Visualized identification of the maximal surgical delay effect in a rat flap model

Abstract

Currently, experimental evidence suggests that the surgical delay can increase flap survival area, but its effect may decrease if the optimal delay period is missed. The aim of this study is to establish a sensitive and objective modality based on the visualized and individualized infrared thermography for identifying the maximal surgical delay effect. A rectangular three‐angiosome flap was designed on the unilateral dorsum of the rat. Ninety‐six rats were randomly divided into six groups according to the various delay time. Both the relative temperature and the relative temperature ratio were measured by the infrared thermography. Arterial density, number of vessels >0.1 mm in diameter, microvessel density, VEGF concentration, and flap viability were measured. Receiving operating characteristic curve with the highest Youden‐Index was used to detect and identify an optimal cutoff point of the relative temperature ratio in the maximal surgical delay effect. The criteria for identifying the flap maximum delay effect based on the infrared thermography included the surface of the postdelayed flaps presented white color (higher temperature) instead of the red and white pattern of the normal skin and the optimal cutoff point of the relative temperature ratio was ≥1.17 with a sensitivity of 84.6% and a specificity of 77.3%. Instead, the sensitivity and specificity of the conventional method based on the delay time were 38.5 and 90.9%, respectively. Infrared thermal imaging can accurately identify the maximum delay effect when combined with the relative temperature ratio.

Intra- and Early Postoperative Evaluation of Malperfused Areas in an Irradiated Random Pattern Skin Flap Model Using Indocyanine Green Angiography and Near-Infrared Reflectance-Based Imaging and Infrared Thermography

“…From the three imaging methods tested, the indocyanine green angiography was shown to be the most precise. The advantages of the infrared thermography such as its noninvasive use have been already shown in other studies [13]. In contrast to the study of Li et al; infrared thermography was shown not to reproduce evaluable results in our study.…”

“…To determine tissue perfusion, different imaging modalities have been tested, such as laser Doppler flowmetry for cutaneous circulation [12], infrared thermography [13], indocyanine green angiography [1,14] and near-infrared reflectance-based imaging [15]. While these devices may eventually predict the malperfusion accurately, there might be differences in their features such as application handling and invasivity.…”

The Effects of Angiosome Morphology on Choke Vessels and Flap Necrosis in a Rat Multiterritory Perforator Flap

“…There are 3 angiosomes in the right dorsum of Sprague-Dawley rats. These are, from the caudal side to the cranial side of the rat, the ILAV, the PIAV, and the TDAV, [14][15][16] designated as angiosomes I, II, and III, respectively. The anastomosis between angiosomes I and II was termed choke 1, and the anastomosis between angiosomes II and III was described as choke 2.…”

Correlation of vascular change with TRPV1, TRPV4, and TRPA1 in a rat model of inferior gluteal artery perforator flap

“…Finally, the most distinct and significant morphological alteration is the vascular changes, such as the choke vessels dilation and neovascularization 3 . Our previous studies demonstrated that the maximum survival area after perforator flap elevation is mainly achieved through the vasodilation and angiogenesis, and the flap is characterised by a first increase and then decrease in temperature over time 5,6 . Mao et al 7 reported that blood flow, vascular diameters, and microvascular count are clearly increased after flap elevation, and vascular changes are closely associated with the shear stress caused by the increased blood perfusion after surgery.…”

“…3 Our previous studies demonstrated that the maximum survival area after perforator flap elevation is mainly achieved through the vasodilation and angiogenesis, and the flap is characterised by a first increase and then decrease in temperature over time. 5,6 Mao et al 7 reported that blood flow, vascular diameters, and microvascular count are clearly increased after flap elevation, and vascular changes are closely associated with the shear stress caused by the increased blood perfusion after surgery. Previous studies indicated that shear stress can activate some mechanosensors situated on the endothelial cell (EC) membrane to trigger several acute signalling pathways, including the synthesis of nitric oxide (NO) by endothelial NO synthase (eNOS) or release of endothelial-derived hyperpolarisation factor, ultimately increasing the vasodilation.…”