2025 Proffered Presentations
S290: ONCO-FUNCTIONAL BALANCE IN LARGE VESTIBULAR SCHWANNOMAS SURGERY: IS THERE A SWEET SPOT BETWEEN EXTENT OF RESECTION AND QUALITY OF LIFE?
Marco Schiariti, MD, Neurosurgeon1; Jacopo Falco, MD, Neurosurgeon1; Luca Mattioli, MD2; Leonardo Maresca, MD2; Edoardo Barbieri, MD2; Riccardo Ciocca, MD2; Emanuele La Corte, MD, PhD, Neurosurgeon3; Francesco Restelli, MD, Neurosurgeon1; Morgan Broggi, MD, Neurosurgeon1; Michela Moretti, Psychologist1; Paolo Ferroli, MD, Neurosurgeon1; 1Fondazione IRCCS Istituto Neurologico Carlo Besta; 2Università Statale of Milan; 3Ospedale Policlinico San Martino
INTRODUCTION: Vestibular schwannomas (VS) are benign entities, but due to neurovascular relations they are among the most challenging tumors of the skull base. Possible management strategies are: observational wait-and-scan, irradiation, surgery, or a combination of them. The surgical dilemma concerns the balance between pursuing an extensive resection or leaving tumor remnants along eloquent structures: to date, there is still no unambiguous opinion. The main purpose of this retrospective study is to analyze surgical strategies and philosophies, oncological outcomes and complications of VSs surgery.
METHODS: Our Institution’s surgical database was retrospectively reviewed looking for patients operated for VS during the period 2012-2023. Baseline clinical and surgical data, operative records, oncological treatments, neuroimaging and long-term clinical data were obtained. Surgery was performed under general anesthesia assisted by IONM in all cases; resection was stopped when an easy dissection plane between tumor and neurovascular structures was undetectable, or an A-train on EMG recording was encountered. Data were analyzed by means of statistical analysis.
RESULTS: 220 patients (15-83 years) underwent surgery for VS. Mortality rate was 1.4%; morbidity rate (CDG>1) was 18.15%. GTR was achieved in 103 patients (46.8%), near-total resection (NTR, i.e. residual tumor capsule thickness ≤ 5mm along at most two among the IAC, the 7th-8th CN, or the brainstem) in 73 (33.2%), PR or STR in 44 (20%). Facial nerve functioning worsening occurred in 142 patients (64.5%), in 21.3% defined severe (drop≥ 3 points in HB score). Good facial nerve function (HB I and II) was achieved in 46.5% of patients immediately postoperative and was associated with: smaller preoperative tumor diameters (p < 0.001), larger percentage of residual tumor and its superficial extension (“residual tumor spread”) (p < 0.001). At long-term FU, tumor dimension remains relevant (p = 0.019) whereas residual volume loses significance (t = 0.232 p = 0.817) with an overall improvement of 7thCN function registered in 74%. An immediate postoperative CN deficit (diplopia, trigeminal disturbances, lower cranial nerves impairment) is strictly related to VS diameter, especially the ventro-dorsal petrosal one (p < 0.001); and weakly associated with the EOR (p = 0.05). These remain significant for long-term persistency of CN deficits. Oncological control was defined by no necessity for further therapies (stable residual or no tumor recurrence): indication for adjuvant treatment is strongly related (t = 7.606 p < 0.001) to tumor diameters and EOR, with GTR and NTR having the same rate of disease control (p = 0.001) whereas other groups are at higher risk of tumor regrowth. Quality of life (PANQOL-It) resulted good overall with a total average value of 75.16: higher scores are associated with preoperative KPS (p < 0.001), absent brainstem edema (p = 0.002), and smaller tumor maximal diameter (p = 0.029); a pejorative longitudinal trend is detected after PR and STR with adjuvant treatment, but no difference with GTR and NTR was shown (p = 0.006).
CONCLUSIONS: QoL and oncological control are superimposable for GTR and NTR in VS surgery: we advocate for NTR when pushing resection further becomes riskier.
