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. 2008 Oct 21:6:Doc11.

Improvement of wound healing by water-filtered infrared-A (wIRA) in patients with chronic venous stasis ulcers of the lower legs including evaluation using infrared thermography

James B Mercer  1 , Stig Pors Nielsen, Gerd Hoffmann
Affiliations

Improvement of wound healing by water-filtered infrared-A (wIRA) in patients with chronic venous stasis ulcers of the lower legs including evaluation using infrared thermography

James B Mercer et al. Ger Med Sci. .

Abstract
in English, German

Background: Water-filtered infrared-A (wIRA) is a special form of heat radiation with a high tissue-penetration and with a low thermal burden to the surface of the skin. wIRA is able to improve essential and energetically meaningful factors of wound healing by thermal and non-thermal effects.

Aim of the study: prospective study (primarily planned randomised, controlled, blinded, de facto with one exception only one cohort possible) using wIRA in the treatment of patients with recalcitrant chronic venous stasis ulcers of the lower legs with thermographic follow-up.

Methods: 10 patients (5 males, 5 females, median age 62 years) with 11 recalcitrant chronic venous stasis ulcers of the lower legs were treated with water-filtered infrared-A and visible light irradiation (wIRA(+VIS), Hydrosun radiator type 501, 10 mm water cuvette, water-filtered spectrum 550-1400 nm) or visible light irradiation (VIS; only possible in one patient). The uncovered wounds of the patients were irradiated two to five times per week for 30 minutes at a standard distance of 25 cm (approximately 140 mW/cm(2) wIRA and approximately 45 mW/cm(2) VIS). Treatment continued for a period of up to 2 months (typically until closure or nearly closure of the ulcer). The main variable of interest was "percent change of ulcer size over time" including complete wound closure. Additional variables of interest were thermographic image analysis, patient's feeling of pain in the wound, amount of pain medication, assessment of the effect of the irradiation (by patient and by clinical investigator), assessment of feeling of the wound area (by patient), assessment of wound healing (by clinical investigator) and assessment of the cosmetic state (by patient and by clinical investigator). For these assessments visual analogue scales (VAS) were used.

Results: The study showed a complete or nearly complete healing of lower leg ulcers in 7 patients and a clear reduction of ulcer size in another 2 of 10 patients, a clear reduction of pain and pain medication consumption (e.g. from 15 to 0 pain tablets per day), and a normalization of the thermographic image (before the beginning of the therapy typically hyperthermic rim of the ulcer with relative hypothermic ulcer base, up to 4.5 degrees C temperature difference). In one patient the therapy of an ulcer of one leg was performed with the fully active radiator (wIRA(+VIS)), while the therapy of an ulcer of the other leg was made with a control group radiator (only VIS without wIRA), showing a clear difference in favour of the wIRA treatment. All mentioned VAS ratings improved remarkably during the period of irradiation treatment, representing an increased quality of life. Failures of complete or nearly complete wound healing were seen only in patients with arterial insufficiency, in smokers or in patients who did not have venous compression garment therapy.

Discussion and conclusions: wIRA can alleviate pain considerably (with an impressive decrease of the consumption of analgesics) and accelerate wound healing or improve a stagnating wound healing process and diminish an elevated wound exudation and inflammation both in acute and in chronic wounds (in this study shown in chronic venous stasis ulcers of the lower legs) and in problem wounds including infected wounds. In chronic recalcitrant wounds complete healing is achieved, which was not reached before. Other studies have shown that even without a disturbance of wound healing an acute wound healing process can be improved (e.g. reduced pain) by wIRA. wIRA is a contact-free, easily used and pleasantly felt procedure without consumption of material with a good penetration effect, which is similar to solar heat radiation on the surface of the earth in moderate climatic zones. Wound healing and infection defence (e.g. granulocyte function including antibacterial oxygen radical formation of the granulocytes) are critically dependent on a sufficient energy supply (and on sufficient oxygen). The good clinical effect of wIRA on wounds and also on problem wounds and wound infections can be explained by the improvement of both the energy supply and the oxygen supply (e.g. for the granulocyte function). wIRA causes as a thermal effect in the tissue an improvement in three decisive factors: tissue oxygen partial pressure, tissue temperature and tissue blood flow. Besides this non-thermal effects of infrared-A by direct stimulation of cells and cellular structures with reactions of the cells have also been described. It is concluded that wIRA can be used to improve wound healing, to reduce pain, exudation, and inflammation and to increase quality of life.

Hintergrund: Wassergefiltertes Infrarot A (wIRA) ist eine spezielle Form der Wärmestrahlung mit hoher Gewebepenetration bei geringer thermischer Oberflächenbelastung. wIRA vermag über thermische und nicht-thermische Effekte wesentliche und energetisch bedeutsame Faktoren der Wundheilung zu verbessern.

Ziel der Studie: prospektive Studie (primär randomisiert, kontrolliert, verblindet geplant, de facto mit einer Ausnahme nur eine Kohorte möglich) mit wassergefiltertem Infrarot A (wIRA) in der Therapie von Patienten mit therapierefraktären chronischen venösen Unterschenkel-Ulzera mit thermographischer Verlaufskontrolle.

Methoden: 10 Patienten (5 Männer, 5 Frauen, Median des Alters 62 Jahre) mit 11 therapierefraktären chronischen venösen Unterschenkel-Ulzera wurden mit wassergefiltertem Infrarot A und sichtbarem Licht (wIRA(+VIS), Hydrosun®-Strahler Typ 501, 10 mm Wasserküvette, wassergefiltertes Spektrum 550–1400 nm) oder mit sichtbarem Licht (VIS; nur bei einem Patienten möglich) bestrahlt. Die unbedeckten Wunden der Patienten wurden zwei- bis fünfmal pro Woche über bis zu 2 Monate (typischerweise bis zum Wundschluss oder Fast-Wundschluss des Ulkus) für jeweils 30 Minuten mit einem Standardabstand von 25 cm bestrahlt (ungefähr 140 mW/cm2 wIRA und ungefähr 45 mW/cm2 VIS). Hauptzielvariable war die „prozentuale Änderung der Ulkusgröße über die Zeit“ einschließlich des kompletten Wundschlusses. Zusätzliche Zielvariablen waren thermographische Bildanalyse, Schmerzempfinden des Patienten in der Wunde, Schmerzmittelverbrauch, Einschätzung des Effekts der Bestrahlung (durch Patient und durch klinischen Untersucher), Einschätzung des Patienten des Gefühls im Wundbereich, Einschätzung der Wundheilung durch den klinischen Untersucher sowie Einschätzung des kosmetischen Zustandes (durch Patienten und durch klinischen Untersucher). Für diese Erhebungen wurden visuelle Analogskalen (VAS) verwendet.

Ergebnisse: Die Studie ergab eine vollständige oder fast vollständige Abheilung der Unterschenkel-Ulzera bei 7 Patienten sowie eine deutliche Ulkusverkleinerung bei 2 weiteren der 10 Patienten, eine bemerkenswerte Minderung der Schmerzen und des Schmerzmittelverbrauchs (von z.B. 15 auf 0 Schmerztabletten täglich) und eine Normalisierung des thermographischen Bildes (vor Therapiebeginn typischerweise hyperthermer Ulkusrandwall mit relativ hypothermem Ulkusgrund, bis zu 4,5°C Temperaturdifferenz). Bei einem Patienten wurde ein Ulkus an einem Bein mit dem Vollwirkstrahler (wIRA(+VIS)) therapiert, während ein Ulkus am anderen Bein mit einem Kontrollgruppenstrahler (nur VIS, ohne wIRA) behandelt wurde, was einen deutlichen Unterschied zugunsten der wIRA-Therapie zeigte. Alle aufgeführten VAS-Einschätzungen verbesserten sich während der Bestrahlungstherapie-Periode sehr stark, was einer verbesserten Lebensqualität entsprach. Ein kompletter oder fast kompletter Wundschluss wurde nur bei Patienten mit peripherer arterieller Verschlusskrankheit, Rauchern oder Patienten mit fehlender venöser Kompressionstherapie nicht erreicht.

Diskussion und Schlussfolgerungen: wIRA kann sowohl bei akuten Wunden als auch bei chronischen Wunden (in dieser Studie für chronische venöse Unterschenkelulzera gezeigt) und Problemwunden einschließlich infizierter Wunden Schmerzen deutlich mindern (mit eindrucksvoller Abnahme des Schmerzmittelverbrauchs) und die Wundheilung beschleunigen oder einen stagnierenden Wundheilungsprozess verbessern sowie eine erhöhte Wundsekretion und Entzündung mindern.

Bei chronischen therapierefraktären Wunden werden vollständige Abheilungen erreicht, die zuvor nicht erreicht wurden. Andere Studien haben sogar ohne Wundheilungsstörung eine Verbesserung (z.B. Schmerzreduktion) der akuten Wundheilung durch wIRA gezeigt.

wIRA ist ein kontaktfreies, verbrauchsmaterialfreies, leicht anzuwendendes, als angenehm empfundenes Verfahren mit guter Tiefenwirkung, das der Sonnenwärmestrahlung auf der Erdoberfläche in gemäßigten Klimazonen nachempfunden ist.

Wundheilung und Infektionsabwehr (z.B. Granulozytenfunktion einschließlich antibakterieller Sauerstoffradikalbildung der Granulozyten) hängen ganz entscheidend von einer ausreichenden Energieversorgung (und von ausreichend Sauerstoff) ab. Die gute klinische Wirkung von wIRA auf Wunden und auch auf Problemwunden und Wundinfektionen lässt sich über die Verbesserung sowohl der Energiebereitstellung als auch der Sauerstoffversorgung (z.B. für die Granulozytenfunktion) erklären. wIRA bewirkt als thermischen Effekt im Gewebe eine Verbesserung von drei entscheidenden Faktoren: Sauerstoffpartialdruck im Gewebe, Gewebetemperatur und Gewebedurchblutung. Daneben wurden auch nicht-thermische Effekte von Infrarot A durch direkte Reizsetzung auf Zellen und zelluläre Strukturen mit Reaktionen der Zellen beschrieben.

Es wird geschlossen, dass wIRA verwendet werden kann, um Wundheilung zu verbessern, Schmerzen, Sekretion und Entzündung zu reduzieren und die Lebensqualität zu steigern.

Keywords: chronic venous stasis ulcers of the lower legs; energy supply; infrared thermography; oxygen supply; problem wounds; prospective study; quality of life; reduction of pain; thermographic image analysis; tissue blood flow; tissue oxygen partial pressure; tissue temperature; visual analogue scales (VAS); water-filtered infrared-A (wIRA); wound healing; wound infections.

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Figures

Table 1
Table 1. Overview over patients, ulcer classification, ulcer sizes, treatments, and concomitant problems
Patient number. Age (years). Sex (m = male; f = female). Ulcer classification (v = venous; a = arterial). Ulcer size start (mm2) = size of ulcer before the start of the first treatment with wIRA. Ulcer size end (mm2) = size of ulcer at last treatment. Change in size (%) = relative change in size during the treatment period (– = reduction; + = increase). Number of treatments (n). Total treatment time (days) = time between first and last treatment. Concomitant problems = arterial insufficiency (ai), diabetes (dia) (here: diabetes type II), smoker (smo), lacking compression garment therapy (lcgt). 10R and 10L = patient 10 right (R) and left (L) leg, respectively. 10L: first 13 treatments with control group radiator (VIS only), further treatments with fully active radiator (wIRA(+VIS)). A detailed presentation of all relevant data from each patient – including detailed anamnesis and conventional digital photographic images and digital infrared images (thermograms) – can be found in Appendices 1–10 (one per patient).
Figure 1
Figure 1. Spectrum with spectral irradiation intensity E (mW · cm–2 · (10 nm)–1 = W · m–2 · nm–1) of a wIRA radiator (Hydrosun® 501)
Calculated for Hydrosun® 501 with 10 mm water cuvette and standard orange filter at approximately 185 mW/cm2 (= 1.85 x 103 W/m2) total irradiation intensity (at a distance of 25 cm) with approximately 140 mW/cm2 wIRA and 45 mW/cm2 VIS, from Measurement of University of Applied Sciences Munich, dated June 30, 1999
Figure 2
Figure 2. Experimental set-up for testing a wIRA radiator
The photograph shows a porous rubber mat being heated by a wIRA radiator. The surface temperature of the irradiated porous rubber mat is continuously monitored by the infrared camera.
Figure 3
Figure 3. Position of the wIRA radiator during treatment of a leg ulcer
Figure 4
Figure 4. Example of a visual analogue scale VAS as used for assessment of the variables V3 and V5-V10
Visual analogue scales were presented on paper forms with open bars (100 mm) without scaling with the exception that the end points were marked with number and corresponding verbal statement.
Figure 5
Figure 5. Time course showing surface temperatures of a porous rubber mat before, during and after a 10-minute period during which the mat was irradiated with a wIRA radiator
The coloured lines refer to individual measuring points at different positions across the irradiation field. The position of each respective measurement point is shown in the infrared image. A corresponding thermographic video sequence during this experiment is presented in Attachment 11.
Figure 6
Figure 6. Time course showing surface temperatures of a porous rubber mat before, during and after a 10-minute period during which the mat was irradiated with a control group radiator (= VIS radiator)
The coloured lines refer to individual measuring points at different positions across the irradiation field. The position of the respective measuring point is shown in the infrared image.
Figure 7
Figure 7. Irradiation of a venous stasis ulcer of the lower leg with a wIRA radiator
The period of irradiation was 30 minutes. The infrared (IR) thermogram was taken about half way through the treatment (as indicated by the vertical line in the lower panel; orientation of thermogram: lower foot to the left, heel at the bottom, distal part of the lower leg in the right upper corner.) In the thermogram the position of 6 temperature measuring sites is shown (4 circles and 2 spots: spot 1 was located in the centre of the ulcer and spot 2 was located on the bed-sheets beside the foot). The temperature time course of the highest temperature within each circle and the two spots are presented in the lower panel. The respective colours of the temperature curves in the lower panel refer to the different measuring sites (SP = spot; AR = circle) as shown in the infrared thermogram. The centre of the ulcer presented the lowest “maximum temperature” of all 6 measuring sites, the bed-sheets presented the highest “maximum temperature” of all 6 measuring sites. (Concerning all patients typical skin temperatures during irradiation were 37–39°C, on the ulcer base even below 37°C.) The 30-minute heating period commenced 1 min after time point 0 and ended at the end of minute 31 as can be seen from the temperature traces in the lower panel. A corresponding thermographic video sequence of a 30-minute treatment period of this leg ulcer is presented in Attch. 12 (orientation of images of the video sequence: lower foot to the left, heel at the bottom, distal part of the lower leg in the right upper corner. The circular cool area in the right upper corner is from a circular knob mounted on the end of the distance rod of the radiator. Note that in the thermographic video sequence the highest recorded temperature is on the bed-sheets and not on the ulcer or any part of the skin).
Figure 8
Figure 8. Digital photographic image and thermographic images of a chronic venous stasis ulcer of the lower leg
Top left panel: photograph of leg ulcer in lateral ankle region of left leg (same ulcer as shown in Figure 7). Top right panel: infrared (IR) thermogram of the ulcer. The black line indicates the position of the temperature profile shown in the lower left panel. Lower right panel: thermogram as a false three-dimensional image.
Figure 9
Figure 9. Example of a healing process of a chronic venous stasis ulcer of the lower leg under therapy with wIRA (28 times 30 minutes irradiation with water-filtered infrared-A (wIRA) and visible light (VIS) within 52 days = approximately 7 weeks) with digital photographic image, thermographic image, and temperature profile across the ulcer, in each case to the left before therapy and to the right after completion of the course of therapy.
The arrow and the long arm of the piece of wire in the thermographic image point to the place where the ulcer has been. Diameter of the red circles: 16 mm. (adapted from [14])
Figure 10
Figure 10. Relative ulcer size over time in 10 patients being treated with wIRA
Left panel (A): patients with ulcers without concomitant problems; right panel (B): patients with ulcers with concomitant problems. The vertical line at day zero indicates the start (first day) of wIRA treatment. Patient 10 had 2 ulcers, one on each leg; ulcer on left leg (10L): first 13 treatments with control group radiator (VIS only), further treatments with fully active radiator (wIRA(+VIS)).
Figure 11
Figure 11. Patients’ degree of pain sensation in the wound over time in 10 patients being treated with wIRA
Left panels (A and C): patients with ulcers without concomitant problems; right panels (B and D): patients with ulcers with concomitant problems. The patients made their evaluations immediately prior to (top panels, A and B) and immediately after (bottom panels, C and D) wIRA treatment. Patient 10 had 2 ulcers (one on each leg, see Methods for details).
Figure 12
Figure 12. Amount of non-prescription pain relief tablets taken per patient during previous 24-hour period throughout the time course of wIRA treatment
Left panel (A): patients with ulcers without concomitant problems; right panel (B): patients with ulcers with concomitant problems. In patient 6 the results were most dramatic. Prior to the first treatment this patient was taking up to 15 pain relief tablets daily. During the treatment period the patient was able to reduce her intake to 0.
Figure 13
Figure 13. Effect of wIRA treatment over time in 10 patients being treated with wIRA
Left panels (A and C): patients with ulcers without concomitant problems; right panels (B and D): patients with ulcers with concomitant problems. The evaluations were made by both the patients (panels A and B) as well as the investigators performing the treatment (panels C and D). Patient 10 had 2 ulcers (one on each leg, see Methods for details).
Figure 14
Figure 14. Feeling in the wound area over time of 10 patients being treated with wIRA
Left panel (A): patients with ulcers without concomitant problems; right panel (B): patients with ulcers with concomitant problems. The evaluation was made following the end of each treatment. Patient 10 had 2 ulcers (one on each leg, see Methods for details).
Figure 15
Figure 15. Wound healing over time in 7 ulcers of the patients treated with wIRA
Left panel (A): patients with ulcers without concomitant problems; right panel (B): patients with ulcers with concomitant problems. The evaluation was made following the end of each treatment. Patient 10 had 2 ulcers (one on each leg, see Methods for details).
Figure 16
Figure 16. Cosmetic state prior to first wIRA treatment and after final wIRA treatment
Left panels (A and C): patients with ulcers without concomitant problems; right panels (B and D): patients with ulcers with concomitant problems. The evaluations were made by both the patients (panels A and B) as well as the investigators performing the treatment (panels C and D). The evaluations were made for 8 ulcers of the 10 treated patients.
See this image and copyright information in PMC

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