Aggregate Index of Systemic Inflammation and Complicated Clinical Course in Surgically Managed Sinusitis-Related Subperiosteal Orbital Abscess

This study evaluated the association between admission Aggregate Index of Systemic Inflammation (AISI) and complicated clinical course in surgically managed patients with sinusitis-related subperiosteal orbital abscess (SPOA). Thirty-four patients with sinusitis-related SPOA who underwent surgical drainage in addition to systemic antibiotic therapy between June 2020 and January 2026 were retrospectively reviewed. A complicated clinical course was defined as the occurrence or persistence of an intracranial complication and/or requirement for repeat surgical intervention after initial drainage during the same hospitalization. AISI, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic immune-inflammation index, C-reactive protein, white blood cell count, and absolute neutrophil count were evaluated. A complicated clinical course occurred in 8 patients (23.5%); 5 developed intracranial complications, 5 required repeat surgical intervention, and 2 met both criteria. AISI was significantly higher in the complicated group than in the uncomplicated group (median: 3869 versus 1364; P =0.021), whereas other inflammatory markers did not differ significantly. AISI showed the highest numerical area under the receiver operating characteristic curve among the evaluated markers (AUC: 0.774; 95% CI, 0.596–0.953). A cutoff value of ∼1800 yielded 87.5% sensitivity and 69.2% specificity, although superiority over other markers was not statistically significant on DeLong testing. Admission AISI may serve as an adjunctive, hypothesis-generating marker for early risk stratification in surgically managed sinusitis-related SPOA.