Photoacoustic imaging of real-time oxygen changes in chronic leg ulcers after topical application of a haemoglobin spray: a pilot study.

OBJECTIVE To use a non-invasive measurement of oxygen saturation in chronic leg ulcers after the application of a topical haemoglobin spray to investigate if photoacoustic tomography is able to measure the oxygen saturation and if the stimulated oxygen increase can be demonstrated. METHOD We measured the oxygen saturation of the ulcer tissue in five patients with chronic leg ulcers before application and 5 and 20 minutes after application of the haemoglobin spray, using photoacoustic tomography as a new method to assess oxygenation in real-time. RESULTS The average oxygen saturation showed a significant increase from 56.4% before to 69% (p=0.042) after 5 minutes and 78.8% (p=0.043) 20 minutes after the topical haemoglobin application. CONCLUSION The oxygenation status of chronic, hard-to-heal wounds is gaining increasing interest in modern wound therapy. Topical haemoglobin spray is a new and effective method to increase the oxygenation in the ulcer tissue, but until now the link between clinical results and the mode of action was unclear. We were able to show for the first time that the use of a topical haemoglobin spray leads to an increase in oxygen saturation in vivo using photoacoustic tomography. DECLARATION OF INTEREST Joachim Dissemond received financial support from the company SastoMed for several scientific projects as well as for lectures and as an advisor. The haemoglobin spray was provided by SastoMed GmbH (Georgsmarienhütte, Germany).