Volume 50, Issue 3 Fall 2026 JVU 503-bb | Distal-to-Proximal Spectral Doppler Mapping for Rapid Identification of Flow-Limiting Inflow Disease in Patients with Suspected Chronic Limb-Threatening Ischemia (CLTI)-Distal-to-Proximal Spectral Doppler Mapping for Rapid Identification of Flow-Limiting Inflow Disease in Patients With Suspected Chronic Limb-Threatening Ischemia

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

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This technical note proposes a distal-to-proximal spectral Doppler protocol for early screening and triage of patients with suspected chronic limb-threatening ischemia (CLTI), particularly where experienced vascular ultrasound services are not readily available. It is a conceptual approach, not a substitute for comprehensive arterial duplex mapping or definitive diagnosis.<br /><br />The examination begins with a high-frequency linear probe at the dorsalis pedis and posterior tibial arteries; in patients with tissue loss, assessment is directed to the artery supplying the affected wound area. Multiphasic pedal waveforms suggest relatively preserved distal perfusion and may allow the focused examination to stop, although clinical judgment may still warrant further imaging. If any assessed waveform is monophasic, pedal acceleration time (PAT) is measured and the examiner scans sequentially upstream—from the tibial arteries toward the aorta—until multiphasic flow returns or no transition is found. The transition point offers a functional estimate of where pulsatile inflow improves; persistent monophasic flow suggests possible diffuse or multilevel impairment. Abnormal findings should prompt referral for comprehensive vascular evaluation.<br /><br />The rationale is that significant upstream flow limitation is likely to dampen distal pulsatility and delay systolic acceleration. PAT may add useful physiologic information, including when arterial calcification limits other tests, but its thresholds are not standardized.<br /><br />The strategy could provide a rapid initial assessment, support earlier referral, and help focus further imaging. However, it is operator-dependent, and distal waveforms can also be affected by local factors such as microvascular disease, edema, and infection. The protocol has not been prospectively validated; its accuracy, reproducibility, efficiency, and effects on patient outcomes require study.

Keywords

chronic limb-threatening ischemia

spectral Doppler

distal-to-proximal protocol

pedal waveforms

posterior tibial artery

dorsalis pedis artery

pedal acceleration time

multiphasic flow

vascular ultrasound

arterial duplex mapping