Fetoscopic Laser Therapy for Twin-Twin Transfusion Syndrome

Ever since the first randomized, controlled trial revealed that fetoscopic laser photocoagulation achieved better outcomes than serial amnio-drainage for all stages of twin-twin transfusion syndrome (TTTS) before 26 weeks, many centers have launched their fetoscopic laser therapy program for TTTS. Initially the nonselective method of laser therapy was applied, using the dividing membrane as a landmark to coagulate the placenta vessels, but currently selective methods (selective laser photocoagulation of communicating vessels (SLPCV), sequential SLPCV, and Solomon technique) have evolved to become the mainstream laser treatment modalities. Nevertheless, the nonselective method still has a role in difficult operations. Over the years, with regard to the prognoses of TTTS treated by laser, the attention has gradually shifted from survival rate to the neurological outcomes. The incidence of severe neurodevelopmetal delay remains considerably high in survivors of TTTS treated by FLP, which some reports cited ranging from 6 % to 18 %; learning curve effect exists, affecting both the survival rate and neurological outcomes of TTTS treated by laser. Because more, yet smaller and less-experienced, centers are being set up worldwide, the purpose of this manuscript is to review the basic knowledge and update information about the laser therapy for TTTS.