Endoscopic laser surgery in severe second-trimester twin-twin transfusion syndrome: a three-year experience from a Latin American center.
OBJECTIVE
In order to assess the outcome of pregnancies complicated by severe second trimester twin-twin transfusion syndrome (TTTS) undergoing treatment with endoscopic laser surgery, we reviewed our experience following the implementation of an institutional fetal surgery program.


METHODS
Patients presenting with monochorionic-diamniotic twin pregnancies complicated by severe TTTS before 26 weeks of gestation were offered endoscopic laser surgery to coagulate placental vascular anastomoses. Using regional anesthesia and guided by real-time sonography, anastomoses were identified and selectively coagulated. At the end of the procedure, amniodrainage was performed to restore normal amniotic fluid volume. Follow-up and delivery were carried out at the referring institutions. Six-month follow-up was performed in all cases.


RESULTS
During a 3-year period from September 2003 to December 2006, 33 consecutive cases of severe TTTS were operated on at a median gestational age of 21 weeks (range 17-25). Nine (27.3%) cases were classified as stage II, 21 (63.6%) as stage III, and three (9.1%) as stage IV. The placenta was anterior or predominantly anterior in 15 (45.5%) of the cases. Overall, both twins were born alive in 16 (48.5%) cases, only one twin was born alive in 11 (33.3%), and neither was born alive in the remaining six (18.2%). Therefore, 81.8% (27 of 33) of the pregnancies resulted in at least one liveborn infant. Among them, the mean gestational age at delivery was 32 weeks (range 23-38) and the mean birthweight of the liveborn infants was 1591 g (range 350-3800). Thirty-four infants survived the perinatal period, yielding an overall perinatal survival rate of 51.5%, with 75.8% (25 of 33) of the pregnancies resulting in at least one perinatal survivor. All neonatal deaths were associated with extreme prematurity.


CONCLUSIONS
This preliminary experience suggests that selective laser coagulation appears to be a good treatment option in cases of monochorionic twin pregnancies complicated by severe TTTS. However, technical skills and adequate equipment are required for implementing a fetal surgery program. Auditing outcomes during the learning curve would help in identifying potential problems.
Sepulveda
Waldo
W
Fetal Medicine Center, Department of Obstetrics and Gynecology, Clinica Las Condes, Santiago, Chile. fetalmed@yahoo.com
Wong
Amy E
AE
Dezerega
Victor
V
Devoto
Juan C
JC
Alcalde
Juan L
JL
D000328:Adult; D001724:Birth Weight; D004724:Endoscopy / Q000379:methods; D005260:Female; D005330:Fetofetal Transfusion / Q000601:surgery*; D005332:Fetoscopy / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D053685:Laser Therapy; D007843:Latin America; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D014427:Twins