Traumatic non-missile penetrating transnasal anterior skull-base fracture and brain injury with cerebrospinal fluid leak: intraoperative leak detection and an effective reconstruction procedure for a localized skull base defect especially after COVID-19 o

BACKGROUND Cerebrospinal fluid leakage in penetrating skull base injury is relatively rare compared to close head injury involving skull base fracture CASE DESCRIPTION We report a case of a 65-year-old beekeeping man who presented with epistaxis and serous rhinorrhea When he fell down on the ground near his bee boxes, a garden pole poked into his right nostril He instantly removed the pole from his nostril by himself Immediately after the removal of the pole, he developed some nasal bleeding and serous rhinorrhea He then drove to our emergency room Computed tomography showed pneumocephalus with minor cerebral contusion in the left frontal lobe, and penetrating injury in the left anterior skull base His cerebrospinal fluid (CSF) leakage did not resolve spontaneously within one week after the injury under a strict bed rest We repaired the CSF leakage using a fat (adipose tissue)-on-fascia autograft plug and caulked the defect in the anterior skull base with the fat-on-fascia graft (FFG) plug through the left nostril under endoscopic vision The CSF rhinorrhea was successfully controlled Intranasal local application of fluorescein aided in the detection of the flow direction of CSF leakage CONCLUSIONS Endonasal endoscopic caulking of a skull base defect using FFG plug is useful for CSF leakage due to localized skull base defect, in particular for the post-COVID-19 era, because it is simple, low-cost, and timesaving: requiring no special skills or no sophisticated instruments, thus reducing infection risks during the surgery (239 words)