經尿道導尿管對小兒尿動力學檢查結果之影響

曾聖修、林利憶、趙梓辰、楊緒棣、蔡秉軒、陳仲均、陳品鍵

佛教慈濟醫療財團法人台北慈濟醫院 外科部 泌尿科 

The impact of transurethral catheterisation on urodynamic results in paediatric patients

Shen-Shiou Tseng, Li-Yi Lim, Tzu-Chen Chao, Shei-Dei Yang, Pin-Hsuan Tsai, Chung-Chun Chen, Pin Jian Tan

Divisions of Urology, Department of Surgery, Taipei Tzu Chi Hospital, New Taipei, Taiwan 

Purpose: Transurethral catheters may modify voiding mechanics and confound interpretation of paediatric urodynamics. We quantified the effect of catheterisation on flow and voiding efficiency.

Materials and Methods: We retrospectively reviewed children/adolescents (<18 years) who underwent free uroflowmetry followed by two urodynamic studies at our centre (Jan 2017–Dec 2022): one with an 8-Fr urethral catheter in place during voiding and one with the catheter removed for voiding. Bladders were filled with sterile water at 10% expected bladder capacity (EBC) per minute to EBC or maximum urge (EBC = [age+1]×30 mL). Outcomes included maximum flow rate (Q_max), post-void residual (PVR), and voiding efficiency (VE = voided volume/bladder volume). Group comparisons used Kruskal–Wallis tests (α=0.05).

Results: Seventy-six patients were included (33 girls, 43 boys; mean age 10.2±4.3 years). Median (IQR) Q_max was 12.7 mL/s (8.8–18.5) for free flow, 5.0 (1.4–9.5) with catheter, and 10.2 (4.7–14.4) without catheter during urodynamics (p<0.001). Median PVR was 9.9 mL (3.6–27.7), 25.0 (0–103.0), and 0 (0–25.3), respectively (p<0.001). VE was 93.0% (83.4–96.8), 79.2% (31.2–100), and 100% (80.3–100), respectively (p<0.001). Diagnostic discrepancies between catheterised and catheter-free urodynamics occurred in 8/76 (10.5%), including failure to void with the catheter that resolved after removal and one missed posterior urethral valve detected on catheter-free videourodynamics.

Conclusions: An 8-Fr urethral catheter substantially depresses Q_max, reduces voiding efficiency, increases PVR, and can alter diagnosis in paediatric urodynamics. Interpretation should account for catheter effects; whenever feasible, obtain a free uroflow, use the smallest suitable catheter, and consider a catheter-free voiding phase to improve diagnostic validity.