Efeito do bevacizumabe na viabilidade de retalho inguinal livre em ratos

Abstract

The incidence of cancer is increasing in Brazil and worldwide. Bevacizumab (Avastin®, Genentech) is currently among the most used drugs in the treatment of the most common tumors. However, there is evidence that it may cause a significant reduction in flap survival rate. The aim of this study is to evaluate the effect of Bevacizumab (BVZ on the viability of free groin flaps in rats. Twenty-nine WISTAR rats were randomized to one of three different groups. The rats included in the Graft Group received intravascular saline solution preoperatively and were submitted to a full thickness skin graft in the groin area. The animals from Saline-Flap Group underwent a free groin flap receiving intravascular saline solution one week before. The animals from BVZ-Flap Group underwent free groin flap after having received intravascular administration of Bevacizumab one week before the procedure. The following variables were evaluated postoperatively: viable flap area, vascular pedicle patency tests and histological analysis of tissue from the flap and from the vascular pedicle. Statistical analysis was performed using GraphPad Prism version 8.0 Software. Analysis of variance (ANOVA) was performed and Tukey test was applied to verify differences between groups in pairs. A P value ≤ 0.05 was considered statistically significant. The Graft group presented a lower percentage of viable area (22.81%) as compared to the Saline-Flap Group (83.98 %%) (P<0,0001) and to the BVZ-Flap Group (60.50%) (P<0,0048). Regarding vascular pedicle patency, the BVZ-Flap group had lower results: 60% of the arteries and 80% of the veins were patent. The Saline-Flap Group presented patency in 100% of the arteries and 90% of the veins, but the difference between both groups was not significant either in arterial vessels (P=0,0867) or venous vessels (P=0,9999). Regarding the histological analysis, there was significantly higher necrosis in the Graft (87.50%) and Flap-BVZ (60.00%) groups, compared to the Flap-SF group (0%) (P=0,0010). The occurrence of inflammation was lower in the Saline-Flap Group (33.33%) compared to the Graft Group (87.5%) and BVZ-Flap Group (70.00%), but difference did not reach significance (P = 0.0588). ). There were no significant differences in the occurrence of hemorrhage or intraluminal thrombosis between the groups. The administration of BVZ caused a higher occurrence of flap necrosis, but did not significantly alter the percentage of viable area and vascular pedicle patency. Keywords: Bevacizumab. Free groin flap. Rats.