Endoscopic Perfusion Utilizing ICG Fluorescence Technology

Over the past decade, a technique widely used by ophthalmologists to assess retinal blood
flow, near-infrared ICG angiography, has been applied to neurosurgical patients undergoing a
wide variety of cerebrovascular procedures. This technique offers the advantage of real-time
visualization of cerebral blood flow through the operating microscope at the time the
procedure is being performed. Indocyanine green is an ideal agent for imaging vessels as it
is tightly bound to plasma albumin, has a short half-life, and maintains an acceptable safety
profile. Furthermore, the excitation and emission profiles for ICG lie in the near-infrared
wavelengths, which allow penetration and imaging of vessels below a few millimeters of
tissue.

Patients with either an aneurysm, compressive syndromes or pituitary and intracranial tumor
will be enrolled in the study. By taking advantage of the natural fluorescence of indocyanine
green (ICG) within the red spectrum and applying a light filter to the endoscope eyepiece and
camera it will show as to whether this technique provides adequate visual information to
differentiate perfusion in tumor and surrounding structures and to evaluate normal vessels
for aneurysm and compressive syndromes procedures.

Inclusion Criteria:

- Patient population would include those patients with pituitary tumors, intracranial
tumors, aneurysms, and normal tissue adjacent to tumors to clarify normal from
abnormal. Also, patients with compressive syndromes to ensure patency of normal
vessels. This would be all patients undergoing endoscopic surgery, both endonasal and
open (retromastoid or transcranial).

Exclusion Criteria:

- Less than 18 years of age

- Iodine allergy

- Shellfish allergy

- Contrast allergy

- Previous anaphylactic reaction to ICG

- Pregnant

- Anyone with any evidence of renal or hepatic dysfunction