Postoperative pneumocephalus in unilateral chronic subdural hematoma and its correlation with recurrence: a retrospective single-center study

However, data on volumetric assessment of subdural air (SA), its risk factors, and correlation with recurrence remain limited.</p> <p>We retrospectively included patients with unilateral CSDH who underwent surgery. Three analyses were performed: (1) comparison of absolute versus relative SA to preoperative hematoma volume (HV) for predicting recurrence; (2) evaluation of the relationship between SA and recurrence using regression and stratification into four SA-volume subgroups; (3) identification of risk factors for pneumocephalus.</p> <p>Recurrence was defined as symptomatic re-accumulation of CSDH requiring re-surgery within the first three months of surgery.</p> <p>142 patients were included.

Absolute SA demonstrated a stronger correlation with recurrence, with a cut-off value of 6.95 ml. Each additional 1 ml of SA was associated with a 4.3% increase in the odds of recurrence, and rates ranged from 12.4% in patients (<7 ml) to 45% (>21 ml) (<i>p</i> < 0.001). Patients with ≥7 ml of SA were older (<i>p</i> = 0.04), more frequently had hemispheric hematomas (<i>p</i> = 0.02), and exhibited greater mass effect, reflected by width, HV, and midline shift (all <i>p</i> < 0.001).