Outcome after fetoscopic selective laser ablation of placental anastomoses vs equatorial laser dichorionization for the treatment of twin-to-twin transfusion syndrome

Perinatal and neonatal outcomes for fetoscopic laser ablation for the treatment of twin twin transfusion syndrome at a single center

OBJECTIVE

To describe the perinatal and neonatal outcomes of fetal laser ablation (FLA) for the treatment of twin-twin transfusion syndrome (TTTS) in our single center institution.

STUDY DESIGN

Retrospective study of 76 treated pregnant women. Procedural complications, perinatal and neonatal outcomes analyzed. Differences in outcomes between two procedural techniques, selective and Solomon, compared.

RESULTS

FLA occurred at median gestational age (GA) of 20.8 weeks (IQR 18.1-22.9) with low incidence of procedural complications (5.3%). High survival rate with delivery of at least one neonate (96%) [95% CI: 88.9-99.2%]; 73.7% [95% CI: 62.3-83.1%] were twins. Median GA at birth was 33.1 weeks (IQR 28.0-35.0). Neonatal mortality and morbidities were 9.4% and 48.3% of cases respectively, and associated with lower GA. Solomon cases had comparatively higher median GA, and lower incidences of neonatal morbidities.

CONCLUSION

Our small single center study showed favorable outcomes for using the Solomon technique in the treatment of TTTS.

Solomon versus selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: A systematic review and meta-analysis

This meta-analysis aims to compare the perinatal outcome of twin-twin transfusion syndrome (TTTS) pregnancies undergoing selective versus vascular equator (Solomon) fetoscopic laser photocoagulation (FLP). We performed a systematic search in PubMed and Web of Science from inception up to 25 July 2021. Studies comparing the Solomon and selective techniques of FLP for treatment of TTTS pregnancies were eligible. Random-effects or fixed-effect models were used to pool standardized mean differences (SMD) and log odds ratio. Seven studies with a total of 1664 TTTS pregnancies (n = 671 undergoing Solomon and n = 993 selective techniques) were included. As compared to the selective FLP, Solomon was associated with a lower risk of recurrent TTTS compared to the selective technique (Log odds ratio [OR]: -1.167; 95% credible interval [CrI]: -2.01, -0.33; p = 0.021; I² : 67%). In addition, Solomon was significantly associated with a higher risk of placental abruption than the selective technique (Log [OR]: 1.44; 95% CrI: 0.45, 2.47; p = 0.012; I² : 0.0%). Furthermore, a trend for the higher risk of preterm premature rupture of membranes was observed among those undergoing Solomon (Log [OR]: 0.581; 95% CrI: -0.43, 1.49; p = 0.131; I² : 17%). As compared to selective FLP, the Solomon technique for TTTS pregnancies is associated with a significantly lower recurrence of TTTS; however, it significantly increases the risk of placental abruption.

Molecular Mechanisms Underlying Twin-to-Twin Transfusion Syndrome

Twin-to-twin transfusion syndrome is a unique disease and a serious complication occurring in 10–15% of monochorionic multiple pregnancies with various placental complications, including hypoxia, anemia, increased oxidative stress, and ischemia-reperfusion injury. Fetoscopic laser photocoagulation, a minimally invasive surgical procedure, seals the placental vascular anastomoses between twins and dramatically improves the survival rates in twin-to-twin transfusion syndrome. However, fetal demise still occurs, suggesting the presence of causes other than placental vascular anastomoses. Placental insufficiency is considered as the main cause of fetal demise in such cases; however, little is known about its underlying molecular mechanisms. Indeed, the further association of the pathogenic mechanisms involved in twin-to-twin transfusion syndrome placenta with several molecules and pathways, such as vascular endothelial growth factor and the renin–angiotensin system, makes it difficult to understand the underlying pathological conditions. Currently, there are no effective strategies focusing on these mechanisms in clinical practice. Certain types of cell death due to oxidative stress might be occurring in the placenta, and elucidation of the molecular mechanism underlying this cell death can help manage and prevent it. This review reports on the molecular mechanisms underlying the development of twin-to-twin transfusion syndrome for effective management and prevention of fetal demise after fetoscopic laser photocoagulation.

Selective vs complete fetoscopic coagulation of vascular equator: a matched comparative study

BACKGROUND

Complete coagulation of the vascular equator (as in the Solomon technique) has been suggested to reduce postoperative complications such as twin anemia polycythemia syndrome and the recurrence of twin-twin transfusion syndrome following fetoscopic laser coagulation of chorionic vessels for twin-twin transfusion syndrome.

OBJECTIVE

We aimed to evaluate the benefit of this technique on perinatal outcomes compared with selective ablation of anastomoses.

STUDY DESIGN

We conducted a monocentric retrospective study comparing selective laser coagulation of anastomoses to the Solomon technique from January 2006 to August 2020. To adjust for potential confounders, the cases operated by selective surgery were matched to the cases operated with the Solomon technique according to the gestational age at laser therapy, placental localization, and Quintero stage using propensity score matching.

RESULTS

With a total of 994 cases, 399 matched pairs were included in the analysis. Compared with selective ablation, the Solomon technique was associated with significantly improved survival: the overall twin survival at delivery and discharge was 72% vs 79% (P=.003) and 69% vs 75% (P=.006), respectively; the double twin survival rate at discharge was 55% vs 65% (P=.02), respectively, and the rate of intrauterine death dropped from 18% to 12% (P=.003), respectively. The Solomon technique significantly reduced the rate of twin anemia polycythemia syndrome (10% vs 4%; P=.02), leading to fewer secondary rescue procedures (13% vs 7.3%; P=.01). However, the Solomon technique was associated with an increased risk of preterm rupture of membranes, especially at early gestational ages (3.8% vs 11%; P<.001 for preterm rupture of membranes <24 weeks). Among the survivors at delivery, both the groups had similar gestational ages at birth. Both neonatal mortality and severe neurologic morbidity were similar in both the groups. However, an increased risk of bronchopulmonary dysplasia was found in the Solomon group (4.5% vs 12%; P<.001).

CONCLUSION

Although the risk of preterm premature rupture of membranes has increased, the introduction of the Solomon technique has significantly improved perinatal outcomes in pregnancies affected with twin-twin transfusion syndrome.

Pathophysiology, diagnosis, and management of twin anemia polycythemia sequence in monochorionic multiple gestations

Twin anemia polycythemia sequence (TAPS) is a consequence of unequal sharing of red blood cells between monochorionic twins resulting in anemia in the donor and polycythemia in the recipient twin. Prenatally TAPS can occur spontaneously or complicate incomplete laser surgery for twin transfusion syndrome. While there may be clinical overlap with twin transfusion syndrome or selective fetal growth restriction, diagnosis relies on Doppler measurement of middle cerebral artery peak systolic velocities. Significantly discordant velocities are diagnostic, while severity staging is based on signs of cardiovascular compromise. Conservative management, fetoscopic laser coagulation, selective twin reduction, fetal blood and exchange transfusion, and delivery may be selected guided by the gestational age of diagnosis, the severity of the condition, the likelihood of success, and the patients' priorities. Prenatal curative treatment that minimizes the risk for prematurity and residual morbidity at birth is most likely to offer the greatest short-term and long-term benefits.

Twin-to-twin transfusion syndrome: Controversies in the diagnosis and management

In twin-to-twin transfusion syndrome (TTTS) communicating placental vessels on the chorionic plate between the donor and recipient twins are responsible for the chronic imbalance of blood flow. Evidence demonstrates that fetoscopic laser ablation is superior to serial amnioreductions in terms of survival and neurological outcome for stages II-IV TTTS. However, the optimal management of stage I TTTS remains poorly understood. It is well established that all chorionic plate anastomoses should be closed by laser ablation. Compared to the selective laser method, the Solomon technique yields a significant reduction of recurrent TTTS and post-laser twin anemia polycythemia sequence (TAPS). Over the past 25 years, survival rates after fetoscopic laser surgery have significantly increased. High volume centers report up to 70% double survival and at least one survivor in >90% cases. In this review, we discuss the controversies in the diagnosis and management of TTTS, especially, the optimal management in stage I cases, very early or late diagnosis, and the optimal laser technique. Furthermore, we will discuss a stage-related outcome after laser surgery and examine whether it is necessary at all to distinguish between stages I and II. Finally, the optimal timing as well as mode of delivery after TTTS laser treatment will be discussed.

Fetoscopic laser ablation therapy in monochorionic diamniotic twin pregnancies with twin-to-twin transfusion syndrome treated at a single centre over 10 years: a retrospective study

OBJECTIVES

To review experience with fetoscopic laser ablation of placental anastomoses to treat monochorionic diamniotic (MCDA) twin pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) in a single centre over a ten-year period.

METHODS

A retrospective study on 142 MCDA twin pregnancies complicates by TTTS treated with equatorial laser ablation of placental anastomoses (2008-2018). Solomon technique was also applied after 2013. Survival rates, neonatal outcome, intraoperative and post-laser complications were recorded, and prognostic factors analysed.

RESULTS

A total of 133 cases were included in the final analysis; 41 patients were at stage II (30.8%), 73 were at stage III (62.9%), while only 12 (9%) at stage I and two patients (1.7%) at stage IV. Solomon technique was applied in 39 cases (29.3%). Survival of both twins was 51.1% (68/133), of a single twin 20.3% (27/133), and of at least one 71.5% (95/133), with an overall survival of 61.3% (163/266). TAPS and recurrent TTTS occurred in 8 (6%) and 15 (11.3%) patients. Survival of both fetuses increased over time (44.6 vs. 57.3%). A posterior placenta (p<0.003) and the use of the Solomon technique (p<0.02) were more frequent in cases with survival of both fetuses, while TTTS recurrence was significantly associated to the loss of one or two fetuses (p<0.01). Such associations were confirmed at logistic regression analysis.

CONCLUSIONS

Survival of both twins can improve over time and seems to be favourably associated with a placenta in the posterior location and the use of the Solomon technique.

Understanding Sociodemographic Disparities in Maternal-Fetal Surgery Study Participation

BACKGROUND/PURPOSE

Although maternal-fetal surgery to treat fetal anomalies such as spina bifida continues to grow more common, potential health disparities in the field remain relatively unexamined. To address this gap, we identified maternal-fetal surgery studies with the highest level of evidence and analyzed the reporting of participant sociodemographic characteristics and representation of racial and ethnic groups.

METHODS

We conducted a systematic review of the scientific literature using biomedical databases. We selected randomized control trials (RCTs) and cohort studies with comparison groups published in English from 1990 to May 5, 2020. We included studies from across the globe that examined the efficacy of fetal surgery for twin-twin transfusion syndrome (TTTS), obstructive uropathy, congenital diaphragmatic hernia (CDH), myelomeningocele (MMC), thoracic lesions, cardiac malformations, or sacrococcygeal teratoma. We determined the frequency of reporting of age, gravidity/parity, race, ethnicity, education level, language spoken, insurance, income level, and relationship status. We identified whether sociodemographic factors were used as inclusion or exclusion criteria. We calculated the racial and ethnic group representation for studies in the USA using the participation-to-prevalence ratio (PPR).

RESULTS

We included 112 studies (10 RCTs, 102 cohort) published from 1990-1999 (8%), 2000-2009 (30%), and 2010-2020 (62%). Most studies were conducted in the USA (47%) or Europe (38%). The median sample size was 58. TTTS was the most common disease group (37% of studies), followed by MMC (23%), and CDH (21%). The most frequently reported sociodemographic variables were maternal age (33%) and gravidity/parity (20%). Race and/or ethnicity was only reported in 12% of studies. Less than 10% of studies reported any other sociodemographic variables. Sociodemographic variables were used as exclusion criteria in 13% of studies. Among studies conducted in the USA, White persons were consistently overrepresented relative to their prevalence in the US disease populations (PPR 1.32-2.11), while Black or African-American, Hispanic or Latino, Asian, American-Indian or Alaska-Native, and Native-Hawaiian or other Pacific Islander persons were consistently underrepresented (PPR 0-0.60).

CONCLUSIONS

Sociodemographic reporting quality in maternal-fetal surgery studies is poor and inhibits examination of potential health disparities. Participants enrolled in studies in the USA do not adequately represent the racial and ethnic diversity of the population across disease groups.

Perinatal outcome of pregnancy complicated by twin anemia-polycythemia sequence: systematic review and meta-analysis

OBJECTIVE

To report the perinatal outcome of monochorionic diamniotic (MCDA) twin pregnancies complicated by twin anemia-polycythemia sequence (TAPS), according to the type of TAPS (spontaneous or postlaser) and the management option adopted.

METHODS

MEDLINE, EMBASE and The Cochrane Library databases were searched for studies reporting on the outcome of twin pregnancies complicated by TAPS. Inclusion criteria were non-anomalous MCDA twin pregnancies with a diagnosis of TAPS. The primary outcome was perinatal mortality; secondary outcomes were neonatal morbidity and preterm birth (PTB). The outcomes were stratified according to the type of TAPS (spontaneous or following laser treatment for twin-twin transfusion syndrome) and the management option adopted (expectant, laser surgery, intrauterine transfusion (IUT) or selective reduction (SR)). Random-effects meta-analysis of proportions was used to analyze the data.

RESULTS

Perinatal outcome was assessed according to whether TAPS occurred spontaneously or after laser treatment in 506 pregnancies (38 studies). Intrauterine death (IUD) occurred in 5.2% (95% CI, 3.6-7.1%) of twins with spontaneous TAPS and in 10.2% (95% CI, 7.4-13.3%) of those with postlaser TAPS, while the corresponding rates of neonatal death were 4.0% (95% CI, 2.6-5.7%) and 9.2% (95% CI, 6.6-12.3%), respectively. Severe neonatal morbidity occurred in 29.3% (95% CI, 25.6-33.1%) of twins after spontaneous TAPS and in 33.3% (95% CI, 17.4-51.8%) after postlaser TAPS, while the corresponding rates of severe neurological morbidity were 4.0% (95% CI, 3.5-5.7%) and 11.1% (95% CI, 6.2-17.2%), respectively. PTB complicated 86.3% (95% CI, 77.2-93.3%) of pregnancies with spontaneous TAPS and all cases with postlaser TAPS (100% (95% CI, 84.3-100%)). Iatrogenic PTB was more frequent than spontaneous PTB in both groups. Perinatal outcome was assessed according to the management option adopted in 417 pregnancies (21 studies). IUD occurred in 9.8% (95% CI, 4.3-17.1%) of twins managed expectantly and in 13.1% (95% CI, 9.2-17.6%), 12.1% (95% CI, 7.7-17.3%) and 7.6% (95% CI, 1.3-18.5%) of those treated with laser surgery, IUT and SR, respectively. Severe neonatal morbidity affected 27.3% (95% CI, 13.6-43.6%) of twins in the expectant-management group, 28.7% (95% CI, 22.7-35.1%) of those in the laser-surgery group, 38.2% (95% CI, 18.3-60.5%) of those in the IUT group and 23.3% (95% CI, 10.5-39.2%) of those in the SR group. PTB complicated 80.4% (95% CI, 59.8-94.8%), 73.4% (95% CI, 48.1-92.3%), 100% (95% CI, 76.5-100%) and 100% (95% CI, 39.8-100%) of pregnancies after expectant management, laser surgery, IUT and SR, respectively.

CONCLUSIONS

The present meta-analysis provides pooled estimates of the risks of perinatal mortality, neonatal morbidity and PTB in twin pregnancies complicated by TAPS, stratified by the type of TAPS and the management option adopted. Although a direct comparison could not be performed, the results from this systematic review suggest that spontaneous TAPS may have a better prognosis than postlaser TAPS. No differences in terms of mortality and morbidity were observed when comparing different management options for TAPS, although these findings should be interpreted with caution in view of the limitations of the included studies. Individualized prenatal management, taking into account the severity of TAPS and gestational age, is currently the recommended strategy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Outcomes of laparoscopy-assisted fetoscopic laser photocoagulation for twin-twin transfusion syndrome: An established alternative for inaccessible anterior placenta

OBJECTIVE

To evaluate laparoscopy-assisted fetoscopic laser photocoagulation (FLPC) of placental anastomoses in the treatment of twin-to-twin-transfusion syndrome (TTTS).

STUDY DESIGN

We performed a retrospective cohort study analyzing pregnancies complicated by TTTS who underwent FLPC in a single university-affiliated tertiary medical-center. Outcomes were compared between patients who received laparoscopy-assisted FLPC (study group) and patients who underwent the conventional FLPC technique (control group). Baseline characteristics, sonographic findings, procedure details, and neonatal outcomes were compared between groups.

RESULTS

The cohort included 278 women with 31 in the study group and 247 in the control group. Sonographic parameters, including fetal biometry and TTTS stage, were comparable between study groups. Gestational age at delivery did not differ between the groups (29.22 ± 4.55 weeks in the study group vs. 30.62 ± 4.3 weeks in the control group, p = 0.09). There were no differences in neonatal survival rates at birth and at 30 days between both groups. A subanalysis comparing the laparoscopy-assisted group to only those patients with anterior placenta in the control group, showed a lower rate of incomplete Solomonization in the laparoscopy-assisted study group (3.4% vs. 33%, p = 0.01).

CONCLUSION

Laparoscopy-assisted FLPC is a reasonable and safe option that may be offered in cases of FLPC where an anterior placenta restricts adequate surgical access.

Re-evaluation of the predictive value of Quintero staging of twin-twin transfusion syndrome for fetal death after fetoscopic laser photocoagulation

OBJECTIVE

To elucidate the significance of sonographic indices, including Doppler waveforms, that constitute the Quintero classification for predicting death of the recipient or donor after fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome (TTTS).

METHODS

Prospectively collected data of twins who underwent FLP for TTTS were reviewed. Among the abnormal indices of ultrasound performed just before FLP, factors that were significantly associated with fetal and neonatal deaths in the log-rank test, including fetal demise of co-twins and preterm birth before 28 weeks of gestation, were introduced into the Cox proportional-hazards model to calculate risk ratio (RR).

RESULTS

We included 235 cases with a prevalence of recipient and donor deaths of 7% and 14%, respectively. In the proportional-hazards model, absent or reversed umbilical artery end-diastolic velocity (UA AREDV) of recipients (n = 7) was independently associated with recipient death (RR = 6.97). In recipients without UA AREDV, reversed ductus venosus (DV) a-wave of recipients (RR = 3.55) was independently associated with recipient death. In donors, UA AREDV with a visible bladder (stage III atypical donor) was independently associated with donor death (RR = 4.24).

CONCLUSION

Some individual components of the Quintero stage are associated with death of either recipient or donor twins following FLP.

Placental Abruption after Fetoscopic Laser Surgery in Twin-Twin Transfusion Syndrome: The Role of the Solomon Technique

INTRODUCTION

Twin-twin transfusion syndrome (TTTS) is a complication in monochorionic twin pregnancies which is preferably treated with fetoscopic laser surgery. A few small studies suggested a possible association between the Solomon laser technique and placental abruption.

METHODS

The objective of this study is to compare the rate of and to explore potential risk factors for placental abruption in TTTS treated with fetoscopic laser surgery according to the Selective and Solomon laser technique. We conducted a large retrospective cohort study of consecutive TTTS-cases treated with fetoscopic laser surgery in Shanghai, China, and Leiden, The Netherlands treated with either the Selective laser technique (Selective group) or Solomon laser technique (Solomon group).

RESULTS

The rate of placental abruption in the Selective group versus the Solomon group was 1.7% (5/289) and 3.4% (15/441), respectively (p = 0.184). No risk factors for placental abruption were identified. Placental abruption was associated with lower gestational age at birth (p = 0.003) and severe cerebral injury (p = 0.003).

CONCLUSION

The prevalence of placental abruption in TTTS after fetoscopic laser surgery is low, although it appears higher than in the overall population. Placental abruption is associated with a lower gestational age at birth, which is associated with severe cerebral injury. The rate of placental abruption was not significantly increased with the use of the Solomon technique. Continued research of placental abruption in TTTS is necessary to determine why the rate is higher than in the overall population.

Implementation Process and Evolution of a Laparotomy-Assisted 2-Port Fetoscopic Spina Bifida Closure Program

INTRODUCTION

Prenatal closure of open spina bifida via open fetal surgery improves neurologic outcomes for infants in selected pregnancies. Fetoscopic techniques that are minimally invasive to the uterus aim to provide equivalent fetal benefits while minimizing maternal morbidities, but the optimal technique is undetermined. We describe the development, evolution, and feasibility of the laparotomy-assisted 2-port fetoscopic technique for prenatal closure of fetal spina bifida in a newly established program.

METHODS

We conducted a retrospective cohort study of women consented for laparotomy-assisted fetoscopic closure of isolated fetal spina bifida. Inclusion and exclusion criteria followed the Management of Myelomeningocele Study (MOMS). Team preparation involved observation at the originating center, protocol development, ancillary staff training, and surgical rehearsal using patient-matched models through simulation prior to program implementation. The primary outcome was the ability to complete the repair fetoscopically. Secondary maternal and fetal outcomes to assess performance of the technique were collected prospectively.

RESULTS

Of 57 women screened, 19 (33%) consented for laparotomy-assisted 2-port fetoscopy between February 2017 and December 2019. Fetoscopic closure was completed in 84% (16/19) cases. Over time, the technique was modified from a single- to a multilayer closure. In utero hindbrain herniation improved in 86% (12/14) of undelivered patients at 6 weeks postoperatively. Spontaneous rupture of membranes occurred in 31% (5/16) of fetoscopic cases. For completed cases, median gestational age at birth was 37 (range 27-39.6) weeks and 50% (8/16) of women delivered at term. Vaginal birth was achieved in 56% (9/16) of patients. One newborn had a cerebrospinal fluid leak that required postnatal surgical repair.

CONCLUSION

Implementation of a laparotomy-assisted 2-port fetoscopic spina bifida closure program through rigorous preparation and multispecialty team training may accelerate the learning curve and demonstrates favorable obstetric and perinatal outcomes.

Early laser surgery is not associated with very preterm delivery or reduced neonatal survival in TTTS

OBJECTIVE

To evaluate the association of laser photocoagulation of placental anastomoses (LPA) prior to 18 weeks' gestation (early LPA) with very preterm delivery and neonatal survival in pregnancies with twin-twin transfusion syndrome (TTTS).

METHODS

This was a retrospective cohort study of monochorionic diamniotic twin pregnancies with TTTS undergoing LPA between 2002 and 2018 at two institutions. The rates of delivery < 28, < 30 and < 32 weeks' gestation, preterm prelabor rupture of membranes (PPROM) and 30-day survival of one or both infants were compared between pregnancies undergoing early LPA and those undergoing LPA ≥ 18 weeks' gestation. Regression analysis was performed to determine the association of early LPA with very preterm delivery and 30-day survival, adjusted for Quintero stage, study phase, selective fetal growth restriction, gestational age at delivery, maternal age ≥ 35 years, body mass index > 35 kg/m² , placental location, use of Seldinger method to place the operative trocar, size of the trocar, participating center, use of Solomon technique, cerclage and PPROM. Survival analysis using the Cox proportional hazard model was applied to examine the LPA-to-delivery interval according to the timing of surgery, adjusted for confounding variables.

RESULTS

A total of 414 TTTS pregnancies were included in the study, of which 68 (16.4%) underwent early LPA. In the total cohort, the incidence of delivery at < 28, < 30 and < 32 weeks' gestation was 22.7%, 39.6% and 53.4%, respectively. Survival of both twins and survival of at least one twin at 30 days were 67.5% and 90.8%, respectively. No significant difference was noted between pregnancies that underwent early LPA and those that had LPA ≥ 18 weeks in the rate of delivery < 28 weeks (19.1% vs 23.4%; P = 0.4), < 30 weeks (38.2% vs 39.9%; P = 0.8) and < 32 weeks (44.1% vs 55.2%; P = 0.1) and PPROM (29.0% vs 24.1%; P = 0.4), or in the incidence of double-twin survival (63.9% vs 68.1%; P = 0.5) and survival of at least one infant (91.8% vs 90.6%; P = 0.7) at 30 days. Early LPA was not associated with very preterm delivery or neonatal survival in the regression analyses. Early LPA was associated with a longer LPA-to-delivery interval compared with LPA performed ≥ 18 weeks (median, 106.9 days (range, 2-164 days) vs median, 69.3 days (range, 0-146 days); P < 0.001) when adjusted for confounding variables (hazard ratio, 2.56 (95% CI, 1.76-3.73); P < 0.001).

CONCLUSION

Laser surgery before 18 weeks is not associated with an increased rate of very preterm delivery and PPROM or with reduced neonatal survival when compared with LPA after 18 weeks. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Outcomes of fetoscopic laser surgery for twin-to-twin transfusion syndrome between 26 and 27 weeks of gestation in Japan

AIM

The purpose of this study was to investigate the outcomes of fetoscopic laser photocoagulation (FLP) for twin-to-twin transfusion syndrome (TTTS) in Japan.

METHODS

The retrospective cohort study (2012-2018) was conducted in monochorionic twin pregnancies that underwent FLP for TTTS between 26 and 27 weeks from 2012 to 2018. The perioperative data, maternal complications, gestational age (GA) at delivery, neonatal complications, and survival of infants at 28 days of age were analyzed. At term-equivalent age, severe neurological complications were identified by imaging study.

RESULTS

Of 644 patients, 28 (4.3%) underwent FLP between 26 and 27 weeks, and 26 were analyzed. FLP procedures were technically successful in all cases. There were no cases of major maternal complications after surgery. Preterm rupture of membranes occurred in 34.6% of cases, and the mean GA at delivery was 33.2 ± 3.1 weeks. The survival of both twins was found in 23 (88.4%) cases, and the perinatal survival rate of at least one twin at 28 days of age was 100%. Severe neurological complications were found in six (12.2%) cases out of 49.

CONCLUSIONS

FLP for TTTS between 26 and 27 weeks provided a good prognosis and caused no major maternal complications. However, severe neurological findings were found in 12% of infants.

Twin to twin transfusion syndrome

Twin to twin transfusion syndrome (TTTS) is a common complication that typically presents in the second trimester of pregnancy in 10-15% of monochorionic twins due to net transfer of volume and hormonal substances from one twin to the other across vascular anastomoses on the placenta. Without recognition and treatment, TTTS is the greatest contributor to fetal loss prior to viability in 90-100% of advanced cases. Ultrasound diagnosis of monochorionicity is most reliable in the first trimester and sets the monitoring strategy for this type of twins. The diagnosis of TTTS is made by ultrasound with the findings of polyhydramnios due to volume overload and polyuria in one twin and oligohydramnios due to oliguria of the co-twin. Assessment of bladder filling as well as arterial and venous Doppler patterns are required for staging disease severity. Assessment of fetal cardiac function also provides additional insight into the fetal cardiovascular impacts of the disease as well as help identify fetuses that may require postnatal follow up. Fetoscopic laser ablation of the communicating vascular anastomoses between the twins is the standard treatment for TTTS. It aims to cure the condition by interrupting the link between their circulations and making them independent of one another. Contemporary outcome data after laser surgery suggests survival for both fetuses can be anticipated in up to 65% of cases and survival of a single fetus in up to 88% of cases. However, preterm birth remains a significant contributor to postnatal morbidity and mortality. Long term outcomes of TTTS survivors indicate that up to 11% of children may show signs of neurologic impairment. Strategies to minimize preterm birth after treatment and standardized reporting by laser centers are important considerations to improve overall outcomes and understand the long-term impacts of TTTS.

Risk Profiling of the Solomon Technique versus Selective Technique of Fetoscopic Laser Surgery for Twin-Twin Transfusion Syndrome

We evaluated the outcomes and adverse events after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) using the Solomon technique in comparison to the selective technique. A retrospective analysis of a single-center consecutive cohort of FLS-treated TTTS using the selective (January 2010 to July 2014) and Solomon (August 2014 to December 2017) techniques was performed. Among 395 cases, 227 underwent selective coagulation and 168 underwent the Solomon technique. The incidence rates of recurrent TTTS (Solomon vs. selective: 0% vs. .9%, p = .510) and twin anemia-polycythemia sequence (.6% vs. .4%, p = .670) were very low in both groups. The incidence rates of placental abruption (Solomon vs. selective: 10.7% vs. 3.5%, p = .007) and preterm premature rupture of the membranes (pPROM) with subsequent delivery before 32 weeks (20.2% vs. 7.1%, p < .001) were higher in the Solomon group. The median birth recipient weight was significantly smaller in the Solomon group (1790 g vs. 1933 g, p = .049). The rate of survival of at least one twin was significantly higher in the Solomon group (98.2% vs. 93.8%, p = .046). The Solomon technique and total laser energy were significant risk factors for pPROM (odds ratio: 2.64, 1.07, 95% CI [1.32, 5.28], [1.01, 1.13], p = .006, p = .014, respectively). These findings suggest that the Solomon technique led to superior survival outcomes but increased risks of placental abruption, pPROM and fetal growth impairment. Total laser energy was associated with the occurrence of pPROM. Close attention to adverse events is required for perinatal management after FLS to treat TTTS using the Solomon technique.

Management of Twin Pregnancies: A Comparative Review of National and International Guidelines

Importance

Twin pregnancies are associated with a higher risk of perinatal mortality and morbidity compared with singleton and require more intensive prenatal care.

Objective

The aim of this study was to review and compare the recommendations from published guidelines on twin pregnancies.

Evidence Acquisition

A descriptive review of guidelines from the Royal College of Obstetricians and Gynaecologists, the International Society of Ultrasound in Obstetrics and Gynecology, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, the National Institute for Health and Care Excellence, the Institute of Obstetricians and Gynaecologists of the Royal College of Physicians of Ireland, the International Federation of Gynecology and Obstetrics, the Society of Obstetricians and Gynaecologists of Canada, and the American College of Obstetricians and Gynecologists on the management of twin pregnancies was conducted.

Results

All the guidelines highlight the importance of an accurate assessment of chorionicity, amnionicity, and gestational age in the first trimester. They also recommend the performance of nuchal translucency and a detailed anomaly scan. The ultrasound surveillance protocol is similar in all guidelines, that is, every 2 weeks for monochorionic and every 4 weeks for dichorionic twins. On the other hand, there are differences regarding the timing and mode of delivery, especially in monochorionic diamniotic twins, in the definition and management of fetal growth discordance, the use of cervical length to screen for preterm birth, and the timing of corticosteroids' administration.

Conclusions

The differences in the reviewed guidelines on the management of twin pregnancies highlight the need for an adoption of an international consensus, in order to improve perinatal outcomes of twin pregnancies.

Asymmetrical Hemodynamic Influence of Twin-Twin Transfusion Syndrome on Fetal E/e' by the Dual Gate Doppler Method in Recipient Twins

OBJECTIVES

To assess the hemodynamic influence of twin-twin transfusion syndrome (TTTS) on diastolic function, using left ventricle (LV) and right ventricle (RV) E/e' measured in the same cardiac cycle using the dual-gate Doppler (DD) method.

METHODS

This study included 56 monochorionic twin pregnancies that underwent fetoscopic laser surgery (FLS) for TTTS in 2015-2018. E/e' by the DD method was measured 24 h before and 4-7 days after FLS.

RESULTS

Recipients showed higher LV-E/e' Z score in stage I-, II-, and III-recipients (IIIr) and higher RV-E/e' Z score in stage III-donors and IIIr than donors (p < 0.05). After FLS, LV-E/e' Z score of recipients significantly decreased due to LV-E velocity Z score decrease (p < 0.05). RV-E/e' Z score after FLS significantly decreased due to RV-e' velocity Z score increase in recipients (p < 0.05).

CONCLUSIONS

E/e' by the DD method helped assess cardiac changes of recipients. LV-E/e' could assess early hemodynamic changes by TTTS, and RV-E/e' can assess later influence on cardiac diastolic function. Furthermore, in recipient twins, the decrease in LV-E/e' after FLS might reflect the improvement of volume overload and the decrease in RV-E/e' might reflect the improvement of diastolic relaxation function in the RV.

Maternal complications following open and fetoscopic fetal surgery: A systematic review and meta-analysis

OBJECTIVE

To establish maternal complication rates for fetoscopic or open fetal surgery.

METHODS

We conducted a systematic literature review for studies of fetoscopic or open fetal surgery performed since 1990, recording maternal complications during fetal surgery, the remainder of pregnancy, delivery, and after the index pregnancy.

RESULTS

One hundred sixty-six studies were included, reporting outcomes for open fetal (n = 1193 patients) and fetoscopic surgery (n = 9403 patients). No maternal deaths were reported. The risk of any maternal complication in the index pregnancy was 20.9% (95%CI, 15.22-27.13) for open fetal and 6.2% (95%CI, 4.93-7.49) for fetoscopic surgery. For severe maternal complications (grades III to V Clavien-Dindo classification of surgical complications), the risk was 4.5% (95% CI 3.24-5.98) for open fetal and 1.7% (95% CI, 1.19-2.20) for fetoscopic surgery. In subsequent pregnancies, open fetal surgery increased the risk of preterm birth but not uterine dehiscence or rupture. Nearly one quarter of reviewed studies (n = 175, 23.3%) was excluded for failing to report the presence or absence of maternal complications.

CONCLUSIONS

Maternal complications occur in 6.2% fetoscopic and 20.9% open fetal surgeries, with serious maternal complications in 1.7% fetoscopic and 4.5% open procedures. Reporting of maternal complications is variable. To properly quantify maternal risks, outcomes should be reported consistently across all fetal surgery studies.

Fetal Survival Immediate after Fetoscopic Laser Ablation in Twin to 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.

CONCLUSION

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.

Outcome reporting across randomized trials and observational studies evaluating treatments for twin-twin transfusion syndrome: systematic review

OBJECTIVE

Twin-twin transfusion syndrome (TTTS) is associated with significant mortality and morbidity. Potential treatments for the condition require robust evaluation. The aim of this study was to evaluate outcome reporting across observational studies and randomized controlled trials assessing treatments for TTTS.

METHODS

Cochrane Central Register of Controlled Trials, EMBASE and MEDLINE were searched from inception to August 2016. Observational studies and randomized controlled trials reporting outcome following treatment for TTTS in monochorionic-diamniotic twin pregnancy and monochorionic-triamniotic or dichorionic-triamniotic triplet pregnancy were included. Outcome reporting was systematically extracted and categorized.

RESULTS

Six randomized trials and 94 observational studies were included, reporting data from 20 071 maternal participants and 3199 children. Six different treatments were evaluated. Included studies reported 62 different outcomes, including six fetal, seven offspring mortality, 25 neonatal, six early childhood and 18 maternal/operative outcomes. Outcomes were reported inconsistently across trials. For example, when considering offspring mortality, 31 (31%) studies reported live birth, 31 (31%) reported intrauterine death, 49 (49%) reported neonatal mortality and 17 (17%) reported perinatal mortality. Four (4%) studies reported respiratory distress syndrome. Only 19 (19%) studies were designed for long-term follow-up and 11 (11%) of these reported cerebral palsy.

CONCLUSIONS

Studies evaluating treatments for TTTS have often neglected to report clinically important outcomes, especially neonatal morbidity outcomes, and most are not designed for long-term follow-up. The development of a core outcome set could help standardize outcome collection and reporting in TTTS studies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome treatment: initial experience in tertiary reference center in Brazil

Objective

To evaluate the initial maternal and perinatal outcomes of fetoscopic laser photocoagulation for the treatment of twin-to-twin transfusion syndrome (TTTS) in a referral center in Brazil.

Methods

This prospective observational study analyzed 24 fetoscopic laser photocoagulation procedures at 18–26 weeks of gestation. TTTS severity was determined using the Quintero classification. Blood vessels that crossed the interamniotic membrane were nonselectively photocoagulated. The χ² test and Mann-Whitney U test were used for the statistical analysis.

Results

The mean (±standard deviation) age of pregnant women, gestational age at surgery, surgical time, gestational age at birth, and newborn weight were 32.2±4.1 years, 20.7±2.9 weeks, 51.8±16.7 minutes, 30.5±4.1 weeks, and 1,531.0±773.1 g, respectively. Using the Quintero classification, there was a higher percentage of cases in stage III (54.2%), followed by stages IV (20.8%), II (16.7%), and I (8.3%). Ten (41.7%) donor fetuses died and 14 (58.3%) donor fetuses survived until the end of gestation. Placental insertion location (anterior vs. posterior) did not affect the incidence of iatrogenic septostomy, surface bleeding, and premature rupture of membranes until the end of gestation. The death rate of donor and recipient fetuses before 24th gestational week increased with severity of TTTS.

Conclusion

The maternal and perinatal outcomes resulting from the implementation of a new minimally invasive surgical technique are in line with those obtained in major centers worldwide, considering the learning curves and infrastructures.

Fetoscopic laser photocoagulation for twin-twin transfusion syndrome

The aim of this study was to review fetoscopic laser photocoagulation (FLP), which ablates placental vascular anastomoses to treat twin–twin transfusion syndrome (TTTS). A review of studies reporting on the procedures, outcomes, complications and nonconventional applications of FLP for TTTS was conducted. FLP has been established as the primary treatment for monochorionic twin pregnancy associated with TTTS at 16–26 weeks. FLP is the only therapy that directly addresses the underlying pathophysiology. The recent technique modification of FLP, referred to as the ‘Solomon technique’, induces selective coagulation to connect the anastomoses ablation sites and has been introduced to reduce residual anastomoses. The perinatal survival following FLP improved significantly with advances in the technique after its introduction. The recent survival rates of both twins and at least one twin are 70% and more than 90%, respectively. However, there is still an 11–14% risk of long‐term neurodevelopment impairment. The premature rupture of membranes that leads to preterm labor is a common complication after FLP. FLP is a valuable treatment option for feto‐fetal transfusion syndrome in triplets and for TTTS after 26 weeks. FLP for selective intrauterine growth restriction may be potentially beneficial when accompanied by abnormal Doppler findings and oligohydramnios. FLP is the optimal treatment option for TTTS at 16–26 weeks of gestation. FLP appears to be applicable in triplets, TTTS after 26 weeks and cases of selective intrauterine growth restriction with abnormal Doppler findings and oligohydramnios. FLP is the most common and successful fetal intervention. Improvement in the neurodevelopmental outcomes after FLP is a future focus.

Solomon Technique Versus Selective Coagulation for Twin-Twin Transfusion Syndrome

Monochorionic twin pregnancies can be complicated by twin-to-twin transfusion syndrome (TTTS). The best treatment option for TTTS is fetoscopic laser coagulation of the vascular anastomoses between donor and recipient. After laser therapy, up to 33% residual anastomoses were seen. These residual anastomoses can cause twin anemia polycythemia sequence (TAPS) and recurrent TTTS. In order to reduce the number of residual anastomoses and their complications, a new technique, the Solomon technique, where the whole vascular equator will be coagulated, was introduced. The Solomon technique showed a reduction of recurrent TTS compared to the selective technique. The incidence of recurrent TTTS after the Solomon technique ranged from 0% to 3.9% compared to 5.3-8.5% after the selective technique. The incidence of TAPS after the Solomon technique ranged from 0% to 2.9% compared to 4.2-15.6% after the selective technique. The Solomon technique may improve dual survival rates ranging from 64% to 85% compared to 46-76% for the selective technique. There was no difference reported in procedure-related complications such as intrauterine infection and preterm premature rupture of membranes. The Solomon technique significantly reduced the incidence of TAPS and recurrent TTTS and may improve survival and neonatal outcome, without identifiable adverse outcome or complications; therefore, the Solomon technique is recommended for the treatment of TTTS.

Twin-twin transfusion and laser therapy

PURPOSE OF REVIEW

Twin-to-twin transfusion syndrome (TTTS) is an uncommon, but dangerous, complication of monochorionic diamniotic twin gestations. The purpose of this review is to provide an update on the evolving treatments in TTTS as it pertains primarily to laser photocoagulation, as well as to provide recently published information on outcomes.

RECENT FINDINGS

The Solomon laser technique, in which selective fetoscopic laser photocoagulation is first performed and then followed by laser of the vascular equator from one side of the placenta to the other, reduces TTTS complications of twin anemia-polycythemia syndrome and recurrent TTTS. The addition of fetal echocardiography to the historical staging of TTTS adds important information that may guide future therapies. The postlaser ablation rate of neurodevelopmental delay in TTTS has recently been reported to be 14%. Cotwin demise is a significant complication of untreated TTTS and survival carries a 25% risk of cystic periventricular leukomalacia, middle cerebral artery infarction, and injury to other central nervous system structures as noted by neuroimaging.

SUMMARY

Laser therapy for TTTS is clearly the only therapy that halts the disease process, allows both fetuses an opportunity to survive and protects a surviving cotwin in the event of the demise of one twin. Laser techniques have evolved greatly over the last 25 years and recent reports with the addition of the Solomon technique appearing to reduce some postlaser complications (twin anemia-polycythemia sequence and recurrent TTTS). Future focus of TTTS therapy should be centered on understanding the pathophysiology of the disease better with improvement in staging of the disease and on comparison of different laser techniques with the overall goal of not only increasing twin survival rates but also reducing long term neurodevelopmental morbidity.

Laser Treatment of Twin–to–Twin Transfusion Syndrome

Objective: Laser ablation of all placental vascular anastomoses is the optimal treatment for twin–twin transfusion syndrome (TTTS). However, two important controversies are apparent in the literature: (a) a gap between concept and performance, and (b) controversy regarding whether all the anastomoses can be identified endoscopically and whether blind lasering of healthy placenta is justified. The purpose of this article is: (a) to address the potential source of the gap between concept and performance by analyzing the fundamental steps needed to successfully accomplish the surgery, and (b) to discuss the resulting competency benchmarks reported with the different surgical techniques. Materials and Methods: Laser surgery for TTTS can be broken down into two fundamental steps: (1) endoscopic identification of the placental vascular anastomoses, (2) laser ablation of the anastomoses. The two steps are not synonymous: (a) regarding the endoscopic identification of the anastomoses, the non-selective technique is based upon lasering all vessels crossing the dividing membrane, whether anastomotic or not. The selective technique identifies and lasers only placental vascular anastomoses. The Solomon technique is based on the theory that not all anastomoses are endoscopically visible and thus involves lasering healthy areas of the placenta between lasered anastomoses, (b) regarding the actual laser ablation of the anastomoses, successful completion of the surgery (i.e., lasering all the anastomoses) can be measured by the rate of persistent or reverse TTTS (PRTTTS) and how often a selective technique can be achieved. Articles representing the different techniques are discussed. Results: The non-selective technique is associated with the lowest double survival rate (35%), compared with 60–75% of the Solomon or the Quintero selective techniques. The Solomon technique is associated with a 20% rate of residual patent placental vascular anastomoses, compared to 3.5–5% for the selective technique (p < .05). Both the Solomon and the selective technique are associated with a 1% risk of PRTTTS. Adequate placental assessment is highest with the selective technique (99%) compared with the Solomon (80%) or the ‘standard’ (60%) techniques (p < .05). A surgical performance index is proposed. Conclusion: The Quintero selective technique was associated with the highest rate of successful ablation and lowest rate of PRTTTS. The Solomon technique represents a historical backward movement in the identification of placental vascular anastomoses and is associated with higher rate of residual patent vascular communications. The reported outcomes of the Quintero selective technique do not lend support to the existence of invisible anastomoses or justify lasering healthy placental tissue.

Evolution of Stage 1 Twin-to-Twin Transfusion Syndrome (TTTS): Systematic Review and Meta-Analysis

Objectives: The natural history of stage 1 Twin-to-twin transfusion syndrome (TTTS) remains unclear and its optimal management is yet to be established. The main aims of this meta-analysis were to quantify the incidence of progression in stage 1 TTTS and to ascertain survival in these pregnancies.

Methods: MEDLINE, EMBASE, and The Cochrane Library were searched. Reference lists within each article were hand-searched for additional reports. The outcomes included incidence of progression and survival in stage 1 TTTS. Randomized controlled trials, cohort and case-control studies were included. Case reports, studies including three or fewer cases of stage 1 TTTS, and editorials were excluded. Proportion meta-analysis was used for analysis (Registration number: CRD42016036190).

Results: The search yielded 3,085 citations; 18 studies were included in the review (172 pregnancies to assess progression and 433 pregnancies to assess the survival). The pooled incidence of progression in stage 1 TTTS was 27% [95% CI 16–39%]. The pooled overall survival, double survival and at least one survival in the pregnancies managed expectantly were 79% [95% CI 62–92%], 70% [95% CI 54–84%] and 87% [95% CI 69–98%], respectively. In those undergoing amnioreduction, the corresponding figures were 77% [95% CI 68–85%], 67% [95% CI 57–76%] and 86% [95% CI 76–94%], respectively. The survival rates were 68% [95% CI 54–81%], 54% [95% CI 36–72%], and 81% [95% CI 69–90%], when laser surgery was performed.

Conclusions: The optimal initial management of stage 1 TTTS remains in equipoise. The ongoing randomized trial comparing immediate laser surgery versus conservative management should provide a definitive answer.

The Impact of Entry Technique and Access Diameter on Prelabour Rupture of Membranes Following Primary Fetoscopic Laser Treatment for Twin-Twin Transfusion Syndrome

Objective: To evaluate the impact of entry method and access diameter at fetoscopic surgery for twin-twin transfusion syndrome in twin pregnancies with at least one survivor. The outcomes evaluated were prelabour rupture of membranes (PROM) and birth <4 weeks, preterm birth (PTB) <28 weeks, and latency to birth. Methods: A retrospective analysis of prospectively collected data of consecutive laser procedures from 6 centers was performed. Three entry methods (sheath + trocar; cannula + trocar; cannula + Seldinger) and 6 access diameters (2.3, 3.0, 3.3, 3.5, 3.8, 4.0 mm) were used. Exclusion criteria were subsequent invasive interventions, termination of pregnancy or double fetal death after laser. Multivariate analysis was performed to determine risk factors for the study outcomes. Results: Six hundred seventy three fetoscopic laser cases were analyzed. The use of different entry methods and access diameters did not affect PROM or birth <4 weeks, or latency from laser to birth. Access diameter was associated with PTB <28 weeks. Cervical length was associated with PROM and birth <4 weeks, and latency from laser to birth. Conclusion: Instrument choice at fetoscopic laser procedures did not affect outcomes <4 weeks. Access diameter may affect the likelihood for PTB <28 weeks. Cervical length is critically associated with obstetrical outcomes following laser surgery.

Postnatal survival after endoscopic equatorial laser for the treatment of twin-to-twin transfusion syndrome

BACKGROUND

Endoscopic laser coagulation of placental anastomoses is the first-line treatment for severe twin-to-twin transfusion syndrome. A recent randomized controlled trial reported that laser coagulation along the entire vascular equator was associated with a similar dual survival and survival of at least 1 twin compared with the group that was treated with the selective technique. In addition, there was a significantly lower incidence of postoperative recurrence of twin-to-twin transfusion syndrome and the development of twin anemia-polycythemia sequence in the equatorial group.

OBJECTIVE

The purpose of this study was to report on neonatal survival in twin-to-twin transfusion syndrome pregnancies that were treated with endoscopic laser therapy with the use of the equatorial technique and to examine the relationship between preoperative factors and twin loss.

STUDY DESIGN

Endoscopic equatorial laser therapy was carried out as the primary treatment for twin-to-twin transfusion syndrome in all consecutive monochorionic diamniotic twin pregnancies that were referred at a single fetal surgery Center over a 4-year period. All visible placental anastomoses were coagulated; additional laser ablation of the placental tissue between the coagulated vessels was carried out. Pre-laser ultrasound data, periprocedural complications, pregnancy outcome, and postnatal survival at hospital discharge were recorded and analyzed.

RESULTS

A total of 106 pregnancies were treated during the study period. Median gestational age at laser therapy was 19.7 weeks (range, 15.1-27.6 weeks). There was postoperative recurrence of twin-to-twin transfusion syndrome or the development of twin anemia-polycythemia sequence in 2 (1.9%) and 2 (1.9%) cases, respectively. The survival rates of both and at least 1 twin were 56.6% and 83.0%, respectively. Donor survival was significantly lower compared with the recipient co-twin (64.2% vs 75.5%, respectively; P < .05). The rate of fetal death, which was the most common cause of twin loss, was significantly higher in donors compared with recipient fetuses (23.6% vs 10.4%, respectively; P < .05). In cases with absent or reversed end-diastolic velocity in the donor umbilical artery, dual and donor survival rates were significantly lower compared with the remaining twin-to-twin transfusion syndrome pregnancies (40.0% vs 64.8% and 40.0% vs 76.1%, respectively; P < .05). There were no significant differences between the 2 groups in the survival of at least 1 twin and in the recipient survival.

CONCLUSIONS

Endoscopic equatorial laser therapy was associated with a survival of both and at least 1 twin of approximately 55% and 83%, respectively, with a low rate of recurrent twin-to-twin transfusion syndrome and twin anemia-polycythemia sequence. In addition, the preoperative finding of abnormal donor umbilical artery Doppler on ultrasound identified a subgroup of twin-to-twin transfusion syndrome pregnancies with a lower dual survival rate caused by increased intrauterine deaths of donor twins.

Twin Anemia-Polycythemia Sequence: Perinatal Management and Outcome

Objective: To determine the perinatal outcome of monochorionic twin pregnancies complicated by twin anemia-polycythemia sequence (TAPS). Methods: All monochorionic twins diagnosed with TAPS between 2011 and 2014 were included. Each twin pair with TAPS (study group) was compared with 2 uncomplicated monochorionic twin pairs who were matched for gestational age at delivery (control group). Neonatal morbidity and mortality were evaluated. Results: During the study period, 179 monochorionic twins were followed at our center, of whom 46 underwent laser ablation due to twin-to-twin transfusion syndrome. TAPS was diagnosed in 10 cases; 8 of them were spontaneous, and 2 occurred following laser surgery. Out of 7 patients diagnosed prenatally with TAPS, 5 cases were managed expectantly, and 2 cases were treated with intrauterine blood transfusion. The rates of severe and mild central nervous system lesions on postnatal ultrasound were similar in the TAPS group and control group (5.0 vs. 2.5%, p = 0.61, and 5.0 vs. 12.5%, p = 0.25, respectively). Additionally, severe neonatal morbidity was comparable between the groups. All neonates were alive at 1 month of age. Conclusion: The neonatal outcome of monocohorionic twins affected by TAPS is favorable and comparable to gestational age-matched uncomplicated monochorionic twins.

Comparison of Solomon technique with selective laser ablation for twin-twin transfusion syndrome: a systematic review

OBJECTIVE

To compare the Solomon and selective techniques for fetoscopic laser ablation (FLA) for the treatment of twin-twin transfusion syndrome (TTTS) in monochorionic-diamniotic twin pregnancies.

METHODS

This was a systematic review conducted in accordance with the PRISMA statement. Electronic searches were performed for relevant citations published from inception to September 2014. Selected studies included pregnancies undergoing FLA for TTTS that reported on recurrence of TTTS, occurrence of twin anemia-polycythemia sequence (TAPS) or survival.

RESULTS

From 270 possible citations, three studies were included, two cohort studies and one randomized controlled trial (RCT), which directly compared the Solomon and selective techniques for FLA. The odds ratios (OR) of recurrent TTTS when using the Solomon vs the selective technique in the two cohort studies (n = 249) were 0.30 (95% CI, 0.00-4.46) and 0.45 (95% CI, 0.07-2.20). The RCT (n = 274) demonstrated a statistically significant reduction in risk of recurrent TTTS with the Solomon technique (OR, 0.21 (95% CI, 0.04-0.98); P = 0.03). The ORs for the development of TAPS following the Solomon and the selective techniques were 0.20 (95% CI, 0.00-2.46) and 0.61 (95% CI, 0.05-5.53) in the cohort studies and 0.16 (95% CI, 0.05-0.49) in the RCT, with statistically significant differences for the RCT only (P < 0.001). Observational evidence suggested overall better survival with the Solomon technique, which was statistically significant for survival of at least one twin. The RCT did not demonstrate a significant difference in survival between the two techniques, most probably owing to the small sample size and lack of power.

CONCLUSION

This systematic review of observational, comparative cohort and RCT data suggests a trend towards a reduction in TAPS and recurrent TTTS and an increase in twin survival, with no increase in the occurrence of complications or adverse events, when using the Solomon compared to the selective technique for the treatment of TTTS. These findings need to be confirmed by an appropriately-powered RCT with long-term neurological follow-up.

Twenty-Five Years of Fetoscopic Laser Coagulation in Twin-Twin Transfusion Syndrome: A Systematic Review

Objective: The aim of this study was to assess the perinatal outcome of pregnancies with twin-twin transfusion syndrome (TTTS) treated with laser therapy over the past 25 years, and in relation to different techniques used in this time period. Methods: A systematic review of studies reporting on perinatal outcome according to the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines was conducted. The MEDLINE, Embase and Cochrane Library databases were systematically searched. Comparisons were made in respect to time period and laser technique and Quintero stages. Results: In total, 34 studies reporting on 3,868 monochorionic twin pregnancies were included. The mean survival of both twins increased from 35 to 65% (p = 0.012) and for at least one twin from 70 to 88% (p = 0.009) over the past 25 years. Mean gestational age at birth remained stable over the years at 32 weeks gestation. Also, we showed a significantly improved perinatal survival with the evolution of the laser technique from non-selective to selective, selective sequential and the Solomon technique (p = 0.010). Discussion: Since the introduction of laser therapy for TTTS more than two decades ago, perinatal survival improved significantly. Improved outcome is probably associated with several factors, including evolution of the laser technique, learning curve effect, better referral and improved early neonatal care.

Outcome following selective fetoscopic laser ablation for twin to twin transfusion syndrome: an 8 year national collaborative experience

OBJECTIVE

With the recognition of the role of fetoscopic laser ablation for twin to twin transfusion syndrome (TTTS), there is a requirement for auditable standards for this technically challenging and specialized treatment. The purpose of this study is to report on the perinatal and medium-term neurodevelopmental outcomes following an 8-year national single center experience in the management of TTTS using the selective fetoscopic laser ablation technique.

STUDY DESIGN

An audit of all cases of TTTS treated with selective laser ablation by a single national fetal medicine team was performed. Overall perinatal survival and medium-term neurodevelopmental outcomes were reported and correlated with gestational age at diagnosis, placental location, volume of amnio-reduction, Quintero staging and percentage inter-twin growth discordance. Procedure-related complications were recorded.

RESULTS

The overall fetal survival for the first 105 consecutive cases of TTTS was 61% (128/210 fetuses). Dual survival occurred in 47% (49/105) of cases, and with a single survival rate of 28% (30/105), perinatal survival of least one infant was achieved in 75% (79/105) of cases. No correlation was found between any clinical or sonographic marker and perinatal outcome, although dual survival was noted to be significantly decreased with increasing Quintero stage (p=0.041). Currently, 86% of survivors have been reported to have a normal medium-term neurological outcome.

CONCLUSION

Fetoscopic laser ablation is the established optimal treatment for severe twin to twin transfusion syndrome (TTTS). We report comparable short and medium-term outcomes following the selective fetoscopic technique comparing results from our national program with internationally published single-center outcomes, supporting the efficacy and safety of this treatment at our center.

Long-term neurologic outcomes after common fetal interventions

OBJECTIVE

Fetal interventions have clearly decreased mortality, but the neurological outcomes of survivors are of critical concern. Here we consolidated available data on long-term neurological outcomes after common fetal interventions to guide counseling, management, and future research.

STUDY DESIGN

Published studies assessing long-term neurological outcomes after common fetal interventions from 1990 through 2014 were collected. We included all studies with a cohort of more than 5 patients and with follow-up of 1 year or longer. We divided procedures into those performed for singletons and for multiples. Singleton procedures included amnioinfusion for preterm premature rupture of membranes, intrauterine transfusion for red cell alloimmunization-associated anemia, intrauterine transfusion for parvovirus-associated anemia, vesicoamniotic shunts, thoracoamniotic shunts, ventriculoamniotic shunts, fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia, and open fetal cases by myelomeningocele and others. Multiple procedures included those done for monochorionic twins including serial amnioreduction, selective fetoscopic laser photocoagulation, and selective termination.

RESULTS

Of 1341 studies identified, 28 met the inclusion criteria. We combined available literature for all procedures. Studies varied in their length of follow-up and method of assessing neurological status. Neurological outcome after intervention varied by procedure but was normal in 40-93%, mildly impaired in 3-33%, and severely impaired in 1-40%. Follow-up to school age was rare with the exception of procedures for monochorionic twins.

CONCLUSION

Fetal treatments have been successful in achieving survival in previously hopeless cases, but success should also be determined by the outcomes of survivors. Except for monochorionic twins, there is a dearth of reported long-term outcomes. Standardized reporting of long-term neurological sequelae is imperative so that meaningful analysis and study comparisons can be made.

High-intensity focused ultrasound applied to the placenta using a toroidal transducer: a preliminary ex-vivo study

OBJECTIVE

To demonstrate in an ex-vivo model the feasibility of applying high-intensity focused ultrasound (HIFU) using a toroidal transducer for the creation of placental lesions.

METHODS

In this study we used a toroidal transducer, composed of 32 ring-shaped emitters with an ultrasound probe at the center, operating at a frequency of 2.5 MHz. We examined 45 human placentae, following either normal vaginal delivery or medical termination of pregnancy between 17 and 40 gestational weeks. First, the attenuation coefficients of 12 human placentae were measured and integrated into a numerical model for simulating HIFU lesions. Then, using acoustic parameters from this preliminary study, we performed ex-vivo experiments with 33 human placentae, each overlain with an animal abdominal wall to simulate the maternal wall. We created single HIFU lesions in 25 of these placentae, and a series of six juxtaposed lesions in eight, studying these both sonographically and macroscopically.

RESULTS

Human placental attenuation coefficients of the 12 human placentae ranged from 0.072 to 0.098 Np/cm/MHz, according to gestational age. The 25 single HIFU lesions created had an average diameter of 7.1 ± 3.2 mm and an average depth of 8.2 ± 3.1 mm. The average diameter of the eight series of six juxtaposed HIFU lesions was 23.0 ± 5.0 mm and the average depth was 11.0 ± 4.7 mm. The average thickness of the abdominal walls was 10.5 ± 1.8 mm. No lesions or damage were observed in intervening tissues.

CONCLUSION

This study demonstrates, using an ex-vivo model, the feasibility, reproducibility, harmlessness and effectiveness of HIFU applied to the human placenta.

Residual anastomoses in twin-twin transfusion syndrome after laser: the Solomon randomized trial

OBJECTIVE

Residual anastomoses after fetoscopic laser surgery for twin-to-twin transfusion syndrome (TTTS) may lead to severe postoperative complications, including recurrent TTTS and twin anemia-polycythemia sequence (TAPS). A novel technique (Solomon technique) using laser coagulation of the entire vascular equator was recently investigated in a randomized controlled trial (Solomon trial) and compared with the Standard selective laser technique. The aim of this secondary analysis was to evaluate the occurrence and characteristics of residual anastomoses in placentas included in the Solomon trial.

STUDY DESIGN

International multicenter randomized controlled trial in TTTS, randomized 1:1 ratio to either the Solomon laser technique or Standard laser technique. At time of laser, surgeons recorded whether they considered the procedure to be complete. Placental dye injection was performed after birth in the participating centers to evaluate the presence of residual anastomoses.

RESULTS

A total of 151 placentas were included in the study. The percentage of placentas with residual anastomoses in the Solomon group and Standard group was 19% (14/74) and 34% (26/77), respectively (P = .04). The percentage of placentas with residual anastomoses in the subgroup of cases where the procedure was recorded as complete was 8/65 (12%) and 22/69 (32%) in the Solomon group and Standard group, respectively (P < .01).

CONCLUSION

The Solomon laser technique reduces the risk of residual anastomoses. However, careful follow-up remains essential also after the Solomon technique, as complete dichorionization is not always achieved.

Current principles and practice of ethics and law in perinatal medicine

One of the most controversial discussion topics in modern bioethics, science or philosophy is represented by the beginning of the individual human life. It is ethically, medically and scientifically correct that the human conception product to be born, so to gain personality and individuality, to be treated as a patient since the intrauterine life. Intrauterine foetal interventions, performed in various therapeutic purposes are still in the experimental stage even in centres with rich experience in perinatal medicine. Progresses truly outstanding are present especially in the prenatal diagnostic methods. Non invasive prenatal testing represents without a doubt a great progress in prenatal diagnosis, but from this point of view, the role of practitioners in the field of perinatal medicine, on counselling and addressing the indication of this test becomes essential. Beyond cultural, national, social or related differences, in perinatal medicine practice is particularly important to respect and permanently reassess the ethical codes. Our paper is targeting to spotlight the essential principles and practice of ethics and law in perinatal medicine nowadays on one hand, and to bring an update review on a controversial topic on the other hand.

Fetoscopic laser coagulation of the vascular equator versus selective coagulation for twin-to-twin transfusion syndrome: an open-label randomised controlled trial

BACKGROUND

Monochorionic twin pregnancies complicated by twin-to-twin transfusion syndrome are typically treated with fetoscopic laser coagulation. Postoperative complications can occur due to residual vascular anastomoses on the placenta. We aimed to assess the efficacy and safety of a novel surgery technique that uses laser coagulation of the entire vascular equator (Solomon technique).

METHODS

We undertook an open-label, international, multicentre, randomised controlled trial at five European tertiary referral centres. Women with twin-to-twin transfusion syndrome were randomly assigned by online randomisation (1:1) with permuted blocks to the Solomon technique or standard laser coagulation. The primary outcome was a composite of incidence of twin anaemia polycythaemia sequence, recurrence of twin-to-twin transfusion syndrome, perinatal mortality, or severe neonatal morbidity. Analyses were by intention to treat, with results expressed as odds ratios (ORs) and 95% CIs. This trial is registered with the Dutch Trial Registry, number NTR1245.

FINDINGS

Between March 11, 2008, and July 12, 2012, 274 women were randomly assigned to either the Solomon group (n=139) or the standard treatment group (n=135). The primary outcome occurred in 94 (34%) of 274 fetuses in the Solomon group versus 133 (49%) of 270 in the standard treatment group (OR 0·54; 95% CI 0·35-0·82). The Solomon technique was associated with a reduction in twin anaemia polycythaemia sequence (3% vs 16% for the standard treatment; OR 0·16, 95% CI 0·05-0·49) and recurrence of twin-to-twin transfusion syndrome (1% vs 7%; 0·21, 0·04-0·98). Perinatal mortality and severe neonatal morbidity did not differ significantly between the two groups. Outside of the common and well-known complications of twin-to-twin transfusion syndrome and its treatment, no serious adverse events occurred.

INTERPRETATION

Fetoscopic laser coagulation of the entire vascular equator reduces postoperative fetal morbidity in severe twin-to-twin transfusion syndrome. We recommend that fetoscopic surgeons consider adopting this strategy for treatment of women with twin-to-twin transfusion syndrome.

FUNDING

Netherlands Organization for the Health Research and Development (ZonMw 92003545).

Pathophysiological mechanisms of high-intensity focused ultrasound-mediated vascular occlusion and relevance to non-invasive fetal surgery

High-intensity focused ultrasound (HIFU) is a non-invasive technology, which can be used occlude blood vessels in the body. Both the theory underlying and practical process of blood vessel occlusion are still under development and relatively sparse in vivo experimental and therapeutic data exist. HIFU would however provide an alternative to surgery, particularly in circumstances where serious complications inherent to surgery outweigh the potential benefits. Accordingly, the HIFU technique would be of particular utility for fetal and placental interventions, where open or endoscopic surgery is fraught with difficulty and likelihood of complications including premature delivery. This assumes that HIFU could be shown to safely and effectively occlude blood vessels in utero. To understand these mechanisms more fully, we present a review of relevant cross-specialty literature on the topic of vascular HIFU and suggest an integrative mechanism taking into account clinical, physical and engineering considerations through which HIFU may produce vascular occlusion. This model may aid in the design of HIFU protocols to further develop this area, and might be adapted to provide a non-invasive therapy for conditions in fetal medicine where vascular occlusion is beneficial.