Background Endoscopic ICG (e-ICG) is a new technology amenable to skull base surgery. Few reports
have presented its benefits in visualization of vascular structures, harvesting the
nasoseptal flap and during resection of different skull base pathologies.
Objective To assess the benefit of the ICG in endoscopic skull base surgery while gathering
information from previous studies and combining with our experience to provide practical
indications for the use of this technology.
Methods In this prospective study, eight patients enrolled including pituitary adenomas (n = 5), dorsum sellae meningiomas (n = 2), and chordoma (n = 1). One vial of ICG is used for each patient. One shot dose (25 mg) or two divided
doses (12.5 mg each) are given to each patient in different stages of the operation.
For the e-ICG we used a 0° rod-lens endoscope (5.8 mm in diameter,19 cm in length)
and Image 1 H3-Z FI three-chip ICG Full HD Camera Head (KARL STORZ). Timing of the
carotid fluorescence and the sequence of the structures visualized were reported.
Results Structures visualized by the e-ICG can be categorized into vascular structures, the
pituitary gland, and tumors. The aim of e-ICG should be planned before surgery and
designed individually for each case in correlation with the radiology of the patients.
In the corridor stage, assessing the flaps, localizing the internal carotid artery
to plan the extent of sellar drilling or avoid its injury particularly for tumors
with close proximity to the vessel. e-ICG helped identify and then cauterize the meningeal
feeders of the dural attachment of meningiomas. In addition, it helps identify the
pituitary gland aiding to follow a more precise plane for extracapsular dissection,
thus avoiding injury of the pituitary gland in adenomas. During the dissection phase,
the persistence of the fluorescence guided the dissection toward tumor that maybe
hidden by bone, especially in chordoma; following the resection, e-ICG helped confirm
the integrity of perforating vessels, identify pituitary gland and its stalk and to
identify sources of bleeding.
Conclusion E-ICG is a useful tool in skull base surgeries. In addition to the few previous experiences,
findings such as staining of chordomas and meningiomas have the potential to improve
the extent of resection and better Simpson grading, respectively.
