Introduction: In non-ideal endoscopic reconstructive candidates, endoscopic skull base reconstruction (ESBR) following expanded-endoscopic endonasal approaches (EEA) remains inspiring, and further innovations are required. Evidently, the osteoconductive paste is a well-known material that improves bone healing and epithelialization. The reconstructive knowledge gap following expanded-EEA was studied and we introduce the watertight robust osteoconductive (WRO) barrier as an alternative durable preference.
Methods: As a novel, we focused on ten clinical conditions. A 3D-skull base-water system model was innovated for practicing ESBR under realistic/stressful conditions. A large-irregular defect (31x89 mm) extending from the anterior-to-posterior fossae was achieved. Then, WRO-barrier was fashioned and its tolerance was evaluated under specific settings, including an exceedingly high (55 cmH2O) pressure, with radiological assessment. Afterward, the whole WRO-barrier was drilled to examine its practical-safe removal (simulating redo-EEA) and the whole experiment was repeated. Lastly, WRO-barrier was kept into place to value its 10-month long-term high-tolerance.
Results: WRO-barriers were satisfactorily fashioned (80%) to conform the geometry of the created defect under realistic circumstances via EEA, tolerated an exceedingly high pressure without evidence of leak even under stressful settings, resisted sudden-elevated pressure (80%), remained in its position to maintain long-term watertight seal, efficiently evaluated with neuroimaging and simply removed-and-reconstructed when redo-EEA is needed. Nevertheless, risk of intracranial fashioning-induced herniation might occur.
Conclusions: WRO-barriers were successfully fashioned (80%) to conform the geometry of the created defect under realistic circumstances via EEA, tolerated an exceedingly high pressure without evidence of leak even under stressful settings, resisted sudden-elevated pressure (80%), remained in its position to maintain long-term watertight seal, efficiently evaluated with neuroimaging and simply removed-and-reconstructed when redo-EEA is needed. Nevertheless, risk of intracranial fashioning-induced herniation might occur.
Patient Care: WRO-barrier as an osteoconductive watertight robust design for endoscopic cranial base reconstruction can contribute in decreasing the CSF leak rate and can be considered as a promising alternative durable option for designated patients with complex/invasive skull base tumours that require aggressive removal (with large defect) and postoperative adjunctive chemo-radiotherapy (avascular environment).
Learning Objectives: By concluding experts’ experiences based on the Congress of Neurological Surgeons; Endoscopic series webinars and a thorough survey of the English literature, along with our results, we were able to study the reconstructive knowledge gap. If there is an available water-tight robust barrier that is enough to withstand postoperative adjunctive radiation and chemotherapy, applicable for irregular-deep-critical bone defects, efficiently evaluated with neuroimaging, simple in its technique, without donor site complications and can be considered as a good endoscopic reconstructive alternative, it will be a great advantage. We selected a well-known malleable osteoconductive material, which became a robust barrier within a few minutes that have good biocompatibility and can survive avascular environment. Herein, we present the watertight robust osteoconductive barrier (WRO-barrier) for ESBR as an alternative durable option and we will discuss its distinct qualities and limitations.