Purpose: To investigate whether Doppler ultrasound (DUS) blood flow parameters could serve as quantifiable functional endpoints of peripheral endovascular arterial procedures for chronic limb-threatening ischemia (CLTI), influencing wound healing.
Methods: This is a prospective single-center study investigating intraprocedural DUS parameters (pulsatility index [PI] and pedal acceleration time [PAT]) in quantifying immediate hemodynamic alterations in consecutive CLTI patients with wound, ischemia, and foot infection wound class ≥1 undergoing endovascular interventions. Primary endpoints were feasibility of preendovascular and postendovascular treatment measurements of PI/PAT, quantification of immediate PI/PAT modifications of the posterior and anterior foot circulation following revascularization, the correlation between PI and PAT, and 6-month complete wound healing. Secondary endpoints included the 6-month limb salvage (no major amputation) and complete and partial wound healing rates.
Results: A total of 28 patients (75.0% male) were enrolled, and 68 vessels were treated. The overall mean PAT values significantly decreased from 154.15±70.35 ms preprocedural to 107.21±49.6 ms postprocedural (p<0.01), and the mean PI values significantly increased from 0.93±0.99 to 1.92±1.96 (p<0.01). Postprocedural PAT at the anterior tibial (r2=0.804; p=0.346) and the posterior tibial arteries (r2=0.784; p=0.322) had a strong correlation and postprocedural PI at the anterior tibial (r2=0.704; p=0.301) and the posterior tibial arteries (r2=0.707; p=0.369) had a good correlation with 6-month complete wound healing. The 6-month complete and partial wound healing rates were 38.1% and 47.6%, respectively. Limb salvage was 96.4% and 92.4% at 6 and 12 months of follow-up, respectively.
Conclusions: Pedal acceleration time and PI accurately detected immediate hemodynamic changes of foot perfusion following revascularization and could serve as prognostic factors of wound healing in patients with CLTI.
Clinical impact: Intraprocedural measurement of simple Doppler ultrasound blood flow parameters, Pulsatility Index (PI) and Pedal Acceleration Time (PAT), accurately detected immediate hemodynamic changes of foot perfusion following endovascular revascularization and could therefore serve as intraprocedural prognostic factors of wound healing in patients with chronic limb-threatening ischemia. This is the first time that PI has been proposed as a hemodynamic index of successful angioplasty outcome. The optimization of intraprocedural PAT and PI could be used to guide angioplasty and predict clinical success.
Keywords: Doppler ultrasound; chronic limb-threatening ischemia; endovascular treatment; pedal acceleration time; peripheral arterial procedures; pulsatility index; wound healing.