Análise histológica do músculo reto do abdome de ratos submetidosà desvascularização cranial e caudal

Abstract

Introduction breast reconstructions with transverse rectus abdominis myocutaneous (TRAM) flap have had good results despite the high rates of complications, especially necrosis. Objective To evaluate the microscopic changes in the rectus abdominis muscle of rats subjected to five devascularization techniques with views to their delay procedure. Material and methods - 30 male holtzmann rats, weighting between 250 and 350 grams, were used. The animals were divided into five groups (n=6): A right muscle cranial section; B right muscle caudal section; C right muscle cranial and caudal section; D cranial section overlaying the right muscle in the cranial-caudal direction; E - caudal section overlaying the right muscle in the caudal-cranial direction. On the seventh post surgery day a resection was done of a cranial and caudal fragment of the right and the left muscles, respectively, for microscopic study. Histological alterations were quantified and compared the right and to left muscles fragments (control). For statistical purposes, Fisher exact test was used, with significance level of 5%. Results - the comparison between right and left muscles showed statistical significance in group A inflammatory infiltrate in the cranial fragment (p=0,015); in group C inflammatory infiltrate (p=0,000) and necrosis (p=0,015) in the caudal fragment; and in group E - edema in the caudal fragment (p=0,000). No significant alterations were noted in groups B and D. Conclusions researches on the devascularization techniques of the rectus muscle of rats abdomens, with views to their delay procedure, allowed the conclusion that: the exclusive irrigation by the perforating muscular vessels is inappropriate, and the maintenance of the superior or inferior irrigation is vital ; the exclusive irrigation by the cranial pedicle causes non-significant, less accentuate histological alterations, comparing to the exclusive irrigation by the caudal pedicle; the exclusive irrigation by the caudal pedicle causes non-significant, more accentuate histological alterations comparing to other devascularization forms.