J Neurol Surg B Skull Base 2020; 81(S 01): S1-S272
DOI: 10.1055/s-0040-1702348
Oral Presentations
Georg Thieme Verlag KG Stuttgart · New York

Endoscopic Endonasal Skull Base Surgery using Indocyanine Green and Relationship to Preoperative Radiological Imaging

Mostafa Shahein
1   Department of Neurological Surgery, The Ohio State University, Wexner Medical Center, Columbus, Ohio, United States
2   Department of Neurosurgery, Aswan University, Aswan, Egypt
,
Thomas L. Beaumont
3   Department of Neurological Surgery, University of California, San Diego, California, United States
,
Luciano M. Prevedello
4   Department of Radiology, The Ohio State University, Wexner Medical Center, Columbus, Ohio, United States
,
Khaled Ismail
2   Department of Neurosurgery, Aswan University, Aswan, Egypt
,
Radwan Nouby
2   Department of Neurosurgery, Aswan University, Aswan, Egypt
,
Marilly Palettas
5   Department of Biomedical Informatics—Center for Biostatistics, The Ohio State University, Wexner Medical Center Columbus, Ohio, United States
,
Ricardo L. Carrau
6   Department of Otolaryngology–Head and Neck Surgery, The Ohio State University, Wexner Medical Center Columbus, Ohio, United States
,
Bradley A. Otto
6   Department of Otolaryngology–Head and Neck Surgery, The Ohio State University, Wexner Medical Center Columbus, Ohio, United States
,
Daniel M. Prevedello
1   Department of Neurological Surgery, The Ohio State University, Wexner Medical Center, Columbus, Ohio, United States
› Author Affiliations
Further Information

Publication History

Publication Date:
05 February 2020 (online)

 

Background: Endoscope integrated Indocyanine green (E-ICG) has been recently introduced to skull base surgery. Quantitative correlation between ICG fluorescence and T1-weighted gadolinium (T1WGd) that enhanced images for skull base tumors has never been assessed.

Objective: Propose indications, limitations of E-ICG, and correlate the endoscopic fluorescence pattern with MRI contrast enhancement.

Methods: Following IRB approval, 20 patients undergoing endoscopic endonasal skull base surgery between June 2017 and August 2018 were enrolled in the study. Tumor fluorescence was measured using a blue color value and blood fluorescence as a control. Signal intensity (SI) of tumor T1-wGd images was measured and the internal carotid artery (ICA) SI was used as control. For pituitary adenoma, the pituitary gland fluorescence was also measured. The relationship between ICG fluorescence and MRI enhancement measures were analyzed ([Fig. 1]).

Results: Data showed that in pituitary adenoma, there was a strong correlation between the gland/blood fluorescence to gland/ICA SI ratios (n = 8; r = 0.92; p = 0.001) and tumor/blood fluorescence to tumor/ICA SI ratios (n = 9; r = 0.82; p = 0.006). In other pathologies there was a strong correlation between the tumor/blood fluorescence and tumor/ICA SI ratios (n = 9; r = 0.74; p = 0.022). The ICG fluorescence allowed assessment of the pituitary gland perfusion as well as that of the nasoseptal flaps. Visualization of the surrounding vasculature was also feasible ([Fig. 2]).

Conclusion: Defining the indications and understanding the limitations are critical for the effective use of E-ICG. Tumor fluorescence seems to correlate with preoperative MRI contrast enhancement.

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Fig. 1 (A) Axial post contrast MRI showing the measurement of signal intensity of the pituitary gland and the adenoma. (B) Intraoperative endoscopic ICG scene showing the measurement of the blue color value of both the pituitary gland and the adenoma.
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Fig. 2 Scatter plots showing the relationship between the ICG fluorescence and the MRI T1WGd SI in pituitary adenoma and other pathologies subgroup. (A) represents the relationship between MRI tumor/ICA SI ratio on the vertical axis to the tumor/blood ICG fluorescence ratio on the horizontal axis in both subgroups. (B) represents the relationship between the pituitary gland/ICA MRI SI ratio on the vertical axis to the pituitary gland/blood ICG fluorescence ratio on the horizontal axis in pituitary adenoma subgroup. (C) represents the relationship between the difference between the ratio of MRI gland/ICA and tumor/ICA SI on the vertical axis to the difference between the ratio of ICG gland/blood and tumor/blood fluorescence on the horizontal axis in pituitary adenoma subgroup.