Membrane Surface Area to Volume Ratio in Chronic Subdural Hematomas: Critical Size and Potential Postoperative Target

Because surgical total SA to V ratio was ≈2:1, one neomembrane may indeed dominate the dynamic growth-resorption equilibrium. CSDH critical size therefore appears to be when SAOM ≈ V, which is intuitive. Practically, subtotal CSDH evacuation which approximately doubles total SA to V ratio or SAOM to V ratio implies CSDH resolution without recurrence. This could guide subdural drain removal timing, discharge, or transfer. Prospective validation studies are required.