Distal-to-Proximal Spectral Doppler Mapping for Rapid Identification of Flow-Limiting Inflow Disease in Patients With Suspected Chronic Limb-Threatening Ischemia

Chronic limb-threatening ischemia requires timely physiologic assessment of limb perfusion, yet access to comprehensive vascular ultrasound may be limited in many clinical settings. In this context, we propose a distal-first spectral Doppler approach with selective proximal extension as a conceptual framework for focused physiologic assessment when full arterial duplex mapping by experienced examiners is not readily available. The aim is to support early screening and triage within the diagnostic pathway, not to replace standard comprehensive (proximal-to-distal) mapping. The approach is based on the principle that preserved multiphasic distal arterial waveforms are unlikely in the presence of hemodynamically significant proximal inflow impairment. The protocol begins with distal waveform assessment and extends proximally only when findings suggest hemodynamic compromise. The article outlines the physiologic rationale and provides a stepwise description of the protocol, including acquisition, interpretation, and reporting elements.