Hyperbaric Oxygen Therapy in Management of Diabetic Foot Ulcers: Indocyanine Green Angiography May Be Used as a Biomarker to Analyze Perfusion and Predict Response to Treatment.

SUMMARY: The authors present indocyanine green angiography to assess the effects of hyperbaric oxygen therapy and as a potential biomarker to predict healing of chronic wounds. They hypothesize that favorable initial response to hyperbaric oxygen therapy (improved perfusion) would be an early indicator of eventual response to the treatment (wound healing). Two groups were recruited: patients with chronic wounds and unwounded healthy controls. Inclusion criteria included adults with only one active wound of Wagner grade III diabetic foot ulcer or caused by soft-tissue radionecrosis. Patients with chronic wounds underwent 30 to 40 consecutive hyperbaric oxygen therapy sessions, once per day, 5 days per week; controls underwent two consecutive sessions. Indocyanine green angiography was performed before and after the sessions, and perfusion patterns were analyzed. Healing was determined clinically and defined as full skin epithelialization with no clinical evidence of wound drainage. Fourteen chronic-wound patients and 10 controls were enrolled. Unlike unwounded healthy volunteers, a significant increase in indocyanine green angiography perfusion was found in chronic-wound patients immediately after therapy (p < 0.03). Moreover, the authors found that 100 percent of the wounds that demonstrated improved perfusion from session 1 to session 2 went on to heal within 30 days of hyperbaric oxygen therapy completion, compared with none in the subgroup that did not demonstrate improved perfusion (p < 0.01). This study demonstrates a beneficial impact of hyperbaric oxygen therapy on perfusion in chronic wounds by ameliorating hypoxia and improving angiogenesis, and also proposes a potential role for indocyanine green angiography in early identification of those who would benefit the most from hyperbaric oxygen therapy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Hyperbaric Oxygen Therapy: Descriptive Review of the Technology and Current Application in Chronic Wounds.

Hyperbaric oxygen therapy (HBOT) serves as "primary" or "adjunctive" therapy in a wide range of pathologies. It is considered the mainstay of management for potentially life-threatening conditions such as carbon monoxide poisoning, decompression illness, and gas embolisms. Moreover, HBOT has been utilized for decades as an adjunctive therapy in a variety of medical disciplines, including chronic wounds, which affect approximately 6.5 million Americans annually. In general, chronic wounds are characterized by hypoxia, impaired angiogenesis, and prolonged inflammation, all of which may theoretically be ameliorated by HBOT. Nonetheless, the cellular, biochemical, and physiological mechanisms by which HBOT achieves beneficial results in chronic wounds are not fully understood, and there remains significant skepticism regarding its efficacy. This review article provides a comprehensive overview of HBOT, and discusses its history, mechanisms of action, and its implications in management of chronic wounds. In particular, we discuss the current evidence regarding the use of HBOT in diabetic foot ulcers, while digging deeply into the roots of controversy surrounding its efficacy. We discuss how the paucity of high-quality research is a tremendous challenge, and offer future direction to address existing obstacles.