Transcranial CSF leak repair

Depending on the specific case the neurosurgeon will choose an extradural or an intradural repair in presence of a large skull base defect.

Indications for intradural repair include:

• Pneumocephalus
• Increased intracranial pressure
• Other neurological symptoms
• Bony fragments displaced into the parenchyma of the brain.
• Dural injury

Indications for extradural repair include:

• Significant pneumocephalus
• Increased intracranial pressure
• Other neurological symptoms
• Displaced fracture(s) of the anterior skull base with suspected dural injury
• Intraparenchymal lesion

The standard approach is a coronal incision. However, previous craniotomy incisions may also be utilized.

A bifrontal craniotomy offers the possibility of inspection of the whole anterior skull base including the two lateral as well as the central portions. Special care should be taken to perform the craniotomies as far basal as possible, even if the frontal sinus has to be opened. Correct management of the frontal sinus with cranialization is highly recommended to avoid possible postoperative complications.

Note: To achieve a real reliable closure of dural defects on the anterior skull base a microscopic intradural inspection as well as microsurgical repair is highly recommended.

Depending on the specific case the neurosurgeon will choose an extradural or an intradural repair.

Localize the leak.

Separate the dura from the anterior skull base.

In order to have less retraction to the frontal lobes, it is highly recommended to open the frontal sinus.

Use a dissector in order to free the dura from the anterior skull base.

The amount of posterior dissection will depend on the site of the CSF leak. Elevation of the subfrontal dura from the planum sphenoidale can reach as far as the tuberculum sellae and the medial sphenoid ridge. It is possible to retract the frontal lobes away from the anterior skull base using self-retaining retractors on each side.

Localize the fracture fragments, dural defect, and remove any displaced bony fragments.

The dural substitute is sutured to the defect margins. Whenever possible, the flap should also be sutured to the outer dura margin.
To achieve a watertight closure, the use of collagen-based sealants applied to the suture line is highly recommended.

The pericranial flap is brought in and should reline the bone defect of the anterior skull base.

Whenever possible, the pericranial flap should be sutured to the dura.

Tacking the dura to the bone flap is highly recommended to avoid possible postoperative epidural hematoma.

Replace the bone flap using internal fixation in a stable three point fixation technique.

Open the dura by making a curvilinear incision on one or both sides of the superior sagittal sinus (SSS) starting from SSS going laterally at the level of the skull base.

Elevate the frontal lobes using one or more retractors. The surface of the brain is protected by neurosurgical cottonoids. The use of magnification is recommended.
Inspect the dura of the whole anterior fossa and locate the exact location of the defect. Inspect carefully for evidence of brain or vascular injury and, of course, take great care to avoid creating such injuries.

In case there is any perforation by bone fragments either remove them or smooth them using cutting forceps or special instrumentation.

Inset the pericranial flap in that way that the defect is covered by the flap including a margin of at least 1 cm, when possible.

The intradural positioned flap is fixed by primary suture to hold it in place.
In addition the use of fibrin glue and collagen-based tissue sealant techniques under the pericranial flap is highly recommended in order to achieve a watertight closure.

The dural substitute is sutured to the defect margins. Whenever possible, the flap should also be sutured to the outer dura margin.

The pericranium is also sutured to the upper free margin of the dural incision.

Tacking the dura to the bone flap is highly recommended to avoid possible postoperative epidural hematoma.

Replace the bone flap using internal fixation in a stable three point fixation technique.

• Intensive care 24 hours
• Hospitalization 5-8 days (to rule out reoccurrence of CSF leak)
• The use of broad-spectrum antibiotics during and after the procedure for the next 5-7 days is recommended.
• Radiologic control examinations are performed routinely the next day after leaving the intensive care unit.
• Patient follow-up after discharge. The patient is seen 4 weeks after, and if necessary, for the long-term follow-up a year postoperatively.