Step by step endoscopic CSF leak repair: cribriform defect

Abstract

Background: Cerebrospinal fluid (CSF) rhinorrhea from anterior skull base defects carries a significant risk of
ascending bacterial meningitis and mandates definitive surgical repair. Spontaneous leaks occurring in the context
of elevated intracranial pressure represent a distinct and increasingly recognised clinical subset associated with
identifiable radiological markers of idiopathic intracranial hypertension. Transnasal endoscopic repair has emerged
as the preferred approach, offering direct visualisation, low morbidity, and success rates exceeding 90%.
Objective: To present a detailed step-by-step video account of transnasal endoscopic CSF leak repair employing
a multilayer gasket-seal closure augmented with a vascularised nasoseptal flap, with full documentation of surgical
decision-making, intraoperative technique, and perioperative management principles.
Case Description: A 45-year-old female presented with a 3-month history of spontaneous, left-sided, posturedependent
clear rhinorrhea. High-resolution CT of the paranasal sinuses demonstrated a focal bony defect (2 mm)
in the left cribriform plate with adjacent fluid density. MRI cisternography confirmed active CSF communication
through this defect at the junction of the nasal septum and the middle turbinate attachment, along with an empty
sella and periventricular white matter signal changes indicative of chronically elevated intracranial pressure.
Surgical Technique: The procedure was performed under general anaesthesia using a fully endoscopic transnasal
approach. Sequential operative steps comprised: (1) anterior septoplasty via a Killian incision using a bovine-tip
electrode for corridor creation and concurrent harvest of cartilage for gasket use; (2) endoscopic identification and
cauterisation of the herniated meningocele sac, followed by precise delineation of the cribriform defect measuring
8 mm 3 mm straddling the middle turbinate attachment; (3) partial middle turbinectomy for optimal exposure
and margin preparation; (4) intracranial underlay placement of fascia lata harvested from the ipsilateral thigh; (5)
press-fit insertion of a carved autologous cartilage gasket within the bony defect; (6) extracranial overlay placement
of a second fascia lata layer; and (7) inset of a posteriorly pedicled nasoseptal flap based on the posterior septal
branch of the sphenopalatine artery, secured with fibrin glue over the entire repair construct.
Results: No intraoperative complications were encountered. Complete resolution of rhinorrhea was achieved
immediately postoperatively. The patient was discharged on postoperative day 3. Follow-up endoscopy at 6 weeks
demonstrated full mucosalisation of the repair site with intact flap healing. Acetazolamide therapy was initiated for
presumed raised intracranial pressure and continued under ophthalmological surveillance.