Estudio Comparativo entre Dos Intensidades de Ultrasonido Continuo en la Reparación del Nervio Espinal Lesionado por Compresión

El ultrasonido continuo fundamenta su efectividad en la energia termica que genera, favoreciendo la reparacion nerviosa. Es por esto que surge la interrogante de que si al aplicar diferentes intensidades de ultrasonido continuo sobre el nervio espinal lesionado, la respuesta reparativa sera igual o distinta. Para ello se utilizaron 12 ratas de sexo masculino a las que se les aislo quirurgicamente el nervio isquiatico, el cual fue pinzado durante 45 segundos con una fuerza constante de 40N. La compresion se realizo a 10mm sobre la bifurcacion, luego se desinfecto y suturo. Inmediatamente despues de la operacion las ratas fueron agrupadas de a 3: A) control sano, B) control lesionado, C) aplicacion de ultrasonido terapeutico de 0,5w/cm2 y D) aplicacion de ultrasonido terapeutico de 1w/cm2. El grupo A se utilizo como control sano y no recibio irradiacion. Las ratas del grupo B fueron lesionadas y no recibieron irradiacion y las del grupo C y D fueron lesionadas e irradiadas transcutaneamente en la region correspondiente al recorrido del nervio isquiatico utilizando intensidades de 0,5w/cm2 y 1w/cm2, 3 MHZ de frecuencia, un cabezal de 0,5cm2, durante 1 minuto y 10 dias consecutivos. 28 dias post operatorio se extrajeron los nervios isquiaticos y fueron sometidos a tecnicas de tincion de H-E y Van Gieson. Se realizo el diagnostico histopatologico y la morfometria: se midio el Grosor del Perineuro, Perimetro del nucleo del Schwannocito, Perimetro del Axon Mielinicoy Perimetro de la Mielina. Los resultados revelan que el ultrasonido continuo es efectivo en la reparacion del nervio espinal, siendolo mas con 1w/cm2 que con 0,5w/cm2.(AU) The continuous ultrasound bases its efficiency on the heat energy it generates, favoring the nervous repair. Therefore, the question arises whether the reparative response will be equal or different under varying intensities of continuous ultrasound application on the disabled spinal nerve. For the study we used 12 male rats; the ischiatic nerve was surgically isolated and compressed during 45 seconds with a constant force of 40N. The compression was realized at 10 mm on the bifurcation, and was subsequently disinfected and sutured. Immediately following the operation the rats were separated in groups of 3: A) Healthy control, B) Injured control, C) Application of therapeutic ultrasound of 0.5 w/cm2 and D) Application of therapeutic ultrasound of 1 w/cm2. Group A was used as healthy control and did not receive irradiation. The rats in group B were injured and did not receive irradiation and those of groups C and D were injured and were transcutaneously irradiated in the area corresponding to the ischiatic nerve using intensities of 0.5 w/cm2 and 1 w/cm2, 3 MHZ of frequency. We used a compress of 0.5 cm2, during 1 minute and for 10 consecutive days. 28 days post operative ischiatic nerves were removed and submitted to technologies of H.E and VG stain. Histopathological and morphometrical diagnosis was realized: Thickness of the Perineurium, schwannocyte perimeter, Myelin Axon and Myelin perimeters were measured. The results revealed that the continuous ultrasound is effective in the repair of the spinal nerve, more so with 1 w/cm2 than with 0.5 w/cm 2.(AU)