Infrared imaging contribution for intestinal ischemia detection in wound healing

Abstract

Purpose: To study thermal variations obtained through infrared image in rats, and to evaluate the relationship between intestinal ischemic time and histopathological findings. Methods: Thirty Wistar rats were operated after distribution in 5 groups with different times of ischemia. Thermograms were obtained by using a infrared camera. The surgical technique has been standardized for all groups: abdominal cavity opening by a 5cm length incision in the midline, abdominal wall plans section and cavity exposure, and exteriorization of the intestine. In group I (control), it was proceeded only laparotomy without superior mesenteric artery ligature. After first thermogram done, incision was closed with continuing suture. In each rat in groups II, III, IV and V, the superior mesenteric artery was located at its origin on abdominal aorta, dissected and occluded with a vascular microclamp, subjecting the intestine to ischemia in variable times. Results: Rats submitted to a 30 minutes ischemia presented reactive hyperemia, thermal differential of 1.8°C and normal pathological examination. The 1 hour ischemia produced reactive hyperemia with ischemic areas, thermal differential of 1.0°C and injuries at villosities' tips. However, the 90 minutes ischemia had not shown reactive hyperemia with large ischemic areas, thermal differential of -1.0°C and injury in the upper third of the villosities. The 2 hours ischemia demonstrated a severe ischemia, thermal differential of -2.0°C and injury throughout the all villosities' extension. Conclusion: It has been possible studying thermal variations through infrared image in rats, showing correlation between thermal response in thermograms, ischemic time and histopathological findings. Key words: Spectrophotometry, Infrared. Tissue Survival. Ischemia. Wound Healing. Rats. RESUMOObjetivo: Estudar as variações térmicas obtidas por meio da imagem infravermelha em ratos, e avaliar sua correlação com o tempo de isquemia intestinal e os achados histopatológicos. Métodos: Trinta ratos Wistar foram operados após distribuição em cinco grupos com diferentes tempos de isquemia. Os termogramas foram obtidos utilizando-se uma câmera infravermelha. A técnica operatória foi padronizada para todos os grupos, abertura da cavidade abdominal por uma incisão na linha média de 5 cm de comprimento com secção de todos os planos da parede abdominal e exposição da cavidade e as alças intestinais exteriorizadas. No grupo I (controle) foi feito apenas laparotomia sem ligadura da artéria mesentérica superior. Após realizado o primeiro termograma, foi fechada a incisão com sutura contínua. Em cada rato dos grupos II, III, IV e V a artéria mesentérica superior foi localizada em sua origem na aorta abdominal, dissecada com e ocluída por um microclampe vascular submetendo o intestino à isquemia em tempos variáveis. Resultados: Os ratos submetidos à isquemia de 30 minutos apresentaram hiperemia reativa, diferencial térmico de 1,8°C e exame anatomopatológico normal. A isquemia de 1 hora produziu hiperemia reati...

Comparative thermographic analysis at pre‐ and postcryolipolysis treatment: Clinical case report

“…The images were analyzed using a temperature ranging from 36.0°C to 27.0°C, with a mean temperature of 28.5°C, following the values of the Continuous Colorimetric Scale, in which the colors white, red, yellow, green, blue, purple, and black, represented, respectively, a decreasing range of temperature areas, from the hottest to the coldest …”

“…The images were analyzed using a temperature ranging from 36.0°C to 27.0°C, with a mean temperature of 28.5°C, following the values of the Continuous Colorimetric Scale, in which the colors white, red, yellow, green, blue, purple, and black, represented, respectively, a decreasing range of temperature areas, from the hottest to the coldest. 11 The quantitative analysis of Figure 1(A,B), used for basal control, according to the area, shape, symmetry, and temperature distribution showed an asymmetric pattern due to the presence of fat located in the lower abdomen and showed a higher temperature in Sp2 (32.…”

Fluorescent test accurately predicts leak of ischemic colon anastomosis in rats

“…The ideal evaluation method of intestinal perfusion should be easily accessed in the operating room, quick to use, have good accuracy, low cost and be minimallyinvasive 12 . The fluorescence method with intravenous administration of fluorescein and examination under ultraviolet light meet all these criteria 7,[10][11][12]14 . The present study comprised a control group (non-ischemic anastomosis) and three intervention groups with varying degrees of ischemic colonic anastomosis in rats.…”

“…Therefore, a rigorous intraoperative evaluation of the intestinal perfusion is essential for the prevention of anastomotic dehiscence 1,6 . Clinical tests to predict the occurrence of anastomotic dehiscence have very low accuracy, with a failure rate up to 60% 4,[7][8][9] . Several studies have been conducted to find an objective and reliable method of intraoperative evaluation of intestinal blood supply in the last four decades 2,3,7,[10][11][12][13][14] .…”

“…Clinical tests to predict the occurrence of anastomotic dehiscence have very low accuracy, with a failure rate up to 60% 4,[7][8][9] . Several studies have been conducted to find an objective and reliable method of intraoperative evaluation of intestinal blood supply in the last four decades 2,3,7,[10][11][12][13][14] . To present date, no method has been accepted as the standard for this matter, however fluorescence tests have gained some attention [16][17][18][19][20][21][22] .…”