2025 Proffered Presentations
S060: TECHNICAL NUANCES FOR MAXIMISING THE SUBLACERUM VERSUS SUPRALACERUM ENDOSCOPIC ENDONASAL TRANSCLIVAL APPROACH: IMPLICATIONS FOR RESECTION OF CHORDOMAS AND CHONDROSARCOMAS
Muhammad Baqai; Evangelos Drosos; Mahmoud Asad; Jahangir Sajjad; Patricio Gimenez; Warren Bennett; Kumar Abhinav; Southmead Hospital
Objectives: Expanded endoscopic endonasal transclival approach (EETA) is increasingly used for resection of chordomas and chondrosarcomas. Radical resection requires adjuncts towards expanding the endonasal corridor. In chondrosarcomas, challenges include accessing the petrous bone and inferolateral petroclival fissure. We aimed to define and compare these adjuncts in a step-wise fashion from supra- to sublacerum compartments using anatomical dissections and demonstrate their application in illustrative cases.
Subjects: Five silicon–injected human head specimens (10 sides) underwent EETA followed by illustration of operative principles in 10 skull base sarcoma patients.
Methods: Out Of 10 skull base sarcoma cases, 8 primary cases (3 chordoma and 5 chondrosarcoma) were performed via EETA over 24 months by senior author utilising these surgical adjuncts.
Results: In the supralacerum compartment key manoeuvres included: exposure of paraclinoidal internal carotid artery (ICA); interdural/ transcavernous pituitary transposition and posterior clinoidectomy; skeletonization of paraclival ICA followed by its detethering (by division of pterygosphenoidal fissure at the foramen lacerum and extended transposition) and use of the Caldwell-Luc if applicable. These facilitated access to upper clival and lateral aspects of the mid-clival bone and petrous temporal bone. In the sublacerum compartment key adjuncts included: skeletonization of paraclival ICA with its detethering as above followed by inferior mobilisation of the eustachian tube to access inferolateral petroclival fissure and jugular tubercle.
Of 8 cases undergoing EETA, none suffered new neurological deficit with four recovering to improved bulbar and other cranial nerve function.
Conclusion: Supra- and sublacerum transclival approaches centred on foramen lacerum require a thorough understanding of the loco-regional anatomy with particular attention to the anatomy of the lacerum. These adjuncts permit safe maximal resection of chondroid tumours with implications for resection of other lesions like petroclival meningiomas.