[Fetoscopic guided laser occlusion for twin-to-twin transfusion syndrome in 33 cases].

OBJECTIVE: To evaluate the clinical effect of fetoscopic laser occlusion of chorioangiopagous vessels (FLOC) for monochorionic diamniotic twins (MCDA) pregnancies complicated with twin-to-twin transfusion syndrome(TTTS). METHODS: The clinical data of 33 consecutive cases of TTTS from Mainland China, who had FLOC in the Department of Obstetrics and Gynaecology of Prince of Wales Hospital (The Chinese University of Hong Kong) from November 2003 to December 2010, were reviewed and analyzed for peri-operative complications, perinatal outcomes and fetal survival rate. Clinical stage of TTTS was according to the Quintero staging system. RESULTS: (1) Pregnancy characteristics: the mean maternal age was 30; the median gestational age at FLOC was 23(+4) weeks; according to the Quintero staging system, 3 cases were Quintero staging I, 14 cases were Quintero staging II, 7 cases were Quintero staging III and 9 cases were Quintero staging IV. For the 3 stage I cases, FLOC was performed for severe maternal symptoms of polyhyramnios or severe fetal cardiac dysfunction. (2) COMPLICATIONS: intraoperative complications occurred in 5 patients including four uterine bleedings at the puncture site, one placental vascular anastomosis bleeding. Postoperative complications occurred in 6 patients including 2 abortions and 1 intrauterine death within one week after operation, 2 abortions and 1 amniotic band syndrome occurred from two to four weeks after operation. (3) Perinatal outcome and fetal survival rate: the median interval of 33 patients between FLOC and delivery was 9(+4) weeks; the median gestational age at delivery was 31(+6) weeks; the gestation at delivery was less than 24 weeks in 6% (2/33), 24 to 28 weeks in 21% (7/33), 28 to 32 weeks in 18% (6/33), 32 to 37 weeks in 55% (18/33). The mean birth weight of the donor was 1600 g (350 - 2520 g); the mean birth weight of the recipiert was 1930 g (400 - 3040 g). The overall survival rate, the double infant survival rate, the single survival rate and survival rate for at least one twin was 59% (39/66), 52% (17/33), 15% (5/33) and 67% (22/33), respectively. The overall survival rate dropped from 61% (17/28) in Quintero staging II to 9/18 in Quintero staging IV. CONCLUSIONS: FLOC for MCDA complicated with TTTS is associated with an overall survival of about 60%. Major complications are rare. The outcome is not only related to Quintero staging but also the close monitoring and timely termination of pregnancy.

Use of three-dimensional (3D) sonography to assess the true midsagittal plane of fetal spine.

OBJECTIVES: To study the angle of the deviation of a presumed midsagittal plane of the fetal spine from the true midsagittal planes by three-dimensional (3D) ultrasound and to investigate whether the experience of operators has an effect on the degree of this deviation. METHODS: Eight sonographers, four were trained to perform routine anomaly scan (Trained Group) and four were trained to perform fetal biometric measurement only (Non-trained Group), were asked to use a 3D transducer to obtain a 2D image which they thought to represent the true midsagittal plane of the fetal spine. A 3D volume was then acquired. Stored volumes were analyzed using the multiplanar mode. In the transverse plane, the angle of the deviation of presumed midsagittal planes from the true midsagittal planes was measured. RESULTS: The mean angle of deviation of the trained group was significantly lower than that of the non-trained group (7.9 vs. 21.1, p < 0.001). There were no significant variations among the four operators within each group. However, even among the Trained Group, the angle of deviation could be as large as 27.2°. CONCLUSIONS: Training improved the ability to obtain a midsagittal plane of the fetal spine. 3D ultrasound might provide potential useful information to guide the acquisition of standard image planes.