Application of Intraoperative Indocyanine Green Videoangiography During Skull Base Surgery—Case Report

Introduction: Indocyanine green (ICG) videoangiography was introduced to neurosurgery several years ago, but its use is limited to vascular surgery. Some authors described the use of this substance during resection of brain tumor. We describe two cases in which the use of intraoperative ICG videoangiography helped the removal of infiltrative tumors, avoiding vascular injury.

Case Description: The first case is a 49-year-old woman with a 7-year history of multiple cranial nerves palsies, with normal muscle strength and no sensory deficit. MRI showed a right sphenopetroclival lesion, with contrast enhancement, and brainstem compression. Conventional cerebral angiography revealed lateral displacement of right ICA (petrous and cavernous portions) without stenosis. The patient was operated on through combined approach (fronto-orbitozygomatic and transpetrosal) in different moments. Histopathological analysis after the first surgery revealed a grade I chondrosarcoma. During a petrosal approach, lateral displacement of ICA and infiltrative nature of the tumor increased the risk of ICA injury. ICG videoangiography helped to identify the petrous portion of the right ICA, avoiding inadvertent vascular complications during tumor resection.

The second case is a 22-year-old woman with a fast-growing right posterior neck mass. MRI revealed a large soft tissue mass with extension to the cervical spine and foramen magnum. Magnetic resonance angiography (MRA) showed displacement and stenosis of the right vertebral artery (VA). Tumor removal was made by suboccipital craniotomy and laminectomy of atlas. ICG videoangiography guided tumor resection around the VA, preventing vascular injury during the procedure. Histopathological analysis revealed a peripheric primitive neuroectodermal tumor.

Discussion: Usefulness of intraoperative ICG videoangiography has been shown during vascular neurosurgery, and recently some authors advocate its use during brain tumor removal (tumoral circulation and peritumoral vessels). It is a safe, cost-effective method, which is easily repeatable. In these particular cases, it provided useful information during resection of infiltrative tumors, with preservation of petrous ICA and VA, which were displaced and circumscribed by the lesions. ICG videoangiography can be an alternative method to Doppler ultrasonography and conventional intraoperative angiography.