The applicability of established clinical and histopathological risk factors for tumor recurrence during long-term postoperative care in meningioma patients.

Risk factors to predict late-onset tumor recurrence in meningioma patients are urgently needed to schedule control intervals during long-term follow-up. We therefore analyzed the value of established risk factors for postoperative meningioma recurrence for the prediction of long-term prognosis. Correlations of clinical and histopathological variables with tumor relapse after 3, 5, and 10 years following microsurgery were analyzed in uni- and multivariate analyses, and compared to findings in the entire cohort. In the entire cohort (N = 1218), skull base location (HR: 1.51, 95%CI 1.05-2.16; p = .026), Simpson ≥ IV resections (HR: 2.41, 95%CI 1.52-3.84; p < .001), high-grade histology (HR: 3.70, 95%CI 2.50-5.47; p < .001), and male gender (HR: 1.46, 95%CI 1.01-2.11; p = .042) were independent risk factors for recurrence. Skull base location (HR: 1.92, 95%CI 1.17-3.17; p = .010 and HR: 2.02, 95%CI 1.04-3.95; p = .038) and high-grade histology (HR: 1.87, 95%CI 1.04-3.38; p = .038 and HR: 2.29, 95%CI 1.07-4.01; p = .034) but not subtotal resection (HR: 1.53, 95%CI .68-3.45; p = .303 and HR: 1.75, 95%CI .52-5.96; p = .369) remained correlated with recurrence after a recurrence-free follow-up of ≥ 3 and ≥ 5 years, respectively. Postoperative tumor volume was related with recurrence in general (p < .001) but not beyond a follow-up of ≥ 3 years (p > .05). In 147 patients with a follow-up of ≥ 10 years, ten recurrences occurred and were not correlated with any of the analyzed variables. Skull base tumor location and high-grade histology but not the extent of resection should be considered when scheduling the long-term follow-up after meningioma surgery. Recurrences ≥ 10 years after surgery are rare, and predictors are lacking.

Management of Spinal Dumbbell Tumors via a Minimally Invasive Posterolateral Approach and Carbon Fiber-Reinforced Polyether Ether Ketone Instrumentation: Technical Note and Surgical Case Series.

OBJECTIVE: Stand-alone minimally invasive approaches for the surgical management of spinal dumbbell tumors carry the risk of incomplete resections and impaired hemostasis. More-extensive approaches require subsequent instrumentation with metal artifacts impairing follow-up imaging. Here, we present a technical note on percutaneous instrumentation using carbon fiber-reinforced polyether ether ketone (CFR-PEEK) hardware combined with a minimally invasive posterolateral approach for tumor resection. METHODS: We present a Technical Note and according case series of 7 patients with dumbbell tumors in the lumbar and thoracolumbar spine operated on between 2017 and 2020. CFR-PEEK pedicle screws and rods were inserted percutaneously. Afterwards, a dedicated self-standing retractor for posterolateral approaches was connected to the screws. Following a unilateral facetectomy, the tumor was resected in a microsurgical fashion. Clinical data are reported with respect to the Preferred Reporting Of CasE Series in Surgery (PROCESS) guidelines. RESULTS: Four patients presented with de novo tumors. Three patients were treated for residual tumor mass after previous surgeries. Gross total resection was achieved in all 7 cases, as demonstrated by early postoperative magnetic resonance imaging. Histopathology demonstrated 5 World Health Organization grade I schwannomas, 1 grade II hemangiopericytoma, and 1 cavernous hemangioma. No postoperative complications were observed. CFR-PEEK hardware allowed unambiguous visualization of the resection cavity on follow-up imaging. CONCLUSIONS: Resection of dumbbell tumors via a minimally invasive posterolateral approach and instrumentation with CFR-PEEK hardware allows maximal and safe resection. Due to lack of major metal artifacts, carbon fiber hardware improves the interpretation of follow-up imaging as well as planning of radiation if required for tumor recurrence.