Glucose level evaluation in monopedicled rectus abdominis myocutaneous flap after venous occlusion: experimental study in rats.

OBJECTIVE: to validate an experimental model for the measurement of glycemic levels in surgical flaps with the use of common glucometers, and to analyze the diagnostic criteria for hypoperfusion of such flaps. METHODS: we performed vertical myocutaneous rectus abdominis flaps with upper pedicles bilaterally in 20 male Wistar rats, divided into two groups: with and without venous occlusion of the pedicle. We measured glucose levels in the flaps and in the systemic circulation with standard glucometers. We tested the accuracy of alternative diagnostic criteria for the detection of hypoperfusion. RESULTS: from 15 minutes of venous occlusion on, there was a significant reduction in glucose levels measured in the congested flap (p<0.001). Using a minimum difference of 20mg/dl in the glycemic levels between the flap and systemic blood, 30 minutes after occlusion, as a diagnostic criterion, the sensitivity was 100% (95% CI 83.99-100%) and specificity of 90% (95% CI 69.90-97.21%) for the diagnosis of flap congestion. CONCLUSION: It is possible to measure glucose levels in vertical myocutaneous rectus abdominis flaps of Wistar rats, perfused or congested, using a common glucometer. The diagnostic criteria that compare the glucose levels in the flaps with the systemic ones were more accurate in the evaluation of tissue perfusion.

Glucose level evaluation in monopedicled rectus abdominis myocutaneous flap after venous occlusion: experimental study in rats / Avaliação do nível glicêmico em retalho miocutâneo do reto abdominal monopediculado após oclusão venosa: estudo experimental em ratos

ABSTRACT Objective: to validate an experimental model for the measurement of glycemic levels in surgical flaps with the use of common glucometers, and to analyze the diagnostic criteria for hypoperfusion of such flaps. Methods: we performed vertical myocutaneous rectus abdominis flaps with upper pedicles bilaterally in 20 male Wistar rats, divided into two groups: with and without venous occlusion of the pedicle. We measured glucose levels in the flaps and in the systemic circulation with standard glucometers. We tested the accuracy of alternative diagnostic criteria for the detection of hypoperfusion. Results: from 15 minutes of venous occlusion on, there was a significant reduction in glucose levels measured in the congested flap (p<0.001). Using a minimum difference of 20mg/dl in the glycemic levels between the flap and systemic blood, 30 minutes after occlusion, as a diagnostic criterion, the sensitivity was 100% (95% CI 83.99-100%) and specificity of 90% (95% CI 69.90-97.21%) for the diagnosis of flap congestion. Conclusion: It is possible to measure glucose levels in vertical myocutaneous rectus abdominis flaps of Wistar rats, perfused or congested, using a common glucometer. The diagnostic criteria that compare the glucose levels in the flaps with the systemic ones were more accurate in the evaluation of tissue perfusion.

RESUMO Objetivo: validar um modelo experimental para mensuração de níveis glicêmicos em retalhos cirúrgicos com a utilização de glicosímetros comuns, e analisar os critérios diagnósticos para hipoperfusão destes retalhos. Métodos: foram realizados retalhos miocutâneos verticais de reto abdominal com pedículos superiores, bilateralmente, em 20 ratos Wistar machos, divididos em dois grupos: com e sem oclusão venosa do pedículo. Os níveis de glicose foram mensurados nos retalhos e na circulação sistêmica com glicosímetros comuns. A acurácia de critérios diagnósticos alternativos foi testada para a detecção de hipoperfusão. Resultados: a partir de 15 minutos de oclusão venosa, houve uma redução significativa dos níveis de glicose medidos no retalho congesto (p<0,001). Utilizando como critério diagnóstico uma diferença mínima de 20mg/dl nos níveis glicêmicos do retalho e do sangue sistêmico, 30 minutos após a oclusão, a sensibilidade foi de 100% (intervalo de confiança de 95% - 83,99 a 100%) e especificidade de 90% (intervalo de confiança de 95% - 69,90 a 97,21%) para o diagnóstico de congestão do retalho. Conclusão: os resultados demonstraram que é possível medir níveis de glicose em retalhos miocutâneos verticais de reto abdominal de ratos Wistar, perfundidos ou congestos, utilizando um glicosímetro comum. Os critérios diagnósticos que comparam os níveis de glicose nos retalhos com os níveis sistêmicos foram mais precisos na avaliação da perfusão tecidual.