Optimal hematoma volume cutoffs and efficacy of minimally invasive surgery for thalamic hemorrhage: a propensity score-matched analysis

Spontaneous thalamic hemorrhage (TH) is associated with substantial morbidity and mortality. The optimal hematoma volume (HV) thresholds for prognostic stratification and the comparative effectiveness of minimally invasive surgery (MIS) versus conservative treatment remain uncertain. We retrospectively analyzed consecutive patients with spontaneous TH admitted to a comprehensive stroke center n = 436 using a two-stage design. Stage 1: In the conservatively treated cohort n = 280, predictors of poor 90-day functional outcome (modified Rankin Scale mRS 3–6) were identified using multivariable logistic regression; a prognostic nomogram was constructed and validated. Receiver operating characteristic (ROC) analyses were used to determine HV cutoffs for predicting poor functional outcome and mortality. Stage 2: Patients with HV ≥ 7 mL were included in a comparative effectiveness analysis of MIS versus conservative treatment n = 208. Propensity score matching (PSM) was performed (1:1 nearest-neighbor without replacement; caliper = 0.2 SD of the logit of the propensity score) to balance baseline covariates, including age, sex, systolic blood pressure (SBP), Glasgow Coma Scale (GCS), National Institutes of Health Stroke Scale (NIHSS), intraventricular hemorrhage (IVH), Graeb score, and HV. In conservatively treated patients n = 280, older age, higher SBP, and larger HV were independently associated with increased odds of poor 90-day outcome, whereas higher GCS was protective. The nomogram demonstrated good performance. ROC analyses identified 7 mL as the optimal HV cutoff for predicting poor functional outcome AUC = 0.86, and 13 mL for predicting mortality AUC = 0.81. After PSM in patients with HV ≥ 7 mL (n = 102; 51 matched pairs), MIS was associated with lower 90-day mortality compared with conservative treatment 9.8% vs. 29.4%, P = 0.01. However, the rate of functional independence did not differ significantly between groups 31.4% vs. 33.3%, P = 0.83. HV is a key prognostic marker in TH, with 7 mL and 13 mL serving as clinically relevant thresholds for functional impairment and mortality, respectively. Among patients with HV ≥ 7 mL, MIS was associated with reduced 90-day mortality but not improved functional independence compared with conservative treatment. This study adheres to the principles of the Declaration of Helsinki and is retrospectively registered in ClinicalTrials.gov (No. NCT05548530),Registration Date:08/31/2022.