This is a presentation shared by Prof. Zan, regarding Expert consensus and hospital level standardized protocol on skull base reconstrction. It was shared during Thee Pituitary Frontier_Global Webinar.
For webinar background, surgery week case discussion and t-holding chopstick technique, please view:
The Pituitary Frontier Webinar (1): https://www.medprin.com/de/article/index/article_id/493.html
The Pituitary Frontier Webinar (2): https://www.medprin.com/de/article/index/article_id/494.html
The Pituitary Frontier Webinar (3): https://www.medprin.com/de/article/index/article_id/495.html
The Pituitary Frontier Webinar (4): https://www.medprin.com/de/article/index/article_id/496.html
4. Skull Base and Sellar Reconstruction & CSF Leak Control
Prof. Zan also systematically presented West China Hospital’s principles for sellar and skull base reconstruction, especially how to minimize the risk of CSF leak in high-risk regions (sellar, suprasellar, and sphenoid sinus areas).
Reconstruction goal:
“The real endpoint is not just ‘the tumor is removed,’ but that ‘the skull base is re-established as a closed structure.’ The goal is watertight closure to prevent CSF leakage and postoperative infection.”
Reconstruction principles:
(1) Multilayer reconstruction rather than a single layer of graft.
– Soft-tissue reconstruction (soft reconstruction): the aim is to separate the intracranial compartment (subarachnoid / subdural space) from the nasal and paranasal cavities. Preferred sequence of materials:
Pedicled local flaps with vascular supply, especially the vascularized nasoseptal flap.
Other regional flaps (e.g., temporalis muscle) or free autologous tissue (fascia, fat).
Synthetic materials and sealants used only when necessary.
ENT collaboration is crucial for large or complex defects.
– Rigid reconstruction (hard reconstruction): the goal is to resist intracranial pressure and close the bony defect, restoring bony support of the skull base.
West China Hospital places special emphasis on the “inside bone flap” (a preserved and later replaced autologous bony flap from the sellar / sphenoid region) as a key element.
By replacing this bone flap “like putting a door back into its frame,” a rigid barrier is created that can almost completely seal off the CSF pathway.
In some extended skull base approaches, nasal septal or sphenoid bone plates can also be used as rigid coverage.
(2) Hemostasis and elimination of dead space:
first, meticulous hemostasis to avoid postoperative hematoma or re-expansion of cavities;
then layered packing (e.g., fat) and closure to prevent residual spaces from becoming new CSF channels.
(3) Stratified decision-making based on the grade of CSF leak (in line with national expert consensus on skull base reconstruction):
– Low-risk / small defects (intact arachnoid and dura, or defects < 1 cm): inlay artificial dura or patch, sealant, replacement of the inside bone flap, and local flap coverage.
– High-risk / high-flow leaks (> 1 cm, significant arachnoid disruption, wide exposure after extended approaches):
Traditionally, many centers use fat packing + fascia + vascularized nasoseptal flap + extracranial support, often with lumbar drainage.
At West China Hospital, the trend is toward simplification: the core is the combination of inside bone flap + vascularized nasoseptal flap, with sealant and buttress as needed, forming a “hard + soft” double-layer barrier.
In many cases, small dural patches are no longer routinely sutured, and fat/fascia harvesting from the leg is often avoided to reduce donor-site morbidity and shorten operative time.
Using this “bone flap + soft flap” concept, their CSF leak rate in extended endonasal approaches has been kept around 0.5%, which is considered very low.
(4) Reconstruction timing and verification:
at the end of surgery, they perform a “reverse pressure test,” injecting fluid and transiently raising intracranial pressure to confirm the absence of leakage.
If the closure is stable, postoperative lumbar drainage is often unnecessary, and patients can mobilize and be discharged relatively early.
(5) CSF leak management strategies (for complications):
– For postoperative high-flow leaks with a clear defect, necrotic flap, or displaced bone flap, they prefer to return to the operating room promptly for revision, rather than waiting.
– For small leaks with an intact reconstruction (inside bone flap + flap), short-term lumbar drainage for 3–5 days may be used to assist healing; such leaks often close spontaneously.
– Their experience suggests that even if part of the nasoseptal flap becomes necrotic, as long as the rigid inside bone flap is in place, CSF leakage can still be effectively prevented. This reinforces the central importance of the bony reconstruction.
Key points:
The reconstruction philosophy at West China Hospital can be summarized as: soft-tissue separation, rigid bony support, multilayer closure, and intraoperative pressure testing.
The most critical factor is whether an inside bone flap (or similar rigid element) is preserved and replaced to truly resist intracranial pressure and seal the communication.
This approach—with particular emphasis on extended endonasal cases—has reduced the high-flow CSF leak rate to around 0.5%, while reducing donor-site harvesting and the need for prolonged lumbar drainage.
5. Key Academic Takeaways
(1) The Pituitary Surgery Week model at CMJAH demonstrates that it is possible to simultaneously address a backlog of pituitary surgeries and use the same initiative to co-develop a practical, auditable dural / sellar closure protocol.
(2) The discussion of three real cases focused on: approaches and intracranial pressure management for large suprasellar tumors; biochemical cure targets and cavernous sinus management for functioning adenomas; and combined endonasal + transcranial strategies for giant, vessel-encasing tumors. Each area was illustrated with concrete decision-making examples.
(3) Prof. Zan shared an integrated surgical pathway: the logic of intraoperative lumbar drainage, strategies for managing the medial wall of the cavernous sinus, decisions on staged / combined approaches, the uni-nostril bimanual T-holding technique, and a multilayer skull base reconstruction system centered on bone flap fixation, with CSF leak rates as low as around 0.5%.
Acknowledgements
We would like to express our sincere gratitude to all clinical and organizational teams who contributed to this academic exchange:
Prof. Zan Xin and the Department of Neurosurgery at West China Hospital, Sichuan University, for sharing high-quality operative videos and detailed explanations of endonasal approaches, the T-holding chopstick technique, and multilayer skull base reconstruction strategies, providing highly practical experience for the South African team.
The Neurosurgery team at Charlotte Maxeke Johannesburg Academic Hospital / University of the Witwatersrand in South Africa, especially Dr. Ashvir Rajkumar and Prof. Dinesh Naidoo, for openly presenting real cases and local system challenges such as surgical backlog and limited imaging/medication resources, keeping the discussion firmly grounded in frontline clinical needs.
The teams from Selective Surgical (South Africa) and Medprin Biotech, for their support in cross-border coordination, meeting organization, and multi-party communication, which enabled this online academic exchange between Africa and Asia to take place smoothly.
We hope that The Pituitary Frontier – Global Webinar will serve as a starting point for long-term, pragmatic, patient-centered international collaboration in pituitary and skull base surgery, and that together we can explore safer, more efficient, and more reproducible endonasal surgical pathways and skull base reconstruction strategies to benefit patients in South Africa, China, and worldwide.