Introduction: The potential utility of intraoperative indocyanine green(ICG)fluorescnence angiography and intraoperative digital subtraction angiography in the evaluation of completeness of brain arteriovenous malformation(AVM) resection is debatable. Post-operative angiogram is considered the gold standard. We evaluated the value of ICG and intra-operative angiography in this setting.
Methods: Between March 2010 to March 2013, 32 patients with brain AVM underwent surgical resection. ICG videoangiography and intraoperative angiogram was performed in all cases and a routine post-operative angiogram was performed within 24-48 hours after surgery.
The ability to confirm total resection and to identify residual nidus or persistent shunt was assessed based on ICG angiographic findings and compared to intra-operative and post-operative imaging.
Results: There were 18 grade A, 11 grade B and 3 grade C modified Spetzler classification AVM. ICG angiography helped to distinguish AVM vessels in 25 patients. In 31 patients, it demonstrated that there is no residual shunting. In one patients, a residual AVM was identified, and further resected. Intra-operative angiogram detected 2 additional small residuals that were missed by ICG angiography, both deep in the surgical cavity. One was grade B and the other grade C. Further resection of the AVM was performed and total resection was confirmed by repeat intra-operative angiogram.
Post-operative angiogram in a patient with grade C lesion, revealed one additional small deep residual AVM nidus with persistent late shunting missed on both ICG and intra-operative angiography. Overall ICG angiography missed 3 out of 4(75%) residual AVM after initial resection, while intra-operative angiogram missed 1(25%).
Conclusions: Despite ICG angiography usefulness in intracranial vascular surgery, its yield in detecting residual AVM nidus or shunt is low, especially for deep seated residual AVMs and higher grade. For those AVMs, post-operative digital subtraction angiogram remains the best test to confidently confirm AVM total resection.
Patient Care: To use the intra-operative ICG in only a selective group of patient as a reliable diagnostic/evaluation tool and to cautiously interprete its results regarding AVM total resection.
Learning Objectives: Understanding of the limitations of ICG videoangiography in assessment of brain AVM surgery and resection.