A rare case of acardiac twin in postterm pregnancy world. Acardiac twinning is also called trapsequence twin reversed arterial perfusion. The acardiac twin is not connected to the placenta but, rather, directly to the umbilical cord of the pump twin. The normal pump twin faces the excess burden of having to send and receive blood to the acardiac mass as well as to its own growing tissues. More or less large arterial anastomoses on the placental surface pump oxygenpoor blood from the donor twin to the acardiac twin mean that the direction of blood flow in the umbilical cord of the acardiac is reversed as compared to normal. A 21yearold unbooked primigravida was seen in labour ward with a ten hours history of labour pains. Trap sequence is a rare complication of monochorionic twins. Robert 2 1department of anatomy, amala institute of medical sciences, thrissur, kerala, india. During the ultrasound diagnostic investigation, placental edema and hydrops were identified in both fetuses, which, in association with maternal anasarca and pressure control, constitute the triad for mirror syndrome, also. The twin reversed arterial perfusion trap sequence is an anomaly unique to monochorionic multiple pregnancies. In cases of trap, the mortality rate for the normal pump twin is reported to be approximately 50%. Recent studies have highlighted the importance of imaging examinations in fetal medicine.
Acardiac twin is a rare anomaly occurring in 1 in 35,000 pregnancies. It was first described in the sixteenth century benedetti, 1533and occurs in 1% of monozygotic twin pregnancies and in one out of 35 000 deliveries james, 1977. In the trap sequence, the acardiac anencephalic twin receives all of its blood supply from the normal, pump twin. Prameela rc, priya r, niveda s, pooja gy and prajwal s. International journal of science and research ijsr is published as a monthly journal with 12 issues per year. The acardiac twin undergoes secondary atrophy of the heart and dependent organs brain and often develops a characteristic set of anomalies including acardia and acephalus. The acardiac twin receives blood from an arterytoartery anastomosis, and therefore receives blood that has already circulated through the pump twin and is thus poor in oxygen and nutrients. A parasitic twin, also known as an asymmetrical or unequal conjoined twin, is the result of the processes that also produce vanishing twins and conjoined twins, and may represent a continuum between the two. One twin is usually structurally completely normal. Twin reversed arterial perfusion sequence trap, refers to a rare, unique complication of monochorionic twin pregnancy in which a twin with. Twin reversed arterial perfusion trap sequence with fetal. Acardiac twin with preserved brain abstract fetal diagnosis and. Twin reversed arterial perfusion sequence acardiac twinning, one of the most severe congenital malformations seen in humans, is unique to monochorionic placentation and occurs with a reported prevalence of 1% of monozygotic twins. Nov 20, 2017 twin reversed arterial perfusion trap sequence resulting in an acardiac twin is a unique complication of monozygotic twin pregnancy sharing a monochorionic and usually monoamniotic placenta, in which anastomoses connect the two fetoplacental circulations 1, 2.
The fatal acardiac syndrome is a rare complication of monochorionic twinning and is reported in 1 of 35000 births. Mirror syndrome in monochorionic twin pregnancy with acardiac. An acardiac twin can present with four morphological types. In twin reversed arterial perfusion sequence, occlusion of the vessel in the acardiac twin can be achieved by an embolisation coil, by bipolar cautery or by laser. Two cases of first trimester diagnosis of acardiac twins. Acardiac twinning is thought to affect 1 in 100 monozygotic twin pregnancies and 1 in 35,000 pregnancies overall 2,3. Selective reduction of acardiac twin by radiofrequency ablation.
A simpler technique for umbilicalcord blockade of an. 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. Acardiac twin is a rare complication of monozygotic twin pregnancies occurring in 1% of monochorionic twin gestations with an incidence of 1 in 35,000 births and perinatal mortality of. Dec 22, 2010 twin reversed arterial perfusion trap sequence is a rare complication of multiple pregnancy caused by defects in early embryogenesis. One twin, called the acardiac twin or trap fetus, is severely malformed. The fetal treatment center combines the talents of specialists in pediatric surgery, genetics, obstetricsperinatology, anesthesia, cardiology, radiology, nursing, and neonatal medicine. Twin reversed arterial perfusion sequence trap sequence. Multiple pregnancies are subject to various complications, the rarest of which is an acardiac fetus, a complication seen in only 1% of all monochorionic twin pregnancies.
The twin reverse arterial perfusion trap sequence is a rare complication occurring in 1 in 35 000 pregnancies but in up to 1 in 100 monochorionic twin pregnancies moore et al. It develops when the following conditions are present. Acardiac twinbrain developmentultrasoundtwintwin transfusion syndrome. Twin reversed arterial perfusion trap sequence resulting in an acardiac twin is a unique complication of monozygotic twin pregnancy sharing a monochorionic and usually monoamniotic placenta, in which anastomoses connect the two fetoplacental circulations 1, 2. Its most distinctive feature, and the main focus of our attention, is the presence of a structurally normal. The parasitic twin, little more than a torso with or without legs, receives its blood supply from the host twin by means of an umbilical cordlike structure, much like a fetus in fetu, except the. It is a very rare complication that manifest as twin reversed arterial perfusion trap sequence as a result of vascular anastomoses at the placenta bed. Twin reversed arterial perfusion trap sequence is a rare complication of monochorionic pregnancies. It is caused by the development of arterioarterial vascular anastomoses between the umbilical arteries of monozygotic twins early in.
The most widely accepted theory on the pathogenesis of acardius is the. Twin reversed arterial perfusion sequence trap sequence, also sometimes called trap syndrome is a condition that occurs only in identical twins that share a placenta monochorionic, in which one twin, lacking a functioning cardiac system, receives blood from the normally developing twin called the pump twin. The acardiac twin usually has a poorly developed heart, upper body and head. Our team of doctors, nurses, and social workers work together to coordinate all aspects of care from diagnosis to postoperative recovery and longterm followup.
Editor in chief of the medscape journal of medicine, for the editors eyes. This malformation occurs in approximately 1% of monozygotic twin pregnancies, or about 0. As such, the normal twin s heart has to work extra hard and is under a lot of stress. The previously reported incidence dating back to 1944 of 1. The presence of an acardiac twin occurs in one of every 35,000 twin pregnancies and in 1% of monochorionic twin pregnancies. It is a rare condition, with an annual incidence of only 3. Special forms in twin pregnancy acardiac twin twin. Twin reversed arterial perfusion radiology reference. Prenatal sonographic diagnosis of acardiac twin embedded. The outcome is fatal for the acardiac twin with a 5075% mortality of the normal pump twin. The twin reversed arterial perfusion is a rare condition with a nonviable acardiac twin and a lot of risks to the pump twin prematurity, cardiac failure, hydrops and intrauterine demise.
Pdf occlusion of umbilical artery using a guglielmi. We present a case of multiple pregnancy with acardiac twin in a 26 year old lady with gestational diabetes mellitus. Trap sequence or acardiac twin ucsf fetal treatment center. Acardiac medical definition merriamwebster medical.
The development of the acardiac anomaly is a rare complication of monozygotic multiple pregnancies. Acardiac twinning, or the twin reversed arterial perfusion trap sequence, occurs in 1% of monozygotic twins, or 1 in 35,000 births. The acardiac twin with a single umbilical artery was delivered in a separate amniotic sac, together with the monochorionic placenta. Twin reversed arterial perfusion syndrome trap, acardius. Our circulation is audited by bpa who confirms these numbers. Thus, the phrase twin reversed arterial perfusion trap sequence has been used to describe this condition. Since the richest blood arrives through the iliac arteries via umbilical arteries, there is relative sparing of the lower extremities. The pump twin has a 50% mortality rate due to congestive. The prognosis of healthy twin depends on the pulsatility index in umbilical artery infusing the fetus acardiac and size.
Acardiac twinning, a rare congenital anomaly of monozygotic twin. Abstracts released on the occasion of the 10th sasuog congress. The diagnosis of an acardiac twin in a monochorionic diamniotic pregnancy one normal male fetus and one acardius, and a dichorionic triplet normal female fetus was only made at 25 weeks. Jul 29, 2017 acardiac anomaly is more common in monozygotic female twins and mortality is 100%. Acardiac anomaly is a rare complication of multiple pregnancies. The anatomically normal twin is termed the pump twin whilst the. Twin reversed arterial perfusion trap sequence occurs only in the setting of a monochorionic pregnancy and complicates 1% of monochorionic twin gestations, with an incidence of 1 in 35, 000 births. We currently do this using a thin needle, which we guide into the place where the blood vessels feed into the acardiac twin. We present the unusual sonographic features of a trap sequence in the first trimester in a monochorionic monoamniotic twin while the pump twin is associated with anencephaly. Acardiac twinning twin reversed arterial perfusion. Diagnosis and management of twin reversed arterial perfusion.
The acardiac twin almost always presents involution of the brain, together with the absence or malformation of other organs. If acardiac twin weighs less than 25 % of the weight of the donor, evolution is often favorable. Notably, it is a referred, highly indexed, online international journal with high impact factor. Twin reversed arterial perfusion trap sequence is a rare complication of multiple pregnancy caused by defects in early embryogenesis. The second point of interest is more philosophical. It is caused by the development of arterioarterial vascular anastomoses between the umbilical arteries of monozygotic twins early in embryogenesis. The acardiac twin is a parasitic twin that fails to properly develop a heart, and therefore generally does not develop the upper structures of the body. A complication of monozygotic twin pregnancies in which one fetus. We present a case of acardius anephus, which was mistaken for a live anomalous singleton fetus. Twin reversed arterial perfusion trap sequence or acardiac twinning is a very rare problem, occurring in approximately 1% of monochorionic twins mc, twins sharing one placenta. Twin reversed arterial perfusion sequencealso called trap sequence, traps, or acardiac twinningis a rare complication of monochorionic twin pregnancies. Twin, acardiac, acephalus luis izquierdo, md, james smith, md, george gilson, md, gerardo del valle, md, gary joffe, md, molly chatterjee, md, luis curet, md.
We report a unique case of twin reversed arterial perfusion sequence with a prenatal. Twin reversed arterial perfusion sequence trap, refers to a rare, unique complication of monochorionic twin pregnancy in which a twin with an absent or a nonfunctioning heart acardiac twin is perfused by its cotwin pump twin via placental arterial anastomoses. It is a severe variant of twintotwin transfusion syndrome ttts. Acardiac definition of acardiac by the free dictionary. The risk in multiple pregnancies of a higher order is even greater nicolaidis et al. Since the acardiac twin would not survive, reported the surgeons in the massachusetts case, the incision for separation was performed far toward her side of the fusion plane so that her tissue could be used to achieve complete closure of the ventral defect in the surviving twin. A rare case of acardiac twin in postterm pregnancy. Acardiac twin definition of acardiac twin by medical dictionary. The other is an abnormal mass of tissue, consisting usually of legs and a lower body, but no upper body, head or. In the trap sequence, the acardiacanencephalic twin receives all of its blood supply from the normal, pump twin. Twin reversed arterial perfusion trap sequence with.
The twin reversed arterial perfusion, or trap sequence, results in an acardiac twin, a parasitic twin that fails to develop a head, arms and a heart. Occlusion of umbilical artery using a guglielmi detachable coil for the treatment of trap sequence. A 32yearold female patient who was pregnant with twins presented for a regular prenatal checkup with her obstetrician at 25 weeks of gestation. The management options were discussed with the couple including termination of pregnancy as there was a high probability of cardiac failure in the pump twin. International journal of obstetrics and gynaecology research ijogr vol. Twin a, pump twin was structurally normal but had significantly increased amniotic fluid volume polyhydramnios, twin b was acardiac with blood flows seen in the paravesical arteries. Figure 3 the acardiac twin without well defined head and limbs. Twin, acardiac, acephalus cases, lectures, articles, cmes. Pdf acardiac twin is a rare complication of monozygotic twin pregnancies occurring in 1% of monochorionic twin. Although the pathophysiology of an acardiac twin is not well known, it is believed that there are vascular. Acardiac medical definition merriamwebster medical dictionary.
Two cases of first trimester diagnosis of acardiac twins by. Mirror syndrome in monochorionic twin pregnancy with. The acardiac twin is wholly dependent upon circulatory support from the pump twin, and its upper body and head are often poorly developed. The parasitic twin, little more than a torso with or without legs, receives its blood supply from the host twin by means of an umbilical cordlike structure which often only has 2 blood vessels, instead of 3, much like a fetus. We report a case of twin reversed arterial perfusion. Arterialtoarterial vascular anastomoses between twins, in the presence of a fused.
We report the case of a 20yearold patient, primigravida, with twin monochorionic pregnancy, with a weight gain of 6 kg in one week and increased blood pressure. Regression of the weight of the acardiac twin against its longest dimension l resulted in this equation for prediction of acardiac weight. The management of a twin pregnancy complicated by an. The presence of an acardiac twin requires the normal twin to provide circulation for itself as well as the acardiac sibling by means of reversal of circulation through large artery. Acardiac twin or trap sequence is a rare complication of monochorionic twin pregnancies. Letters to the editor boerhaaves syndrome is the spontaneous perforation of the esophagus resulting from a sudden increase in intraesophageal pressure combined with negative intrathoracic pressure1. Acardiac twins refer to a developmental anomaly unique to monochorionic pregnancies. The other option, if the acardiac twin is large enough and we are worried about the amount of blood flow to it causing heart failure in the healthy twin is to stop the blood flow with fetal imageguided surgery figsit. Cytogenetic analysis revealed a normal banded karyotype. Management options include conservative management, medical therapy, occlusion of connecting vessels and selective termination of the acardiac twin. Letters to the editor unsuccessful management of acardiac fetus with intrafetal alcohol injection twin reversed arterial perfusion trap sequence is an extreme form of twintotwin transfusion in which the normal pump twin perfuses its acardiac cotwin. Acardiac twinning twin reversed arterial perfusion sequence. Acardiac twin definition of acardiac twin by medical. Twin reversed arterial perfusion trap sequence is a rare complication of monozygotic multiple pregnancy.
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