Invasive Physiological Assessment of Lower Limb Peripheral Arterial Disease: A Narrative Review.

Peripheral arterial disease (PAD) affects over 236 million people globally, with endovascular treatment as the predominant mode of revascularization. While pre-procedural lesion assessment typically relies on non-invasive Doppler measurement, invasive physiological assessment offers a promising approach to guide lesion selection and provide real-time evaluation of angioplasty success. This review explores the current methods, challenges, and future directions of invasive physiological assessment in PAD. Sensor-tipped wires, particularly pressure sensor-tipped wires (pressure-wires), enable precise evaluation of stenoses through indices such as peripheral fractional flow reserve (pFFR) measured during hyperaemia. pFFR can identify significant flow-limiting lesions, assess angioplasty efficacy, and predict tissue healing. Additional indices, including Doppler-wire derived flow reserves and resistance measurements, further enhance the understanding of lesion physiology. Early data support the utility of these techniques for guiding treatment decisions, although the variability in methodologies highlights the need for standardization and outcome-driven cut-off values. This review uniquely consolidates evidence on invasive physiological assessment in PAD, addressing critical gaps and providing a framework for future research. By advancing lesion-specific evaluation and procedural optimization, this work underscores the transformative potential of these techniques in improving patient outcomes and redefining PAD management.