Cerebrospinal fluid (CSF) leak is a rare condition. When it involves the ventral skull base, a surgical closure may be achieved using endoscopic skull base surgery techniques. The major principles remain in achieving a watertight closure that can also support the brain (and avoid brain sagging) in case of extensive skull base defects. Surgical techniques are well described. Many clinical factors may influence the successful rate of the reconstruction. However, there is a lack of clinical study on perioperative management of CSF leaks. The purpose of this study is to gather the opinion of skull base surgeons on the post-operative management of patients to avoid CSF leak recurrence.

•Methods: The investigators will collect data from skull base surgeons using an electronic survey questionnaire (Google Form, Google, Mountain View, California, U.S.A.) submitted by e-mail to the members of the French Association of Rhinology, to the European Rhinologic Society, to the French college of neurosurgeons, to the Italian skull base society members, and to the former students of the European endoscopic skull base diploma. This is an anonymous 60-items survey. Questions were classified in eight sections: general questions, material used at the end of the surgical procedure, post-operative resting position, drugs, CSF depletion, post-operative advices, explorations in case of early recurrence of the rhinorrhoea, and follow-up modalities.

•Discussion: The investigators aim to understand the actual practice of skull base surgeons after closure of ventral skull base CSF leaks. This can serve as a basis for conducting clinical studies in the future.

Inclusion criteria

An individual must fulfill all of the following criteria in order to be eligible for study enrollment:

• Active skull base surgery practice (ENT surgeon or neurosurgeon)
• Volunteering

Non inclusion criteria

• Subject unable to read or/and write
• Undergraduate students
• Refusal to participate

ENT surgeon or neurosurgeon skull base surgery practice

NC