Management of twin reversed arterial perfusion (TRAP) sequence with microwave ablation: A case report and review of the literature.

Twin reversed arterial perfusion (TRAP) sequence carries a high mortality risk to the "pump twin." Management involves disrupting blood flow to the acardiac mass. In this case, the pregnant patient presented at 20 weeks 6 days with Stage IIb TRAP Sequence and underwent percutaneous ultrasound-guided microwave ablation (MWA) of the acardiac mass at 21 weeks 0 days. The probe traversed the thorax of the acardiac mass and ablated the confluence of the umbilical vessels. A healthy child was delivered at 33 weeks 5 days gestation. This report demonstrates the utility of MWA in TRAP sequence and describes a novel approach.

A systematic review of early intrauterine intervention at 12 + 0 to 16 + 6 weeks in twin reversed arterial perfusion sequence.

There is some evidence that in twin reversed arterial perfusion sequence, intervention at early gestational age could prevent a spontaneous death of the pump twin, achieving a better global survival. OBJECTIVE: To review the perinatal outcomes of early intervention in pregnancies complicated by twin reversed arterial perfusion (TRAP) sequence. STUDY DESIGN: A comprehensive search from inception to December 2022 was conducted on databases including MEDLINE, EMBASE, Cochrane Library and LILACS. All studies that reported intervention in twin or triplet pregnancy complicated with TRAP sequence at 12 + 0 to 16 + 6 weeks of gestation were eligible. A descriptive and bivariate analysis was performed. RESULTS: Out of the 222 full-text articles, 44 studies reporting 108 cases of early intervention in TRAP sequence were included. A successful procedure was achieved in 105 (95.5 %) interventions: 89 (94.7 %) among twin pregnancies and 16(100 %) among triplet pregnancies. An overall livebirth rate was achieved in 75 patients (70.8 %): intrafetal laser group 55 (73.3 %), radiofrequency 10 (76.9 %) and endoscopic laser 3 (75.0 %). The median gestational age at delivery was 38 + 0 (37 + 4 - 39 + 4) weeks. The median treatment-delivery interval was 23 + 2 (IQR, 21 + 0-25 + 6) weeks. The most frequent adverse outcomes reported were preterm labor in 7 (13.7 %) patients. There were no severe adverse maternal outcomes. CONCLUSION: Early intervention with intrafetal laser and radiofrequency in TRAP sequence achieves a livebirth rate of the pump twin of about 75 %.

The Management of Acardiac Twinning: Twin Reverse Arterial Perfusion Sequence - An International Survey.

INTRODUCTION: The optimal approach and therapy method for the acardiac twin with a reverse arterial perfusion sequence has not yet been established. The aim of this study was to determine the clinical practice patterns among international fetal therapy units in their management of these cases. METHODS: A survey was sent to fetal centers across the world via email between December 2020 and December 2021. RESULTS: Responses were obtained from 77% contacted centers. The most frequent ultrasound variables used in the evaluation of twin reverse arterial perfusion sequence include echocardiographic assessment of the pump twin and umbilical artery Doppler waveforms in the acardiac and pump twins, in 90% and 80% of the centers, respectively. Most centers in Europe and Latin America propose an in utero intervention in all cases. Most centers in Europe and Latin America prefer interstitial laser ablation, whereas radiofrequency ablation (RFA) is preferred in North America. The earliest gestational age for an intervention is on mean 13 weeks in Europe, which is earlier than the other geographic areas (p = 0.001). CONCLUSIONS: Most centers agreed that antenatal evaluation should include echocardiography along with the UA Doppler waveform measurements, and the most frequently used interventions were interstitial laser ablation or RFA at a median between 14 and 26 weeks.

Vanishing acardiac twin with TRAP syndrome: A case report.

Acardiac twin is a rare complication of monochorionic twin pregnancy. We present case of a 24 years-old primigravida with monochorionic pregnancy having an amorphous acardiac twin diagnosed during routine first trimester ultrasound scan. She was managed expectantly since there were no signs of hemodynamic compromise in the normal twin with close ultrasound fetal surveillance using gray scale and color Doppler ultrasound. Spontaneous regression of vascularity with reduced size of the acardiac twin was seen subsequently.

Twin Reversed Arterial Perfusion.

Twin reversed arterial perfusion (TRAP) sequence is a rare condition found only in monochorionic pregnancies. It is a sequence in which a severely anomalous twin with an absent or rudimentary heart, also called an "acardiac twin," is perfused by its co-twin. The cardiac system of this co-twin (pump twin) provides circulatory support to the acardiac twin from as early as the first trimester. The exact pathogenesis of TRAP sequence is still unknown. However, the mere presence of vascular anastomoses in the placenta alone cannot lead to the development of TRAP sequence. Moreover, the presence of retrograde blood flow through arterio-arterial anastomoses increases the possibility of TRAP sequence diagnosis in a suspected monochorionic twin pregnancy. This report presents a case of TRAP sequence, which was undiagnosed till the delivery of twins. A 26-year-old patient gravida 3 para 2 (G3P2+0) with previous two normal deliveries, was referred to our emergency labor room at (assumed) 37 weeks of pregnancy, from a primary health center with complaints of vaginal leakage and a non-reassuring fetal status. She was immediately shifted to Operation Theatre and an emergency lower-segment cesarean section was performed. At the time of delivery, she was diagnosed as having a monochorionic diamniotic twin with TRAP sequence as one of the twins was acardiac, while the other was a live male baby (the pump twin) with massive ascites. A TRAP sequence pregnancy with a poor prognostic factor requires twin cord occlusion therapy or another form of intervention. Termination of the pregnancy is also an option, as it saves the patient from unnecessary obstetrical complications and morbidity.

Twin reversed arterial perfusion sequence-a rare and dangerous complication form of monochorionic twins: A case report.

BACKGROUND: Twin reversed arterial perfusion (TRAP) sequence is an extremely rare congenital anomaly in monochorionic (MC) twins. The condition is characterized by a malformed fetus (acardiac twin) without cardiac activities being perfused by a structurally normal one (pump twin) via an artery-to-artery anastomosis in a reverse direction. CASE SUMMARY: We described the first case of TRAP to receive laser surgery in Vietnam. The 26-wk pregnancy was originally misdiagnosed in another hospital as MC twins with single intrauterine fetal death. Following admission to our center, the diagnosis was amended to a 26-wk TRAP sequence stage IIb. The acardiac twin was 7.5 cm at the longest length, the ratio of the weight of the acardiac twin to the weight of the pump twin was more than 90%, the pump twin showed fetal distress with absent diastolic flow in umbilical artery of pump twin, and the peak systolic velocity in the middle cerebral artery = 1.6 MoM. We performed emergency laser photocoagulation of the acardiac twin's umbilical cord. After surgery, we successfully maintained the pregnancy for 8 wk and ended it electively by cesarean section at 34 wk of gestation due to rupture of membranes. CONCLUSION: TRAP should be appropriately diagnosed and treated early to avoid complications of the pump twin. Fetoscopic laser photocoagulation is a new and effective treatment for this condition.

Acardius acephalus with spontaneous umbilical cord occlusion: Reporting a rare case.

Twin reversed arterial perfusion syndrome is a rare obstetric condition that occurs in monochorionic twin pregnancies, resulting in coexistence of a normal "pump" twin and an acardiac twin. The acardiac twin is dependent upon the normal twin to provide circulation by means of vascular anastomosis, thereby putting the pump fetus at risk of high output cardiac failure. Overall only 50% of pump twins survive. Mortality for acardiac twin is 100%. We present a case of 26-year-old primigravida female presenting with 8 months of amenorrhea with unsure LMP. Ultrasonography followed by fetal MRI was carried out which revealed acardius acephalus twin with absence of blood flow in umbilical vessels. Pump twin had multicystic dysplastic left kidney with single umbilical artery. Following delivery, the pump twin survived well and the deformed fetus showed features of twin reversed arterial perfusion syndrome.

Outcome of Monochorionic Monoamniotic Twin Reversed Arterial Perfusion Sequence Diagnosed in the First Trimester.

INTRODUCTION: The aim of this study is to evaluate the outcome of pregnancies complicated by monochorionic monoamniotic twin reversed arterial perfusion sequence (MOMA TRAP) diagnosed in the first trimester. METHODS: All patients diagnosed with MOMA TRAP sequence <14.0 weeks of gestation in a 10-year study period were retrospectively analyzed for intrauterine course and outcome. All patients were offered either expectant management or intrauterine intervention. Adverse outcome was defined as either intrauterine death (IUD), neonatal death or preterm birth <34.0 weeks of gestation. RESULTS: In the study period, 17 cases with MOMA TRAP sequence were diagnosed. Of these, 2 couples opted for termination of pregnancy. The remaining 15 were divided into 2 groups depending on the management: group A (n = 8) with expectant management and group B (n = 7) with intrauterine intervention. All fetuses in group A died before 20 weeks. Survival in group B was significantly better with 4/7 (57.1%) life births at a median of 39.6 weeks of gestation (p = 0.0256). The reasons for IUD in the 3 cases in group B were hemodynamic, strangulation, and bleeding complications during intervention. CONCLUSIONS: Intrauterine intervention in MOMA TRAP pregnancies significantly improves neonatal survival, although it is still associated with a substantial risk for IUD by hemodynamic complications or entanglement.

Fetal Hemodynamic Responses to Arterial Occlusion of Acardiac Twins.

The objective of this study was to comprehensively assess fetal hemodynamic adaptions to occlusive procedures. Twin pregnancies complicated with acardiac twin and hydrops fetalis of the pump twin were recruited. The occlusive procedures - either alcoholization, radiofrequency ablation, coil embolization or occlusive glue - were performed under ultrasound guidance. Various hemodynamic parameters were assessed before, shortly after, then every 6 h for 48 h and 2-4 weeks after the procedures. Seven pregnancies were recruited. The median (range) gestational age of intervention was 21 (17-26) weeks of gestation. Before the procedures, all cases showed normal cardiac function. Just after the procedures, all cases showed an increase in Tei index and isovolumic relaxation time but returned to preocclusion levels within 6-48 h, except for two cases that were persistently high. Increased preload and poor shortening fraction were observed in two cases, leading to heart failure, with one recovery and one death in utero. Five out of the seven cases got through the critical period with a gradual return to normal hemodynamics, ending with the disappearance of hydrops and successful outcomes. It was concluded that the occlusive procedure could aggravate the overworked heart, leading to heart failure. Preocclusion preload index and Tei index may predict risk of heart failure due to the occlusion. This small series strongly suggests that the occlusion should be performed before the deterioration of cardiac function.

Secuencia de perfusión arterial reversa en embarazo gemelar; coagulación de arteria nutricia. Reporte del primer caso en el país / Twin reversed arterial perfusion sequence; coagulation of the umbilical cord. A report on the first case in Uruguay / Seqüência reversa de perfusão arterial na gravidez gemelar; coagulação da artéria nutritiva. Relato do primeiro caso no país

Resumen: La secuencia de perfusión arterial reversa (TRAP) es una complicación muy poco frecuente y grave de los embarazos gemelares monocoriónicos. Generalmente ocurre cuando el corazón de un gemelo de apariencia normal sirve como bomba para uno o más gemelos dismórficos cuya cabeza, órganos torácicos y extremidades superiores no se desarrollan completamente o no se desarrollan en absoluto y, por lo tanto, carecen de actividad cardíaca. La arquitectura placentaria vascular anómala provoca un cambio en el flujo arterial hacia el gemelo acardíaco. Los mecanismos fisiopatológicos exactos que conducen a este fenómeno devastador no se conocen bien. Compartiremos el caso clínico de una paciente de 19 años, cursando un embarazo gemelar monocorial monoamniótico, en que realizamos diagnóstico de TRAPS, y realizamos la coagulación laser de la arteria nutricia del feto acárdico.

Abstract: Twin reversed arterial perfusion sequence (TRAPS) is rather an unusual and severe complication of monochorionic twin pregnancies. It usually occurs when the normal-appearance heart of a twin acts as a pump for one or more dysmorphic twins whose head, thoracic organs and upper limbs fail to totally develop or do not develop at all and thus, have no cardiac activity. The abnormal vascular architecture at the placenta changes the arterial flow towards the acardiac twin. The exact pathophysiological mechanisms that result in this devastating phenomenon are still unknown. The study presents the clinical case of a 19-year- old patient pregnant with monoamniotic, monochorionic twins and a diagnosis of TRAPS, treated by laser coagulation of the acardiac twin's umbilical cord.

Resumo: A seqüência reversa de perfusão arterial (TRAPS) é uma complicação muito rara e grave de gestações gemelares monocoriônicas. Geralmente ocorre quando o coração de um gêmeo de aparência normal serve como uma bomba para um ou mais gêmeos dismórficos cuja cabeça, órgãos torácicos e membros superiores não se desenvolvem totalmente ou não se desenvolvem e, portanto, não têm atividade cardíaca. A arquitetura vascular placentária anormal causa uma mudança no fluxo arterial para o gêmeo acardíaco. Os mecanismos fisiopatológicos exatos que levam a esse fenômeno devastador não são bem compreendidos. Descrevemos o caso clínico de uma paciente de 19 anos, portadora de gestação gemelar monocoriônica monoamniótica, na qual fizemos o diagnóstico de TRAPS e realizamos coagulação a laser da artéria nutritiva do feto acardíaco.

Acardiac twin pregnancies part V: Why does an acardiac twin with renal tissue produce polyhydramnios?

BACKGROUND: Acardiac twinning is a complication of monochorionic twin pregnancies. From literature reports, 30 of 41 relatively large acardiac twins with renal tissue produced polyhydramnios within their amniotic compartment. We aim to investigate the underlying mechanisms that cause excess amniotic fluid using an established model of fetal fluid dynamics. METHODS: We assumed that acardiac onset is before 13 weeks, acardiacs with renal tissue have normal kidney function and produce urine flow from 11 weeks on, and acardiac urine production requires a pressure of half the pump twin's mean arterial pressure. We apply a resistance network with the pump twin's arterio-venous pressure as source, pump umbilical arteries, placenta, placental arterio-arterial (AA) anastomoses and acardiac resistances. Acardiac amniotic fluid dynamics excluded acardiac lung fluid secretion, swallowing and the relatively small intramembranous flow. RESULTS: In small acardiacs with sufficient urine production, polyhydramnios will occur due to the lack of amniotic fluid resorption. Urine production is dependent upon having sufficient mean arterial pressure, which requires nearly a two-fold larger resistance within the acardiac as compared to the placental AA resistance. Subphysiologic arterial pressure may result in renal dysgenesis. CONCLUSION: Our findings suggest the potential for prediction of which clinical acardiac cases may or may not develop polyhydramnios based upon noninvasive assessments of renal tissue, blood flow and urine production. This information would be of great value in determining early obstetric interventions as opposed to conservative management. These findings may also contribute to an improved knowledge of the fascinating pathophysiology that surrounds acardiac twinning.

A Taiwan's experience: A case report and review of literature of successful early intrauterine treatment with radiofrequency ablation in twin reversed arterial perfusion (TRAP) sequence.

Acardiac twin or twin reversed arterial perfusion (TRAP) sequence is a rare medical complication of Monozygotic twins. Taiwanese Obstetricians usually treat TRAP sequence conservatively. Occasionally, repeated amnio-reduction is performed to decompress the polyhydramnios caused by the TRAP sequence, even though there was no correction of the pathophysiologic mechanism. Radiofrequency ablation is a minimally invasive, percutaneous technique that can effectively obliterate blood supply to an acardiac twin to preserve and protect the pump twin. This recent technique has never been used before for the treatment of the TRAP sequence in Taiwan. This article reported the first-hand experience of acardiac twin management with RFA in Taipei Chang Gung Memorial Hospital.

Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.

OBJECTIVE: Twin-Reversed Arterial Perfusion (TRAP) sequence is a rare complication of monochorionic multiple gestation. Conservative management should be considered if there is no poor prognostic factor. CASE REPORT: This is a 35 year-old female with twin pregnancy with acardiac monster. Under the request of the patient, there was no intervention during the whole pregnancy. We keep regular and close sonography weekly follow up. There was no maternal complication and there was also no heart failure sign or polyhydramnios of the donor twin. Minimal blood flow was noted at the anastomotic vessels under the sonography at late gestational age. Due to breech presentation, cesarean section was performed at gestational age 37 + 1/7 weeks. She delivers a healthy baby smoothly. CONCLUSION: Antenatal sonography is an important tool to evaluate the fetus status. Under special condition, term pregnancy is still possible without any treatment. CASE REPORT: Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.

Fetus Acardiac Amorphous Presenting as Placental Tumor: A Rare Case and Differentiating the Two.

Fetus acardius is a rare manifestation of twin reversed arterial perfusion and is a parasite due to vascular circulation from donor twin and lacks any resemblance to human embryos. Antenatal diagnosis is challenging as there are no well-defined features. We report here a case which presented as placental mass, the diagnosis of which was evident after delivery. Antenatal diagnosis, review of the literature, and differential diagnosis from the placental mass are discussed. A primigravida in the late third trimester had ultrasonography (USG) showing a 7 cm × 5 cm mass adjacent to the placenta. She had no complaints and fetal biometry was normal. She delivered a healthy baby; placenta showed an attached mass without identifiable fetal body or limbs, and was covered with skin having scanty hairs, which was identified as an amorphous fetus. Early diagnosis is possible by early USG; an acardiac amorphous fetus may present as placental mass. Characteristic feature on USG supplemented by magnetic resonance imaging may help in reaching a correct diagnosis and optimal management.

Secuencia de perfusión arterial reversa gemelar (TRAP): reporte de caso clínico de manejo expectante / Twin Reverse Arterial Perfusion Sequence (TRAP): clinical case report of expectant management

TRAP describe la perfusión crónica de un gemelo acardíaco por un gemelo de bomba a través de canales vasculares entrelazados permeables. La secuencia TRAP ocurre en 1 de cada 35.000 nacimientos o en 1 de cada 100 pares de gemelos monocigóticos. Se diagnostica mediante los hallazgos ecográficos de un feto de desarrollo normal y una masa amorfa con frecuencia con partes fetales perceptibles. El Doppler color revela el flujo sanguíneo reverso hacia el gemelo acardíaco dentro de la arteria umbilical lo que lleva a las complicaciones típicas del cuadro. El manejo expectante es razonable en ausencia de características pronósticas deficientes. El propósito de este artículo es revisar los aspectos básicos y el estado actual de esta condición, haciendo énfasis en el diagnóstico y el manejo expectante.

TRAP describes the chronic perfusion of an acardiac twin by a pump twin through permeable interlocking vascular channels. TRAP occurs in 1 in 35,000 births or 1 in 100 pairs of monozygotic twins. It is diagnosed by ultrasound findings of a normally developing fetus and an amorphous mass often with noticeable fetal parts. Color Doppler reveals the reverse blood flow to the acardiac twin within the umbilical artery, leading to typical complications of the condition. Expectant management is reasonable in the absence of poor prognostic characteristics. The purpose of this article is to review the basic aspects and current status of this condition, emphasizing the diagnosis and expectant management.

Twin Reversed Arterial Perfusion Sequence: Current Treatment Options.

Twin reversed arterial perfusion (TRAP) sequence is a specific and severe complication of monochorionic multiple pregnancy, characterized by vascular anastomosis and partial or complete lack of cardiac development in one twin. Despite its rarity, interest in the international literature is rising, and we aimed to review its pathogenesis, prenatal diagnostic features and treatment options. Due to the parasitic hemodynamic dependence of the acardiac twin on the pump twin, the management of these pregnancies aims to maximize the pump twin's chances of survival. If treatment is needed, the best timing of intervention is still debated, although the latest studies encourage intervention in the first trimester of pregnancy. As for the technique of choice to interrupt the vascular supply to the acardiac twin, ultrasound-guided laser coagulation and radiofrequency ablation of the intrafetal vessels are usually the preferred approaches.

Therapeutic dilemma in twin reversed arterial perfusion sequence.

The dissemination of minimally invasive in utero surgery reduced the mortality of twin reversed arterial perfusion sequence, but the mortality of expectantly treated surgical candidates remains high. A 26-year-old, non-parous, Japanese woman at 13 weeks of gestation had been diagnosed with twin reversed arterial perfusion sequence and was judged as a surgical candidate for radiofrequency ablation. However, she did not undergo surgery because of the anatomical location of the acardiac twin. At 18 weeks of gestation, the blood flow to the acardiac twin disappeared spontaneously. The pump twin began to demonstrate fetal growth retardation during the third trimester. The patient delivered a 1891 g female at term. We macroscopically identified the cause of the fetal growth retardation as velamentous insertion of the umbilical cord and microscopically diagnosed the acardiac twin with acardiac acephalus. We should give the same attention to the management of post-twin reversed arterial perfusion sequence as twin reversed arterial perfusion sequence itself.

Secuencia perfusión arterial reversa: Reporte de caso / Twin reversed arterial perfusion sequence: A case report

Twin reversed arterial perfusion sequence is a complication of monochorionic twin pregnancies in which one twin that exhibits lethal anomalies, including acardia, is perfused by the other 'pump' twin via anastomoses between placental arteries. This results in growth and characteristic anomalies of the acardiac twin, and possible heart failure of the pump twin. The exact pathophysiological mechanisms that lead to this devastating phenomenon are not well known. It occurs in about 1% of monochorionic pregnancies and in one out of 35 000 pregnancies. Mortality is usually due to anemia and cardiac complications which can lead to cardiac failure, appear early during pregnancy and cause the death of the pump twin. We report a case of twin reversed arterial perfusion in a 28-year-old patient with 12 weeks monochorionic-diamniotic pregnancy that was referred for absent cardiac activity in one twin. Ultrasound showed an acardiac twin with flow reversal seen in the umbilical artery and umbilical vein and a normal second twin. At 28 weeks an emergency cesarean section was done due preterm labor and transverse situation of the second twin. The first twin was malformed and the second twin died two days later due to complications of prematurity. Accurate prenatal diagnosis of twin reversed arterial perfusion sequence is essential to improve the prognosis of this rare entity.

La secuencia de perfusión arterial reversa en gemelos es una complicación del embarazo gemelar monocoriónico, en la que un gemelo muestra anomalías mortales, incluyendo acardia, y es perfundido por el otro gemelo 'bomba' a través de anastomosis arteriales placentarias, produciendo el crecimiento y las anomalías características del gemelo acárdico, con posible insuficiencia cardíaca en el gemelo bomba. Los mecanismos fisiopatológicos exactos que conducen a este fenómeno devastador no son bien conocidos. Ocurre en aproximadamente 1% de los embarazos monocoriónicos y en 1 de cada 35 000 embarazos. La mortalidad se debe generalmente a anemia y complicaciones cardíacas que pueden conducir a insuficiencia cardíaca, que aparecen temprano durante el embarazo y causan la muerte del gemelo bomba. Se presenta un caso de perfusión arterial reversa en gemelos en paciente de 28 años de edad con un embarazo monocoriónicodiamniótico de 12 semanas quien fue referida por ausencia de actividad cardíaca de uno de los gemelos. La ecografía mostró un gemelo acárdico con reversión de flujo visto en arteria-vena umbilical y un segundo gemelo normal. A las 28 semanas se realizó una cesárea de emergencia debido a parto pretérmino y situación transversa del segundo gemelo, obteniendo el primer gemelo marcadamente malformado y un segundo gemelo vivo que murió dos días después de las complicaciones de la prematuridad. El diagnóstico prenatal exacto secuencia de perfusión arterial reversa en gemelos es esencial para mejorar el pronóstico de esta rara entidad.

Twin Reversed Arterial Perfusion: To Treat or Not?

Acardiac twinning or Twin Reverse Arterial Perfusion (TRAP)-sequence is a rare complication of monochorionic twin pregnancy. Whether to start elective or therapeutic treatment in TRAP-sequence is still controversial. In the present case, acardiac twin was not diagnosed till her delivery at 39 weeks. A healthy baby weighing 2.45 kg was delivered along with another amorphous mass (acardiac twin) of about 150 g which was attached to the placenta with a short and separate cord. As outcome of normal twin vary according to the growth of acardiac twin, frequent follow-up of the normal twin is required to look for the features of heart failure. Hence, the diagnosis of acardiac twin is essential in early pregnancy.