What is the study about?

CRANIAL (CSF Rhinorrhoea After Endonasal Intervention to the Skull Base) is a prospective, multicentre observational study seeking to determine: (1) the scope of skull base repair methods, and (2) the corresponding rates of postoperative CSF rhinorrhoea in endonasal transsphenoidal (TSA) expanded endonasal approaches (EEA) for skull base tumours. This is a NANSIG-led and BNTRC supported study, and will run over 12 months.

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Project update – June 2020

Project sign up for data collaborators for CRANIAL is now closed. We would like to thank all of you who registered your interest – 28 centres (across the UK and Ireland) have joined our study! The project will be overseen by steering committee of over 50 neurosurgery and ENT consultants, working alongside a network of over 70 student and trainee leads chosen based on competitive application. If you have been successfully appointed as a 2020 CRANIAL Local project lead, useful documents can be found in the sidebar to the Left, including How to Guides for our data collection platform, Castor.


Pilot data

We have some exciting news to share with you regarding the pilot for CRANIAL, which is now complete! The pilot was undertaken at three neurosurgical centres and successfully confirmed the feasibility and acceptability of the project. For further details on the preliminary results, click here.



The protocol and project design for CRANIAL were presented and well-received at the British Neurosurgical Research Group (BNRG) meeting in Edinburgh in November 2019, as well as at the British Skull Base Society meeting in London in January 2020. Links to the presentations can be found here:

BNRG presentation

BSBS poster

Watch this space for the CRANIAL protocol and pilot manuscripts!


COVID-19 statement

The CRANIAL steering committee are regularly reviewing the start date for the project, which is provisionally August 2020. We understand that this start date may not be feasible for all participants/centres, for example due to junior doctor rotations. If this is the case, please email cranialnansig@gmail.com and we will work with you to find a solution.

For those of you who are keen to start collecting data prior to August 2020, we are running a separate CRANIAL-COVID sub-study from April to July 2020 to understand the impact COVID-19 is having on operative workflows and surgical techniques, given the risks associated with endonasal surgery. If you would like to get involved with this, please email cranialnansig@gmail.com.