Microcirculatory perfusion pulsatility in foot sole skin is a marker of treatment response in chronic limb-threatening ischemia.

The aim of this study was to evaluate microcirculatory perfusion and oxygen saturation in the foot sole of patients with chronic limb-threatening ischemia (CLTI) before and after endovascular intervention using a novel multimodal imaging system. This single-center observational cohort study included patients with CLTI due to infrainguinal arterial disease, scheduled for endovascular intervention over an 11-mo period. Inclusion required a CLTI diagnosis and at least one of the following: hemodynamic transcutaneous partial pressure of oxygen (TcPo2) <30 mmHg, toe pressure (TP) <30 mmHg, ankle-brachial index (ABI) <0.4, or ankle pressure <50 mmHg. For patients with diabetes, the TP threshold was adjusted to <50 mmHg. Measurements were performed preoperatively, early postoperatively, and at 1-mo follow-up using a multimodal optical system combining multi-exposure laser speckle contrast imaging and multispectral imaging to assess real-time microvascular perfusion and oxygen saturation. Conventional measures (toe pressure, TcPo2, and ABI) were used for comparison. Twenty-five patients were included: 20 successfully revascularized and 5 serving as a comparison group. Early postoperative results in the revascularized group showed significant increases in TcPo2 (P = 0.004) and-in the combined region of interest-microcirculatory median perfusion (P = 0.004), perfusion pulsatility (P < 0.001), and oxygen saturation (P = 0.01). At 1 mo, TcPo2 (P = 0.006), TP (P = 0.002), and perfusion pulsatility (P = 0.002) remained significantly elevated, whereas median perfusion (P = 0.642) and oxygen saturation (P = 0.397) returned to baseline levels. No significant changes were observed in the comparison group. The multimodal imaging system detected early microcirculatory improvements after endovascular intervention. Although perfusion and oxygen saturation average levels increased early but transiently, sustained increases in perfusion pulsatility suggest it being a marker of improved and lasting microvascular recovery.NEW & NOTEWORTHY This study presents a novel multimodal imaging system for real-time assessment of microvascular perfusion and oxygen saturation. In 25 patients with chronic limb-threatening ischemia, significant microcirculatory improvements were observed 1 day after endovascular intervention that persisted at 1 mo. Perfusion pulsatility in foot sole skin may serve as an early indicator of sustained microvascular recovery and could complement existing clinical and hemodynamic markers when evaluating treatment response.