Transorbital endoscopic repair of cerebrospinal fluid leaks.

OBJECTIVES: To describe an anatomic and clinical outcome study of transorbital neuroendoscopic surgical (TONES) for the repair of complex anterior cranial fossa (ACF) cerebrospinal fluid (CSF) leaks.
DESIGN: Anatomic cadaver investigation and clinical outcomes evaluation.
METHODS: An anatomic cadaver study was undertaken to determine the anatomic feasibility of the TONES approaches for repair of CSF leaks, and determine the optimal approaches for these repairs. A targeted outcome analysis was performed on 10 consecutive patients who underwent 12 ACF CSF leak repairs by TONES.
RESULTS: The cadaver study demonstrated that the entire ACF can be accessed by TONES. Due to the rise and angulation of the orbital roof above the interorbital ACF, the precaruncular (PC) approach optimal for a coplanar target approach in the interorbital ACF, and the superior lid crease (SLC) trajectory is preferable for procedures involving the supraorbital ACF. There were no complications in the 12 clinical procedures. Fifty percent of the cases were revisions, referred after up to five previous craniotomies and endoscopic procedures; all TONES repairs were successful with a single operation.
CONCLUSIONS: The use of TONES to repair ACF CSF leaks was demonstrated to be technically feasible in cadaver and clinical studies. The SLC approach was optimal for supraorbital ACF leaks; the PC approach was preferable for interorbital ACF pathology. TONES was shown to be highly effective for treating complex pathology that was refractory to correction through frontal craniotomy and /or transnasal endoscopy, providing safe, minimally disruptive direct coplanar routes for target approach and manipulation.