Development and Validation of a Novel Human-Fixed Cadaveric Model Reproducing Cerebrospinal Fluid Circulation for Simulation of Endoscopic Endonasal Skull Base Surgery.

BACKGROUND AND OBJECTIVES: Endoscopic endonasal surgery is a well-established surgical approach to the skull base. Surgeons need a reusable long-lasting tool to acquire the skills needed for skull base reconstruction. The aim of this study was to elaborate and validate a human formalin-fixed cadaveric model that reproduces a realistic cerebrospinal fluid (CSF) circulation and that adequately renders a CSF leak. METHODS: An external ventricular drain that connects with a peristaltic pump is placed in the subarachnoid space, which allows a water circulation that reproduces CSF circulation. Intracranial pressure is measured in real time. Endoscopic endonasal skull base approaches are performed, to create different skull base openings and CSF leaks. Participants were tasked with reconstruction of the defects using a standardized multilayered approach, with the goal of obtaining a watertight closure under normal intracranial pressure ranges. Compiled data included time of reconstruction, years of experience of participants, and success/failure to achieve a watertight reconstruction. A Likert questionnaire was also used. RESULTS: The cadaveric model reproduced CSF circulation in 4 types of dural defects: sellar, suprasellar, transcribriform, and transclival. Intracranial pressures were similar to physiological conditions and were reproducible. Each model was tested multiple times, over several months. Success rates concurred with training levels (r = .8282 and P = .0017). A strong inverse correlation was also found between years of experience and time of reconstruction (r = .4977 and P < .0001). Participants agreed that the model was realistic (median Likert score of 4), and they strongly agreed that it allowed for the improvement of their surgical skills (median Likert score of 5). CONCLUSION: This novel human-fixed cadaveric model for CSF circulation is efficient and adequately reproduces surgical conditions for skull base approaches. The model is unique, easy to reproduce, and reusable. It can be used as a tool for teaching and for research purposes.

Bilateral Recurrent Laryngeal Nerve Palsy following Total Thyroidectomy in Triple A Syndrome, an Unexpected but Critical Complication.

INTRODUCTION: Triple "A" syndrome (TAS) is a rare autosomal recessive disorder that presents in childhood with achalasia cardia, alacrima, ACTH-resistant adrenal insufficiency, with sensorimotor and autonomic polyneuropathy developing later in the course of the disease. Case Presentation. An adult white male affected by this syndrome underwent an uneventful total thyroidectomy for malignancy and suffered delayed bilateral recurrent laryngeal nerve palsy in the early postoperative hours. The palsy spontaneously resolved after a five-week course. CONCLUSION: Given the rarity of this severe condition and the absence of surgical or medical causes identifiable, there is possibility that it is the neurological involvement caused by TAS that predisposed the patient to this adverse outcome, precipitated by standard manipulations during surgery.