Abstract
BACKGROUND: Trigeminal neuralgia (TN) causes severe paroxysmal facial pain and quality-of-life impairment. Percutaneous balloon compression (PBC) is minimally invasive, yet efficacy and complication rates remain variable. We conducted a single-centre prospective cohort study to define phase-specific intraballoon pressure thresholds that maximize pain relief while minimising facial hypoaesthesia and recurrence. METHODS: 115-TN patients undergoing PBC (Jan 2017-Aug 2024) had real-time pressure recorded at 1 Hz. Pressure morphometrics were classified into pear-shaping, maintenance and full-compression phases. Reference intervals (RI) were established with the non-parametric CLSI C28-A2 method (n ≥ 4,000 measurements per phase). Associations between phase pressures and 24-h hypoaesthesia grade or 24-month recurrence were examined with Spearman correlation and Cox regression (Schoenfeld validation). RESULTS: Higher phase pressures correlated with more severe hypoaesthesia (ρ = 0.44-0.62, P < 0.01), whereas lower pressures predicted increased recurrence (HR = 0.87 per 5 kPa, 95% CI 0.80-0.94, P = 0.002). Optimal RI were: pear-shaping 126.5-156.8 kPa, maintenance 117.9-136.1 kPa, full-compression 119.9-141.9 kPa. Operating within these bands produced BNI-I/II pain relief in 98% of patients with only 16% transient Grade-III hypoaesthesia. CONCLUSION: Real-time, phase-adapted pressure control within the proposed RI allows surgeons to standardize PBC while individualizing the therapeutic window, improving safety and durability of pain relief.