For many conditions, “fetal surgery” can refer to a minimally invasive procedure in which the physician uses a needle and thin telescope to treat problems. These less-invasive techniques are safer for both mother and baby, and can be used to treat many conditions with positive outcomes.
These minimally invasive techniques include:
Fetal transfusions: Transfusions are performed when the physician places a needle into the baby’s umbilical cord to provide donor blood to the baby. One condition that would require transfusion is fetal anemia.
Shunt Placement: A surgeon places a small tube, known as a shunt, between the chest and amniotic fluid or the bladder and amniotic fluid. The shunt helps drain the chest or bladder.
Ablation of lesions: Lesions on the fetus can be removed by using ablation, a technique that uses lasers to target the area to be removed.
Common fetal health conditions that are often treated by therapeutic fetal procedures include:
Twin-Twin Transfusion Syndrome (TTTS): Occurs when the developing fetuses of twins in the womb share a placenta that contains abnormal blood vessels. These blood vessels connect the umbilical cords and circulatory systems of the twins. One twin receives more blood than the other – a condition that is harmful to both the baby who doesn’t receive enough blood and the baby who receives too much.
Treatment of TTTS depends largely on how far the syndrome has progressed. One treatment that has been used successfully is fetoscopic laser photocoagulation, in which a thin fiber is inserted through an incision in the mother’s stomach. Blood vessels that are connected between the twin fetuses are closed using the laser technology, and extra amniotic fluid is removed from around the larger twin to regulate.
Amniotic Band Syndrome (ABS): Refers to a condition in which strands of the amniotic sac’s inner lining (amnion) attach to the fetus. These amniotic strands can wrap themselves around body parts and constrict blood flow, making amputation of limbs and birth defects a concern. There is also a strong link between ABS and the birth defect known as clubfoot.
Treatment of ABS is typically performed immediately after the baby is born. In rare cases, fetal intervention may be performed to remove amniotic bands that may amputate a limb or threaten the umbilical cord. One fetal treatment for amniotic band syndrome is fetoscopic laser photocoagulation, in which the amniotic bands constricting the fetus are removed using a fetoscopic laser. Extensive consultations and advanced diagnostics are needed before using fetal surgery to correct ABS, as every case is different and presents a unique set of challenges.
Twin Reversed Arterial Perfusion Sequence (TRAP): A rare birth condition in which a fetus born without a functioning heart takes the blood supply from its fully formed twin, known as a “pump” twin. The heart of the pump twin has to work harder to compensate for the blood that is being taken by the nonviable, acardiac twin. This overexertion of the developing heart puts the pump twin at risk for heart failure.
Treatment of TRAP includes radiofrequency ablation, a procedure in which a very thin needle is inserted into a major blood vessel of the acardiac twin. Special radiofrequency currents are passed into the acardiac fetus’ body, where they burn the area around the major blood vessel to stop the flow. Without the acardiac twin collecting all the blood, this allows the normal fetus to commence the blood circulation it needs to grow and thrive. Another method that may be used is bipolar cord coagulation, in which a needle and fetoscope is placed into the amniotic area of the uterus. The fetoscope is used to determine what space would be best for cauterization, a process which stops blood flow to the abnormal fetus. This procedure often needs to be performed more than once to work effectively.