Ultrasound-Mediated Oxygen Delivery to Lower Extremity Wounds

Critical limb ischemia (CLI), an end result of peripheral arterial disease, remains a major clinical challenge. Wound healing in patients with CLI can be difficult due to diminished tissue oxygenation, often leading to recalcitrant ulcers and frequent limb loss. Numerous therapies, including hyperbaric oxygen therapy (HBOT), have been used to correct this regional ischemia, although often with mixed results. This case series investigates the effects of oxygen therapy delivery augmented by low-frequency ultrasound, a device that combines surface acoustic waveform (SAW) low-frequency ultrasound with hyper-oxygenated saline to deliver oxygen to wounds. Participants included 7 patients (7 men, median age 63 years, all with hypertension) with CLI and full-thickness wounds. Baseline therapy PaO2 measurements were taken before therapy, after provision of hyper-oxygenated saline, and after sonification. The device was found to successfully oxygenate the wound beds; PaO2 levels increased by a median of 59.7%, a maximum of 116%, and a median absolute difference peaking at 10.8 mmHg PaO2 (P = 0.018). In conclusion, the treatment increases wound oxygen levels and may be an option in CLI therapy.