Effectiveness of Risk Analysis Index Frailty Scores as a Predictor of Adverse Outcomes in Lower Extremity Reconstruction.

Abstract

The rising clinical importance of assessing frailty is driven by its predictive capability for postoperative outcomes. This study assesses RAI-rev (Risk Analysis Index) effectiveness in predicting adverse outcomes in lower extremity (LE) flap reconstruction. Analyzing NSQIP data from 2015-2020, we compared demographics, perioperative factors, and 30-day outcomes in all locoregional and free flap cases. Frailty scores, calculated using RAI-rev, were categorized with <15 as non-frail and >35 as the most frail. Adjusted odds-ratios (aOR) for specific complications were calculated using non-frail as the reference group. Frailty scores in locoregional flaps were compared to those in free flaps. We identified 270 locoregional and 107 free flap cases. Higher RAI-rev scores in locoregional flaps correlated with increased complications, such as deep surgical site infection (1% non-frail vs. 20% RAI 31-35), stroke (0% non-frail vs. 17% most-frail), and mortality (0% non-frail vs. 17% most-frail). Locoregional flap cases with RAI-rev scores in the most-frail group had a significantly elevated aOR for stroke (51.0, 95% CI: 1.8-1402.5, p=0.02), mortality (43.1, 95% CI: 1.6-1167.6, p=0.03), and any complication (6.8, 95% CI: 1.2-37.4, p=0.03). In free flap cases, higher RAI-rev scores were associated with increased complications, with only sepsis showing a statistically significant difference (6% non-frail vs. 100% most-frail; aOR 42.3, CI: 1.45 - 1245.3, p=0.03). Free flap cases had a significantly lower RAI-rev score compared to locoregional flap cases (14.91 vs. 17.64, p=0.01). Elevated RAI-rev scores (>35) correlated with more complications in locoregional flaps, while free flap reconstruction patients had generally low RAI-rev scores. This suggests that free flaps are less commonly recommended for presumed higher-risk patients. The study demonstrates that RAI-rev may be able to serve as a risk calculator in lower extremity reconstruction, aiding in the assessment of candidates for limb salvage versus amputation.