Patro, Ankita

ABSTRACT Objective Management of vestibular schwannoma (VS) remains controversial. Very small VSs represent a pivotal group: on one hand, they pose the least risk to the patient from the perspective of being small; yet, not recommending treatment may result in missing a critical window for achieving the best outcome. This debate fundamentally hinges on whether treatment improves upon the natural history of the disease. There is an unproven assumption that very small tumors behave similarly to the broader observed population. To address this central question, we conducted a multicenter retrospective review to compare the natural history of tumor growth and hearing for patients with very small VS (1–3 mm) with a referent cohort with larger tumors. Methods All patients diagnosed with sporadic VS 1–3 mm were reviewed at 3 large skull base referral centers and compared with a referent cohort of patients with tumors > 3 mm. Tumor growth‐free survival rates, treatment‐free survival rates, and rates of maintenance of class A, B, or C hearing were estimated using the Kaplan–Meier method. Results In total, 123 patients with very small VS and a referent cohort of 326 patients were studied. Seventeen patients with very small VS experienced tumor growth at a median of 3.2 years after diagnosis (IQR 2.6–5.1), demonstrating a median growth rate of 1.0 mm per year (IQR 0.9–1.8). In comparison, 167 of the patients in the referent cohort experienced tumor growth at a median of 1.7 years after diagnosis (IQR 0.8–3.1). Tumor growth‐free survival rates (95% CI, number still at risk) at 5 years after diagnosis for the 2 cohorts were 84% (75–93, 39) and 45% (40–52, 100), respectively ( p < 0.001). Six patients with very small VS underwent treatment after tumor growth at a median of 3.2 years after diagnosis (IQR 3.2–3.8), compared with 138 patients in the referent cohort at a median of 2.2 years after diagnosis (IQR 1.4–3.6). Treatment‐free survival rates (95% CI, number still at risk) at 5 years after diagnosis for the 2 cohorts were 92% (86–98, 55) and 54% (49–61, 125), respectively ( p < 0.001). Among the 105 patients with very small VS and class A, B, or C hearing at diagnosis, 3 progressed to class D. Comparatively, among the 225 patients in the referent cohort with class A, B, or C hearing at diagnosis, 70 progressed to class D at a median of 2.6 years after diagnosis (IQR 1.0–4.8). Rates of maintenance of class A, B, or C hearing (95% CI, number still at risk) at 5 years after diagnosis were 96% (92–100, 28) for patients with very small VS and 65% (57–73, 70) for the referent cohort ( p < 0.001). Conclusions The natural history of tumor growth and hearing for very small VS diverges favorably from the cumulative natural history data and provides a more appropriate benchmark to compare clinical outcomes of upfront surgery or radiosurgery for this population. At 5 years after diagnosis, 96% of very small VS maintained class A, B, or C hearing and only 8% received treatment for growth within this multicenter cohort. Cumulatively, these data substantiate initial wait‐and‐scan management via size threshold surveillance in this population. Level of Evidence 3.

Objective To assess Advanced Bionics (AB) HiRes Ultra and Ultra 3D initial version (V1) cochlear implant electrode failures over time at four large cochlear implant programs. Study Design Retrospective cohort. Setting Four tertiary referral centers. Patients Patients receiving AB HiRes Ultra and Ultra 3D initial version (V1) devices as of December 31, 2022. Main Outcome Measures Failure rate, revision surgery, speech recognition scores. Results Over a span of 7 years, 205 (42.6%) of 483 implanted V1 devices have failed. Device failure rate varied across institutions from 32 to 67%. Of the 205 detected failures, 163 (79%) have undergone revision surgery, with 94% of revisions being performed with Advanced Bionics devices. Average time from implantation to diagnosis of device failure was 2.7 ± 1.2 years. Most patients (89.8%) with available testing were matched or exceeded their best prefailure speech performance after implant revision. After revision, patients had an average CNC score improvement of 24.7 percentage points over their most recent pre-revision scores and demonstrated average datalogging of 12.7 ± 4.1 h/d at most recent evaluation. Conclusions Comparison of patients across multiple high-volume implant centers confirms the presence of ongoing device failures. There is variability across institutions in the rate of revision surgery once a patient is diagnosed with a V1 device failure, as well as in the rate of device failure detection. Inter-institutional variability in failure rates may be explained by the variation in the routine use of electrical field imaging. Reimplantation with a new device typically results in a return to prefailure peak performance. Professional Practice Gap & Educational Need To our knowledge, a comparison of AB HiRes (V1) device failures across multiple institutions has not been conducted. Learning Objective To identify device failure rate across multiple institutions with different testing protocols. Desired Result Providers will have an improved understanding of the trajectory of device failures for HiRes (V1) devices over time. Level of Evidence Level IV—Historical cohort or case-controlled studies. Indicate IRB or IACUC IRB #230017; IRB #22-000183; IRB #STU-032018-085; IRB #H-49479.

Abstract Objective To evaluate the safety and outcomes of cochlear implantation (CI) in patients with ventriculoperitoneal (VP) shunts to inform clinical practice. Study Design Historical cohort study. Setting Tertiary referral centers. Methods A multi‐institutional historical cohort of patients with VP shunts and CI was identified and analyzed. Results A total of 46 patients (median age 8 years [interquratile range, IQR: 2‐46]) with VP shunts and CI were identified. Of these, 41 (89%) patients had a VP shunt prior to CI. Based on institutional preference and individual patient factors, CI was performed contralateral to a pre‐existing VP shunt in 24 of these 41 cases (59%) and ipsilateral in 17 (41%). Furthermore, pre‐CI relocation of the VP shunt was performed in 3 cases (7%), and 2 patients (5%) underwent planned revision of their VP shunt concurrent with CI. In total, 2 of 27 pediatric patients (7%) required unanticipated revision shunt surgery, both contralateral to CI device placement, given VP shunt malfunction. One of 19 adult patients (5%) required shunt revision during CI due to shunt damage noted intraoperatively. Among 43 patients with available follow‐up, 38 (88%) are regular CI users, with a median consonant‐nucleus vowel‐consonant word: score of 58% (IQR: 28‐72). Conclusion CI can be performed at low risk, either contralateral or ipsilateral, to a VP shunt, and does not mandate shunt revision in most cases. Additional considerations regarding CI receiver‐stimulator placement are necessary with programmable shunts to mitigate device interaction. Preoperative planning, including coordination of care with neurosurgery, is important to achieving optimal outcomes.