2025 Proffered Presentations
S015: LATERAL TRAP DOOR OSTEOTOMY : KEY TO ACCESSING CAVERNOUS SINUS MENINGIOMA VIA TRANSORBITAL ENDOCSOPIC ROUTE
A Sheikh, MBBS, BSc, FRCSSN; J Robins, M; J Parmar, MBBS, FRCS, OMFS; Leeds General Infirmary
Introduction: A 40 year old female, under surveillance for a right cerebello-pontine meningioma was found to have an enlarging left cavernous sinus meningioma on interval magnetic resonance imaging. Surgical excision was performed via the transorbital corridor utilising a novel osteotomy. In this article we present a technical note utilising the ‘trap-door’ lateral osteotomy technique for excision of this lesion.
Methods: The patient was positioned supine with cranial immobilisation in Mayfield pins. Prior to and, throughout the procedure, the pupil was periodically checked for evidence of injury from retraction.
Following aqueous iodine skin preparation and antibiotic prophylaxis, a lateral canthus incision was performed and extended laterally. The orbit was approached via transconjunctival incision to visualise superior and inferior orbital fissures. A trap door osteotomy in the lateral orbital wall was performed using piezo electric knife and the bone flap plated for later reconstruction.
The trap door lateral orbital wall osteotomy was retracted laterally to create access and a 0 degree rigid endoscope was introduced. Exposure of temporal then frontal dura was performed utilising a coarse diamond burr. Surgical access was further increased via removal of greater wing of sphenoid to the origin of the anterior clinoid process.
Extradural cavernous sinus peeling was non-permissive thus, a transdural approach was utilised via a vertical incision to remove the soft tumour using suction and curettes. The post resection cavity was inspected using the 30 degree endoscope to ensure no remnant followed by haemostasis.
Closure was performed using TISSEELÒ (Baxter, Deerfield, IL) in the 2 layers comprising the cavernous sinus wall, followed by inlay DuraGenÒ (Integra, Princeton, NJ), AdherusÒ (Stryker, Kalamazoo, MI), onlay DuraGenÒ and Adherus. Orbital reconstruction was achieved with low profile stryker plate and screws followed by approximation of the lateral canthal ligament with 4/0 sutures. Layered closure was then performed.
Results: Postoperatively the patient recovered well and, tumour histology was confirmed as WHO Grade 1 meningioma. MR imaging at 48 hours post operatively demonstrated gross total resection and this was maintained radiologically at 3 months. At 4 months follow up, the patient reported normal vision and no diplopia.
Conclusion: In this article we report an early experience with transorbital endoscopic operative corridor to cavernous sinus meningioma. We report a novel trap door osteotomy which is well tolerated by patient and enabled access for gross total resection of a WHO Grade 1 meningioma.
Keywords: Transorbital, endoscopy, skull base, meningioma, cavernous sinus, novel technique