Infrared thermography to prognose the venous leg ulcer healing process—preliminary results of a 12‐week, prospective observational study

Abstract

Venous leg ulcers are complex, and their multifactorial etiology make successful treatment a difficult and long process. Nonhealing ulcers are the greatest challenge because they are resistant to standard therapies. In this study, we analyzed whether monitoring the temperature of the ulcered limb wound area could benefit the diagnosis of the wound's tendency to heal (estimating the presence of a healing or nonhealing wound) in patients with two‐sided venous leg ulcers. This prospective, 12‐week observational study included 57 adult individuals with chronic venous leg ulcers. The dynamics of wound healing was assessed by planimetry and infrared thermography every two weeks. We analyzed temperatures measured at three marked areas—the wound, the periwound skin, and the reference area. An initial wound area larger than 1 cm2 was associated with a temperature increase of 0.027 °C in the periwound skin. A 1‐cm2 decrease in the wound area was associated with a 0.04 °C decrease in the temperature difference between the periwound skin and wound. A strong positive relationship was identified for both the bacteriology variables (the presence of bacteria: temperature increase in the periwound skin of 0.4 °C, p < 0.001; the number of bacterial species in a wound, temperature increase of 0.95 °C, p < 0.001). The temperature in the reference area was significantly correlated with the failure of the superficial and perforating veins (temperature increase of 0.69 °C, p = 0.04). This study reports that the assessment of the temperature a limb may be beneficial in predicting whether an ulcer is a healing or a nonhealing ulcer. The decrease in the temperature differences between the areas referred to as healing wounds was the only beneficial prognostic marker. Other temperature differences in the periwound skin were caused by disorders, such as multibacterial wound infections and superficial venous inflammation.

Venous leg ulcers treated with fish collagen gel in a 12-week randomized single-centre study

“…The difference of the maximum temperatures between an inflamed and a healthy area may equal approximately 1.5-2.2°C and even more in case of infection [56]. Reducing this difference is a good predictive factor, thus IRT assessment may prove helpful in the prognosis for wound healing [40,56]. It has been shown that higher temperature within the wound bed and its surroundings is associated with a several-times increased risk of delayed healing, and even wound deterioration.…”

“…In this manner, we eliminated the direct influence of skin preparation and skin massage on the temperature of the extremities, which would have compromised important measurement data. The results of initial examination and detailed thermographic evaluation of the healing process in patients with VLUs were discussed in another publication [40].…”

Infrared Thermography in Wound Care, Surgery, and Sports Medicine: A Review

“…In the field of venous pathology, infrared thermography has been used to assess wound healing, response to treatment, and predict infection in patients with venous ulcers in a similar manner to patients with diabetic ulcers ( Martínez-Jiménez et al, 2013 , 2018b ; Dini et al, 2015 ; Cwajda-Białasik et al, 2020 ). Finally, infrared thermography has also been used to predict fistula maturation in a cohort of 100 patients with end-stage renal disease who needed vascular access for hemodialysis ( Al Shakarchi et al, 2017 ).…”

Thermotropic Liquid Crystals for Temperature Mapping

“…Among many clinical biomarkers, special attention has been given to pH ( Shukla et al, 2007 ; Schreml et al, 2011 ; Jones et al, 2015 ; Power et al, 2017 ), oxygen ( Schreml et al, 2010 ), and exudate composition, with the focus on matrix metalloproteinase analytes (MMPs) ( Muller et al, 2008 ; Liu et al, 2009 ; Power et al, 2017 ). Also, temperature ( Dini et al, 2015 ; Chanmugam et al, 2017 ; Jaspers et al, 2017 ; Power et al, 2017 ; Cwajda-Białasik et al, 2020 ) and moisture ( Bishop et al, 2003 ; Milne et al, 2016 ) are the physical parameters that are frequently associated with the wound healing process. In particular, the temperature is considered as an informative parameter for all types of wounds, and it can provide information about infections of wounds, even before clinical signs appear ( Power et al, 2017 ).…”

“…This is mainly due to their non-invasive and easily interpretable results obtained in a very short period. Various studies ( Dini et al, 2015 ; Chanmugam et al, 2017 ; Jaspers et al, 2017 ; Martínez-Jiménez et al, 2018 ; Cwajda-Białasik et al, 2020 ; Ganon et al, 2020 ) have used the temperature difference between wound and healthy skin (ΔT), measured by using IR thermography, to characterize the wound status. An increase of ΔT can be related to hyperaemia, inflammation, or infection in venous leg ulcers ( Dini et al, 2015 ; Cwajda-Białasik et al, 2020 ) or pressure ulcers and surgical wounds ( Chanmugam et al, 2017 ).…”