CSF rhinorrhoea after endonasal intervention to the anterior skull base (CRANIAL): proposal for a prospective multicentre observational cohort study

Abstract

Background

The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to treat pituitary adenoma and related sellar pathologies. The recently adopted expanded endonasal approach (EEA) has improved access to the ventral skull base whilst retaining the principles of minimally invasive surgery. Despite the advantages these approaches offer, cerebrospinal fluid (CSF) rhinorrhoea remains a common complication. There is currently a lack of comparative evidence to guide the best choice of skull base reconstruction, resulting in considerable heterogeneity of current practice. This study aims to determine: (1) the scope of the methods of skull base repair; and (2) the corresponding rates of postoperative CSF rhinorrhoea in contemporary neurosurgical practice in the UK and Ireland.

Methods

We will adopt a multicentre, prospective, observational cohort design. All neurosurgical units in the UK and Ireland performing the relevant surgeries (TSA and EEA) will be eligible to participate. Eligible cases will be prospectively recruited over 6 months with 6 months of postoperative follow-up. Data points collected will include: demographics, tumour characteristics, operative data), and postoperative outcomes. Primary outcomes include skull base repair technique and CSF rhinorrhoea (biochemically confirmed and/or requiring intervention) rates. Pooled data will be analysed using descriptive statistics. All skull base repair methods used and CSF leak rates for TSA and EEA will be compared against rates listed in the literature.

Ethics and dissemination

Formal institutional ethical board review was not required owing to the nature of the study – this was confirmed with the Health Research Authority, UK.

Conclusions

The need for this multicentre, prospective, observational study is highlighted by the relative paucity of literature and the resultant lack of consensus on the topic. It is hoped that the results will give insight into contemporary practice in the UK and Ireland and will inform future studies.

Keywords:

• Cerebrospinal fluid
• CSF
• CSF leak
• skull base tumours
• neuroendoscopy
• pituitary surgery

Author contributions

Danyal Z. Khan: Study conception, study design, drafting manuscript, critical revisions of the manuscript; Soham Bandyopadhyay: Study conception, study design, drafting manuscript; Vikesh Patel: Study conception, study design, drafting manuscript; Benjamin Schroeder: Study design, critical revisions of the manuscript; Ivan Cabrilo: Study design, critical revisions of the manuscript; David Choi: Study design, critical revisions of the manuscript; Simon A. Cudlip: Study design, critical revisions of the manuscript; Neil Donnelly: Critical revisions of the manuscript; Neil Dorward: Study design, critical revisions of the manuscript; Daniel M. Fountain: Study design, critical revisions of the manuscript; Joan Grieve: Study design, critical revisions of the manuscript; Jane Halliday: Study design, critical revisions of the manuscript; Angelos G. Kolias: Study design, critical revisions of the manuscript; Richard J. Mannion: Study design, critical revisions of the manuscript; Alice O’Donnell: Study design, critical revisions of the manuscript; Nick Phillips: Study design, critical revisions of the manuscript; Rory J. Piper: Study design, critical revisions of the manuscript; Bhavna Ramachandran: Study design; Thomas Santarius: Study design, critical revisions of the manuscript; Parag Sayal: Study design, critical revisions of the manuscript; Rishi Sharma: Critical revisions of the manuscript; Georgios Solomou: Study design, critical revisions of the manuscript; James R. Tysome: Critical revisions of the manuscript; Hani J. Marcus: Study conception, study design, drafting of the manuscript, critical revisions of the manuscript; British Neurosurgical Trainee Research Collaborative (BNTRC): Study design; Neurology and Neurosurgery Interest Group (NANSIG): Study design; CRANIAL Steering Committee: Study design, drafting of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Hani J. Marcus is supported by the Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS) and the National Institute of Health Research University College London Biomedical Research Centre. Rory J. Piper is supported by an NIHR Academic Clinical Fellowship. Daniel M. Fountain is supported by an NIHR Academic Clinical Fellowship and Cancer Research UK Pre-Doctoral Fellowship. Angelos G. Kolias is supported by the National Institute for Health Research (NIHR) Global Health Research Group on Neurotrauma. This article was produced independently of the about funding sources and represents the views of the authors alone.