Preoperative Frailty Risk in Cranioplasty Patients: Risk Analysis Index Predicts Adverse Outcomes

Cranioplasty is a common surgical procedure used to repair cranial defects, and it is associated with significant morbidity and mortality. Although frailty is a strong predictor of poor postoperative outcomes across surgical specialties, little is known about frailty's impact on cranioplasty outcomes. This study examined the association between frailty and cranioplasty by comparing the effect of the Risk Analysis Index-Administrative (RAI-A) and the Modified Frailty Index-5 (mFI-5) on cranioplasty outcomes.

The National Surgical Quality Improvement Program was queried for patients undergoing cranioplasty between 2012 and 2020. Receiver operating characteristics and multivariable analyses were used to assess the relationship of postoperative outcomes and the RAI-A, mFI-5, and increasing patient age.

There were 2864 included study patients with a median age of 57 years (IQR, 44-67), and a higher proportion of patients were women (57.0%) and White (68.5%). The RAI-A had a more robust predictive ability for 30-day mortality (C-Statistic, 0.741; 95% confidence interval (CI), 0.678-0.804) compared with mFI-5 (C-Statistic, 0.574; 95% CI, 0.489-0.659) and increasing patient age (C-Statistic, 0.671; 95% CI, 0.610-0.732). On multivariable analyses, frailty was independently associated with mortality and other poor postoperative outcomes (P < 0.05).

The RAI-A demonstrated superior discrimination than the mFI-5 and increasing patient age in predicting mortality. Additionally, the RAI-A showed independent associations with nonhome discharge and postoperative complications (CDII, CDIIIb, and CDIV). The high rates of operative morbidity (5.0%-36.5%) and mortality (0.4%-3.2%) after cranioplasty highlight the importance of identifying independent risk factors for poor cranioplasty outcomes.