Effects of sildenafil and tadalafil on skin flap viability.

Vascular complication is one of the causes of skin flap healing failure. Sildenafil and tadalafil, a type-5 phosphodiesterase inhibitor, can improve flap viability, however, the action mechanisms involved in this process are still unclear. To assess the effects of orally administered sildenafil and tadalafil on the healing kinetics and skin flap viability, sixty-two Wistar rats were divided into three groups: control (n = 22), sildenafil (n = 20), and tadalafil (n = 20). The solutions were administered orally (dose: 10 mg/kg) immediately after the surgical procedure and then every 24 h. At postoperative days 7 and 14, the skin flap samples were collected, submitted to histological processing and evaluated under optical microscopy. In experimental groups (sildenafil and tadalafil), we found an increased vascularization (p < 0.05) on the 7th and 14th day associated with the ulcer size decrease on the 14th day, although it was not significant. There was a higher influx of neutrophils and a decrease of mononuclear population on the 7th day (p < 0.05). On the 14th day, these differences were observed only in the tadalafil group (p < 0.05). This study suggested positive results with the use of sildenafil and tadalafil as adjuvant drugs in skin flap viability.

Early fragmentation of polyester urethane sheet neither causes persistent oxidative stress nor alters the outcome of normal tissue healing in rat skin.

Silicone breast implant is associated with complications inherent to the surgical procedure. Prosthesis coating with polyurethane, however, commonly reduces the incidence of such complications. In this paper, the authors evaluated the inflammatory histomorphometric profile and oxidative damage associated to the implant of polyester urethane sheets. Forty-eight Wistar rats were divided into Sham or polyester urethane groups (n = 8/group) and underwent a polyester urethane implant in the dorsal skinfold. Tissue samples were collected on days seven, 30, and 90 after surgery and subjected to histomorphometric analysis and biochemical tests. Results were analyzed by one-way ANOVA (p ≤ 0.05). Peri-implant tissue samples exhibited characteristic inflammatory response associated with the biomaterial, with increased vascularization on day seven and augmented levels of IL1-b and TNF-a after 30 days. Peri-implant fibrocystic population was small on day seven, but increased considerably after 90 days. A rise in the carbonyl group levels of skin samples in the polyester urethane group was observed on day seven. Findings suggest that polyester urethane sheets undergo biodegradation at an early stage after implantation, followed by increased vascularity and microencapsulation of biomaterial fragments, without persistent oxidative damage. Fiber arrangement inside the collagen matrix results in a fibrotic scar because of polyester urethane degradation.

Vascular endothelial growth factor overexpression positively modulates the characteristics of periprosthetic tissue of polyurethane-coated silicone breast implant in rats.

BACKGROUND: Capsular contracture is one of the most common complications associated with silicone breast implants. The surface of the implant is one of the factors often associated with the occurrence of capsular contracture. In this study, the authors evaluated the differences in morphologic and molecular characteristics of the capsule formed around polyurethane-coated versus textured-surface silicone implants in rats, mainly the modifications in angiogenesis and the expression of vascular endothelial growth factor (VEGF). METHODS: A pocket was performed on the animal's back, where the silicone implants were introduced. Two groups of animals received a polyurethane-coated silicone implant and the other groups received a textured-surface silicone implant, and the capsules around the prostheses were submitted to histologic and immunohistochemistry analysis, 30 or 90 days after surgery. RESULTS: The capsules around the polyurethane-coated silicone prostheses were significantly thicker than the textured-surface silicone implants. Furthermore, the layer adjacent to the polyurethane-coated silicone implants was more cellular and irregular than the layer around the textured-surface silicone implants. Textured implant periprosthetic capsules presented fewer inflammatory cells and less vascularization than the polyurethane-coated silicone implants. The collagen layer of periprosthetic tissue of textured implants appears to be more continuous and aligned in parallel fashion than polyurethane-coated implants. Immunohistochemical analysis revealed high levels of transforming growth factor-ß and VEGF in the capsules around the polyurethane-coated silicone implants when compared with the textured-surface silicone implants. CONCLUSION: These findings suggest that the intense VEGF expression in capsules around the polyurethane-coated silicone implant is able to improve the tissue vascularization, resulting in a softer capsule compared with the textured-surface silicone implant.

Cited Brazilian papers in general surgery between 1970 and 2009.

OBJECTIVES: To identify the most cited articles in general surgery published by Brazilian authors. INTRODUCTION: There are several ways for the international community to recognize the quality of a scientific article. Although controversial, the most widely used and reliable methodology to identify the importance of an article is citation analysis. METHODS: A search using the Institute for Scientific Information citation database (Science Citation Index Expanded) was performed to identify highly cited Brazilian papers published in twenty-six highly cited general surgery journals, selected based on their elevated impact factors, from 1970 to 2009. Further analysis was done on the 65 most-cited papers. RESULTS: We identified 1,713 Brazilian articles, from which nine papers emerged as classics (more than 100 citations received). For the Brazilian contributions, a total increase of about 21-fold was evident between 1970 and 2009. Although several topics were covered, articles covering trauma, oncology and organ transplantation were the most cited. The majority of classic studies were done with international cooperation. CONCLUSIONS: This study identified the most influential Brazilian articles published in internationally renowned general surgery journals.

Cited Brazilian papers in general surgery between 1970 and 2009

OBJECTIVES: To identify the most cited articles in general surgery published by Brazilian authors. INTRODUCTION: There are several ways for the international community to recognize the quality of a scientific article. Although controversial, the most widely used and reliable methodology to identify the importance of an article is citation analysis. METHODS: A search using the Institute for Scientific Information citation database (Science Citation Index Expanded) was performed to identify highly cited Brazilian papers published in twenty-six highly cited general surgery journals, selected based on their elevated impact factors, from 1970 to 2009. Further analysis was done on the 65 most-cited papers. RESULTS: We identified 1,713 Brazilian articles, from which nine papers emerged as classics (more than 100 citations received). For the Brazilian contributions, a total increase of about 21-fold was evident between 1970 and 2009. Although several topics were covered, articles covering trauma, oncology and organ transplantation were the most cited. The majority of classic studies were done with international cooperation. CONCLUSIONS: This study identified the most influential Brazilian articles published in internationally renowned general surgery journals.