Selective versus non‐selective laser photocoagulation of placental vessels in twin‐to‐twin transfusion syndrome

Objective We have recently described a surgical technique for the treatment of twin‐to‐twin transfusion syndrome (TTTS) that allows precise identification of vascular anastomoses (selective laser photocoagulation of communicating vessels, or S‐LPCV). The purpose of this study was to compare S‐LPCV with the previous non‐selective technique (NS‐LPCV) that targeted all vessels crossing the dividing membrane. Materials and Methods Patients with TTTS were treated with NS‐LPCV from May 1994 to June 1997 and with S‐LPCV from July 1997 to December 1999. TTTS was defined as polyhydramnios of ≥8 cm maximum vertical pocket (MVP) in the recipient twin and oligohydramnios of ≤2 cm MVP in the donor twin. Outcome was measured as survival per number of pregnancies and per number of fetuses together with limited morbidity data. Results NS‐LPCV was used in 18 patients and 74 were treated with S‐LPCV. Three patients interrupted their pregnancies electively after surgery (S‐LPCV) and were removed from further analysis. Survival of at least one fetus was higher in S‐LPCV (83.1%) than in NS‐LPCV (61.1%) (P = 0.04), mostly due to a lower rate of dual intra‐uterine fetal demise in S‐LPCV (5.6%) than in NS‐LPCV (22%) (P = 0.05). There were more hydropic fetuses in the NS‐LPCV group (27%) than in the S‐LPCV group (5.4%), but this difference did not account for the results. There was no difference in the survival per number of fetuses between the two groups. Conclusions S‐LPCV represents an important evolution in the surgical treatment of TTTS. The use of this technique by all centers should allow better comparison of fetal survival and morbidity rates. S‐LPCV should be the standard technique in trials comparing amniocentesis versus laser for the treatment of severe TTTS. Copyright © 2000 International Society of Ultrasound in Obstetrics and Gynecology