The combination of pressurised topical oxygen therapy and non-contact cyclical compression addresses a trifecta of hypoxia, inflammation and lymphatic dysfunction in chronic wounds, showing promise as an adjunctive therapy to “accelerate healing, enhance clinical outcomes, reduce complications and achieve durable closure in difficult wounds of varied aetiologies”.
This is according to a special communication published in the January issue of the Journal of Vascular Surgery: Venous and Lymphatic Disorders (JVS-VL). Authors of the paper, led by Joann M Lohr (William Jennings Bryan Dorn VA Medical Center, Columbia, USA), carried out a comprehensive review of the mechanistic, translational and clinical evidence—including randomized controlled trials (RCTs) and cohort studies—behind the “integrative approach” of multimodality intermittent topical oxygen therapy.
“Chronic wounds persist due to a self-perpetuating cycle of tissue hypoxia, edema, persistent inflammation, and lymphatic dysfunction, exacerbated by ischaemia/reperfusion injury, bioburden, tissue fibrosis, and comorbidities,” Lohr et al write in JVS-VL. “Interventions that concurrently address multiple drivers of wound chronicity hold significant therapeutic potential.”
Alone, topical oxygen “increases tissue oxygen tension, enhances microbial defence, and promotes inflammation resolution and through redox signaling and [specialised pro-resolving mediators] synthesis”, they explain. “During tissue repair, [topical oxygen therapy] supports angiogenesis and optimal collagen synthesis, crosslinking and [extracellular matrix] remodeling, leading to stronger tissue tensile strength and more durable wound healing.”
Cyclical compression, meanwhile, “improves lymphatic clearance of inflammatory mediators, reduces oedema, restores perfusion, mitigates ischaemia/reperfusion injury, and activates mechanotransductive pathways supporting inflammation resolution, angiogenesis and tissue repair”.
Together, they combine to “increase the partial pressure of oxygen available to wound tissue and exert synergistic effects across multiple wound repair mechanisms”, the authors outline.
They draw on several studies that point to “the benefits” of a cyclical pressure and topical oxygen therapy multimodality approach as an adjunct to current best practice standard wound care.
Lohr et al cite a double-blinded RCT of intermittent topical oxygen therapy in diabetic foot ulcers (DFUs) published in Diabetes Care in 2020, from Robert G Frykberg (Glendale, USA) and colleagues, that demonstrated a 41.7% closure rate at 12 weeks versus 13.5% in the control group (p=0.004); a 56% closure rate at 12 months post-enrolment versus 27% in the control (p=0.013); and a 6.7% recurrence rate at 12 months versus 40% in the control (p=0.070).
The authors also point to a 132-patient prospective controlled study published in Vascular and Endovascular Surgery in 2012 from Wael A Twafick (Galway, Ireland) et al, which compared intermittent topical oxygen therapy with conventional compression dressings in the management of nonhealing venous leg ulcers (VLUs) present for more than two years. Data showed a healing rate of 76% versus 46% (p<0.0001), a median time to closure of 57 versus 107 days (P < .0001), and a healed wound recurrence rate of 6% (3 of 51) versus 47% (14 of 30) at 36 months for patients treated with topical oxygen and compression dressings, respectively (p<0.0001).
The study authorship included Melodie M Blakely (Oceanside, USA), a clinical investigator for AOTI, the company behind the Topical Wound Oxygen (TWO2) technology.
