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-centre observational cohort study included patients with CLTI due to infrainguinal arterial disease, scheduled for endovascular intervention over an 11-month period. Inclusion required a CLTI diagnosis and at least one of: hemodynamic transcutaneous partial pressure of oxygen (TcPO 2 ) <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-month 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, ABI) were used for comparison. Twenty-five patients were included: 20 successfully revascularized and five 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 month, 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. While 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.
Aronsson et al. (Tue,) studied this question.