BACKGROUND: Intraoperative blood transfer between twins during laser surgery for twin-twin transfusion syndrome can vary by surgical technique and has been proposed to explain differences in donor twin survival.
OBJECTIVE: This trial compared donor twin survival with 2 laser techniques: the sequential technique, in which the arteriovenous communications from the volume-depleted donor to the volume-overloaded recipient are laser-occluded before those from recipient to donor, and the selective technique, in which the occlusion of the vascular communications is performed in no particular order.
METHODS: A single-center, open-label, randomized controlled trial was conducted in which twin-twin transfusion syndrome patients were randomized to sequential vs selective laser surgery. Nested within the trial, a second trial randomized patients with superficial anastomoses (arterioarterial and venovenous) to ablation of these connections first (before ablating the arteriovenous anastomoses) vs last. The primary outcome measure was donor twin survival at birth.
RESULTS: A total of 642 patients were randomized. Overall donor twin survival was similar between the 2 groups (274 of 320 [85.6%] vs 271 of 322 [84.2%]; odds ratio, 1.12 [95% confidence interval, 0.73-1.73]; P=.605). Superficial anastomoses occurred in 177 of 642 cases (27.6%). Donor survival was lower in the superficial anastomosis group vs those with only arteriovenous communications (125 of 177 [70.6%] vs 420 of 465 [90.3%]; adjusted odds ratio, 0.33 [95% confidence interval, 0.20-0.54]; P<.001). In cases with superficial anastomoses, donor survival was independent of the timing of ablation or surgical technique. The postoperative mean middle cerebral artery peak systolic velocity was lower in the sequential vs selective group (1.00±0.30 vs 1.06±0.30 multiples of the median; P=.003). Post hoc analyses showed 2 factors that were associated with poor overall donor twin survival: the presence or absence of donor twin preoperative critical abnormal Doppler parameters and the presence or absence of arterioarterial anastomoses. Depending on these factors, 4 categories of patients resulted: (1) Category 1 (347 of 642 [54%]), no donor twin critical abnormal Doppler + no arterioarterial anastomoses: donor twin survival was 91.2% in the sequential and 93.8% in the selective groups; (2) Category 2 (143 of 642 [22%]), critical abnormal Doppler present + no arterioarterial anastomoses: donor survival was 89.9% vs 75.7%; (3) Category 3 (73 of 642 [11%]), no critical abnormal Doppler + arterioarterial anastomoses present: donor survival was 94.7% vs 74.3%; and (4) Category 4 (79 of 642 [12%]), critical abnormal Doppler present + arterioarterial anastomoses present: donor survival was 47.6% vs 64.9%.
CONCLUSIONS: Donor twin survival did not differ between the sequential vs selective laser techniques and did not differ if superficial anastomoses were ablated first vs last. The donor twin\'s postoperative middle cerebral artery peak systolic velocity was improved with the sequential vs the selective approach. Post hoc analyses suggest that donor twin survival may be associated with the choice of laser technique according to high-risk factors. Further study is needed to determine whether using these categories to guide the choice of surgical technique will improve outcomes.

To characterize the neonatal hemodynamic profiles in recipients born after twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic selective laser coagulation (FSLC). Retrospective analysis during the first month of life of recipient twins. Of the 480 newborns born during an 11-year period, 138 recipient twins with prenatal FSLC were classified into four groups: no hemodynamic impairment (NoHI, n = 102, 74%), isolated high blood pressure (HighBP, n = 18, 13%), right ventricular outflow tract obstruction (RVOTO, n = 10, 7%), and cardiac failure (CF, n = 8, 6%). The time (median (IQR)) between FSLC and birth was significantly shorter in the HighBP (36 days (23-54)) and CF (44 days (18-54)) groups than in the RVOTO (91 days (68-112)) and NoHi (82 days (62-104)) groups (p < 0.001).     Conclusion: Four distinct and well-characterized groups of recipients were identified based on their hemodynamics. High blood pressure and heart failure occurred in approximately 20% of the infants and were associated with a time between laser coagulation and birth of less than 2 months. What is Known: • Twin-to-twin transfusion syndrome (TTTS) is characterized by a hemodynamic imbalance that leads to high fetal and neonatal mortality if left untreated. One-third of recipient twins born without prenatal fetoscopic laser coagulation (FSLC) develop a life-threatening cardiac failure. What is New: • Four distinct groups of recipient twins with prenatal FSLC have been identified based on their hemodynamics. High blood pressure and cardiac failure occurred in 20% of the infants and were associated with an interval between FSLC and birth of less than 2 months.

Background: This paper’s intent is to describe the neonatal hemodynamic characteristics of recipient twins of monochorionic pregnancies complicated with twin-to-twin transfusion syndrome (TTTS), born without prenatal fetoscopic selective laser coagulation (FSLC). Methods: Retrospective analysis of hemodynamic characteristics was performed during the first five days of life of recipient twins from untreated TTTS. Results: Forty-two recipient twins were included and divided into three groups: no hemodynamic impairment (NoHI) (n = 15, 36%), isolated high blood pressure (HighBP) (n = 12, 28%), and cardiac failure group (CF) (n = 15, 36%). Patients of both CF and HighBP groups had high systolic blood pressure during the first 12 h of life and ventricular hypertrophy at early echocardiography. Cardiac failure occurred at a median age of 14 h (IQR = 6−24) and was followed by a drop in systolic and diastolic blood pressure. Acute kidney injury was more frequent (93% vs. 25%, p < 0.001) and severe (p <0.001) in the CF group than in the HighBP group. The mortality rate in the CF group was 40%. Factors associated with CF were twin anemia-polycythemia sequence (p = 0.012), very preterm birth (p = 0.040), and polycythemia (p = 0.002). Conclusion: One-third of recipient twins born without prenatal FSLC developed life-threatening cardiac failure during the first 24 h of life.

BACKGROUND: Right ventricular outflow tract obstruction (RVOTO) is the most frequently encountered congenital heart disease in patients with twin -twin transfusion syndrome (TTTS) and is especially prevalent in the recipient twin. In this retrospective study, we evaluated the incidence, prognosis, postnatal management, and perinatal outcomes of and risk factors for RVOTO in the recipient twin in severe TTTS cases which diagnosed before 26 weeks after fetoscopic laser photocoagulation (FLP) at a single center in Taiwan.
METHODS: RVOTO was diagnosed using fetal or postnatal echocardiography. The fetal outcomes evaluated were perinatal survival rate, neonatal brain image anomalies rate, gestational age at delivery, and birth weight.
RESULTS: Total 187 severe TTTS cases were included; 14 (7.49%) had a recipient twin with RVOTO (12 cases of pulmonary stenosis and 2 of pulmonary atresia). Of these 14 cases, 3 (21.4%) demonstrated improvements in outflow obstruction after FLP, and 11 (78.6%) resulted in perinatal survival. Of the 11 survivors, 5 (45.5%) received transcatheter balloon valvuloplasty to alleviate the RVOTO. The perinatal survival rate, gestational age at delivery, neonatal brain image anomaly rate, and birth weights did not significantly differ between the groups in which the recipient twin had versus did not have RVOTO. Generally, the recipient twin had RVOTO received FLP at a younger gestational age (in weeks; 19.3 ± 2.4 vs. 20.7 ± 2.6, p = 0.048) and had a higher percentage of cases at Quintero stage IV (50.0% vs. 12.1%, p < 0.001) than those in which the recipient twin did not have with RVOTO. Using logistic regression, we discovered that FLP at a younger gestational age (p = 0.046, odds ratio = 0.779) and TTTS at Quintero stage IV (p = 0.001, odds ratio = 7.206) were risk factors for the recipient twin developing RVOTO after FLP in severe TTTS cases.
CONCLUSIONS: The post-FLP perinatal outcomes of cases of severe TTTS in which the recipient twin had versus did not have RVOTO were comparable in this study, which may have been due to the similar gestational ages at delivery and strong influence of high Quintero stages (stages III and IV).

暂无摘要。

Despite improvements in fetal survival for pregnancies affected by twin-twin transfusion syndrome since the introduction of laser photocoagulation, prematurity remains a major source of neonatal morbidity and mortality.
To investigate the indications and factors influencing the timing of delivery following laser treatment, we collected delivery information regarding twin-twin transfusion syndrome cases in a large multicenter cohort.
Eleven North American Fetal Therapy Network (NAFTNet) centers conducted a retrospective review of twin-twin transfusion syndrome patients who underwent laser photocoagulation. Clinical, demographic and ultrasound variables including twin-twin transfusion syndrome stage, and gestational age at treatment and delivery were recorded. Primary and secondary maternal and fetal indications for delivery were identified. Univariate analysis was used to select candidate variables with significant correlation with latency and GA at delivery. Multivariable Cox regression with competing risk analysis was utilized to determine the independent associations.
A total of 847 pregnancies were analyzed. After laser, the average latency to delivery was 10.11 ± 4.8 weeks and the mean gestational age at delivery was 30.7 ± 4.5 weeks. Primary maternal indications for delivery comprised 79% of cases. The leading indications included spontaneous labor (46.8%), premature rupture of membranes (17.1%), and placental abruption (8.4%). Primary fetal indications accounted for 21% of cases and the most frequent indications included donor non-reassuring status (20.5%), abnormal donor Dopplers (15.1%), and donor growth restriction (14.5%). The most common secondary indications for delivery were premature rupture of membranes, spontaneous labor and donor growth restriction. Multivariate modeling found gestational age at diagnosis, stage, history of prior amnioreduction, cerclage, interwin membrane disruption, procedure complications and chorioamniotic membrane separation as predictors for both gestational age at delivery and latency.
Premature delivery after laser therapy for twin-twin transfusion syndrome is primarily due to spontaneous labor, preterm premature rupture of membranes and non-reassuring status of the donor fetus. Placental abruption was found to be a frequent complication resulting in early delivery. Future research should be directed toward the goal of prolonging gestation after laser photocoagulation to further reduce morbidity and mortality associated with twin-twin transfusion syndrome.

BACKGROUND: The purpose of this study was to determine prognostic factors that can affect the fetal survival immediate after fetoscopic laser ablation.
METHODS: The study population consisted of consecutive twin pregnant women who underwent fetoscopic laser ablation with the diagnosis of twin to twin transfusion syndrome (TTTS) from 2011 to 2018 in Seoul National University Hospital. Fetal survival immediate after procedure was defined as survival to 48 hours after procedure and neonatal survival was defined as survival to 28 days of life. Clinical characteristics and ultrasound findings were compared according to the fetal survival immediate after procedure.
RESULTS: A total of 57 pregnant women with TTTS were included, and the overall fetal survival immediate after procedure was 71.1% (81/114) after fetoscopic laser ablation. Fetuses who survived immediate after procedure had higher gestational age at procedure and lower frequency of abnormal Doppler studies than those did not survive. However, the frequency of hydrops was not different between cases with fetal survival and those with fetal death. The earlier gestational age at procedure and the presence of abnormal Doppler studies were significant risk factors for fetal death even after adjustment.
CONCLUSIONS: Based on this data, the fetal survival immediate after procedure (fetoscopic laser treatment) in TTTS can be affected by the gestational age at procedure and the presence of abnormal Doppler studies.

OBJECTIVE: To evaluate left myocardial performance index (MPI) and time intervals in fetuses with twin-to-twin transfusion syndrome (TTTS) before and after laser surgery.
METHODS: Fifty-one fetal pairs with TTTS and 47 uncomplicated monochorionic twin pairs were included. Left ventricular isovolumetric contraction time (ICT), ejection time (ET), and isovolumetric relaxation time (IRT) were measured using conventional Doppler.
RESULTS: Recipients showed prolonged ICT (46 ± 12 vs. 31 ± 8 vs. 30 ± 5 ms; p < 0.001) and IRT (51 ± 9 vs. 43 ± 8 vs. 43 ± 5 ms; p < 0.001) and higher MPI (0.57 ± 0.12 vs. 0.47 ± 0.09 vs. 0.44 ± 0.05; p < 0.001) than donors and controls. Donors showed shorter ET than recipients and controls (157 ± 12 vs. 169 ± 10 vs. 168 ± 10 ms; p < 0.001) and higher MPI than controls (0.47 ± 0.09 vs. 0.44 ± 0.05; p = 0.006). Preoperative MPI changes were observed in all TTTS stages. Time intervals partially improved after surgery.
CONCLUSIONS: Donor and recipient twins had higher MPI due to different changes in the time intervals, possibly reflecting the state of hypovolemia in the donor and hypervolemia and pressure overload in the recipient.

Chronic hypertension in adults causes arterial lengthening in major arteries, but the effects of early fetal hypertension on the twin-twin transfusion syndrome recipient\'s vascular architecture remains unknown.
We hypothesize that arterial cord redundancy is related to recipient hypertension and subsequent heart failure. Our objectives were to: (1) establish a 3-dimensional color Doppler ultrasound method of measuring umbilical arterial length relative to its corresponding venous segment in the umbilical cord using artery vein angle; (2) compare recipient artery vein angle to gestational age-matched controls; and (3) test the association of artery vein angle with recipient heart failure.
We compared 3 groups prospectively: twin-twin transfusion syndrome pregnancies undergoing fetoscopic laser surgery (preoperatively) and 2 groups of gestational age-matched controls: uncomplicated monochorionic-diamniotic twin pregnancies and healthy singletons. Using a 3-dimensional color-Doppler volume image of 5 cm of cord near the placental insertion, we traced the umbilical artery and vein producing umbilical artery:vein length, (artery vein index) and measured the artery vein angle between umbilical artery and vein. Correlation of artery vein angle to twin-twin transfusion syndrome stage, maximum vertical pocket, umbilical arterial indices, ductus venosus Doppler, and brain natriuretic peptide were performed. We used pulsed-wave and tissue Doppler to measure tissue Doppler velocities and indexed cardiac output and correlated these with artery vein angle. Comparative statistics, including multivariable linear regression, examined the relationship between umbilical arterial Doppler indices and artery vein angle.
Artery vein angle and artery vein index correlated significantly (R2, 0.86; P < .0001), hence, artery vein angle was used for analysis. Mean artery vein angle was 33.1 ± 31.5 degrees in recipients (n = 44), 9.5 ± 6 degrees in monochorionic-diamniotic (n = 11; 22 fetuses), and 8.9 ± 8.3 degrees in singleton controls (n = 16) (P < .001). An artery vein angle ≥26 degrees (>95th percentile for controls) was measured in 52% recipients. Artery vein angle was higher in twin-twin transfusion syndrome stage 3R vs 1 (P = .001). Artery vein angle increased with increasing umbilical arterial pulsatility index (P < .001), and decreased with increasing resistance index (P = .02) after adjusting for gestational age. Interrater agreements to categorize abnormal artery vein angle values was 95% (P < .001). Abnormal ductus venosus Doppler and elevated recipient amniotic fluid N-terminal pro-brain natriuretic peptide/protein levels correlated significantly with artery vein angle. Abnormal artery vein angles were associated with decreased indexed cardiac output, lower tissue Doppler velocities, higher right-sided Tei indices, and severe tricuspid regurgitation.
Umbilical arterial lengthening occurs in 52% of recipients and is associated with abnormal Doppler flows, low systolic tissue Doppler velocities, reduced cardiac output, and elevated markers of cardiac failure. This may reflect chronicity and severity of hypertension in the recipient fetus. Further research is needed to explore the mechanisms of elongation and long-term implications.

OBJECTIVE: To evaluate the rate of pulmonary stenosis and functional pulmonary atresia (PS/PA) in recipient twins prior to fetal surgery for twin-twin transfusion syndrome (TTTS) and their pre- and postnatal outcomes.
METHODS: We carried out a prospective study including 260 cases of TTTS. Echocardiography was performed before laser surgery to detect the presence of PS/PA. The outcomes of recipients with and without PS/PA were compared. The need of postnatal cardiac interventions and the survival rate at 6 months of age were also evaluated.
RESULTS: PS was observed in 16/260 (6.2%) of recipient twins and PA in 12/260 (4.6%). After fetal surgery, 10/28 (35.7%) recipients died, 9/28 (32.1%) showed in utero regression, and 9/28 (32.1%) had persistence of PS/PA. Postnatally, seven recipients underwent percutaneous balloon pulmonary valvuloplasty, one required surgical valvotomy and one palliative surgery. Pregnancies with recipient twins with PS/PA had lower survival of at least one twin (67.9 vs. 83.6%, p = 0.045) and lower overall survival (57.1 vs. 72.8%, p = 0.015) at 6 months of age.
CONCLUSIONS: PS and PA were observed in 10.8% of recipients. Among these, about one third showed persistence of pulmonary valve pathology after delivery, which stresses the need for strict follow-up.