Twin-to-twin Transfusion Syndrome - Treatment

Treatment

There are a number of different therapies used to treat TTTS, with varying rates of success. The oldest, most traditional treatment is through serial amniocentesis, which involves periodically draining amniotic fluid from around the recipient twin in an effort to reduce the pressure of the amniotic fluid. Because serial amniocentesis increases the risk of premature delivery, it has limited success when performed early in pregnancy, especially before fetal viability. Dr. John Elliot developed the technique of Theraputic Amniocentesis to treat TTTS in 1987. His initial study changed the outcome in TTTS from a mortality of 95% to survival in 76%. (TTTS Foundation website, Aug 2012)

TTTS can also be treated by laser therapy fetal surgery. Dr. Julian DeLia began investigating TTTS in 1983 and pioneered fetoscopic placental laser surgery in 1988 at the University of Utah, Salt Lake City. He subsequently brought his life-saving surgery to Wisconsin and Illinois. Dr. De Lia’s laser procedure is now performed (with some modifications) throughout the United States and the rest of the world. (see De Lia JE: Surgery of the placenta and umbilical cord. Clin Obstet Gynecol 1996;39:607-25).

Dr. Ruben Quintero, utilizing fetoscopy to find the interconnecting blood vessels, and a laser beam to coagulate the blood in these vessels, blocking them. This is called fetoscopic laser ablation, and is only performed in a few hospitals worldwide. Outcomes vary widely from case to case, but as of this writing statistics of fetoscopic laser ablation indicate a 90% chance that at least one twin will survive and 70% for both.

Standard therapy in the United States has most commonly been serial amnioreduction, which appears to improve the overall outcome. Intertwin microseptostomy similarly improves outcome but has no survival advantage over serial amnioreduction. Survivors of TTTS treated by serial amnioreduction have an 18% to 26% incidence of sonographically detectable brain abnormalities. Selective fetoscopic laser photocoagulation of chorioangiopagus has emerged as an alternative treatment strategy in TTTS with at least comparable if not superior survival to serial amnioreduction. The superiority of fetoscopic laser treatment of TTTS remains unproven and is the subject of a National Institutes of Health (NIH)-sponsored prospective randomized clinical trial comparing aggressive serial amnioreduction with selective fetoscopic laser photocoagulation for severe TTTS. More information about treatment follows:

Non-Treatment

Expectant Management

This is equivalent of zero intervention. It has been associated with almost 100% mortality rate of one or all fetuses. Exceptions to this include patients that are still in Stage 1 TTTS and are past 22 weeks gestation.

Treatment through adjustment of amniotic fluid

Serial Amniocentesis

This procedure involves removal of amniotic fluid periodically throughout the pregnancy under the assumption that the extra fluid in the recipient twin can cause preterm labor, perinatal mortality, or tissue damage. In the case that the fluid does not reaccumulate, the reduction of amniotic fluid stabilizes the pregnancy. Otherwise the treatment is repeated as necessary. There is no standard procedure for how much fluid is removed each time. There is a danger that if too much fluid is removed, the recipient twin could die. This procedure is associated with a 66% survival rate of at least one fetus, with a 15% chance of cerebral palsy and average delivery occurring at 29 weeks gestation.

Septostomy, or Iatrogenic Disruption of the Dividing Membrane

This procedure involves the tearing of the dividing membrane between fetuses such that the amniotic fluid of both twins mixes under the assumption that pressure is different in either amniotic sac and that its equilibration will ameliorate progression of the disease. It has not been proven that pressures are different in either amniotic sac. Use of this procedure can preclude use of other procedures as well as make difficult the monitoring of disease progression. In addition, tearing the dividing membrane has contributed to cord entanglement and demise of fetuses through physical complications.

Treatment through adjustment of blood supply

Laser Therapy

This procedure involves endoscopic surgery using laser to interrupt the vessels that allow exchange of blood between fetuses under the assumption that the unequal sharing of blood through these vascular communications leads to unequal levels of amniotic fluid. Each fetus remains connected to its primary source of blood and nutrition, the placenta, through the umbilical cord. This procedure is conducted once, with the exception of all vessels not having been found. The use of endoscopic instruments allows for short recovery time. This procedure has been associated with 85% survival rate of at least one fetus, with a 5% risk of cerebral palsy and average delivery occurring at 33–39 weeks' gestation.

Umbilical Cord Occlusion

This procedure involves the ligation or otherwise occlusion of the umbilical cord to interrupt the exchange of blood between the fetuses. The procedure is typically offered in cases where one of the fetuses is presumed moribund and endangering the life or health of the other twin through resultant hypotension. Use of this treatment has decreased as TTTS is identified and treated in earlier stages and with better outcomes. When used, it is associated with an 85% survival rate of the remaining fetus(es) with 5% risk of cerebral palsy and a 33–39 weeks of gestation at delivery.