Frailty Measures for Adult Patients and Outcomes for Vestibular Schwannoma Surgeries: A Retrospective Cohort Study

Background

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Objectives

To determine whether preoperative frailty [5-item/11-item modified frailty index (mFI-5/mFI-11)] independently predicts length of stay (LOS) and early facial nerve function after vestibular schwannoma (VS) resection when adjusting for tumor and operative factors at a single center with standardized postoperative care.

Methods

This was a single-center, institutional review board-approved, retrospective review of consecutive adults undergoing microsurgical VS resection from 2014 to 2025. Candidate predictors included mFI-5, mFI-11, age, temporal muscle thickness, tumor size, surgical approach, preoperative nonauditory cranial nerve deficits, immediate postoperative facial nerve function, and ventriculoperitoneal shunt requirement. Primary outcomes were LOS (days) and House-Brackmann (HB) grade at discharge, modeled with negative binomial and cumulative odds ordinal logistic regression, respectively (two-sided α = 0.05).

Results

Among 192 patients, larger tumor size was independently associated with longer LOS (adjusted incidence rate ratio [IRR] 1.16 per cm, 95% CI, 1.03-1.31) and worse early facial nerve outcomes. The translabyrinthine approach was associated with shorter LOS than retrosigmoid (IRR 0.72, 95% CI, 0.53-0.96) and ventriculoperitoneal shunt prolonged hospitalization (IRR 2.51, 95% CI, 1.63-3.86). Discharge HB grade was most strongly associated with preoperative HB grade. In contrast, mFI-5 and mFI-11 were not independently associated with LOS or discharge HB (mFI-5 LOS IRR 1.14, 95% CI, 0.99-1.32, P = .07; mFI-11 IRR 1.08, 95% CI, 0.98-1.20, P = .13). Higher mFI-5 was associated with nonhome discharge univariably (P = .017). Substituting individual comorbidities for frailty indices did not materially alter findings.

Conclusion

In VS microsurgery, tumor size rather than frailty was the dominant correlate of early postoperative outcomes after adjustment. Because frailer patients are often selected out before elective surgery, the null adjusted association does not prove frailty is clinically irrelevant but reflects its limited incremental value among already-fit patients. Counseling should prioritize tumor characteristics and surgical approach. These hypothesis-generating findings warrant prospective multicenter confirmation.