Fetoscopy for Twin-to-Twin Transfusion (TTTS)
Fetoscopy involves placing a thin lighted camera into the womb to examine the baby and provide treatment as needed. The fetoscopy procedure for twin-twin transfusion is a procedure called selective laser photocoagulation (S-LPC), which separates the circulation between the two babies. The goal of the procedure is to use laser energy to block or seal off only the communicating vessels connecting the two babies so that they no longer share blood. This is done using a device called a fetoscope, which is a medical telescope, inserted through the mother’s belly and amniotic sac. There are other blood vessels in the placenta that do not allow sharing of blood between the twins and the doctor works to avoid touching them. Only the vessels connecting the two babies are touched because the others bring nourishment to areas of the placenta that belong to each baby.
Normally the procedure is performed under sedation and local anesthesia but in some cases epidural anesthesia (medicine given through the spinal column in which patient is still awake) or general anesthesia (medicine delivered through an IV and breathing equipment which makes the patient very sedated or unconscious) may be necessary. There are cases in which the babies may still be able to move even with local or epidural anesthesia. In those cases, a muscle-blocking drug is injected into the thigh of the recipient twin with a very thin needle. This keeps the baby from moving in order to perform the surgery.
After anesthesia is provided, a small incision is made on your abdomen and a trocar (narrow metal tube) is inserted into the amniotic sac of the recipient twin. The fetoscope inside a protective operating tube is passed through the trocar to observe the blood vessels on the surface of the placenta. An examination will identify the blood vessels that link the circulations between the twins. Only those blood vessels will be sealed off (photocoagulated) using laser energy. The laser will emit short pulses of energy lasting about 3 to 4 seconds for each blood vessel. The laser will be used repeatedly to seal off all of the identified blood vessels. Excess amniotic fluid may be removed from the recipient twin at the end of surgery. Antibiotics will be provided before and after surgery to prevent infection.
You can expect to remain in the hospital for 1-2 days after surgery. The day after surgery, you will have an ultrasound examination to look at the condition of the babies. For at least the next four weeks after surgery, you will be asked to return to your doctor for weekly ultrasounds. Your specialist will continue to monitor the condition of you and your babies.