Estudo da hemostasia em pacientes submetidas a cirurgias plasticas com e sem antecedentes de gastroplastia redutora / Study of hemostasis in pacients undergoing plastic surgery procedures with and without a history of weight reducing by gastroplasty

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Plastic surgery procedures performed in patients who previously underwent weight reducing gas troplasty present a high risk for medical complications, one of the most severe being bleeding during the perioperative period. Although the cause of this bleeding is currently unknown, it is postulated that these patients may present alterations in hemostasis not detected by routine coagulation tests or an increase in microvascular density and/or in the diameter of subcutaneous vessels. The purpose of this study was to evaluate and compare the hemostasis and the number and caliber of subcutaneous vessels in two groups of patients undergoing abdominoplasty, one of them with history of previous weight reducing gastroplasty performed in accordance with the Fobi-Capella technique (group I) and the other without obesity backgrounds (group II). Each group was composed by ten female patients. Vitamins C and K were measured at preoperative period. At the beginning, during, and at the end of surgeries, samples were collected to determine the coagulogram (prothrombin and activated partial thromboplastin times), measurements of coagulation factors and thromboelastography. At the end of each surgery, samples of subcutaneous tissue were collected from six different abdominal topographies. Bleeding during intraoperative period was assessed indirectly by counting and weighing the compresses at the end of each surgical procedure. Data obtained from laboratorial tests and thromboelastography were compared between the groups I and II. Subcutaneous vessels were also assessed by immunohistochemistry using the pan-endothelial marker CD34 and quantified through the variables "microvessel density (MVD), percentage (%EndA) and mean (MEndA) endothelial areas" using computer assisted technology. The statistical analysis (Mood Median Test) showed superior bleeding (p = 0.007), increased prothrombin time (p = 0.007) and factor II (FII) decreased during the intraoperative period (p = 0.007) and factor X (FX) decreased during all studied operative periods in the group I. Thromboelastography, which assess the full process of hemostasia in real time, did not show differences between the groups. Greater concentrations of vitamin K were demonstrated in group I compared to group II. There were not statistically significant differences among the MVD values obtained from different abdominal subregions (p = 0.565) nor between groups I and II regarding the values of MVD (p = 0.88), %EndA (p = 0.364) and MEndA (p = 0.257). The size of the surgical pieces and the duration of surgeries were greater in group I (p = 0.007). The more intense bleeding observed during plastic surgeries carried out in patients that previously underwent weight reducing gastroplasty can not be quite explained by alterations in hemostasis when it is assessed through coagulation laboratorial tests, measurements of coagulation factors and thromboelastography, by decreased levels of vitamins K and C, by a larger number of blood vessels, by a more extensive vascular network, or by the presence of vessels with larger calibers in the subcutaneous adipose tissue of these patients when compared to patients without obesity backgrounds. The results indicate that the greater surgical trauma and the longer duration of surgeries in group I may lead to increased coagulation activation and consume of coagulation factors resulting in more intense bleeding

ASSUNTO(S)

angiogenesis immunohistochemistry hemostasis hemorragia gastroplastia plastic surgery coagulation gastroplasty hemorrhage hemostase neovascularização cirurgia plastica coagulação obesity

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