FAQ on treatment of TTTS
Before the introduction of laser treatment for TTTS, severe TTTS resulted in a greater than 90% loss of the pregnancy. Treatment options depend on the gestation at diagnosis. In general, laser is offered between 18 and 26 weeks’ gestation. Prior to 18 weeks’ laser is challenging with increased risks of complications, so is rarely offered.
After 26 weeks’ survival in a neonatal intensive care nursery is generally excellent and mostly conservative treatments such as draining of amniotic fluid is offered rather than laser. If the condition is progressive, delivery can be offered.
If TTTS is diagnosed at any stage of a pregnancy, referral to the Victorian Fetal Therapy Service (VFTS) is recommended so that the TTTS can be assessed. VFTS is a collaboration between the Mercy Hospital for Women, Monash Medical Centre and the Royal Women’s Hospital, with a team of surgeons from each of these sites. Once the TTTS has been assessed by one of the VFTS team, appropriateness for laser surgery can be determined and organised by this surgeon.
All twin laser surgery in Victoria takes place at Monash Medical Centre, as the equipment and laser safety expertise is located at this site. The VFTS surgeons travel to Monash Medical Centre in Clayton for the surgery and at least one doctor from Mercy Perinatal will be present.
Fetoscopic laser surgery involves a procedure under local anaesthetic, whereby an operative endoscope (fetoscope) is inserted through a mother’s abdomen, through the wall of the uterus, and into the sac of the recipient twin. The blood vessels connecting the twins that are causing the TTTS are identified. A laser fibre is passed down the fetoscope, and the laser is fired at these connections to close them. At the end of the procedure, the excessive amniotic fluid is drained from the recipient twin’s sac to reduce the risk of preterm birth or ruptured membranes. Patients are usually admitted overnight and discharged back to their referring hospital for ongoing follow-up.