Twin Reversed Arterial Perfusion Research Articles

Experience of fetoscopic laser photocoagulation and cord transection for twin-reversed arterial perfusion sequence.

The purpose of this study was to evaluate the usefulness of fetoscopic laser photocoagulation of placental communicating vessels or umbilical cord for twin-reversed arterial perfusion (TRAP) sequence. We report a retrospective case series of all cases of TRAP sequence identified from 2006 to 2014 at out institutions. Fetoscopic laser photocoagulation of placental arterioarterial and venovenous anastomoses was performed in diamniotic twins, and in cases of monoamniotic twins we performed laser photocoagulation and transection of the umbilical cord of the acardiac twin to prevent cord entanglement. Pregnancy and perinatal outcomes were estimated. Ten cases were included in the study. The median gestational age at procedure was 21.3 weeks (range, 16.7-27.3 weeks). All cases completed the procedure. Two cases were treated with laser photocoagulation and transection of the umbilical cord of the acardiac twin. No major immediate complications were noted. Preterm rupture of membranes occurred in four cases (40%). One case resulted in miscarriage. The other fetuses were delivered alive. Median gestational age at delivery was 35.4 weeks (range, 25.6-42.0 weeks). Median interval of treatment to delivery was 85 days (range, 43-153 days). Five out four infants were delivered preterm. The overall neonatal survival was 9/10. This case series demonstrated favorable outcome, and fetoscopic laser photocoagulation seems to be a useful treatment for TRAP sequence. In particular, transection of the umbilical cord is effective to prevent cord entanglement of monoamniotic twins.

Radiofrequency ablation and bipolar umbilical cord coagulation for complicated monochorionic twins

Objective To assess the effects of radiofrequency ablation (RFA) and bipolar cord coagulation (BCC) on the prognosis and complication rate of complicated monochorionic twins. Methods A retrospective review was undertaken in 58 cases of complicated monochorionic twins treated with RFA or BCC at the First Affiliated Hospital of Sun Yat-Sen University, from January 2008 to August 2013. Non-parametric Wilcoxon test, Chi-square test, Fisher exact test or multi-variant Logistic regression analysis were used for statistical analysis. Results Indications for selective termination in the 58 cases were: twin reversed arterial perfusion sequence in 12, severe twin to twin transfusion syndrome in 28, discordance of fetal anomalies in 10, selective intrauterine growth restriction in 7 and twin anemia-polycythemia sequence in 1. Forty-three cases were managed with BCC and 15 with RFA. Preterm labor was more common in the BCC group than in the RFA group [86.0%(37/43) vs 9/15, respectively; χ2=4.598, P=0.032). Premature rupture of the membranes occurred in 48.8%(27/43) of the BCC group vs. 4/15 of the RFA group (χ2=2.229, P=0.135). The median procedure-to-delivery time was 48 (1-150) days for the BCC group vs. 101(14-138) days for the RFA group (Z=-2.245, P=0.025). Overall survival rate was 62.8%(27/43) in the BCC group vs 11/15 in the RFA group (χ2=0.547, P=0.460), which was not significantly different. Neurodevelopmental delay was detected in two neonates in BCC group and in one neonate in RFA group. Logistic regression analysis showed that delivery before 28 gestational weeks was an independent risk factor for the poor prognosis of the co-twins (OR=192.720, 95%CI: 18.610- 994.000, P<0.01). Conclusion Compared with BCC, RFA does not improve the prognosis of complicated monochorionic twins significantly. Key words: Pregnancy, twin; Pregnancy reduction, multifetal; Catheter ablation; Electrocoagulation; Umbilical cord; Prognosis

Fetoscopia y coagulación bipolar selectiva en una gestación gemelar complicada con secuencia arterial reversa. A propósito del primer caso en el Perú

Se presenta el caso de una gestante de 27 semanas de edad gestacional referida a nuestro servicio por presentar una gestación gemelar monocoriónica complicada con secuencia arterial reversa (TRAP). Se realizó una intervención de fetoscopia y coagulación bipolar del gemelo acárdico, con un resultado favorable.

EMBARAZO GEMELAR CON FETO ACARDÍACO: MANEJO CONSERVADOR. A PROPÓSITO DE UN CASO

Se presenta la experiencia en el manejo de una gestación gemelar con feto acardíaco, entidad rara, con una incidencia de 1 en 35000 gestaciones y con una mortalidad que alcanza el 100% para el feto acardíaco y 50% para el feto sano. La existencia del feto acardíaco supone una sobrecarga para el feto normal, pues existen anastomosis arterio-arteriales y veno-venosas que los comunican, manteniendo el corazón del feto normal las circulaciones periféricas de ambos; esta situación origina múltiples anomalías en el feto receptor, mientras que la sobrecarga hemodinámica en el feto perfusor puede condicionar el desarrollo de una insuficiencia cardíaca, hidropesía, polihidramnios y parto pretérmino. En el manejo del presente caso clínico, se optó por una actitud conservadora, combinando tratamiento médico (digitálicos) con amniocentesis descompresivas seriadas.

Twin-reversed arterial perfusion sequence associated with decreased fetal cerebral vascular impedance.

Twin-reversed arterial perfusion (TRAP) sequence affects 1% of monochorionic twin pregnancies and is caused by abnormal vascular connections between a pump twin and an acardiac mass. The effects of abnormal vascular connections on cerebral vasculature in the pump twin are unknown. We hypothesize that abnormal cerebral vascular impedance, as assessed by the pulsatility index (PI), is present in pump twins and that fetal intervention alters cerebral impedance. Fetal echocardiograms performed between 2010 and 2013 in pregnancies diagnosed with TRAP (n = 19), recorded at presentation, and uncomplicated monochorionic twin pregnancies (controls, n = 18; 36 fetuses) were analyzed. In all subjects, the middle cerebral artery (MCA)-PI, combined cardiac output (CCO) and cardiothoracic ratio were calculated, and the values for cases and controls were compared. The mean gestational age at the time of echocardiography was 20 weeks in both groups. MCA-PI was lower in TRAP cases than in controls (1.55 (95% CI, 1.47-1.64) vs 1.74 (95% CI, 1.65-1.82), respectively; P = 0.004). CCO in TRAP cases was mildly elevated for gestational age (199.7 (95% CI, 138.4-261.1) mL/min) compared with that of controls (131.4 (95% CI, 102.2-160.7) mL/min). In six TRAP cases with a second echocardiogram available, the mean MCA-PI increased after intervention, from 1.5 (95% CI, 1.3-1.7) to 1.8 (95% CI, 1.4-2.2). TRAP pump twins have lower cerebral vascular impedance than do controls, suggestive of a brain-sparing effect. MCA-PI appeared to increase in a small group of pump twins after intervention. These findings suggest a fetal cerebral autoregulatory response to a high cardiac output state that begins to change after fetal intervention. The long-term implications for neurodevelopmental outcome warrant further study.

Management of complicated monochorionic twin pregnancies.

Multiple gestation is associated with an increased risk for adverse pregnancy outcome. Monochorionic twins are at risk for complications specific to these pregnancies, such as twin-twin transfusion syndrome (TTTS) or twin reverse arterial perfusion (TRAP) sequence. In this article we give an overview on prenatal diagnosis, treatment and outcome of twin pregnancies complicated by TTTS and TRAP sequence.

English

Fetus Acardiacus is a very rare manifestation of twin gestation. This happens due to TRAP sequence. That is Twin reversed arterial perfusion. In this case an amorphous mass was seen on a routine antenatal scan and followed as there was a live twin also. The case report highlights the importance of careful scanning and follow up of twin gestation.

Enantioselective total synthesis of (-)-nardoaristolone B via a gold(I)-catalyzed oxidative cyclization.

The first enantioselective total synthesis of (−)-nardoaristolone B is accomplished by the implementation of an enantio- and diastereoselective copper(I)-catalyzed conjugate addition/enolate trapping sequence and a gold(I)-catalyzed oxidative cyclization (intermolecular oxidant), employed for the first time in total synthesis.

Twin Reversed Arterial Perfusion (TRAP) Sequence: A Case Report in Fallujah Maternity and Children Hospital, Fallujah, Iraq

Introduction. Twin reversed arterial perfusion (TRAP) sequence is a rare complication of multiple pregnancy caused by defects in early embryogenesis. The pump twin supplies the acardiac recipient twin with blood, and although the pump twin is usually structurally normal, congenital anomalies have sometimes been reported. We report a case of twin reversed arterial perfusion sequence with feet polydactly in the surviving pump twin. This was the 1st case reported in Fallujah city, Iraq. Case report. A 22 years old. gravida 2, para 0. abortion 1, full term lady presented to the delivery room with labour pain with no history of any prenatal care. She gave no history of any familial congenital anomaly and there was no history of consanguinity with her hasbund. She has been referred for cesearian section delivery as an emergency as there was no progress in labour. Ultrasound examination at the delivery room revealed the diagnosis of monozygotic twin, one was normal & the 2nd was diagnosed as (abnormal) with difficulty in visualization of the fetal parts and gender. Conclusion. Twin-Reversed Arterial Perfusion (TRAP) sequence is a rare complication of monozygotic multiple gestation. Accurate antenatal diagnosis is essential to improve the prognosis of this rare entity.

Twin reversed arterial perfusion (TRAP) sequence – a case report and review of literature

Twin reversed arterial perfusion (TRAP) sequence (acardiac twin) is a rare complication of monochorionic pregnancy characterized by single arterial to arterial vascular anastomosis between twins. In this unique haemodynamic arrangement, the structurally normal pump twin will perfuse its abnormal co-twin (acardiac) in a retrograde manner through these anastomoses, with potential for cardiac overload and heart failure in the pump twin and high fetal mortality. Definitive fetal intervention has been recommended in the literature for high (>50%) twin weight ratio (TWR). We present a case of twin reversed arterial perfusion managed expectantly as no signs of cardiac decompensation were encountered in the pump twin.

Acardiac Twin: A rare Complication of Monochorionic Monoamniotic Twin

Acardiac malformation, also known as twin reversed arterial perfusion (TRAP) sequence, is a unique complication of monochorionic twinning., occurring with a reported incidence of 1 in 35 000 deliveries. It is characterized by lack of heart development associated with a spectrum of malformations and anomalies in one of the twins, which is perfused in a paradoxical retrograde fashion by a structurally normal ‘pump’ twin through a single artery-to-artery anastomosis. There is usually a normally formed donor twin who has features of heart failure as well as a recipient twin who lacks a heart (acardius) and various other structures.It is caused in the embryo by a large artery-to-artery placental shunt, often also accompanied by a vein-to-vein shunt. The common complications include congestive cardiac failure in the pump twin, polyhydramnios and preterm delivery.

Acardiac Twin

Acardiac anomaly is a rare complication of multiple pregnancies. It is a hemodyamically disadvantaged nonviable twin which occurs in association with a twin reversed arterial perfusion sequence (TRAP). In TRAP, blood flows from an umbilical artery of the pump twin in reverse direction into umbilical artery of the perfused (or acardiac) twin via an arterial to arterial (AA) anastomosis. Its blood is poorly oxygenated and results in variable degrees of deficient development of the head, heart, and upper limb structures. The lower half of the body is usually better developed, which may be explained by the mechanism of perfusion. The pump twin is at risk of heart failure and problems related to preterm birth with a reported mortality of 50-75%. We present a case of multiple pregnancy with acardiac twin in a 26 year old lady with gestational diabetes mellitus. During ante natal check up several ultrasonographic (USG) screening showed twin pregnancy with one healthy fetus and the other fetus with inconspicuous anatomy and structure. Repeat USG at 36th week of gestation diagnosed twin pregnancy with acardiac twin. Strikingly the pump twin did not develop the usual complications and was delivered by cesarean section at 37th week of gestation. DOI: http://dx.doi.org/10.3329/dmcj.v2i2.20529 Delta Med Col J. Jul 2014; 2(2): 77-80

Monochorionic monoamniotic twin pregnancy: a review of 17 cases

Objective To review the diagnosis,monitoring,management and perinatal outcomes of monochorionic monoamniotic (MCMA) twin pregnancy.Methods From July 2010 to August 2013,there were 17 MCMA twin pregnancies diagnosed and delivered in Shanghai First Maternity and Infant Hospital.According to the MCMA management protocol,induced abortion,elective fetal reduction,and anticipant pregnancy were optional.For those anticipant pregnancies,fetal lung underwent maturation promotion at gestational weeks 28; hospitalization with 40 min/day continual fetal electronic monitoring and umbilical blood monitoring twice weekly at gestational weeks 28-30; 40 min continual fetal electronic monitoring twice daily and umbilical blood monitoring once every other day at gestational weeks 30-32; and 40 min continual fetal electronic monitoring three times daily and umbilical blood monitoring once daily at gestational weeks 32-34; and pregnancy ended on time.The presence of umbilical cord entanglement,congenital malformation,intrauterine fetal death,complications exclusive to monochorionic twins (e.g.selective fetal growth restriction,twin reversed arterial perfusion sequence and twin-twin transfusion syndrome) and the perinatal outcomes were retrospectively analyzed.Results Average maternal age of women with 17 MCMA twins was (29.0±2.7) years,and all were primiparas.They were diagnosed at (18.6± 5.5) weeks on average (11 +5-28+1 weeks).Umbilical cord entanglements were detected in all cases by ultrasonography and confirmed postnatally.There were three cases of complications specific to monochorionic twins,including two with selective fetal growth restriction and one with twin reversed arterial perfusion sequence.There were seven women with fetal congenital malformation; four of whom chose induced abortion; one case of anencephaly chose radiofrequency ablation fetal reduction,and the remaining two cases with congenital malformation and ten cases without chose anticipant pregnancy,and there were no abnormal ultrasonography signs during pregnancy.Among these 12 cases,intrauterine fetal death of both fetuses occurred in two cases at 16 and 21+1 weeks gestation and they were aborted.Intrauterine fetal death of a single fetus occurred in one case at 30+2 weeks gestation (another fetus was delivered by emergency cesarean section).There were a total of eleven live births delivered by cesarean section (four by emergency cesarean section) at a median gestational age of (32.7± 1.6) weeks.There were 20 live neonates with a mean birth weight of (1 850±496) g.Sixteen neonates were transferred to the neonatal intensive care unit and hospitalized for (37.9± 16.4) days.Nine neonates suffered from respiratory distress syndrome but were eventually cured.Conclusions MCMA twin pregnancy has high morbidity and mortality.Early ultrasonography helps to clarify the diagnosis and enhance the monitoring,thus improving the perinatal outcomes. Key words: Twin, monochorionic; Ultrasonography, prenatal; Fetal monitoring; Pregnancy outcome

P18.11: Twin reversed arterial perfusion sequence: a 14‐year experience in a tertiary referral centre

The aim of this study is to review all cases of Twin reversed arterial perfusion (TRAP) sequence managed in a tertiary referral center and to compare the outcome in conservatively managed cases with that of those managed with interventions. This is a retrospective study analyzing all TRAP cases that were managed in a tertiary center from Jan 2000 to October 2013. Details assessed included (1) Gestation at diagnosis (2) Ultrasound features at Diagnosis (3)Treatment options offered (4) Outcome of these pregnancies and (5) Prognostic factors. Wherever possible, the outcomes and prognostic factors were compared between the groups with different management strategies. 59 cases of TRAP were identified during the study period. Follow up was available in 46(77%), among a total of 59 pregnancies complicated by TRAP sequence. Among, these 17 (37.8%) opted for elective termination of pregnancy and 29 (62.2%) continued their pregnancies. Among these 29 women who continued their pregnancies 10 were managed expectantly and 19 had an intervention for the twin with TRAP sequence. The intervention techniques used were alcohol ablation, coil embolization and interstitial laser coagulation. The overall survival rate in the group that had an expectant management was 80% and the mortality rate of the pump twin was 20%. The overall survival rate in the intervention group was 57.8% and the mortality rate was 36.8%. When intra fetal laser was used as the treatment of choice for TRAP sequence the survival rate was 82%.

P18.12: TRAP sequence: diagnosis, management and outcome of co‐twin

<scp>P</scp>18.12: <scp>TRAP</scp> sequence: diagnosis, management and outcome of co‐twin

P18.01: A rare anomaly in twin pregnancy acardiac twin: the role of ultrasound diagnostic

<scp>P</scp>18.01: A rare anomaly in twin pregnancy acardiac twin: the role of ultrasound diagnostic

Histological features of placenta diagnosed with twin anemia-polycythemia sequence

Histological features of placenta diagnosed with twin anemia-polycythemia sequence

Clinical characteristics of monochorionic twins with large hemoglobin level discordance at birth

To evaluate neonatal outcomes and clinical characteristics of monochorionic diamniotic (MCDA) twins with a large intertwin hemoglobin (Hb) difference at birth. This was a retrospective cohort study of MCDA twin gestations delivered at Osaka Medical Center and Research Institute for Maternal and Child Health between 2003 and 2012. Cases of pregnancy termination, acardiac twins or intrauterine death were excluded. A large intertwin Hb difference at birth was defined as > 8.0 g/dL according to the postnatal criteria for twin anemia-polycythemia sequence (TAPS). The intertwin reticulocyte count ratio (RCR) was calculated by dividing the reticulocyte count of the anemic twin by that of the polycythemic twin. Cases with Hb differences were divided into two groups according to the RCR, TAPS when the RCR was > 1.7 and acute fetofetal hemorrhage (AFFH) when the RCR was ≤ 1.7. Neonatal outcomes were compared between the TAPS and AFFH groups. During the study period, 432 MCDA twin pregnancies of a total of 532 born at our hospital were analyzed. There were 12 (2.8%) cases of a large intertwin Hb difference. The median gestational age at birth of these cases was 34 (range, 23-38) weeks, and all were delivered by Cesarean section. There were seven (1.6%) cases of TAPS and five (1.2%) of AFFH. The neonatal survival rate was 91.7%; in one pair of twins with TAPS neonatal death occurred. All (100%) cases with TAPS and two (40%) with AFFH required blood transfusion or partial-exchange transfusion for at least one infant. Although the incidence of TAPS and AFFH may be low in MCDA twins, many affected neonates required treatment for hematological abnormalities. Delivery of MCDA twins via Cesarean section does not appear to prevent AFFH, despite the absence of labor.

Magnetic stratigraphy of the Permian-Triassic traps in the Kotui River valley (Siberian Platform): New paleomagnetic data

The Permian-Triassic effusive traps in the Kotui River valley (Siberian Platform) were studied in detail by a paleomagnetic method, resulting in a summarized magnetic stratigraphic section of the studied sequence. The presence of the reversed polarity zone corresponding to the Khardakh Formation was argued for the section basement. Inside the Kogotok Group, the boundary between the direct and reversed polarity zones occurs in the lower part of the Onkuchak Formation and mismatches the boundary between the formations of the Kogotok Group, as was accepted before. These results contradict the presence of the transition record between the direct and reversed polarity zones in basalts of the lower part of the Onkuhcak Formation. The strong transitional interval between the Ivakinsk Formation and the upper parts of the Nadezhda Formation of the Norilsk section has no analogs in the Kotui section. This means the absence of any significant volcanic activity in the Maimecha-Kotui province during the intense eruptions in the Norilsk region resulting in origination of the greater part of the lower formations of the trap sequence. These data and possible correlations of the traps of the Kotui River valley and Norilsk region indicate that the Norilsk and Maimecha-Kotui sections were temporally overlapped.

TRAP (Twin Reversed Arterial Perfusion) sequence

Abstract TRAP (Twin Reversed Arterial Perfusion) sequence is a rare malformation that occurs in monozygotic twin pregnancies. Twin weight ratio in our case was 76% (body weight of pump twin was 1800 g, acardiac twin 1370 g), but in spite of that the pump twin had a mild clinical picture with premature birth, fetal hydrops (mild pleural effusion; hypoproteinemia; on the 3rd day of life the baby was without edema and the level of his serum proteins were in referral ranges) and mild myocardial hypertrophy of left ventricle (echocardiography performed on the 28th day of life was normal).