Histological modification in TRAM flap in rats treated with pentoxifylline

Abstract

PURPOSE:To investigate the blood vessels' concentration in TRAM flap's rat model, in the presence of pentoxifylline.METHODS: 32 male, Wistar-EPM rats were divided into two groups. Control group (C): 0.5 ml of saline, intraperitoneally, once a day, for seven days before flap elevation; PTX group (P): pentoxifylline (20mg/kg/day), intraperitoneally, for seven days before flap elevation. After that, they were submitted to a caudal unipedicle TRAM flap. On the fifth postoperative day, percentages of flap necrosis were determined via the "paper template" method and Tram flap's zone IV skin biopsies were taken for histological analysis.RESULTS: the mean percentage of flap necrosis in group C was 58.7 % and in group P, 31.1 (Wilcoxon test; p = 0.003). Mean capillary vessels number in zone IV's skin in C group was 33.4 and in P group was 71.9 (p=0.008). CONCLUSIONS:Pentoxifylline was effective reducing the necrosis in the caudal unipedicle TRAM flap in the rat as well as increasing the number of capillaries in an ischemic zone (zone IV).

Viability of randomized skin flaps—an experimental study in rats

“…Statistical analysis of the percent necrotic area on day 7 of the experiment revealed that the CTL-I (M ¼ 48.17%; SD ¼ AE9. 18) and CTL-II (M ¼ 46.24%; SD ¼ AE8.02) groups showed a higher percentage of the necrotic area compared with the PTX (M ¼ 33.16%; SD ¼ AE7.75), HLD (M ¼ 21.4%; SD ¼ 7.13%), and PTX-HLD (M ¼ 28.04%; SD ¼ AE10.50) (Fig. 2, top panel and Fig.…”

“…This is probably because of the different mechanisms of action of these drugs. PTX enhances blood cell flexibility, including erythrocytes, favoring blood flow in peripheral vessels, 9,14,17,18 promotes platelet disaggregation, and increases fibrinolysis, contributing to reduced blood viscosity. 10,14,[18][19][20] Perhaps these effects require more time to begin to manifest.…”

“…PTX decreased the V V of macrophages and myofibroblasts, an effect that can be explained by its ability to inhibit the production of some proinflammatory substances such as integrin, IL-2, 21 IL-1, and tumor necrosis factor a. 14,18,20,22 It is important to emphasize that PTX has the ability to shift the macrophage phenotype from inflammatory to anti-inflammatory, [31][32][33] probably improving flap healing.…”

“…6,8,9 Pentoxifylline (PTX) is a nonselective phosphodiesterase inhibitor, a methylxanthine derivative [10][11][12][13] whose molecular formula is C 13 H 18 N 4 O 3 , with a molecular weight of 278.31 Da. PTX is a drug with multiple pharmacologic properties, 14 promotes relaxation of vascular smooth muscle, causing vasodilatation and preventing vascular spasm, 15,16 enhances blood cell flexibility, including erythrocytes, favoring blood flow in peripheral vessels, 9,14,17,18 promotes platelet disaggregation, and increases fibrinolysis, contributing to reduced blood viscosity. 10,14,[18][19][20] PTX modulates the immunologic activity by acting on cytokines, suppresses leukocyte hyperactivity by reducing superoxide release and neutrophil adhesion, 17 inhibits the action of integrin and interleukin 2 (IL-2), preventing lymphocyte adhesion to endothelial cells, 21 and reduces the synthesis of IL-1 and tumor necrosis factor a.…”

“…10,14,[18][19][20] PTX modulates the immunologic activity by acting on cytokines, suppresses leukocyte hyperactivity by reducing superoxide release and neutrophil adhesion, 17 inhibits the action of integrin and interleukin 2 (IL-2), preventing lymphocyte adhesion to endothelial cells, 21 and reduces the synthesis of IL-1 and tumor necrosis factor a. 14,18,20,22 It is used clinically to treat diseases of peripheral vessels. 15,21,23,24 Hyaluronidase (HLD) is an enzyme of approximately 60,000 Da that acts on hyaluronic acid (HA) by temporarily depolarizing it and consequently reducing the viscosity of the intercellular medium, which in turn increases tissue permeability to other substances, whereas promoting the absorption of excess fluids, mobilizing edemas, and infiltrations.…”