Orientador : Miguel A. AgulhamCo-orientador : Antonio Carlos L. CamposDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Ciencias da SaúdeAbstract: The operations for the treatment of the inguinal diseases are the most frequent in the childhood. The bleeding due to the traumatic lesion of the spermatic vessels is frequent and can cause testicular atrophy. The goal of this work was to determine the effects of the lesion of the spermatic vessels in the early and late histopathological alterations in an experimental model in Wistar rats. The 80 animals were divided in 4 groups for the histopathological analysis. In group A they were submitted to digital compression of the spermatic vessels for 45 seconds, in group B we performed the clamping of the spermatic vessels with hemostats for 5 seconds, in group C we performed the cauterization of the spermatic vessels for 2 seconds. Group D was the control group, in which the animals were submitted to inguinotomy solely. The early histopathological alterations were significant in group A for the testicular weight (0,97±0,10); in group B for the testicular weight (0,81±0,24),testicular volume (0,522±0,192)and mean testicular biopsy score (7,2±2,7);and in group C for the five parameters studied, testicular weight (0,69±0,28),testicular weightll00 g of body weight (0,498±0,188),testicular volume (0,765±0,308), mean seminiferous tubular diameter (236,6±62,5)and mean testicular biopsy score (6,9±3,1). The late histopathological alterations were not significant for the five parameters studied, in the three groups. Therefore, the histopathological alterations were more intense in the group submitted to cauterization of the spermatic vessels, intennediate in the group submitted do clamping of the spermatic vessels with hemostats and less severe in the rats submitted to digital compression of the spermatic vessels. The late histopathological alterations were not significant for the parameters studied in any of the three groups, showing the capability of the young testicle to recuperate from a vascular lesion.