Use of Indocyanine Green Angiography for Real-Time Assessment of a Sternocleidomastoid Muscle Flap During Complex Facial Reconstruction

Correlation and asynchronization of electroencephalogram and cerebral blood flow in active and passive stimulations

Objective.Real-time brain monitoring is of importance for intraoperative surgeries and intensive care unit, in order to take timely clinical interventions. Electroencephalogram (EEG) is a conventional technique for recording neural excitations (e.g. brain waves) in the cerebral cortex, and near infrared diffuse correlation spectroscopy (DCS) is an emerging technique that can directly measure the cerebral blood flow (CBF) in microvasculature system. Currently, the relationship between the neural activities and cerebral hemodynamics that reflects the vasoconstriction features of cerebral vessels, especially under both active and passive situation, has not been elucidated thus far, which triggers the motivation of this study.Approach.We used the verbal fluency test as an active cognitive stimulus to the brain, and we manipulated blood pressure changes as a passive challenge to the brain. Under both protocols, the CBF and EEG responses were longitudinally monitored throughout the cerebral stimulus. Power spectrum approaches were applied the EEG signals and compared with CBF responses.Main results.The results show that the EEG response was significantly faster and larger in amplitude during the active cognitive task, when compared to the CBF, but with larger individual variability. By contrast, CBF is more sensitive when response to the passive task, and with better signal stability. We also found that there was a correlation (p< 0.01,r= 0.866,R2= 0.751) between CBF and EEG in initial response during the active task, but no significant correlation (p> 0.05) was found during the passive task. The similar relations were also found between regional brain waves and blood flow.Significance.The asynchronization and correlation between the two measurements indicates the necessity of monitoring both variables for comprehensive understanding of cerebral physiology. Deep exploration of their relationships provides promising implications for DCS/EEG integration in the diagnosis of various neurovascular and psychiatric diseases.

Use of Indocyanine Green Fluorescent Imaging in the Assessment of a Tongue Flap After Lateral Hemiglossectomy

Indocyanine green (ICG) angiography is a real-time imaging modality that can be used to assess intraoperative tissue perfusion. ICG dye has proven to be feasible, safe, and cost-effective, especially for muscle flaps during complex reconstructions. To our knowledge, we discuss the first use of ICG angiography for the real-time assessment of a tongue flap following left lateral hemiglossectomy. ICG angiography showed excellent perfusion of the tongue and tongue flap, which subsequently led to an uncomplicated postoperative recovery.

Near-Infrared Fluorescence Imaging for Sentinel Lymph Node Identification in Melanoma Surgery

Although less common than other types of skin cancers, melanoma is accountable for the majority of skin cancer-related deaths. The standard management for patients with clinically negative nodes includes a sentinel lymph node (SLN) biopsy, which is commonly performed using a combination of radioactive tracer (Tc-99) and a blue dye (isosulfan or patent blue). There are numerous drawbacks associated with Tc-99 and blue dyes such as elevated costs, logistical challenges, and anaphylactic reactions among others. In recent years, near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has emerged as a safe, effective, less costly, and more convenient alternative for the identification of SLNs in melanoma. We discuss the case of a 51-year-old man with melanoma in his left upper back. Two SLNs in the left axilla were successfully identified using NIR fluorescence. NIR fluorescence with ICG for SLN identification has proven to increase the sensitivity and accuracy when used in combination with lymphoscintigraphy.