Twin Reversed Arterial Perfusion Research Articles

Management of twin-reversed arterial perfusion (TRAP) sequence: a systematic review and meta-analysis.

Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic twin pregnancies characterized by placental anastomoses between a normally developed twin and an acardiac mass. Though several treatment modalities exist, the optimal management strategy is unclear. This study aims to compare the various treatment strategies for TRAP sequence. A systematic review of the literature was performed using PRISMA guidelines including PubMed, Scopus, Web of Science and the Cochrane Library. Studies were imported into Covidence, where they were independently screened by two authors. Studies included described interventions for TRAP sequence. Those excluded were unavailable in English and lacked differentiation between intervention strategies for TRAP and other monochorionic twin pregnancies. Fisher's exact test and random effects modeling were used for statistical analysis. 2340 abstracts were screened, of which 218 articles progressed to full review and 120 qualified for data extraction. 757 twin pregnancies were described. Most were treated with radiofrequency ablation (RFA) (n=363, 47.95%) and laser ablation (n=220, 29.06%). Statistically significant differences amongst the modalities were seen in technical success (p = 0.005), gestational age at presentation (p < 0.01), intervention (p = 0.01), and delivery (p = 0.01), respectively, and time between treatment and delivery (p < 0.01). Notably, pump twin survival did not differ based on treatment modality used (p = 0.196). Overall, complication rates were low with no differences in preterm premature rupture of membranes (PPROM) (p = 0.66), preterm labor (p = 0.58) or maternal hemorrhage between modalities (p = 0.28). Suture cord ligation, however, had a greater hemorrhage rate than RFA (p = 0.03). This embodies the first meta-analysis comparing treatment modalities for TRAP sequence with outcomes and complications. RFA is the most technically successful strategy. Prospective data is required to further understand the optimal modality and gestational age at treatment to ensure best overall outcomes. .

Distinguishing PEX gene variant severity for mild, severe, and atypical peroxisome biogenesis disorders in Drosophila.

Peroxisomal biogenesis disorders (PBD) are autosomal recessive disorders caused by loss-of-function mutations of one of the PEX genes responsible for peroxisomal formation. Impaired peroxisome assembly causes severe multisystemic failure with patient phenotypes ranging from epilepsy, liver disease, feeding issues, biochemical abnormalities, and neurodegeneration. Variants in the same PEX gene can produce wide differences in severity, ranging from individuals with death in the first year of life to adults with milder complications. To study this strong genotype-phenotype correlation, we selected specific human PEX gene mutations and utilized Drosophila as a model organism. We generated flies replacing the coding sequence of our Pex gene of interest with a KozakGAL4 (KZ) promoter trap sequence. These cassettes simultaneously knock-out of the Pex gene and knock-in a GAL4 driver, ideal for making "humanized" flies in which the human PEX gene can replace the fly loss. We assessed Pex2 KZ and Pex16 KZ lines in lifespan, bang sensitivity, and climbing assays and confirmed that these are strong loss-of-function alleles. In parallel, we generated human reference and variant UAS-cDNA lines of PEX2 and PEX16 variants in Drosophila . We observed nearly complete phenotypic rescue of Drosophila Pex2 and Pex16 loss when human PEX2 Ref or PEX16 Ref , respectively, were expressed. We also provide evidence for an allele severity spectrum in PEX2 and PEX16 in which some missense alleles, such as PEX2 C247R , are equally severe as early truncations, such as PEX2 R119* . We also observed that alleles associated with mild PBD, such as PEX2 E55K , show variability depending on the assay but do not fully rescue. Finally, alleles associated with atypical ataxia phenotypes, such as PEX16 F332Del , can perform as well as PEX16 Ref , depending on the assay. Altogether, these Drosophila lines effectively model the range of severity of peroxisomal biogenesis disorders.

Photocatalysis Meets Copper Catalysis: A New Opportunity for Asymmetric Multicomponent Radical Cross-Coupling Reactions.

ConspectusIn recent years, radical-mediated cross-coupling reactions have emerged as a compelling strategy for achieving a rich diversity in molecular topologies under benign conditions. However, the inherent high reactivity of radicals presents considerable challenges in controlling reaction pathways and selectivity, which often results in a limited range of substrates and a constrained reaction profile. Given the capacity of visible-light photoredox catalysis to generate a wide variety of reactive radicals and radical ions in a controlled manner and the propensity of copper complexes toward radical species, we envisaged that the synergy between chiral copper catalysts and photoactive catalysts would pave the way for developing innovative strategies. This integration is poised to unlock a broad spectrum of enantioselective multicomponent radical cross-coupling reactions.In this Account, we describe our insights and recent efforts in the realm of enantioselective multicomponent radical cross-coupling reactions. These advancements have been achieved through the innovative application of dual photoredox/copper catalysis or bifunctional copper catalysis under visible light irradiation. Our work is systematically divided into two sections based on the activation modes. The first section focuses on photoinduced copper-catalyzed chiral C-C and C-O bond formation through a radical addition/nucleophilic trap sequence. Our discussion of chiral C-C bond formation is particularly concentrated on the asymmetric carbocyanation and carboarylation of vinylarenes, 1,3-enynes, and 1,3-dienes. Our findings underscore that irradiation with visible light can adeptly modulate the pace of radical generation, thus orchestrating consecutive reaction stages and ensuring the attainment of both chemo- and stereoselectivity. In the domain of chiral C-O bond formation, leveraging carboxylic acids as a nucleophilic oxygen source, we introduce a suite of esterification reactions of benzylic, allylic, and propargylic radicals. These radicals are derived from a variety of radical precursors, showcasing the versatility of our approach. The following section highlights our innovative discovery in the field of dual photoredox/copper catalysis, which enables enantioselective three-component radical transformations via the direct activation of aromatic alkenes. This methodology begins with the generation of formal distonic radical anions through the photocatalytic single-electron reduction of aromatic alkenes, thus, enabling orthogonal reactivity. Employing H2O, D2O, and CO2 as external electrophile agents, we have developed three types of radical cyanofunctionalization reactions: hydrocyanation, deuteriocyanation, and cyanocarboxylation. These reactions provide practical access to diversely functionalized chiral nitriles with high enantiomeric excess.Collectively, these synthetic methodologies highlight the immense potential inherent in the synergistic integration of photocatalysis and asymmetric copper catalysis. This Account aspires to deepen our comprehension of the advantages conferred by these catalytic systems, elucidating the crucial role of photocatalysis in facilitating enantioselective multicomponent radical cross-couplings. We anticipate that this Account will provide valuable insights and stimulate the evolution of innovative methodologies within this rapidly expanding field.

Cord occlusion in twin reversed arterial perfusion sequence: a retrospective study of laser photocoagulation vs radiofrequency ablation.

Twin reversed arterial perfusion (TRAP) sequence is a rare condition complicating monozygotic multiple gestations. Prenatal management via umbilical cord occlusion (UCO) of the anomalous twin has been shown to improve pump twin survival. We compared outcomes of gestations with high-risk TRAP sequence treated with mid-trimester UCO using laser photocoagulation vs radiofrequency ablation (RFA). This is a retrospective, single-center, cohort study of all patients with high-risk TRAP sequence who underwent UCO from 2006-2023. High-risk criteria were defined as follows: larger abdominal circumference of the anomalous twin, polyhydramnios, critically abnormal Doppler waveforms in the pump twin, hydrops in the pump twin, and/or monoamniotic twins. The primary outcome was 30-day survival of the pump twin. The 74 patients were divided equally between the laser and RFA groups. For the 2 groups, mean gestational age (GA) at UCO (20.5 ± 2.3 vs 20.7 ± 3.1 weeks, P=.987) and mean GA at delivery (35.2 ± 4.6 vs 34.5 ± 5.7 weeks, P=.812) were similar. The 30-day neonatal survival rate did not differ (91.9% [34/37] vs 89.2% [33/37], OR: 1.37 [0.29-6.61], P=.692). No difference in 30-day neonatal survival was identified in patients with high-risk TRAP sequence who underwent mid-trimester UCO by laser vs RFA.

Enantioselective Synthesis of Planar Chiral Ferrocene Triflones

AbstractA multi‐gram scale synthesis of ferrocenetriflone was optimised from ferrocenesulfonyl fluoride and Me3SiCF3 (Ruppert reagent). Enantioselective deprotolithiations were then optimised using alkyllithiums in the presence of catalytic (+)‐sparteine to afford 2‐substituted ferrocene triflones in 79–84% ee. The use of chiral lithium amides in the presence of in situ traps was also optimised and was found to outperform alkyllithium⋅chiral diamine chelates for the first time in the ferrocene series, with 89–93% ee. Crystallisation of derivatives afforded enantiopure compounds that were engaged in deprotolithiation‐electrophilic trapping sequences, a halogen ‘dance’ reaction and transition metal‐promoted coupling to afford a wide range of variously polysubstituted ferrocene triflones.

Acardiac twinning: A rare case of noninterventional positive resolution

Abstract Twin reversed arterial perfusion (TRAP) sequence refers to a rare pregnancy complication caused by an abnormality in the umbilical artery in monochorionic twins. Here, we present a case report of a 28-year-old female who was referred to our hospital upon detection of TRAP on midtrimester ultrasonography. After careful examination of the condition of the patient, she was successfully treated. Early diagnosis of TRAP can provide the mother with treatment and care that might aid in minimizing damage to the healthy twin. Management options depend on the clinical and radiological parameters of each case.

Twin-Reversed Arterial Perfusion (TRAP) Sequence: Case Report and Literature Review

Introduction and Importance: The TRAP sequence or cardiac mass is a serious pathology that occurs in monochorionic twin pregnancies, characterised by the absence of development of cardiac structures with a series of malformations in the transfused fetus, which is never viable, and numerous complications affecting the transfused twin. Case Presentation: We report a case of TRAP sequence in a presumed pregnancy at 7 months. Discussion: The TRAP sequence is an exceptional and specific complication of monochorionic twin pregnancies, affecting on average one birth in 35,000 and 1% of monozygotic pregnancies. The differential diagnosis includes in utero fetal death of a twin without anomalies, anencephaly associated with cystic hygroma and placental tumour. Management of the TRAP sequence in complicated twin pregnancies is aimed at the survival and compensation of the transfused fetus. Conclusion: Analysis of this observation highlights the importance of prenatal diagnosis in the prevention of its consequences.

Twin reversed arterial perfusion sequence in monochorionic diamniotic pregnancy: A rare occurrence

Twin reversed arterial perfusion is a rare complication occurring in monochorionic multifetal pregnancies. This condition is characterized by a malformed fetus being perfused by a normal twin through an artery-to-artery anastomosis in the reverse direction. Herein, we report a case of a multigravida female with a twin pregnancy at 27 weeks 5 days of gestation referred in view of twin pregnancy with the intra-uterine demise of one twin. Gray scale and color Doppler imaging revealed a monochorionic diamniotic pregnancy with a viable, normal twin, and an amorphously developed acardiac twin. The patient was monitored with weekly ultrasonography, echocardiography, and Doppler ultrasound examination to ascertain the well-being of the pump twin. She delivered a normal live baby at term and an acardius acephalus fetus. The perinatal mortality of the pump twin is significantly high. Therefore, it is necessary to diagnose this entity at an early gestational age through improved imaging techniques, so that timely intervention can be planned.

Intrauterine Treatment of Monochorionic Triamniotic Triplet Pregnancy with Twin Reverse Arterial Perfusion Sequence

Intrauterine Treatment of Monochorionic Triamniotic Triplet Pregnancy with Twin Reverse Arterial Perfusion Sequence

Fetal magnetic resonance imaging, ultrasound, and echocardiography findings in twin reversed arterial perfusion sequence.

Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic multiple gestation pregnancies, in which the pump twin provides hemodynamic support to a nonviable co-twin (acardius). Fetal magnetic resonance imaging (MRI) is used to detect pump twin abnormalities, particularly brain ischemia, prior to fetal intervention to interrupt umbilical blood flow to the acardius. To summarize the imaging findings of TRAP sequence pregnancies in a large series. A single-center retrospective review was performed of all TRAP sequence pregnancies referred for fetal MRI (2004-2021). Fetal MRI, ultrasound, and echocardiography data were collected. Eighty-eight TRAP sequence pregnancies with MRI were included (mean gestational age, 19.8±2.8 weeks). Demise of the pump twin was noted in two pregnancies at the time of MRI. By MRI, 12% (10/86) of live pump twins had abnormalities, including 3% (3/86) with brain abnormalities and 9% (8/86) with extra-cranial abnormalities. By echocardiography, 7% (6/86) of pump twins had structural cardiac abnormalities. Three acardius morphological subtypes were identified by MRI: acephalus (55%, 48/88), anceps (39%, 34/88), and amorphous (7%, 6/88). The mean ultrasound acardiustopump twin ratioA/Pratio, calculated for each twin pair as the ratio of the acardius trunk (and head, if present) plus limb volume to the pump twin estimated fetal weight) differed among the three acardius subtypes (P=.03). The mean A/P ratio moderately correlated with pump twin cardiothoracic ratio and combined cardiac output (Pearson's r=0.45 and 0.48, respectively, both P<.001). Fetal MRI of TRAP sequence pregnancies found anomalies in a substantial number of pump twins. The three acardius subtypes differed in A/P ratio, which moderately correlated with the pump twin cardiothoracic ratio and combined cardiac output.

Twin reverse arterial perfusion sequence

Twin Reverse Arterial Perfusion Sequence (TRAP) is a rare condition specific to identical twins. Overall, TRAP affects around 1% of all monozygotic twins, with 75% occurring in monochorionic-biamniotic twins and the remaining 25% in monoamniotic twins. TRAP is characterized by a normal-appearing pump twin supporting a dysmorphic acardiac twin through aberrant arterio-arterial anastomoses in the shared single placenta.

224 Umbilical cord occlusion of twin reversed arterial perfusion (TRAP) sequence: laser photocoagulation vs radiofrequency ablation

224 Umbilical cord occlusion of twin reversed arterial perfusion (TRAP) sequence: laser photocoagulation vs radiofrequency ablation

TRAP Sequence, Diagnosis, Treatment, and Outcome

TRAP Sequence, Diagnosis, Treatment, and Outcome

SFM Fetal Therapy Practice Guidelines: Fetal Interstitial Laser

AbstractFetal laser therapy was first used in complicated monochorionic pregnancies such as twin-to-twin transfusion syndrome or twin-reversed arterial perfusion sequence. There are some other less common indications such as amniotic band syndrome, chorioangiomas, lower urinary tract obstructions, sacrococcygeal teratomas, and fetal thoracic masses. These practice guidelines discuss the indications, contraindications, and risks of the procedure along with information for patients and draft consent form.

Twin reverse arterial perfusion sequence: A case report and literature review

Twin reverse arterial perfusion sequence (TRAPS) is one of the complications of monochorionic twin gestation. It is characterised by large intertwined arterial-arterial anastomosis in which blood flows from one twin (pump twin) to the other twin (perfused twin) In a retrograde pattern. We report a case of monochorionic diamniotic twin gestation complicated by TRAPS in a 38-year-old G4P3 trader who was referred to the antenatal clinic of Rivers State University Teaching Hospital on account of unusual abdominal distension of one-week duration at 31 weeks gestational age. Ultrasound scan done at presentation showed a monochorionic diamniotic twin with the first twin in a transverse lie with an estimated foetal weight of 1.7kg, foetal heart rate of 150 beats per minute, and Twin 2, had no foetal head, no cardiac pulsation with significant tissue swelling. A diagnosis of TRAPS was made for which she was admitted and delivered by emergency caesarean section. The pump twin was admitted into the Special Care Baby Unit (SCBU) And succumbed to cardiac failure 24 hours after delivery

Outcome of Monochorionic Diamniotic Twins with Twin Reversed Arterial Perfusion Sequence: Interstitial Laser versus Endoscopic Cord Occlusion.

Twin reversed arterial perfusion sequence (TRAP) is a rare complication of monochorionic twins (MC). This study aimed to describe and compare the short- and long-term outcomes of MC pregnancies with the TRAP sequence treated with two different techniques: interstitial fetal laser (IFL) (n = 22) versus endoscopic cord occlusion (CO) (n = 24). The study population included 46 MC pregnancies with TRAP. Pregnancy loss within 2 weeks after the procedure occurred in 27% of cases (6/22) in the group treated with IFL and in 8% of cases (2/24) in the group treated with CO. The survival rate of the pump twin was 73% (16/22) in the IFL group and 83% (20/24) in the group treated with CO. The median gestational age at birth was 38 weeks in the group treated with IFL and 35 weeks in the group treated with CO. The rate of preterm birth before 34 weeks was 12.5% (2/16) in the group treated with IFL and 32% (7/22) in the group treated with CO. In the group treated with IFL, there were no cases of neurological disabilities reported by the parents compared to three cases in the CO group. IFL is associated with a higher risk of early pregnancy loss; however, if the pregnancy progresses, it is associated with lower risks of preterm birth and neurological disabilities in the survivors.

Perinatal outcomes of monochorionic triplet pregnancies: multicenter cohort study.

Monochorionic triplet pregnancies are extremely rare and information on these pregnancies and their complications are limited. We aimed to investigate the risk of early and late pregnancy complications, perinatal outcomes, and the timing and methods of fetal intervention in monochorionic triplet pregnancies. This was a multicenter retrospective cohort study including monochorionic triamniotic (MCTA) triplet pregnancies. The exclusion criteria were twins, or multiple pregnancies with higher order than triplets (e.g. quadruplets, quintuplets), and dichorionic or trichorionic triplet pregnancies. Data on maternal age, mode of conception, diagnosis of major fetal structural anomalies or aneuploidy, gestational age (GA) at diagnosis of anomalies, twin to twin transfusion syndrome (TTTS), twin anemia polycythemia syndrome (TAPS), twin reversed arterial perfusion sequence (TRAP), or selective fetal growth restriction (sFGR) were ascertained from the patient records. Data on antenatal interventions were collected, including selective (fetal) reduction (3 to 2 or 3 to 1), laser surgery, or any active fetal intervention (including amniodrainage). Finally, perinatal outcomes included livebirth, intrauterine demise (IUD), neonatal death (NND), perinatal death (PND) and termination of pregnancy (TOP). Neonatal data such as GA at birth, birthweight, neonatal intensive care unit (NICU) admission, and neonatal morbidity were also collected. In our cohort of MCTA triplet pregnancies (n=153 after excluding early miscarriages, TOP and loss to follow-up), the majority (90%) were managed expectantly. The incidence of fetal abnormalities and TRAP was 13.7% and 5.2%, respectively. The most common antenatal complication related to chorionicity was TTTS, which complicated just over a quarter (27.6%) of the pregnancies, followed by sFGR (16.4%), while TAPS (both spontaneous and post-laser) occurred in only 3.3%; no antenatal complication was recorded in 49.3% of pregnancies. Survival was largely associated with the development of these complications: 85.1%, 100% and 47.6% of pregnancies had at least one surviving newborn in those without antenatal complications, complicated by sFGR, or complicated by TTTS, respectively. The overall rates of preterm birth prior to 28 weeks and prior to 32 weeks' gestation were 14.5% and 49.2%, respectively. MCTA triplet pregnancies represent a challenge in counseling, surveillance and management as monochorionicity-related complications occur in almost half of these pregnancies, which negatively impact their perinatal outcomes. This article is protected by copyright. All rights reserved.

EP14.38: A case report on twin reverse arterial perfusion sequence

EP14.38: A case report on twin reverse arterial perfusion sequence

EP14.21: Outcome of TRAP Sequence: a single centre's experience in South China

EP14.21: Outcome of TRAP Sequence: a single centre's experience in South China

Overview of Swine Congenital Malformations Associated with Abnormal Twinning.

A review of congenital malformations in swine relating to abnormal twinning was carried out. The aim was to describe and estimate these defects. Among the recorded twins, the most common defect was the syncephalus thoracopagus or cephalothoracopagus. A couple of dicephali and diprosopus congenital anomalies were also registered. At last, some cases of thoraco-omphalopagus piglets were surveyed. There was also a report of an acardiac twin (hemiacardius acephalus) and a case of a conjoined parasitic twin. The pathogenetic mechanisms of this condition, frequently reported in veterinary practice, are discussed. The importance of embryonic imperfect twinning is commonly associated with dystocia.