CSF rhinorrhoea after endonasal intervention to the skull base (CRANIAL) - Part 1: multicentre pilot study

Background 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 used; and (2) corresponding rates of postoperative CSF rhinorrhoea in endonasal transsphenoidal (TSA) expanded endonasal approaches (EEA) for skull base tumours. We sought to pilot the project - assessing the feasibility and acceptability by gathering preliminary data. Methods A prospective, observational cohort pilot study was carried out at twelve tertiary UK neurosurgical units. Feedback regarding project positives and challenges were qualitatively analysed. Results 187 cases were included, 159 TSA (85%) and 28 EEA (15%). The most common pathologies included: pituitary adenomas (n=141/187), craniopharyngiomas (n=13/187) and skull-base meningiomas (n=4/187). The most common skull base repair techniques used were tissue glues (n=132/187, most commonly Tisseel®), grafts (n=94/187, most commonly fat autograft or Spongostan™) and vascularised flaps (n=51/187, most commonly nasoseptal). These repairs were most frequently supported by nasal packs (n=125/187) and lumbar drains (n=22/187). Biochemically-confirmed CSF rhinorrhoea occurred in 6/159 (3.8%) TSA and 2/28 (7.1%) EEA. Four TSA (3%) and two EEA (7%) cases required operative management for CSF rhinorrhoea (CSF diversion or direct repair). Qualitative feedback was largely positive (themes included: user-friendly and efficient data collection, strong support from senior team members) demonstrating acceptability. Conclusions Our pilot experience highlights the acceptability and feasibility of CRANIAL. There is a precedent for multicentre dissemination of this project, in order to establish a benchmark of contemporary skull base neurosurgery practice, particularly with respect to EEA cases. Keywords Cerebrospinal fluid rhinorrhoeaCSFCerebrospinal fluid leakskull base surgeryendoscopic endonasalEE