Application of Intraoperative FLOW 800 Indocyanine Green Videoangiography Color-Coded Maps for Microsurgical Clipping of Intracranial Aneurysms.

OBJECTIVE

Indocyanine green (ICG) videoangiography (VAG) is an established method for assessment of cerebral blood flow during microsurgical clipping of intracranial aneurysms. FLOW 800 is a surgical microscope-integrated software program that shows the cerebral blood flow in color-coded maps, thus providing semi-quantitative and real-time analysis of ICG data. We aimed to establish reference values for FLOW 800 parameters before and after microsurgical clipping of intracranial aneurysms and to evaluate the potential of FLOW 800 to guide intraoperative decisions.

METHODS

We retrospectively reviewed 54 patients (mean age, 53.6 ± 11.6 years) who underwent microsurgical clipping for 60 aneurysms and intraoperative evaluation of ICG fluorescence dynamics using FLOW 800 color-coded maps. FLOW 800 data were correlated with patient characteristics, clinical outcomes, and intraoperative decision making.

RESULTS

There were no significant differences in FLOW 800 data between ruptured and unruptured aneurysms (P > 0.05). Likewise, the hemodynamic parameters were not significantly different before and after definite clip placement (P > 0.05). However, in 2 cases, analysis of transit times by FLOW 800 analysis showed a hemodynamically significant clip stenosis that might have been missed by conventional ICG-VAG and resulted in adjustment of the clip position. Overall, there was 1 cerebral infarction, which was not related to clip placement.

CONCLUSIONS

FLOW 800 is a useful adjunct to ICG-VAG for intraoperative assessment of cerebral perfusion and may help to identify hemodynamically relevant clip stenosis. The beneficial impact of FLOW 800 on clinical outcome after microsurgical clipping needs to be confirmed by comparative studies.