Assessment of thoracoamniotic shunt catheter patency using pulsed‐wave Doppler and color flow mapping: A case report

Thoracoamniotic shunting is an effective treatment for fetal pleural effusion. Catheter obstruction is a serious and frequently occurring phenomenon that often requires re-shunting; however, accurate diagnosis remains challenging. We present a case in which pulsed-wave Doppler and color flow mapping were used to evaluate fluid flow through a thoracoamniotic shunt catheter. The Doppler assessment revealed alternating fast inflow (median: 69.2 cm/s) and slow outflow (median: 19.0 cm/s) synchronized with fetal breathing movements. Following the cessation of fetal breathing movements, a continuous and steady outflow with a constant velocity was observed. This case highlights the potential utility of Doppler ultrasound in assessing catheter patency, providing valuable information for the diagnosis of catheter obstruction in thoracoamniotic shunting.