2025 Proffered Presentations
S126: A SURGICAL APPROACH AND INSTITUTIONAL EXPERIENCE WITH PARTIAL LABYRINTHECTOMY PETROUS APICECTOMY SURGERY: A TECHNICAL DESCRIPTION AND SUMMARY OF INSTITUTIONAL EXPERIENCE OF 66 CASES
Celine D Hounjet, MD, BSc1; Jeremy Kam, MBBS, FRACS, PFET2; Serge Makarenko, MD, FRCSC1; Benjamin Brakel1; Brian Westerberg, MD, MHSc, FRCSC1; Ryojo Akagami, MD, BSc, MHSc, FRCSC1; 1University of British Columbia; 2Monash University
Introduction: Partial labyrinthectomy petrous apicectomy (PLPA) is a trans-petrous route for approaching clival pathology that is intended to preserve hearing while offering the advantages of labyrinthectomy. A single surgeon team composed of a fellowship trained skull base neurosurgeon, otolaryngologist, and neurophysiologist at a tertiary care centre have completed a total of 66 cases utilizing this approach.
Methods: A description, diagrams, and intraoperative imaging of this surgical approach utilized at our centre is provided. Four handed surgery is performed using a diploscope which has been shown to reduce operating time, blood loss, and improve resection rates in skull base surgery. A cosmetic superficial mastoidectomy is performed prior to drilling, allowing for replacement with titanium fixation. Removal of the lateral and superior semicircular canals is performed by the otolaryngology team in addition to exposure of the sigmoid sinus and petrous apicectomy offering a robust exposure that minimized required retraction throughout the procedure. Intraoperative neurophysiological monitoring is utilized in all cases but tailored to the requirements of the patient. Typically for pathology in this region EMGs/motor evoked potentials of the relevant cranial nerves, 4 limb SSEPs and MEPs, and brainstem auditory-evoked responses are utilized. Additionally, a chart review was completed on all PLPA cases performed by our surgical team for patient’s demographic, clinical, pathological, and radiographic information pre and post operatively.
Results: A total of 66 cases, age 16-74, were completed using a PLPA approach from 2002-2023 by our surgical team. The most common pathology approached with a PLPA exposure at our institution was petroclival meningioma totalling 44/66 (66.7%) of cases. Other pathology approached via PLPA at our institution include epidermoid tumours: 13/66 (19.7%), vestibular schwannoma: (3/66) 4.5%, trigeminal schwannoma: 2/66 (3%), and 1/66 (1.5%) each of facial nerve and solitary fibrous tumours. The average diameter of these lesions was 4.4 cm (range 1.3-7.2 cm). A gross total resection was achieved in 25/66 (37.8%), near total, defined as >90% tumour resection was achieved in an additional 14/66 (21.2%). An attempt to preserve hearing was made in all patients with hearing at preoperative assessment totalling 44/65 patients. Of these patients, hearing was preserved in 31/44 (70.45%). There were 27/66 (40.1%) cranial nerve deficits. There were 2/66 (3%) CSF leaks that required readmission to hospital. One required operative repair. 27/66 (40.1%) of patients had post-operative cranial nerve deficits. 4/66 (6%) of patients had new motor deficits post operatively. 11/66 (16.7%) had transient worsening of existing hemiparesis post operatively. All cases improved. There was a single case of post-operative dysphasia (1.5%), attributed to temporal lobe retraction. There were zero mortalities at 90 days post op.
Conclusion: Use of a PLPA approach is safe and robust in properly selected patients with reasonable hearing preservation. Modifications to surgical technique can help to improve the safety and efficacy of this approach.