Impact of vascular flow reserve and below-knee runoff on tissue perfusion after lower extremity endovascular therapy
R Akashi, T Muroya, K Furukawa, T Honda, S Ikeda, H Kawano, K MaemuraAbstract
Background
The physiological determinants of peripheral blood flow after endovascular therapy (EVT) for lower extremity artery disease (LEAD) remain incompletely understood. Below-knee (BK) runoff reflects distal inflow status, whereas vascular flow reserve (VFR) measured at the popliteal artery reflects microcirculatory function. However, the relationship between these parameters and post-EVT tissue perfusion assessed by skin perfusion pressure (SPP) remains unclear.
Methods
Fifty-seven consecutive patients who underwent EVT of the femoropopliteal artery were prospectively enrolled. Concomitant BK intervention was performed in patients with chronic limb-threatening ischemia (CLTI). BK runoff was evaluated, and VFR and fractional flow reserve (FFR) were measured in the popliteal artery immediately after EVT. Post-EVT SPP was assessed during hospitalization. Associations between clinical or physiological variables and low post-EVT SPP (<40 mmHg), defined as impaired lower leg tissue perfusion, were evaluated using logistic regression analyses.
Results
Univariate analysis identified VFR (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.12–0.88; p=0.017), hemoglobin (OR, 0.52; 95% CI, 0.26–0.90; p=0.019), absence of BK runoff (OR, 27.5; 95% CI, 4.5–245; p=0.0003), diabetes (p<0.0001), and CLTI (OR, 7.5; 95% CI, 1.41–57.3; p=0.017) as associated with low post-EVT SPP. In multivariate analysis including BK runoff and VFR, absence of BK runoff was an independent predictor of low post-EVT SPP (OR 28.1, 95% CI 3.3–395; p=0.002), whereas VFR was not.
Conclusions
VFR was associated with impaired tissue perfusion after EVT; however, distal inflow status represented by BK runoff was the dominant determinant. These findings suggest that optimization of distal runoff may be essential to achieve adequate tissue perfusion after femoropopliteal EVT.