gms | German Medical Science

Objective: Indocyanine green (ICG) videoangiography aids in the intraoperative characterization of flow dynamics in visible parts of an arteriovenous malformation (AVM). Complete nidus resection should eliminate all demonstrable shunts. We present our observations in a patient with an eloquently located AVM with persistent early filling of veins draining the surrounding parenchyma despite microsurgical complete resection of the angioma and discuss implications for intra-operative decision-making.

Method: A 16-year-old right-handed man presenting with refractory seizures underwent microsurgical resection of a Spetzler-Martin Grade II AVM in the dominant gyrus supramarinalis. Imaging included preoperative and postoperative digital subtraction angiography and MRI. Intraoperative ICG videoangiography using ICG Pulsion^® 5mg/ml and Zeiss OPMI^® Pentero^® equipped with Infrared 800^® flourescence module was used throughout the resection. The video clip of the ICG angiography will be presented.

Results: After completion of nidus resection, the surrounding parenchyma showed signs of mild hyperemia. ICG angiography confirmed the absence of residual pathological vessel structures within the angioma cavity, but from the surrounding parenchyma small early filling vessels entered the major vein draining the area. Under visible light, this vein did not correspond to a perfect “blue vein”. The small shunting vessels as well as parts of the major vein were cauterized despite originating from probably eloquent cortex. Postoperatively, the patient showed a temporary dysphasia that resolved completely within two weeks. Conventional angiography did not show any residual pathological vessel.

Conclusions: The significance of early-filling draining veins despite complete resection of an AVM nidus as well as the best strategy to deal with such a situation in an eloquent area is, to our knowledge, unknown. The filling of these veins might be (a) a hint to a remnant of the AVM, (b) a temporary phenomenon related to perinidal hyperemia, or (c) a hitherto unknown phenomenon in AVM patients (presenting with seizures). Elimination of these veins might be necessary to cure the patient but can also inflict additional neurological damage.