Combined Treatment With Hyperbaric Oxygen Therapy and Endovascular Therapy for Patients With Chronic Limb-Threatening Ischemia　― Study Protocol for the HOTFOOT Multicenter Randomized Controlled Trial ―

Background: Hyperbaric oxygen therapy (HBOT) is regarded as one of the therapeutic options added to standard care to improve lower-limb outcomes in patients with chronic limb-threatening ischemia (CLTI). However, the current guidelines specify that HBOT should not be offered instead of revascularization to prevent limb loss in CLTI patients. The aim of the HOTFOOT study is to examine the impact of HBOT on wound healing in CLTI patients after successful endovascular therapy (EVT). Methods and Results: The HOTFOOT study is a multicenter prospective randomized open blinded-endpoint trial that is to be conducted at 10 trial centers in Japan between February 2021 and February 2022. This study will enroll 140 patients with CLTI receiving successful EVT. Eligible participants will be allocated 1 : 1 to either the EVT+HBOT or EVT group; participants in the EVT+HBOT group will receive 30 HBOT sessions. The primary outcome is the time to complete wound healing over the 6-month follow-up. Secondary outcomes during the 6-month follow-up are the proportion of patients who achieved complete wound healing, freedom from major lower-limb amputation, amputation-free survival, and freedom from target lesion reintervention. Conclusions: This study is expects to assess whether HBOT, in combination with successful EVT, can improve lower-limb outcomes in CLTI patients.