Related Experiment Video
Updated: Jun 2, 2026

Intrathecal Application of a Fluorescent Dye for the Identification of Cerebrospinal Fluid Leaks in Cochlear Malformation
Published on: February 29, 2020
Repair of cerebrospinal fluid leak via petrous bone using multilayer technique with hydroxyapatite paste
Takahiro Ota1, Kyousuke Kamada, Nobuhito Saito
1Department of Neurosurgery, The University of Tokyo, Tokyo, Japan.
Objective:
Repairing bone defects after drilling in skull base surgery is difficult in deeper locations, the posterior wall of the internal auditory canal, and the petrous apex. These defects traditionally have been repaired by soft tissue, such as fascia, muscle, or adipose tissue, coupled with lumbar drainage for several days postoperatively.
Methods:
To repair cerebrospinal fluid (CSF) leakage through air cells in the petrous bone, we applied a multilayer technique using hydroxyapatite cement (HAC) in three patients with postoperative CSF leakage. The opening of air cells was drilled widely to visualize the whole site of the opening and then packed with HAC covered with dura mater, fat, and fibrin glue.
Results:
In all patients, CSF leak did not recur after repair with HAC, and there was no postoperative would infection, local inflammation, or cranial nerve damage.
Conclusion:
HAC is an effective biomaterial for the repair of refractory CSF leakage due to the opening of air cells in deeper surgical fields such as the petrous bone.
