Psoas Muscle Density and Charlson Comorbidity Index on Disposition in Head and Neck Surgery

Introduction: Determining operative risk in patients undergoing head and neck free flap surgery has traditionally been difficult. Psoas muscle mass, a proven frailty marker in abdominal surgery, has not been evaluated in this population. This study demonstrates the potential of radiologic sarcopenia and clinical frailty to identify patients at higher risk for unfavorable discharge disposition and prolonged ICU stay.

Methods: A retrospective review was performed on 95 patients who underwent head and neck free flap surgery between 2014 and 2024 and had preoperative abdominal or pelvic CT scans. Psoas muscle area was measured bilaterally at L3, and Psoas Muscle Index (PMI) was calculated as total area divided by patient height squared (cm²/m²). Patients were stratified into grades (G) by PMI percentiles: G1 (0-25th), G2 (25-50th), G3 (50-75th), and G4 (75-100th). PMI grades and post-operative outcomes were analyzed alongside Charlson Comorbidity Index (CCI) to assess the impact of radiologic sarcopenia and clinical frailty on surgical risk and recovery.

Results: Discharge home differed significantly across CCI frailty groups (p = 0.017), with more “Less Frail” patients discharged home (100%) compared to “Frail” (58%) or “Severely Frail” (48%). Higher CCI reduced odds of discharge home (OR = 0.75, 95% CI: 0.57-0.99). Compared to G1, higher PMI grades had increased odds of discharge home: G2 (OR=2.78, 95% CI: 0.83-9.35), G3 (OR=1.44, 95% CI: 0.45-4.68), and G4 (OR=3.23, 95% CI: 0.93-11.2). Higher PMI was also significantly associated with shorter ICU length of stay (p = 0.003).

Conclusions: Radiologic sarcopenia measured by PMI and clinical frailty assessed by CCI independently predict discharge disposition, while only PMI is significantly associated with ICU length of stay. Incorporating PMI may improve risk stratification and postoperative management in head and neck free flap patients.