DFU: Advancing Practice

With the increasing burden of the disease of diabetes, we are seeing more methods develop to treat diabetic foot ulcers (DFU). At our presentation at SAWC Virtual, we evaluated the potential of several emerging treatments, such as point of care bacteria fluorescence, ultraviolet light, negative pressure wound therapy (NPWT) with irrigation, topical oxygen therapy, hyperspectral imaging, and laser therapy. 

A 2019 study of 19 patients (17 with venous leg ulcers and two with DFUs) found real-time bacterial fluorescence imaging can accurately identify wounds with a moderate-to-heavy bacterial burden.¹ An analysis of qPCR found 95% of patients were positive for moderate-to-heavy bacterial loads (≥10⁴ CFU/g), while only 21% of patients were identified as positive based on clinical signs and symptoms. 

As for ultraviolet light, one randomized controlled trial evaluated the use of a C-100 ultraviolet C (UV-C) treatment lamp on 40 patients with venous stasis ulcers.² Patients received light therapy for 30 minutes 3 times a week for 6 weeks. Researchers noted complete wound healing was faster in the light treatment group compared to controls (18 vs. 42 days), and that patients who did not heal had significantly smaller wounds (area 0.4 cm² vs 2.8 cm²). 

Does NPWT with irrigation improve clinical outcomes? Three studies compare NPWT with irrigation to traditional NPWT.^3–5 Researchers found no difference in clinical outcomes, such as wound healing, time to heal, adverse events like infection, and serious adverse events like hospitalization for infection. 

Topical oxygen aims to provide a local increase of oxygen at the wound site, on the theory that topical oxygen increases the local concentration of oxygen at the wound bed by increasing the solubility and dissolution of oxygen through an increase in oxygen partial pressure. However, the mechanism is still unclear. There are several novel devices that deliver topical oxygen. Several randomized controlled trials have found topical oxygen to be successful for DFUs.^6–8 

Medical hyperspectral technology (HT) provides a novel diagnostic tool that quantifies tissue oxygenation and presents it in an anatomically relevant map. HT quantifies tissue oxy- and deoxyhemoglobin to predict diabetic foot ulcer healing. 

A recent study evaluated the yttrium aluminum garnet (YAG) laser’s potential to improve wound healing in 22 DFUs that failed to heal with standard of care. Eighteen patients received treatment with a 2,940-nm laser and found positive results after 12 weeks.

To access the SAWC Virtual session, “DFU: Advancing Practice,” click here.     

Kathryn E. Davis, PhD, is an Associate Professor in the Department of Plastic Surgery and the Director of Diabetic Limb Salvage Fellowship at the University of Texas Southwestern Medical Center in Dallas. 

Lawrence A. Lavery, DPM, MPH, is a Professor in the Department of Plastic Surgery and the Director of Diabetic Limb Salvage Fellowship at the University of Texas Southwestern Medical Center in Dallas. 
 

References
 

1. Serena TE, Harrell K, Serena L, Yaakov RA. Real-time bacterial fluorescence imaging accurately identifies wounds with moderate-to-heavy bacterial burden. J Wound Care. 2019;28(6).

2. Mercer JB, Nielsen SP, Hoffmann G. 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. Ger Med Sci. 2008;6:11.

3. Davis KE, La Fontaine J, Farrar D, et al. Randomized clinical study to compare negative pressure wound therapy with simultaneous saline irrigation and traditional negative pressure wound therapy for complex foot infections. Wound Repair Regen. 2020;28(1):97-104.

4. Lavery LA, Davis KE, La Fontaine J, et al. Does negative pressure wound therapy with irrigation improve clinical outcomes? A randomized clinical trial in patients with diabetic foot infections. Am J Surg. 2020; epub Feb. 27.

5. Kim PJ, Lavery LA, Galiano RD, et al. The impact of negative-pressure wound therapy with instillation on wounds requiring operative debridement: Pilot randomised, controlled trial. Int Wound J. 2020; epub June 21.

6. Fries RB, Wallace WA, Roy S, et al. Dermal excision wound healing in pigs following treatment with topically applied pure oxygen. Mutat Res. 2005;579(1–2):172-181.

7. Gordillo GM, Roy S, Khanna S, et al. Topical oxygen therapy induces vascular endothelial growth factor expression and improves closure of clinically presented chronic wounds. Clinical Exp Pharmacol Physiol. 2008;35(8):957-964.

8. Gordillo GM Sen CK. Evidence-based recommendations for the use of topical oxygen therapy in the treatment of lower extremity wounds. J Low Extrem Wounds. 2009;8(2):105-111.

9. Johnson M, Crisologo PA, Truong DH, et al. Erbium: yttrium aluminum garnet laser accelerates healing in indolent diabetic foot ulcers. J Foot Ankle Surg. 2019;58(6):1077-1080.