BACKGROUND: To determine the presence of smooth muscle fibers (SMF) in the peritoneal sacs of indirect, direct, recurrent and strangulated hernias and to evaluate the influence of sex, color and patients'age well as location, width, length and thickness of the hernia sac collected biopsy. METHOD: 252 hernia sacs - obtained between February 1999 and December 2000 - were sent to histopathological examination using hematoxylin and eosin stain and Gomori Trichrome. The ages varied between 1 month to 87 years with a mean age of 42,3± 22,5 years. RESULTS: SMF were observed in 76,5% of the patients with indirect hernia, 55,9% with direct hernia, 46,4% with strangulated hernia and 68,7% with recurrent hernia. Overall , SMF were found in 67,9% of the specimens , with larger incidence in the proximal portion of the hernia sac (53,2%) , and in melanodermic patients (75%). SMF were present, in larger frequency, on the right side (67,7%) and in the feminine sex (73,3%). Of the total of 252 samples of examined hernia sacs , SMF were found in 171 biopsies, wich wass less frequent in direct and strangulated hernias when compared with to indirect and recurrent hernias. CONCLUSIONS: The presence of SMF in the hernia sac wall could represent tissue reinforcement by hindering peritoneal sac growth, behaving as factor of elastic and dynamic resistance to the hernia expansion. On the other hand, it could also mean an aberrant formation or persistence of a structure that could be subject to regression or even disappear during normal development.
Inguinal hernias; Hernia sac; Hernia sac
