In addition to routine post-operative care, participants assigned to the nurse-led prevention arm receive:

• Graded early-movement plan starting within 24 h of surgery
• Unconscious patients: passive leg exercises 10-15 min, 3× daily
• Conscious patients: assisted leg, sitting and walking sessions escalated daily (target ≥ 40 min total activity, logged automatically by a wrist-band activity tracker)
• Intermittent pneumatic compression (IPC)
• 2 h/session, 2× daily, 30-45 mmHg while in bed, continued until independent walking
• D-dimer blood checks on post-op days 1, 3, 7 and 14; any rise ≥ 20 % or level > 2 mg/L triggers an extra leg ultrasound
• Continuous safety watch (heart rate, blood pressure, intracranial pressure if monitored); IPC or movement is paused if pressure > 20 mmHg or vital signs become unstable

All steps are recorded in the electronic nursing chart and coordinated by a neurosurgery-rehabilitation-data

Participants in the control arm receive the hospital's standard post-neurosurgical care, which follows current Chinese and U.S. VTE-guidelines and includes:

• Routine hydration and general health-education advice
• Graduated compression stockings (class II, knee-high) worn 8-12 h each day until the patient is walking independently
• Gentle passive leg movements (about 10 min, 1-2 times daily) when nursing staff judge it safe
• Low-molecular-weight heparin (40 mg enoxaparin subcutaneous once daily) only for patients judged to be at low bleeding risk (Caprini 4-7) and with no intracranial hemorrhage

No systematic Caprini re-assessments, no scheduled early-mobilization protocol, no IPC machines, no D-dimer surveillance, and no activity trackers are used.

Graded early-movement plan starting within 24 h of surgery

• Unconscious patients: passive leg exercises 10-15 min, 3× daily
• Conscious patients: assisted leg, sitting and walking sessions escalated daily (target ≥ 40 min total activity, logged automatically by a wrist-band activity tracker) Intermittent pneumatic compression (IPC)
• 2 h/session, 2× daily, 30-45 mmHg while in bed, continued until independent walking D-dimer blood checks on post-op days 1, 3, 7 and 14; any rise ≥ 20 % or level > 2 mg/L triggers an extra leg ultrasound Continuous safety watch (heart rate, blood pressure, intracranial pressure if monitored); IPC or movement is paused if pressure > 20 mmHg or vital signs become unstable

diagnosed by blinded duplex ultrasound using standard non-compressibility or intraluminal thrombus criteria.

Time from surgery to first objectively confirmed DVT (days)

All-cause mortality within 30 days