Fetoscopic Laser Therapy Research Articles

Fetoscopic Laser Therapy for Twin-Twin Transfusion Syndrome

Ever since the first randomized, controlled trial revealed that fetoscopic laser photocoagulation achieved better outcomes than serial amnio-drainage for all stages of twin-twin transfusion syndrome (TTTS) before 26 weeks, many centers have launched their fetoscopic laser therapy program for TTTS. Initially the nonselective method of laser therapy was applied, using the dividing membrane as a landmark to coagulate the placenta vessels, but currently selective methods (selective laser photocoagulation of communicating vessels (SLPCV), sequential SLPCV, and Solomon technique) have evolved to become the mainstream laser treatment modalities. Nevertheless, the nonselective method still has a role in difficult operations. Over the years, with regard to the prognoses of TTTS treated by laser, the attention has gradually shifted from survival rate to the neurological outcomes. The incidence of severe neurodevelopmetal delay remains considerably high in survivors of TTTS treated by FLP, which some reports cited ranging from 6 % to 18 %; learning curve effect exists, affecting both the survival rate and neurological outcomes of TTTS treated by laser. Because more, yet smaller and less-experienced, centers are being set up worldwide, the purpose of this manuscript is to review the basic knowledge and update information about the laser therapy for TTTS.

Short and medium-term outcomes of live-born twins after fetoscopic laser therapy for twin-twin transfusion syndromea

To evaluate short and medium term outcomes of children born of monochorionic pregnancies complicated by twin-twin transfusion syndrome treated by fetoscopic laser surgery. This was a retrospective observational study performed between May 2007 and 2012. Neonatal data was from 45 patients under 5 years of age. The prospective observational study was of the neurologic outcome of these children using the Ages and Stages Questionnaire (ASQ), 2nd edition, French version, at up to 5 years of age. Neurologic assessment at discharge from maternity unit was normal for 41 infants (93.2%). Logistic regression suggested that the risk of neurosensory sequelae was significantly related to the status of donor [odds ratio=4.62 (1.18; 18.0)] and significantly preterm birth <32 weeks of gestation [odds ratio=5.50 (1.38; 21.9)]. Eleven questionnaires were considered abnormal (31.1%). Two children presented a severe neurologic abnormality (5.7%). There was no significant correlation between any area of the questionnaire and status at birth (donor or recipient). The data from our cohort, particularly as regards neurologic outcome, were satisfactory and concordant with previously published results. The use of the ASQ as a screening tool for neurologic outcome in children is original, which allowed in our cohort to highlight early neurological disorders.

Embolism in a neonate after TAPS and fetoscopic laser therapy of TOPS - Case Report

Embolism in a neonate after TAPS and fetoscopic laser therapy of TOPS - Case Report

Fetoscopic laser therapy for twin-to-twin transfusion syndrome

Twin-to-twin transfusion syndrome (TTTS) is a unique and complicated phenomenon occurring in 10–15% of monochorionic gestations. The chronic unbalanced distribution of blood volume across placental anastomoses between the donor and recipient fetuses leads to multisystem organ impairment including maladaptive changes in both fetuses. Fetoscopic selective laser photocoagulation (SLPC) is now established as the primary treatment modality for advanced stages of TTTS. SLPC is also associated with a risk reduction in fetal demise and long-term neurological impairment.

Fetoscopic guide laser therapy for twin–twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) affects 1 in 10 monochorionic (MC) twin pregnancies, and is the most important cause of death and neurological injuries in live-born fetuses in MC twins. Since one randomized trial demonstrated that fetoscopic laser photocoagulation achieved better outcomes than serial amniodrainage for all stages of TTTS before 26 weeks, centers of fetoscopic laser therapy for TTTS are currently being initiated worldwide. This review discusses the history, instruments and techniques of fetoscopic laser photocoagulation for TTTS. Finally, we report our current outcomes of TTTS treated by fetoscopic laser photocoagulation in a single center in Taiwan.

Fetoscopic laser therapy for twin-twin transfusion syndrome before 17 and after 26 weeks' gestation

The purpose of this study was to compare perinatal outcomes of pregnancies that undergo "early" (<17 weeks' gestation) or "late" (>26 weeks' gestation) fetoscopic laser ablation of placental vascular anastomoses for twin-twin transfusion syndrome (TTTS) with "conventional" cases that were treated at 17-26 weeks' gestation. We conducted a single center, retrospective analysis of 325 consecutive pregnancies that underwent fetoscopic laser therapy for severe TTTS. Twenty-four "early," 18 "late," and 283 "conventional" pregnancies with severe TTTS underwent laser therapy. Fetoscopy duration, gestation at delivery, survival rate, and complications were comparable among groups, except for preterm premature rupture of membranes at <7 days after laser therapy, which was more common in the "early" group than in either of the other 2 groups. Laser therapy for TTTS at <17 or >26 weeks' gestation has similar outcomes to procedures done at 17-26 weeks' gestation. We suggest that conventional gestational age guidelines of 16-26 weeks for laser therapy for TTTS should be reevaluated.

OP15.06: Right ventricular outflow tract obstruction in recipient twins: impact of fetoscopic laser therapy

OP15.06: Right ventricular outflow tract obstruction in recipient twins: impact of fetoscopic laser therapy

Komplexe Pulsationen in der Nabelschnurvene beim feto-fetalen Transfusionssyndrom: prognostische Aussagekraft

Umbilical vein pulsations (UV-P) are due to various etiologies. The aim of the present study was to investigate the incidence and type of UV-P in monochorionic twins with twin-twin transfusion syndrome (TTTS). TTTS cases diagnosed between 1999 and 2009 were examined retrospectively. The UV flow pattern taken from a free floating loop of the umbilical cord was classified as "non-pulsatile" (NP), "monophasic" (MP) and "complex" (CP). Only Doppler flow analyses prior to intervention were examined. Of 106 cases seen during the study period, 56 cases met the inclusion criteria. Of those, 62.5% were classified as stage III TTTS, and fetoscopic laser therapy was performed in 45 cases. NP flow patterns were more likely found in the donor twin (80.4 vs. 28.6%; p < 0.0001), while the incidence of MP (50 vs. 17.9%; p < 0.0006) and CP flow patterns (21.4 vs. 1.7%; p < 0.01) was higher in the recipient twin. Moreover, the perinatal mortality was highest in cases with CP (CP: 76.9 vs. MP 42.1 vs. NP: 26.2%; p < 0.01) as well as the rate of cases with double death. CP patterns are more frequently found in the recipient twin and are associated with a considerably high mortality rate. Studying the umbilical vein flow pattern in TTTS may provide additional information for counseling and prognosis similar to that obtained by expensive fetal echocardiography.

Incidence and clinical implications of early inadvertent septostomy after laser therapy for twin–twin transfusion syndrome

To evaluate the incidence and clinical outcome of inadvertent septostomy after fetoscopic laser therapy for twin-twin transfusion syndrome (TTTS) and, particularly, to explore its association with the risk of developing pseudoamniotic band syndrome (PABS). In a cohort of 414 consecutive monochorionic twin pregnancies with confirmed TTTS treated with laser, the incidence of postoperative septostomy within 1 week of the procedure was recorded prospectively. Rates of preterm delivery, preterm premature rupture of membranes (PPROM), intrauterine fetal demise (IUFD) and PABS were compared among cases with and without septostomy. The mean gestational age at laser therapy was 20.4 (range, 15.3-27.6) weeks. Postoperative septostomy occurred in 30 (7.2%) cases. Pregnancies complicated with septostomy had a significantly higher proportion of preterm delivery before 32 weeks (76.7% vs. 30.2%, P < 0.001), PPROM before 32 weeks (46.7% vs. 19.0%, P < 0.001), IUFD (43.3% vs. 25.8%, P < 0.05) and PABS (13.3% vs. 1.0%, P < 0.001), compared with pregnancies without septostomy. Inadvertent septostomy occurred in 7% of cases after fetoscopic laser therapy and was associated with a substantially increased risk of adverse perinatal outcome and PABS.

OC07.05: Incidence and clinical implications of unintended septostomy after fetoscopic laser therapy for twin–twin transfusion syndrome

Objectives: Fetoscopic SLP improves outcome in TTTS by promoting resolution of cardiovascular (CV) manifestations. The time course and pattern of disease regression is unknown. We sought to investigate the nature of CV disease regression after SLP by analysis of individual cardiovascular elements through application of the CHOP score for TTTS. Methods: The CHOP score is a fetal echo derived system for detailed CV characterization of TTTS. Elements of the Score include 4 domains in the recipient: 1) ventricular characteristics of dilation, hypertrophy, systolic dysfunction, 2) atrioventricular valve (AV) regurgitation, 3) diastolic properties of Doppler AV inflow (double or single peak), ductus venosus, and umbilical venous flow, 4) right ventricular outflow tract obstruction (RVOTO) as assessed by pulmonary artery measuring smaller than aorta or pulmonary stenosis/atresia; and in the donor, evaluation of umbilical artery diastolic flow. In 32 twin pairs individual elements of the Score as well as myocardial performance indices (MPI) were measured at 1 day and 1 week after SLP and compared to pre-op values using paired t-test. Results: Overall score was unchanged at 1 day (pre-op 6.6 + 4.0 vs. 6.0 + 3.8, P = NS) but significantly improved by 1 week (4.2 + 4.1, P < 0.001) after SLP. At 1 day, there was no improvement in systolic or diastolic parameters and AV regurgitation worsened, however there was slight improvement in RVOTO (P < 0.05) and recipient RV and LV MPI (P = 0.02). At 1 week, improvements in ventricular dilation (P = 0.01), hypertrophy (P = 0.01) and all of the diastolic parameters were noted, with further improvement in RVOTO (P = 0.002) and recipient RV and LV MPI (P < 0.01). Systolic performance and AV regurgitation did not improve. Conclusions: Minimal improvement is seen 1 day after SLP, however diastolic CV elements, but not systolic, improve substantially at 1 week. Acute diastolic relaxation of the recipient right ventricle after SLP may improve filling and result in an increase in pulmonary artery diameter.

Die monochoriale Zwillingsgravidität und ihre Problematik

Monochorionic twin pregnancies have an increased risk of intrauterine and postnatal complications because of the present placental vascular anastomoses. The main problems are the development of twin-to-twin transfusion syndrome,selective intrauterine growth restriction, monoamniotic twins and single intrauterine death on the one hand and congenital abnormalities like twin reversed-arterial perfusion and conjoined twins on the other hand. Fetoscopic laser therapy with selective coagulation of placental intertwin anastomoses is the best option in the treatment of twin-to-twin transfusion syndrome. The risk of preterm delivery, cerebral injury and abnormalities of long-term neurodevelopmental outcome are increased. Perinatal management of monochorionic twin pregnancies should be performed in specialized tertiar centers.

Amniotic fluid markers of fetal cardiac dysfunction in twin-to-twin transfusion syndrome

The objective of the study was to determine whether cardiac troponin T (cTnT) and natriuretic peptides can be isolated from the amniotic fluid (AF) of pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) and whether they correlate with fetal echocardiographic findings and recipient survival. AF samples from the recipient sac were obtained in 52 TTTS cases and 16 controls. Samples were assayed for cTnT and natriuretic peptides. Prior to fetoscopic laser therapy, 34 recipient twins underwent assessment of atrioventricular flow patterns, myocardial performance index (MPI), and precordial venous Dopplers. Fetal survival was assessed 48 hours postoperatively. AF B-type natriuretic peptide and cTnT levels were elevated in TTTS and correlated with functional echocardiographic findings. Postoperative recipient survival was 72% when both AF-cTnT and left ventricular MPI were increased. If 1 of both markers was normal, survival was 100% (P = .046). Combining ultrasound and AF-cTnT measurements allows the identification of fetuses at risk of postoperative demise.

Selective Fetoscopic Laser Photocoagulation of Superficial Placental Anastomoses for the Treatment of Severe Twin-Twin Transfusion Syndrome

OBJECTIVE:To report our initial institutional experience with fetoscopic laser photocoagulation of placental anastomoses in severe twin-twin transfusion syndrome using a 1.0 mm endoscope.METHODS:Between July 2006 and June 2008, 19 monochorionic diamniotic twin pregnancies complicated by severe TTTS (Quintero stages III and IV) underwent fetoscopic laser therapy. Perinatal data were prospectively collected and compared according to the Quintero stages.RESULTS:Nine patients were classified as stage III and ten as stage IV. The Mean gestational ages at diagnosis and procedure were 20 (range: 17–25) and 22.0 (range: 19.0–26.0) weeks, respectively, with no statistical difference between the two groups. Preterm premature rupture of the membranes occurred in two cases (10.5%), and spontaneous preterm delivery in eight (42.1%). Overall mean gestational age at delivery was 32.1 (range: 26.0–38.0) weeks. Prematurity was more severe in stage IV patients (p<0.01). Among all cases, the overall survival rate was 52.6%, and the percentages of pregnancies with survival of both babies and at least one twin were 26.3% and 78.9%, respectively. In the case of stage III patients, the overall survival rate was 61.1%. Of the stage III pregnancies, 33.3% resulted in both babies surviving, and 88.9% of these pregnancies resulted in at least one surviving twin. For stage IV, as the corresponding statistics were 45.0%, 20.0% and 70.0% respectively.CONCLUSIONS:Our initial institutional experience with 1.0 mm fetoscopic laser therapy for severe TTTS showed results similar to those reported in the literature for larger endoscopes.

Fetal cardiac output in monochorionic twins

To compare fetal cardiac output (CO) in donor and recipient twins of twin-twin transfusion syndrome (TTTS) pregnancies after laser therapy with that of monochorionic twins without TTTS and normal singletons. In a longitudinal, prospective study, we sonographically assessed fetal CO in donors (n = 10) and recipients (n = 10) with TTTS after fetoscopic laser therapy, in monochorionic twins without TTTS (n = 20) and in normal singleton pregnancies (n = 20). The fetal CO of TTTS twins was determined 1 day and 1 week after laser treatment, and from then on every 2-4 weeks until birth. Twins without TTTS were examined biweekly until birth. Singletons were examined twice, with an 8-week interval, at different gestational ages between 17 and 35 weeks. Absolute CO increased exponentially with advancing gestational age (P < 0.0001), and was significantly related to fetal weight in all groups (P < 0.0001). The median CO/kg in donors after laser therapy, recipients after laser therapy and non-TTTS monochorionic twins was significantly higher than that in singletons (all P < 0.001). Median CO/kg in donors after laser therapy, recipients after laser therapy, and non-TTTS monochorionic twins was not significantly different between groups. Monochorionic twins with TTTS have higher CO after laser therapy than normal singletons.

The effect of fetoscopic laser therapy on fetal cardiac size in twin–twin transfusion syndrome

To evaluate the influence of fetoscopic laser therapy on fetal cardiac size in monochorionic twins complicated by twin-twin transfusion syndrome (TTTS). In a longitudinal, prospective study, we assessed fetal cardiac size sonographically in monochorionic diamniotic twins with TTTS treated by laser therapy and in monochorionic twins without TTTS. The fetal cardiothoracic ratio (cardiac circumference divided by thoracic circumference) of TTTS twins was determined within 24 h before, 12-24 h after and 1 week after laser treatment, and from then on every 2-4 weeks until birth. TTTS twins were classified into Quintero Stages 1-2 (n = 18) and Stages 3-4 (n = 16), and measurements were compared with biweekly measurements of non-TTTS monochorionic twins matched for gestational age (n = 38). Cardiomegaly was defined as a cardiothoracic ratio above the 97.5th percentile. Before laser treatment, cardiomegaly was observed in 44% (8/18) and 50% (8/16) of recipients in Quintero Stages 1-2 and Stages 3-4, respectively. Cardiomegaly occurred in none of the donors before treatment. After laser treatment, cardiomegaly was observed in 76% (13/17) and 50% (7/14) of recipients in Stages 1-2 and Stages 3-4, respectively, and in 17% (3/18) and 13% (2/15) of donors in Stages 1-2 and Stages 3-4, respectively. Cardiomegaly was present in 18% (7/38) and 8% (2/25) of non-TTTS monochorionic twins and singletons. After laser therapy, the cardiothoracic ratio of recipients in Stages 1-2 and Stages 3-4 was not significantly changed (P = 0.34 and P = 0.67, respectively). The cardiothoracic ratio of donors in Stages 1-2 and Stages 3-4 was increased compared with that before laser therapy (P = 0.0002 and P = 0.005, respectively). Cardiothoracic ratios of non-TTTS monochorionic twins were not significantly different from our reference range in singletons throughout gestation, and were smaller than those in both recipients and donors after laser therapy. TTTS recipients show cardiomegaly before as well as after fetoscopic laser therapy for TTTS. Donors develop cardiomegaly only after laser treatment. Our findings emphasize the significant effect of TTTS and fetoscopic laser therapy on the fetal heart of both recipient and donor twins.

Stage-Related Outcome in Twin–Twin Transfusion Syndrome Treated by Fetoscopic Laser Coagulation

To assess perinatal outcome in monochorionic twin pregnancies according to different stages of severe mid-trimester twin-twin transfusion syndrome managed by fetoscopic laser coagulation of the placental vascular anastomoses. In a prospective study fetoscopic laser therapy was performed in 200 consecutive pregnancies with severe mid-trimester twin-twin transfusion syndrome at a median gestational age of 20.7 weeks (range 15.9-25.3 weeks). Outcome data were analyzed for the whole group and separately for each stage according to the Quintero staging system. The overall survival rate was 71.5% (286/400), with survival of both twins in 59.5% (119/200) and survival of at least one of the twins in 83.5% (167/200). The median gestational age at delivery of liveborn neonates was 34.3 weeks (range 23.1-40.4 weeks). There was a significant trend toward reduced survival rates with increasing stage (P=.038). The percentage of pregnancies with survival of both fetuses was 75.9% (22/29) for stage I, 60.5% (49/81) for stage II, 53.8% (43/80) for stage III, and 50% (5/10) for stage IV. At least one of the twins survived in 93.1% (27/29) at stage I, 82.7% (67/81) at stage II, 82.5% (66/80) at stage III, and 70% (7/10) at stage IV. The overall survival rate for donor fetuses was 70.5% (141/200) and for recipient fetuses, 72.5% (145/200). These data show that laser therapy is an effective therapeutic option for all stages of severe twin-twin transfusion syndrome and provide information to counsel patients according to the stage of the syndrome.

Prevalence and management of late fetal complications following successful selective laser coagulation of chorionic plate anastomoses in twin-to-twin transfusion syndrome

This study was undertaken to report on the prevalence and management of late complications in twin-to-twin transfusion syndrome (TTTS) treated by laser therapy when both twins are alive 1 week after surgery. A total of 151 consecutive TTTS cases were treated by selective fetoscopic laser therapy. Cases in which both twins were alive 1 week after surgery were followed up with ultrasound and Doppler examination, including middle-cerebral artery peak systolic velocity measurement (MCA-PSV). In the 151 cases treated with laser, both twins were still alive 7 days after the procedure in 101 cases. Intrauterine death of 1 and both twins occurred in 7 and 1 cases, respectively. Recurrence of TTTS with the polyhydramnios-oligohydramnios sequence occurred in 14 (14%) cases. In another 13 (13%) cases, amniotic fluid remained normal in both sacs, but MCA-PSV increased above 1.5 MoM in 1 twin and decreased concomitantly below 0.8 MoM in the co-twin. This was related to anemia and polycythemia, respectively, and resulted from unidirectional feto-fetal blood transfusion, mainly from former recipients into former donors. Late complications were managed accordingly by repeat laser, amnioreduction, cord coagulation, intrauterine blood transfusion, or elective delivery. MCA-PSV Doppler measurements are useful in the follow-up of double survivors to detect and manage late complications after selective laser therapy.

Twin-twin transfusion syndrome: etiology, severity and rational management.

The twin-twin transfusion syndrome is a serious complication of monochorionic twin pregnancies. Partly as a result of an inadequate understanding of the pathophysiology of the syndrome, there is a lack of consensus in clinical management. We sought to review the available information on the etiology of twin-twin transfusion syndrome, to identify parameters that contribute to the severity of the syndrome, and propose a rational management plan based on pathophysiology, clinical presentation and the efficacy of therapies. We therefore amalgamated recent advances in twin-twin transfusion syndrome computer modelling and clinical studies, particularly on therapeutic outcomes. We found that the oligo-polyhydramnios sequence that defines twin-twin transfusion syndrome prenatally represents a wide continuum of severity in the imbalance between the fetoplacental circulations of both twins. In severe twin-twin transfusion syndrome cases, in which the circulatory imbalance deteriorates beyond fetal control, fetoscopic laser therapy of all anastomoses along the placental vascular equator is predicted to have significantly better survival rates and fewer neurological sequelae than amnioreduction. In contrast, mild twin-twin transfusion syndrome cases have better outcomes after one or at most a few amnioreductions than laser therapy, as a result of significantly fewer procedure-related risks. In conclusion, optimal individual therapy may possibly achieve an 85% survival rate in twin-twin transfusion syndrome, but requires advancement in non-invasive criteria that predict the severity of the syndrome. Identifying such criteria is a future challenge. For the interim, twin-twin transfusion syndrome diagnosed before 26 weeks' gestation has significantly better survival rates and fewer neurological sequelae after laser therapy than amnioreduction. Twin-twin transfusion syndrome diagnosed after 26 weeks can best be treated by amnioreduction, or delivery. Contrary to previous claims, fetoscopic laser therapy has outgrown its experimental status. Although improvements in technique and technology are likely, laser placental ablation has a firm scientific and clinical basis.