais alternativos no estudo da nocicepção, tanto pela simplicidade do seu tecido nervoso como por permitirem uma abordagem filogenética sobre o tema. Um desses modelos é a secção do nervo isquiático (SNI), o qual simula os sintomas clínicos do “membro fantasma”, uma condição que ocorre nos humanos após amputação ou secção completa da medula espinal. Em mamíferos, a SNI aumenta o metabolismo da glicose no sistema nervoso central, e o lactato é uma fonte energética para as células nervosas. Porém é desconhecido se essa é a situação em gânglio da raiz dorsal (GRD). Como a glicose é o principal substrato energético para o tecido nervoso de rãs, e a concentração plasmática de lactato está aumentada nesses animais em distintas situações, a rã-touro Lithobates catesbeianus foi usada para demonstrar os efeitos da SNI sobre a captação de 1-[14C] 2-deoxi-D-glicose (14C-2-DG), na presença e ausência de lactato, em GRD e medula espinal. Foram demonstrados ainda os efeitos dessa condição experimental sobre a formação de 14CO2 a partir de 14C-glicose e 14C-L-lactato, e a concentração plasmática de glicose e lactato. A captação de 3-O-[14C] metil-D-glicose (14C-3-OMG) foi usada para demonstrar a relação tecido/meio estável da glicose nessas condições. A captação de 14C-2-DG aumentou três dias após a SNI, sem qualquer alteração na captação de 14C-3-OMG. O aumento foi reduzido quando o lactato foi acrescentado ao meio de incubação. A taxa de oxidação da glicose e do lactato não modificou após SNI, mas houve redução na concentração plasmática de glicose e lactato. Assim, a SNI aumenta o metabolismo da glicose no GRD e medula espinal de rãs. Os efeitos do lactato sobre essa captação sugerem o uso da glicose na via glicolítica após a SNI.

Atrapamiento del nervio ciático en el espacio subglúteo: tratamiento endoscópico / Deep gluteal syndrome. Endoscopic treatment

Se ha sugerido el término síndrome de glúteo profundo (deep gluteal syndrome) (SGP) para definir la compresión del nervio ciático en la región anatómica del espacio glúteo, o aquellas ciáticas no discogénicas con origen en esta región. Este síndrome tiene una alta prevalencia pero un bajo diagnóstico. Existen numerosas causas que pueden originar su afectación y compresión a nivel de dicho espacio. El uso rutinario de los test de evaluación, junto con una sospecha diagnóstica, determinará la incidencia real de este síndrome. La cirugía abierta ha sido descripta y utilizada como tratamiento. El tratamiento endoscópico es efectivo y disminuye el índice de morbilidad y eficacia en comparación con la cirugía abierta. El objetivo del trabajo es presentar una actualización de las características clínicas, test diagnósticos, métodos complementarios, causas y alternativas de tratamiento del SGP, haciendo hincapié en los detalles técnicos del procedimiento endoscópico.

The term Deep Gluteal Syndrome (DGS) has been suggested to define the compression of the sciatic nerve in the anatomical region of the gluteal space, or those ciatic non-discogenic pain with origin in this region. Pathology that is presented with a high prevalence, but at the moment underdiagnosed. There are numerous causes that can originate their affectation and compression at level of this space. The routine use of the evaluation test, together with a diagnostic suspicion, it will determine the real incidence of this problem. The open surgery has been described and used as treatment. The endoscopic treatment is effective and adds less morbidity and effectiveness in comparison with the open surgery. The objective of this article is to present an upgrade of the clinical features, diagnostic test, complementary methods, causes and alternative of treatment of the DGS, making stress in the surgical technique of the endoscopic release.

Evaluation of nerve regeneration in diabetic rats

PURPOSE: To compare sciatic nerve regeneration between non-diabetic (control) and streptozotocin-induced diabetic Wistar rats. METHODS:Four subgroups were evaluated. CN: Non-diabetic rats submitted to neurorrhaphy (n=9); DN: Diabetic rats submitted to neurorrhaphy (n=9); CG: Non-diabetic rats submitted to nerve grafting (n=10); DG: Diabetic rats submitted to nerve grafting (n=9). The nerve regeneration was evaluated by walking track analysis (sciatic functional index), electrophysiological test, histomorphometric analysis and triceps surae muscle weight. RESULTS:At 60 days post-surgery, functional recovery of DN was similar to that of the non-diabetic rats (CN, CG), but DG didn't achieve the same. Evoked potential amplitudes showed no statistically significant differences among subgroups. Triceps surae muscle was heavier in CN. No statistically significant differences were observed between the control and diabetes subgroups with respect to histomorphometric analysis. CONCLUSION: After 60 days, DN had a functionally similar recovery to that of the control animals, whereas nerve grafting in diabetic rats didn't allow the same. The muscle atrophy was lower in CN. In the rest of evaluations, as electrophysiological and histomorphometric, diabetic rats were not different from control ones.

Analysis of the expression of neurotrophins during regeneration of peripheral nerves in rats with vein graft / Análise da expressão de neurotrofinas durante a regeneração de nervo periférico de rato por enxerto venoso

Vein grafts have been employed to bridge the gap in transected peripheral nerves to produce better functional recovery. However several disadvantages such as secondary graft constriction were observed and a new alternative to this technique was developed by simply reversing the vein inside out. Both inside out and standard vein grafts were successfully used in recovering the sensory segmental defect in humans. Neurotrophins are a family of eurotrophic factors known to play an important role in the regeneration of peripheral nerves. The neurotrophin family consists of Nerve Growth Factor (NGF), Brain Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT-3) and Neurotropinh-4 (NT-4). In the neurobiology field, several authors have been using PCR technique in order to gain more information regarding regenerated nerves. In this study, we employed this molecular biology technique to explore the role and level of the neurotrophins during the peripheral nerve regeneration with vein graft. The sciatic nerve of rats were sectioned and repaired with Inside out vein graft (IOVG) and standard vein graft techniques (SVG). In the control group the rats were sham operated wherein the sciatic nerve was kept intact. The animals were euthanized at 6 and 12 weeks and the grafts were harvested to observe the level the neurotrophins. EDL and Sol muscles were excised and measured to determine any weight difference between the groups. A small segment of the distal stumps from both the SVG and IOVG groups were also excised and were subjected to histological process to examine the amount of regenerated axon. In addition, another small segment of the distal stump was processed for RT-PCR to further examine the level of the neurotrophins in this area. At 6 weeks, no significant neuronal growth was observed in the distal stump of both graft types but a distinct growth was seen at 12 weeks. Walk track analysis showed poor motor function recovery ...

Análise da expressão de neurotrofinas durante a regeneração de nervo periférico de rato por enxerto venoso Enxertos de veias têm sido empregados para preencher lacunas em nervos periféricos transeccionados para melhor recuperação funcional. No entanto, vários inconvenientes, como a constrição do enxerto secundário foram observados. Uma nova alternativa para esta técnica foi desenvolvida. Simplesmente invertendo a veia de dentro para fora, chamado do Inside- out vein graft. As neurotrofinas são uma família de fatores neurotróficos conhecidos por desempenhar um papel significativo na regeneração de nervos periféricos. A família da neurotrofina é constituído por fator de crescimento nervoso (NGF), fator neurotrófico derivado do cérebro (BDNF), Neurotrofina-3 (NT-3) e Neurotrofina-4 (NT-4). No campo da neurobiologia, vários autores têm utilizado a técnica de PCR a fim de obter mais informações sobre os nervos regenerados. Neste estudo, foi utilizada a técnica de biologia molecular para explorar o papel e o nível das neurotrofinas durante a regeneração de nervos periféricos com enxerto de veia. O nervo isquiático de ratos foi seccionado e reparado com enxerto de veia invertida (IOVG) e técnicas de enxerto de veia padrão (SVG). No grupo controle, os ratos foram operados e o nervo isquiático foi mantido intacto. Os animais foram sacrificados após 6 e 12 semanas e os enxertos foram colhidos para observar o nível das neurotrofinas. Músculos EDL e Sóleo foram excisados e pesados para determinar a diferença de peso entre os grupos. Um pequeno segmento dos cotos distais de ambos os grupos SVG e IOVG também foram excisados e foram processados histologicamente para examinar a quantidade de axónios regenerados. Além disso, um outro pequeno segmento do coto distal foi processado para RT-PCR para analisar o nível das neurotrofinas nesta área.A tecnica do walk track analysis foi realizada para determinar o índice funcional do nervo isquiático nos grupos...

Analysis of the expression of neurotrophins during regeneration of peripheral nerves in rats with vein graft / Análise da expressão de neurotrofinas durante a regeneração de nervo periférico de rato por enxerto venoso

Vein grafts have been employed to bridge the gap in transected peripheral nerves to produce better functional recovery. However several disadvantages such as secondary graft constriction were observed and a new alternative to this technique was developed by simply reversing the vein inside out. Both inside out and standard vein grafts were successfully used in recovering the sensory segmental defect in humans. Neurotrophins are a family of eurotrophic factors known to play an important role in the regeneration of peripheral nerves. The neurotrophin family consists of Nerve Growth Factor (NGF), Brain Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT-3) and Neurotropinh-4 (NT-4). In the neurobiology field, several authors have been using PCR technique in order to gain more information regarding regenerated nerves. In this study, we employed this molecular biology technique to explore the role and level of the neurotrophins during the peripheral nerve regeneration with vein graft. The sciatic nerve of rats were sectioned and repaired with Inside out vein graft (IOVG) and standard vein graft techniques (SVG). In the control group the rats were sham operated wherein the sciatic nerve was kept intact. The animals were euthanized at 6 and 12 weeks and the grafts were harvested to observe the level the neurotrophins. EDL and Sol muscles were excised and measured to determine any weight difference between the groups. A small segment of the distal stumps from both the SVG and IOVG groups were also excised and were subjected to histological process to examine the amount of regenerated axon. In addition, another small segment of the distal stump was processed for RT-PCR to further examine the level of the neurotrophins in this area. At 6 weeks, no significant neuronal growth was observed in the distal stump of both graft types but a distinct growth was seen at 12 weeks. Walk track analysis showed poor motor function recovery...

Análise da expressão de neurotrofinas durante a regeneração de nervo periférico de rato por enxerto venoso Enxertos de veias têm sido empregados para preencher lacunas em nervos periféricos transeccionados para melhor recuperação funcional. No entanto, vários inconvenientes, como a constrição do enxerto secundário foram observados. Uma nova alternativa para esta técnica foi desenvolvida. Simplesmente invertendo a veia de dentro para fora, chamado do Inside- out vein graft. As neurotrofinas são uma família de fatores neurotróficos conhecidos por desempenhar um papel significativo na regeneração de nervos periféricos. A família da neurotrofina é constituído por fator de crescimento nervoso (NGF), fator neurotrófico derivado do cérebro (BDNF), Neurotrofina-3 (NT-3) e Neurotrofina-4 (NT-4). No campo da neurobiologia, vários autores têm utilizado a técnica de PCR a fim de obter mais informações sobre os nervos regenerados. Neste estudo, foi utilizada a técnica de biologia molecular para explorar o papel e o nível das neurotrofinas durante a regeneração de nervos periféricos com enxerto de veia. O nervo isquiático de ratos foi seccionado e reparado com enxerto de veia invertida (IOVG) e técnicas de enxerto de veia padrão (SVG). No grupo controle, os ratos foram operados e o nervo isquiático foi mantido intacto. Os animais foram sacrificados após 6 e 12 semanas e os enxertos foram colhidos para observar o nível das neurotrofinas. Músculos EDL e Sóleo foram excisados e pesados para determinar a diferença de peso entre os grupos. Um pequeno segmento dos cotos distais de ambos os grupos SVG e IOVG também foram excisados e foram processados histologicamente para examinar a quantidade de axónios regenerados. Além disso, um outro pequeno segmento do coto distal foi processado para RT-PCR para analisar o nível das neurotrofinas nesta área.A tecnica do walk track analysis foi realizada para determinar o índice funcional do nervo isquiático nos grupos...

Sciatic nerve regeneration in rats by a nerve conduit engineering with a membrane derived from natural latex / Regeneração do nervo ciático em ratos através de um conduto confeccionado com uma membrana de látex natural

PURPOSE: To evaluate the capacity of natural latex membrane to accelerate and improve the regeneration quality of the of rat sciatic nerves. METHODS: Forty male adult Wistar rats were used, anesthetized and operated to cut the sciatic nerve and receive an autograft or a conduit made with a membrane derived from natural latex (Hevea brasiliensis). Four or eight weeks after surgery, to investigate motor nerve recovery, we analyzed the neurological function by walking pattern (footprints analysis and computerized treadmill), electrophysiological evaluation and histological analysis of regenerated nerve (autologous nerve graft or tissue cables between the nerve stumps), and anterior tibial and gastrocnemius muscles. RESULTS: All functional and morphological analysis showed that the rats transplanted with latex conduit had a better neurological recovery than those operated with autologous nerve: quality of footprints, performance on treadmill (p<0.01), electrophysiological response (p<0.05), and quality of histological aspects on neural regeneration. CONCLUSION: The data reported showed behavioral and functional recovery in rats implanted with latex conduit for sciatic nerve repair, supporting a complete morphological and physiological regeneration of the nerve.

OBJETIVO: Avaliar a capacidade de uma membrana de látex natural em acelerar e melhorar a qualidade da regeneração do nervo ciático seccionado de ratos. MÉTODOS: Foram utilizados 40 ratos machos adultos da linhagem Wistar, anestesiados e operados com autoenxerto ou com interposição de um tubo confeccionado com uma membrana derivada do latex natural (Havea brasiliensis). Quatro ou oito semanas após a cirurgia, para investigar a recuperação motora do nervo, foram analisadas a função neurológica através do padrão da marcha (análise das pegadas e esteira computadorizada), avaliação eletrofisiológica e análise histológica do nervo regenerado (enxerto de nervo autólogo ou formação de nervo novo entre os cotos nervosos) e músculos gastrocnêmio e tibial anterior. RESULTADOS: Todas as análises morfológicas e funcionais demonstraram que os ratos transplantados com o conduto de látex tiveram recuperação melhor do que aqueles operados com nervo autólogo: qualidade das pegadas impressas, desempenho em esteira (p<0,01), resposta eletrofisiológica (p<0,05), e qualidade histológica da regeneração nervosa. CONCLUSÃO: Os dados apresentados demonstraram recuperação comportamental e funcional nos ratos implantados com o conduto de látex para a reparação do nervo ciático por meio de uma completa regeneração morfológica e fisiológica do nervo.

Effect of Hyaluronic Acid-Carboxymethylcellulose Solution on Perineural Scar Formation after Sciatic Nerve Repair in Rats

BACKGROUND: Scar tissue formation is the major cause of failure in peripheral nerve surgery. Use of a hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane (Seprafilm) as a solid anti-adhesion barrier agent is one of the therapeutic approaches to reduce postoperative scar tissue formation. However, a solid membrane may not be suitable for repair of a weak peripheral nerve site. This study examined the effect of HA-CMC solution on perineural scar formation after peripheral nerve repair in rats. METHODS: The sciatic nerves of 40 rats were transected and then immediately repaired using 10-0 nylon. The nerves were divided randomly into two groups. Saline and HA-CMC solution were applied topically to the nerve repair sites in the control and experimental groups, respectively. Reoperation was performed at 3, 6, 9, and 12 weeks to assess scar tissue formation. The assessment included the quality of wound healing, presence of perinueral adhesion, cellular components of the scar tissue, thickness of the scar tissue and histomorphological organization of the repair site. RESULTS: Topical application of the HA-CMC solution significantly decreased the macroscopic nerve adherence score and the numbers of the cellular components such as fibroblasts and inflammatory cells (p < 0.05, Mann-Whitney U-test). The scar tissue formation index was significantly lower in the experimental group at 12 weeks than that in the control group (p < 0.05, Mann-Whitney U-test). The grading scores of the histomorphological axonal organization at the repair site were significantly higher in the experimental group than those in the control group at 12 weeks (p < 0.05, Mann-Whitney U-test). No evidence of wound dehiscence or inflammatory reactions against the HA-CMC solution was noted. CONCLUSIONS: Topical application of a HA-CMC solution is effective in reducing the perineural scar formation and adhesion after sciatic nerve repair in rats, and is effective in promoting peripheral nerve regeneration at the repair site.

Efeito da exposição cirúrgica de nervos e músculos no teste neurofisiológico em ratos / The effect of surgical exposure of nerves and muscles in neurophysiologic tests on rats

O estudo neurofisiológico, na modalidade da eletroneuromiografia (ENMG), determina e quantifica a integridade de componentes da unidade motora. Os principais dados fornecidos pelo exame eletroneuromiográfico são os estudos de condução nervosa motora, sensitiva e eletromiografia. No entanto, vários fatores podem interferir sobre a resposta nervosa à eletroestimulação, tais como: idade, sexo, temperatura, umidade e outros. O objetivo deste trabalho foi verificar o efeito da exposição cirúrgica dos nervos ciático, fibular comum, tibial e do músculo tibial cranial no teste neurofisiológico em ratos. Foram utilizados 20 ratos, Wistar, machos com aproximadamente 80 dias, divididos em dois grupos. No grupo normal o exame foi realizado sem a exposição cirúrgica do nervo fibular. No grupo cirúrgico houve a exposição do nervo fibular comum. Com o modelo experimental utilizado, concluiu-se que o teste neurofisiológico realizado em animais com nervos e músculos expostos cirurgicamente é viável, uma vez que a alteração da temperatura do animal não interferiu significativamente nos valores dos parâmetros eletrofisiológicos observados. Além disso, a exposição de nervos e músculos permite estimular um ponto exato no nervo alvo.

The neurophysiologic study in the modality of electroneuromyography (ENMG) determined and quantified the components in the motor ambit. The main data supplied by the examination was from the motor and sensory nerve conduction studies and by electromyography. However, many factors can interfere with the nervous response to electro-stimulation, such as: age, gender, temperature, humidity, and other things. The aim of this work was to verify the effect of surgical exposure of the sciatic, common fibular, tibial, and cranial tibial muscle nerves in a neurophysiologic test on rats. Twenty (20) Wistar male rats were utilized, with approximately 80 days of age, divided into two groups. In the normal group the exam was made without the surgical exposure of the fibular nerve. In the surgical group the common fibular nerve was exposed. With the experimental model utilized, it was concluded that the neurophysiologic test done on animals with nerves and muscles surgically exposed is viable, since the alteration in animal temperature did not interfere significantly with the values of the electrophysiological parameters observed. In addition, the exposure of nerves and muscles allows stimulation of an exact point on the target nerve.

Preemptive analgesic effect of lidocaine in a chronic neuropathic pain model / Efeito analgésico preemptivo da lidocaína em modelo de dor crônica neuropática

Preemptive analgesia inhibits the progression of pain caused by surgical lesions. To analyze the effect of lidocaine on postoperative pain relief, we performed compression of the right sciatic nerve in Wistar rats and observed the differences on behavior between the group that received lidocaine and the group that was not treated with the local anesthetics pre-operatively. Group 1 was not operated (control); group 2 underwent the sciatic nerve ligature without lidocaine; group 3, underwent surgery with previous local infiltration of lidocaine. Group 2 showed significantly longer scratching times with a peak on day 14 post-operative (p=0.0005) and reduction in the latency to both noxious (p=0.003) and non-noxious (p=0.004) thermal stimulus. Group 3 presented significantly shorter scratching times (p=0.004) and longer latency times when compared to Group 2. Preemptive use of lidocaine 2 percent can potentially reduce the postoperative neuropathic pain associated with sciatic nerve compression.

A analgesia preemptiva inibe a progressão da dor causada por lesão cirúrgica. Para analisar o efeito da lidocaína na diminuição da dor pós-operatória, submetemos ratos Wistar a compressão cirúrgica do nervo ciático e observamos diferenças em alguns padrões de comportamento entre o grupo tratado com lidocaína pré-operatória e o grupo não-tratado com o anestésico local. O grupo 1 não foi operado (controle); o grupo 2, submetido a ligadura do nervo ciático sem lidocaína, apresentou significativo aumento do tempo de coçar-se com um pico no 14º pós-operatório (p=0.0005) e redução na latência para os estímulos térmicos nocivo (p=0.003) e não-nocivo (p=0.004); o grupo 3, operado com a droga preemptiva, demonstrou significativo decréscimo no tempo de coçar-se (p=0.004) e maiores tempos de latência quando comparados aos do grupo 2. O uso preemptivo da lidocaína 2 por cento pode, potencialmente, reduzir a dor neuropática pós-operatória associada à compressão do nervo ciático.