Real-time visualisation of brain drainage to the deep cervical lymph nodes following intraventricular indocyanine green administration in fresh human donors

To the best of our knowledge, no study has directly and dynamically demonstrated lymphatic drainage from the intracranial compartment to the cervical lymph nodes in humans, nor identified the specific nodal stations involved. The aim of this study was to provide evidence of real-time visualisation of cervical fluorescence following intraventricular administration of indocyanine green (ICG) and to propose a model for the observed pattern of cervical drainage. This was a prospective, anatomical and descriptive study in potential organ donor participants. Indocyanine green fluorescence imaging was used to evaluate lymphatic drainage from the intracranial compartment to the deep cervical lymph nodes. During standard organ procurement procedures, cervical exploration and intracranial indocyanine green injection was performed prior to tissue extraction. Near-infrared fluorescence imaging was then used to assess migration of indocyanine green into the cervical lymphatic system. A descriptive analysis was performed. Five potential organ donor participants were studied. Cervical lymph node fluorescence following intraventricular ICG administration was observed in 4 of 5 participants. In all four participants, cervical level IIA was the first nodal level in which fluorescence was detected within the exposed cervical field. Our findings provide real-time visualisation of cervical tracer uptake following intraventricular ICG administration in fresh human donors, where level IIA was the first nodal level in which fluorescence was detected within the exposed cervical field.