Avaliação histopatológica dos efeitos dos anestésicos locais na cicatrização de feridas cirúrgicas: estudo experimental em ratos

Abstract

INTRODUCTION Pain relief after surgery remains one of the greatest medical challenges. The infiltration of the surgical incision with local anesthetics has been increasingly used. OBJECTIVE To evaluate the interference of infiltration of local anesthetics in the incision on the areas of inflammatory infiltrate and fibrous scar in rats. MATERIAL AND METHOD Study involving 40 Wistar rats. Two linear incisions each were made on the dorsal region of each animal. The left incision was infiltrated with doses of 1.8ml of Bupivacaine, Levobupivacaine, Ropivacaine or 0,9% saline solution, and the right incision did not receive any infiltration. After seven days, samples of the incisions were collected for morphometric evaluation. RESULTS When compared with the control groups, the area of inflammatory infiltrate was found larger in the Bupivacaine, Ropivacaine and Levobupivacaine groups. The Bupivacaine group presented larger inflammatory infiltrate than the Levobupivacaine and Ropivacaine. The fibrous scar area was larger in the Levobupivacaine and Ropivacaine groups. There was no difference between the groups that received anesthetic and saline solution. CONCLUSION Local infiltration of anesthetics was associated with largest area of inflammatory infiltrate and fibrosis. Despite being associated with the largest infiltrate, Bupivacaine was associated with the smallest area of fibrous scar. Despite being associated with the smallest infiltrate, Levobupivacaine was associated with the largest area of fibrous scar. As there was no difference between the anesthetics and saline solution groups, the volume applied or the trauma may have been the cause of the larger areas of infiltrate and scar observed.