Avaliação morfológica e imuno-histoquímica do efeito isolado e combinado da pentoxifilina e da hialuronidase em retalhos cutâneos randomizados em ratos

Abstract

Randomized skin flaps are used very often in plastic surgery, especially for the reconstruction of tissues, but the possibility of necrosis has challenged its use. There have been several studies aimed at finding ways to reduce its occurrence. To evaluate the isolated and combined effect of pentoxifylline and hyaluronidase on randomized skin flaps were used 50 male Wistar rats divided into five groups of ten: Control I (CTL- I) no treatment before or after the surgical procedure; Control II (CTL -II) - saline solution intraperitoneally (IP) twice a day and intralesional (IL) once a day; Pentoxifylline (PTX) pentoxifylline intraperitoneally twice a day and saline solution intralesional once a day; Hyaluronidase (HLD) hyaluronidase intralesional once a day and saline solution intraperitoneally twice daily; Hyaluronidase - pentoxifylline (PTX - HLD) combination of both drugs at the same doses and routes of administration. All substances were administered from 1st to 13th days after surgery, necrotic area was measured on 7th and 14th post-operative days, the animals were killed in 14th of the experiment, then were collected samples for histological and immunohistochemical examination. In the 7th day necrotic area percent was reduced in PTX(M = 33.16 %; SD=±7.75), HLD(M = 21.04 %; SD =±7.13), and PTX-HLD(M = 28.04 %;SD=±10.50) (P<0.0001) compared to CTL -I (M = 48,17 %; DP=±9,18) e CTL - II (M = 46.24 %; SD=±8.02) . In the 14th percentage of the PTX(M = 41.91 %; SD=±6.15), HDL(M = 43 %;SD=±4.711), and PTX-HLD(M = 40.56 %; SD=±8.67) groups was also reduced (P<0.001) compared to to CTL -I (M = 53.61 %;SD=±5.581) and CTL - II (M = 52.07 %; SD=±6.79). PTX and PTX-HLD showed reduced dermis cellularity (P<0.002), VV of macrophages (P<0.003) and myofibroblasts (P<0.0001) compared to controls; PTX showed enhanced LV of blood vessels compared to all other groups (P<0.0001). The use of each substance alone or combined increased flap viability compared to controls. On the 7th day, PTX exhibited lower viability than HLD, while on the 14th day there was no difference between treated groups. PTX alone enhanced the LV of blood vessels while PTX-HLD did not. However, PTX-HLD was more effective in decreasing the dermis cellularity and macrophage VV than HLD alone.