Objective: To study the clinical effect of fetoscopic laser occlusion of chorioangiopagous vessels (FLOC) in treating twin to twin transfusion syndrome.
Methods: The clinical data of 44 consecutive cases of twin to twin transfusion syndrome (TTTS)who had FLOC in the Department of Obstetrics and Gynaecology of Peking University Third Hospital were reviewed and analyzed for perioperative complications, perinatal outcomes and fetal survival rate.
Results: (1) PATIENT CHARACTERISTICS: the mean maternal age was (29±4) years, the median gestational age at TTTS being primarily diagnosed was 20.4 weeks, the median gestational age at FLOC was 21.2 weeks. According to the Quintero staging system, there were 9 cases had stages progressed before the operation. (2) FLOC parameter and intraoperative complications: 44 cases all could tolerate the operation; there was 1 case of placenta vascular rupture in the operation, no fetal body injury by laser or placental abruption. 3 cases underwent cervical cerclage following FLOC. The average operation time of 41 cases alone with FLOC was (60.1±15.1) minutes. (3) Postoperative complications: the rate of intrauterine fetal death was 15% (13/88), the rate of intrauterine growth restriction after FLOC was 5% (4/88), the rate of membranes rupture less than 28 weeks was 16% (7/44), the rate of TAPS after FLOC was 5% (2/44), the rate of membrane sepration after FLOC was 5% (2/44). (4) Perinatal outcome and survival rate: there were 25 patients after FLOC had delivered in the perinatal period. The average gestational age of delivery was (33.5±2.7) weeks. The donor fetuses survival rate was 88% (22/25), the recipient fetuses survival rate was 100% (25/25). The birth weight of donor fetuses was significantly less than that of recipient fetuses (1 631g vs 2 071 g, P = 0.016). From Quintero staging I to IV, the rate that 44 cases of TTTS had entered the perinatal period was 4/7, 11/14, 7/19, 3/4; both twins survival rates were 4/7, 10/14, 5/19, 3/4; all the fetal survival rate was 8/14, 75% (21/28), 32% (12/38), 6/8, respectively. (5) Compared the early stage (I+II) with the advanced stage (III+IV), the rates that 44 cases of TTTS had entered the perinatal period (71% vs 44%) and that both twins survived (67% vs 35%) had no statistically significance. The rate that all the fetus survived in the early stage was significantly (69% vs 39%) more than that in the advanced stage. (6) All the cases of neoborn were followed up till 1 month postpartum, the donor fetuses and the recipient fetuses had 12 and 5 cases of cardiac abnormalities respectively, each had 1 case of neonatal death and 2 cases of neonatal white matter damage.
Conclusions: FLOC for TTTS is associated with a better survival rate. Quintero staging probably does not effectively predict the fetal diagnosis of TTTS after FLOC. When TTTS diagnosed, the sooner FLOC given, the better fetal prognosis had.