Fetal Bladder Shunt for Bladder Outlet Obstruction (BOO)  

Vesicoamniotic shunt surgery, or fetal bladder shunting, can help bypass bladder obstructions in a fetus.  

Bladder outlet obstruction (BOO), which is also known as lower urinary tract infection obstruction (LUTO), is a rare birth defect that occurs in about 1 out of every 5,000 to 7,000 births. The condition most commonly affects male fetuses and occurs when there is a partial or complete blockage or obstruction of the urethra. This tube connects the bladder to the amniotic fluid that surrounds the fetus in the placenta.  Vesicoamniotic shunt surgery is often used to address this condition and allows for urine to drain through a small tube (shunt) that is placed in the fetus’ bladder and removed after birth.  

What Conditions Can Be Treated With Vesicoamniotic Shunt Surgery? 

Performing vesicoamniotic shunt surgery on a fetal bladder may be used to treat: 

• Urethra atresia (UA) – the complete obstruction of the urethra; may be caused by genetics or chromosomal abnormalities 
• Posterior urethra valves (PUV) – occurs when a flap of tissue obstructs the urethra   
• Triad syndrome – a narrowing of the mid-portion of the urethra that severely restricts urine 

In addition, a urethral blockage hinders the passage of urine into the amniotic fluid, which is an essential process. Without the flow of urine, the levels of amniotic fluid may be reduced and lead to: 

• The underdevelopment of the fetal lungs 
• Increased pressure from uterine walls exerted on the fetus, causing secondary deformation of the face and extremities  
• Pressure on the kidneys and potential kidney damage 

Vesicoamniotic shunt surgery is therefore an extremely important treatment in instances of fetal urethral blockages. 

Vesicoamniotic Shunt Surgery Details 

In utero bladder shunt surgery is an outpatient procedure, during which: 

• You’ll receive antibiotics and IV sedation to sedate you and the baby 
• Using ultrasonographic guidance and color-flow Doppler, a large hollow needed is inserted into the mother’s uterus and into the baby’s bladder. 
• A shunt (small tube) is passed through the opening created to allow the flow of urine from the bladder into the amniotic sac.  
• In some cases, an amnioinfusion may also be necessary to replace low levels of amniotic fluid.  

What to Expect With Fetal Bladder Shunting 

The shunt remains in place until the baby is born. Following birth, you can expect a coordinated effort to complete imaging studies and tests and thoroughly evaluate the child’s kidney and bladder function. Postnatal treatments—such as endoscopic resection or vesicostomy—may be required to address the blockage.  

How Effective is Vesicoamniotic Shunt Surgery? 

Bladder shunt surgery is effective in helping babies with a urethral obstruction survive birth, but the risk for long-term kidney problems is higher. In fact, some children eventually require a kidney transplant. In addition, some children may develop long-term respiratory issues, bladder problems and issues with how their muscles and skeleton grow.  

Careful monitoring plays an important role in bladder outlet obstruction treatment. Expectant mothers at Tampa General Hospital have access to advanced evaluation and high-risk obstetrics treatment services for BOO and other complex fetal conditions.