gms | German Medical Science

Objective: Sufficient perfusion is crucial during and after vascular neurosurgical procedures. Thus intraoperative ICG-angiography is a fundamental tool in aneurysm and arterio-venous-malformation surgery. Dynamic ICG fluorescence analysis “flow800”^® leads to a better understanding of local perfusion. We report surgical treatment of three patients with arterio-venous fistulas using dynamic ICG fluorescence.

Method: Three patients with arterio-venous fistulas (complex arterio-venous fistulas at the left and right side at the sinus sagittalis superior in one patient as well as two occipital pial arterio-venous fistulas) were operated using intraoperative dynamic ICG fluorescence “flow 800”^® (5mg ICG bolus via central venous line). Before and after treatment of fistulas the following parameters were detected in the draining vein: maximum, minimum and median intensity in arbitrary intensity units (AI). Parameters are given as mean. Wilcoxon test for dependent variables was performed.

Results: Analysing several venous flow parameters uncovered a significant change of flow dynamics in the draining vein. Maximum, mean and minimum fluorescence intensity was 1199.51 AI, 221.1 AI and 4.84 AI before vs. 629.36 AI, 230.80 AI and 14.71 AI after treatment. In all but one fistula (p=0.649) significant changes of mean fluorescence intensity were achieved by operative treatment (p<0.016, p<0.0001, p<0.0001). Parenchymatic fluorescence intensity was significantly different pre- vs. postoperatively in three cases (p<0.0001) vs. one fistula (p=0.598).

Conclusions: In all three patients dynamic analysis of fluorescence revealed a better understanding of the intravascular rheology intraoperatively. In addition to conventional angiography and the intraoperative ICG-angiography, application of dynamic ICG- fluorescence provides additional information about flow velocity in the draining vein and parenchymatic tissue, which may facilitate surgical treatment of complex arterio-venous fistulas.