gms | German Medical Science

Objective: Microsurgical resection of cerebral arteriovenous malformations (AVMs) requires a distinct understanding of the anatomic relations and angioarchitecture of these lesions. This may usually be obtained preoperatively from catheter angiography (CA) and magnetic resonance imaging (MRI). We investigated the potential of the FLOW 800 software after indocyanine green (ICG)-angiography, obtained by a new robotic visualization system, as an intraoperative real-time tool to visualize the superficial angioarchitecture and flow dynamics of AVM-related vessels, thus guiding to safe and complete AVM resection.

Methods: A cohort of 5 patients who underwent surgical resection of intracranial AVM was studied. ICG-angiography was performed using a novel intraoperative robotic visualization system. In contrast to previously applied microscopes this allows real-time color-coded visualization and quantitative analysis of flow dynamics intraoperatively. ICG-angiography was principally performed at 3 stages: prior to resection (primary assessment), after clipping of feeding arteries (progress analysis), and at the end of resection (terminal assessment). FLOW 800-specific hemodynamic parameters were analyzed and visualized with regard to transit times to differentiate between arterial, early venous, capillary, and venous phases. Intraoperative results were correlated to postoperative catheter angiography.

Results: 15 ICG-angiographies and FLOW 800 analyses were performed in 5 operative procedures. In all cases color-coded visualization as well as quantitative hemodynamic parameters were excellent to analyze arterial, early venous, capillary, and venous phases. The primary assessment provided orientation with regard to the location of the nidus as well as differentiation between terminal and en passant feeders. Progress analyses provided useful information with regard to the localization of en passant feeders, integrity of adjacent arteries, and location of AVM compartments. Terminal assessment allowed for detection or exclusion of a residual flow by assessing filling of the major draining vein. Intraoperative analyses after AVM resection correlated well with the postoperative catheter angiography.

Conclusion: Our data highlight that the FLOW 800-specific hemodynamic parameters may be easily and rapidly derived from intraoperative ICG-angiography and constitute a simple and safe real-time intraoperative tool to guide AVM surgery and lower the risk of periprocedural complications and AVM residuals.