What is the surgical repair for a cerebrospinal fluid (CSF) leak from a previous endonasal endoscopic transsphenoidal surgery called?

Endoscopic Skull Base Reconstruction for CSF Leak After Transsphenoidal Surgery

The surgical repair for cerebrospinal fluid (CSF) leak following endonasal endoscopic transsphenoidal surgery is called "endoscopic skull base reconstruction" or "endoscopic CSF leak repair." 1, 2

Diagnosis and Localization

• Confirmation of CSF leak is essential before surgical planning, typically done through laboratory analysis of the fluid for β2-transferrin or β2-trace protein 2, 1
• High-resolution CT (HRCT) is the first-line imaging study for localizing the skull base defect, with a reported sensitivity of 88-95% 1, 2
• MRI with heavily T2-weighted sequences (MR cisternography) may be used in conjunction with HRCT for improved localization, with a combined sensitivity of 90-96% 1
• CT cisternography is primarily used when multiple osseous defects are identified on HRCT to determine the specific leak site 1

Graded Approach to Surgical Repair

The surgical repair technique is typically determined by the grade of the CSF leak:

Grade 0 (No CSF leak)

• Simple placement of gelatin sponge in the tumor cavity 3, 4

Grade 1 (Small leak without obvious diaphragmatic defect)

• Two-layered collagen sponge repair with intrasellar titanium mesh buttress 4
• Buttress placement significantly decreases postoperative leakage in grade 1 patients 5
• Hydrogel sealant overlay may be used for additional security 3

Grade 2 (Moderate leak)

• Intrasellar and sphenoid sinus fat grafts with collagen sponge overlay and titanium buttress 4
• Both fat graft and buttress placement are required to significantly reduce postoperative CSF leakage 5

Grade 3 (Large diaphragmatic/dural defect)

• Same as Grade 2 with the addition of CSF diversion in most cases 4
• Both fat graft and buttress placement are essential to significantly reduce postoperative CSF leakage 5

Advanced Reconstruction Techniques

• Pedicled nasoseptal flaps may be used for larger defects, especially in grade 2 and 3 leaks 6, 5
• Nonpenetrating titanium clips can be used for primary closure of the dural defect in select cases 7
• Synthetic materials such as hydrogel sealants may be used to augment the repair 3
• BioGlue may be used in higher-grade leaks to enhance the repair 4

Postoperative Considerations

• Provocative tilt testing before discharge can help identify repair failures early 4
• CSF diversion (lumbar drain) is recommended for all Grade 3 leaks 4
• Patients should avoid activities that increase intracranial pressure (straining, sneezing) as these can disrupt the repair 3
• Postoperative imaging (HRCT or MRI) may be performed to assess the integrity of the repair 1

Outcomes and Success Rates

• Overall success rates for endoscopic repair of CSF leaks range from 90-95% 6
• With a graded repair approach, failure rates can be as low as 1% overall and 7% for Grade 3 leaks 4
• Complications include meningitis (0.45%), pneumocephalus, and recurrent leakage 4, 2

Pitfalls and Caveats

• Overaggressive postoperative debridement can disrupt the repair and cause recurrent leakage 6
• Multiple skull base defects may require additional imaging (CT cisternography) to identify the specific leak site 1
• Patients with elevated BMI have a higher risk of CSF leaks and may require more robust reconstruction 6
• Repair failures typically occur within the first 6 weeks after surgery 3