Evaluation of graft anastomosis using time-intensity curves and quantitative near-infrared fluorescence angiography during peripheral arterial bypass grafting.

Near-infrared fluorescence angiography (NIR) visualizes blood perfusion using the fluorescence property of indocyanine green (ICG). This study aimed to retrospectively determine the usefulness of a quantitative analysis using NIR to predict the patency of peripheral arterial bypass grafts by measuring their fluorescence luminance intensities (FLIs).Thirteen grafts in 11 patients who underwent peripheral arterial bypass grafting were divided into a patent graft group (n = 7) and a failed graft group (n = 6). The changes in the FLIs of ICG opacification through the graft and distal host artery were retrospectively analyzed using stored NIR data. The time-intensity curves (TICs) of ICG opacification through the graft (Qgraft) and distal host artery (Qdistal) were measured. Two parameters, Δ(Qgraft - Qdistal) and integral(Qgraft - Qdistal), were also analyzed.Although not significant, decreases in Qgraft were observed in the failed graft groups. The Qdistal of the failed graft group was significantly attenuated as compared with that of the patent graft group. Δ(Qgraft - Qdistal) increased only in the failed graft group, which indicates widening of the gap in FLI. Integral(Qgraft - Qdistal) was higher in the failed graft group, as it reflects the accumulation of ICG opacification.The TICs were influenced by anastomotic stenosis in the distal site of the host arteries. Our results indicate that the comparison of Δ(Qgraft - Qdistal) and integral (Qgraft - Qdistal) quantitatively analyzed using NIR can potentially predict anastomotic stenosis.