Efficacy of FLOW 800 with indocyanine green videoangiography for the quantitative assessment of flow dynamics in cerebral arteriovenous malformation surgery

Objective To evaluate the quantitative assessment of flow dynamics during surgery for arteriovenous malformations (AVMs) with FLOW 800 with indocyanine green videoangiography. Methods Changes in flow dynamics in the superficial AVM components (feeder, nidus, and drainer), the adjacent cortical artery, and the cortical vein surrounding AVM were evaluated. Analysis was performed at predissection, postclipping of the feeders, and postresection of the nidus with the use of quantitative values of the maximum fluorescence intensity, time to half-maximum fluorescence intensity (T_1/2 FI), and the fluorescence intensity rate at T_1/2 FI semiautomatically obtained with the use of FLOW 800 software. Results FLOW 800 assessments were performed in 7 cases. The time difference between the T_1/2 FI, defined as transit time, in the cortical artery and the drainer was prolonged from 0.08 ± 0.65 seconds to 2.63 ± 1.79 seconds (P < 0.0001) at postfeeder clipping phase. The transit time between the cortical artery and the cortical vein was reduced to 3.76 ± 1.37 seconds at post feeder clipping phase (P = 0.024) and 2.63 ± 0.80 seconds at final phase (P = 0.005) compared with 4.56 ± 1.47 seconds at predissection phase. The maximum intensity and the fluorescence intensity rate at T_1/2 FI were not significantly different at these phases, excluding the maximum intensity of the drainer decreasing from 533 ± 271 to 399 ± 217 (P = 0.006) at post feeder clipping phase. Conclusion FLOW 800 analysis with indocyanine green videoangiography provides the real-time hemodynamic status of the AVMs and adjacent brain at various stages of resection. This technique is feasible to resect AVMs more safely and convincingly.