Impact of indocyanine green fluorescent image-guided surgery for parapharyngeal space tumours.
In parapharyngeal space dissection, significant complications such as dysphagia and carotid artery rupture have been reported. In order to resect tumours safely in narrow parapharyngeal space, we propose indocyanine green (ICG) florescence image for navigation surgery.


OBJECTIVE
To evaluate the usefulness of ICG fluorescent image-guided surgery for parapharyngeal space tumours.


METHODS
0.5 mg/kg of ICG was injected via the cephalic vein. Observation of the fluorescent image was performed with HEMS (HyperEye Medical System) at 10-30 min after injection. At first, the position of the tumour was marked over pharyngeal mucosa according to ICG fluorescence imaging with HEMS. We also confirmed submucosal tumours hidden under fascia using HEMS imaging again and resected them.


RESULTS
All tumours displayed bright fluorescence emissions which clearly contrasted with the normal structures. Even with the submucosal tumour covered with and obscured by fasciae, we could observe the tumour clearly under HEMS imaging. Tumours behind the carotid artery and lower cranial nerves also were displayed bright fluorescence emissions and were clearly detected. As a result, we could completely remove the tumour safely and noninvasively to preserve pharyngeal functions.


CONCLUSIONS
ICG fluorescence imaging is effective for the detection and resection of the parapharyngeal space tumours with preserving functions.
Department of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan. Electronic address: jyokoya@juntendo.ac.jp.
Junkichi
J
Yokoyama
Department of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Shinichi
S
Ooba
Department of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Mitsuhisa
M
Fujimaki
Department of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Takashi
T
Anzai
Department of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Ryota
R
Yoshii
Department of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Masataka
M
Kojima
Department of Otolaryngology-Head and Neck Surgery, Juntendo University School of Medicine, Tokyo, Japan.
Katsuhisa
K
Ikeda
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000601:surgery; D005456:Fluorescent Dyes / Q000008:administration & dosage; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000601:surgery; D007208:Indocyanine Green / Q000008:administration & dosage; D007275:Injections, Intravenous; D007431:Intraoperative Complications / Q000517:prevention & control; D008197:Lymph Node Excision / Q000379:methods; D008207:Lymphatic Metastasis / Q000473:pathology; D008875:Middle Aged; D037981:Neck Dissection / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000601:surgery; D009367:Neoplasm Staging; D061848:Optical Imaging / Q000379:methods; D009959:Oropharyngeal Neoplasms / Q000601:surgery; D010610:Pharyngeal Neoplasms / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods*
D005456:Fluorescent Dyes; D007208:Indocyanine Green
Endoscopic surgery; Head and neck cancer; Indocyanine green (ICG); Minimally invasive surgery; Navigation surgery; Parapharyngeal space tumours; Robotic surgery