Acardius Acephalus Research Articles

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.

Twin reversed arterial perfusion sequence: A review of cases in the Philippines from 2000 to 2022

Twin reversed arterial perfusion (TRAP) sequence, or acardiac twinning, is a congenital anomaly associated with monochorionic twin pregnancies. It occurs when the cardiac system of one twin supplies blood for both twins. This congenital anomaly has been previously reported in several case reports from the Philippines. However, there is still limited information about its local epidemiology and management. This study reviewed the previous cases of TRAP sequence and discussed the diagnosis, management, and ways to improve care for pregnant patients affected by this condition. There were five reported cases of TRAP sequence from the Philippines. Ultrasonography was used in diagnosing the disease antenatally. Preterm birth was reported in 60% of the cases, while 80% were delivered via Cesarean section. The most common type of acardiac twinning in the Philippines was the acardius acephalus. The most common placentation observed in TRAP sequence cases was monochorionic, monoamnionic placenta (75%), two of which had arterio-arterial and veno-venous anastomoses. All donor twins in the Philippines were delivered alive, with only one (20%) neonatal death due to Pseudomonas infection. Only a few centers can perform minimally invasive fetal interventions; one center has been performing fetoscopic surgery in the Philippines since 2021. Thus, cases of TRAP sequence in the Philippines have only been managed through antenatal surveillance with serial ultrasound and high-risk prenatal care until their eventual delivery.

Hypothesized pathogenesis of acardius acephalus, acormus, amorphus, anceps, acardiac edema, single umbilical artery, and pump twin risk prediction.

BackgroundAcardiac twinning complicates monochorionic twin pregnancies in ≈2.6%, in which arterioarterial (AA) and venovenous placental anastomoses cause a reverse circulation between prepump and preacardiac embryos and cessation of cardiac function in the preacardiac. Literature suggested four acardiac body morphologies in which select (groups of) organs fail to develop, deteriorate, or become abnormal: acephalus (≈64%, [almost] no head, part of body, legs), amorphus (≈22%, amorphous tissue lump), anceps (≈10%, cranial bones, well‐developed), and acormus (≈4%, head only). We sought to develop hypotheses that could explain acardiac pathogenesis, its progression, and develop methods for clinical testing.MethodsWe used qualitatively described pathophysiology during development, including twin‐specific AA and Hyrtl's anastomoses, the short umbilical cord syndrome, high capillary permeability, properties of spontaneous aborted embryos, and Pump/Acardiac umbilical venous diameter (UVD) ratios.ResultsWe propose that each body morphology has a specific pathophysiologic pathway. An acephalus acardius may be larger than an anceps, verifiable from UVD ratio measurements. A single umbilical artery develops when one artery, unconnected to the AA, vanishes due to flow reduction by Hyrtl's anastomotic resistance. Acardiac edema may result from acardiac body hypoxemia combined with physiological high fetal capillary permeability, high interstitial compliance and low albumin synthesis. Morphological changes may occur after acardiac onset. Pump twin risk follows from UVD ratios.ConclusionOur suggested outcomes agree reasonably well with reported onset, incidence, and progression of acardiac morphologies. Guidance for clinical prediction and testing requires ultrasound anatomy/circulation study, from the first trimester onward.

Role of Ultrasound in Diagnosis of Fetus Acardius Acephalus in Multiple Pregnancies

AbstractThis case report describes an acardiac fetus of the acephalus phenotype in a triplet pregnancy. The diagnosis was confirmed at 13 weeks. In the absence of signs of heart failure in the co-fetus, the pregnancy was managed conservatively. The pregnancy was complicated by preterm labor and the fetuses were delivered at 23 + 4 weeks. Also, the perinatal outcomes of triplet pregnancies complicated by an acardiac fetus, where the median gestational age at delivery is 23 to 24 weeks, are summarized, and the possible therapeutic interventions have been discussed.

EP20.12: The heartless triplet: acardius anceps complicating monochorionic pregnancy

Twin Reversed Arterial Perfusion (TRAP) sequence affects 1% of monochorionic twins and 3% of monochorionic triplets. Acardius acephalus, acardius amorphous, acardius acormus and acardius anceps have been described. In the acardius anceps (9% of cases) the fetal head and body are differentiated. A 28 y.o. woman, G1P0 was referred at 14 weeks gestation with a monochorionic triamniotic triplet pregnancy complicated by demise of triplet 3; the fetus appeared fully formed with a marked cystic hygroma and no heartbeat. At 18 weeks there was a significant increase in size, hydrops and Doppler perfusion into triplet 3; TRAP sequence was diagnosed. End-diastolic flow (EDF) in the umbilical artery and a-wave in the ductus venosus of triplet 2 were absent, therefore interstitial laser coagulation of pelvic vessels was performed in triplet 3. Subsequent positive EDF in umbilical artery of triplet 2 deteriorated at 33+2 weeks, the babies were therefore delivered by emergency Caesarean section. Triplet 1 weight was 2030g with Apgars 10,10 and Triplet 2: 1650g with Apgars 7,9,10. Acardius anceps variant of TRAP was diagnosed on autopsy of triplet 3. Unlike other cases described, the upper body was better developed with normal occipital, parietal and frontal bones. Aortic type vessel was extending rostrally with two apparent brachial arteries and two apparent common carotid-like arteries. The upper limbs had 5 digits on each hand and were held in partially reducible flexion at shoulders and elbows; there was a bilateral cleft palate. In the lower body, the vasculature was difficult to assess, fracture dislocations were seen at knees and ankles, with fusion of the fourth and fifth digits of the feet. QFPCR confirmed a monozygotic pregnancy. The above case highlights the difficulties posed by well differentiated variants of TRAP at early gestations and the importance of a thorough examination, including Doppler studies to aid the diagnosis of these rare and challenging cases.

Acardius acephalus fetus – report of distinctive anatomical anomalies with regards to pathophysiology of TRAP sequence

Acardiac fetuses are consequences of twin reversed arterial perfusion (TRAP). Here the authors present a case of 40-year-old gravida IX who gave birth to a healthy, 2,900 g female child by a cesarean section. Additionally amorphic 1,020 g maldeveloped fetus was removed. There was a diamnion monochorionic type of twin placenta with incorrect single umbilical arteries (SUA) both in umbilical cord of healthy fetus and in atrophic second umbilical cord. A malformed fetus developed a rather well formed lower leg with four digital foot and oval shape amorphous body mass with omphalocele and eventration of the intestines. X-ray picture showed well visible metatarsal and femur bone and anatomically undefined bones cluster in the central part. A cavity of fetal body contained intestines - the only one well-formed organ, nests of heterotopic pilosebaceous residues, remnants of adrenal glands, well-formed ganglia, and nests of neural tissue covered by neuroepithelium.

Acardius acephalus in a goat kid - radiological and gross findings: a case repor

We received a malformed Messinese Black goat foetus for examination. The foetus was part of a triple gestation, from which two male kids presented no morphological abnormalities and underwent regular slaughtering. X-ray examination and necropsy were performed. On the basis of gross and radiological findings the malformation was classified as acardius acephalus. In human medicine, acardius is a rare and severe abnormality reported as a unique complication of monozygotic twin pregnancies, and is known as twin-reversed arterial perfusion (TRAP).

A rare complication of monochorionic twin pregnancy: Twin-reversed arterial perfusion (TRAP) sequence

The twin-reversed arterial perfusion (TRAP) sequence, also known as acardiac twinning, is an anomaly unique to monochorionic multiple pregnancies that affects approximately 1 of 35,000 pregnancies and 1% of monochorionic twins.1 In TRAP, blood flows from an umbilical artery of the pump twin in a reverse direction into the umbilical artery of the perfused twin, via an arterioarterial anastomosis. The perfused (or acardiac) twin is a true parasite. Its blood is poorly oxygenated, and the hypoxemia contributes to 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 transfusion of the acardiac twin. Failure of head growth is called acardius acephalus; a partially developed head with identifiable limbs is called acardius myelacephalus; and failure of any recognizable structure to form is acardius amorphous. We report a case of acardius amorphous.

Acardiac twin: Conservative management

Introduction: Acardiac twin is a rare anomaly occurring in 1 in 35,000 pregnancies. the outcome is fatal for the acardiac twin with a 50–75% mortality of the normal pump twin. Management options include conservative management, medical therapy, occlusion of connecting vessels and selective termination of the acardiac twin. the Management of a twin pregnancy complicated by an acardiac twin is a challenge because the continuous growth of the acardiac fetus is deleterious to the healthy pump twin leading to cardiac insufficiency, polyhydramnios, prematurity and even death of the normal twin. case report: We report three cases of acardiac twinning which presented with different manifestations, acardius acephalus, acardius myelocephalus and acardius amorphous. All the three cases were managed conservatively with

Prenatal diagnosis and outcome of multiple pregnancies with reversed arterial perfusion (TRAP-sequence)

We analyse the prenatal detection and pregnancy outcome of twin reversed arterial perfusion syndrome (TRAP-sequence) in monochorionic twin pregnancies. We included all cases in which the prenatal diagnosis of a TRAP-sequence had been established and reviewed the prenatal, obstetrical, and pathological records of the acardiac twin as well as the neonatal/pediatric records of the donor twin. Minimal follow-up for the donor twin after birth was 6 months. We detected six cases of TRAP-sequence in 412 examined monochorionic multiple pregnancies (incidence 1.46%) Mean gestational age at diagnosis was 20.4 (13.1-28.0) gestational weeks. All donor twins survived without detectable mid- or long-term sequelae. There was neither missed prenatal diagnosis nor a false-positive diagnosis of TRAP-sequence. Mean birthweight of the acardiac twins was 1,400 g (830-2800 g). There was an uneventful medical history in the maternal records of all included women. Fetal karyotype was available for 5/6 twin-pairs, all revealing a normal distribution of the chromosomes. All acardiac twins had post-mortem examination with specification of the subtypes of acardiac twin displaying 3/6 acardius acephalus, 2/6 acardius amorphus, and 1/6 acardius anceps. The antenatal diagnosis of TRAP-sequence is feasible and can be established during the first-trimester-screening. The discrimination of the adequate time to end the pregnancy, though a crucial concern, remains a challenging question. Future studies should address this topic.

Control study of the ultrasonography with the placental vascular casts of the acardiac twins sequence

Objective To investigate the relationship between the ultrasonography diagnosis in prenatal and the postnatal placental vascular casts of the twins reversed arterial perfusion(TRAP) sequence. Methods Six cases of TRAP sequence underwent the two-dimensional and color Doppler ultrasonography, and performed placental vascular casts after termination of pregnance. Results According to the anatomical features and ultrasonography, there were 3 cases of acardius acephalus( IV) ,2 cases of acardius anceps( II ) , and 1 case of acardius acormus( I ). In all 6 cases,there were arterio-arterial and veno-venous anastomoses at the level of the chorionic plate between the normal co-twin and the acardiac twin,these anastmosis vessels were superficial and large calibre, and the distances of the placental insertions of the umbilical cords were different,4 cases <0. 5 cm, 2 cases were 4-5 cm. In 4 cases, the vessels entered and went out of the acardiac twin were just one large umbilical artery and one large umbilical vein. In 2 cases, the umbilical artery and umbilical vein had many vascular branches in the placenta. Out of 6 cases of the pump twin, 4 cases died,and 2 cases survived. Conclusions Ultrasonography was consistent with the placental vascular casts,the contrast observing gives us new information for the further research of the special type of the vascular anastmosis and prognosis of the TRAP sequence. Key words: Ultrasonography; Twins reversed arterial perfusion sequence; Placenta; Corrosion casting

Acardiac fetus: a challenge to pathologists, obstetricians and neonatologists

Acardius is one of the most severe human malformations, a rare complication present only in monozygotic and monochorionic multiple pregnancies. In this disorder, the major defect is the lack of well-defined cardiac structure in acardiac fetus, whose irrigation is maintained through placental vascular anastomoses with the normal fetus, called fetal donor, thereby establishing a reverse arterial perfusion in the umbilical cord of the acardiac twin (TRAP sequence). The poor circulation leads to a state of hypoxia in the early stages of fetal development, causing structural abnormalities, with different phenotypes, which are classified as: Acardius acephalus, anceps, and acormus amorphus. We relate a case of an acardiac anceps fetus that interestingly was reported by the physicians to present spasmodic movements just after the delivery. Due to severe malformations observed in an acardiac twin by the time of delivery, it is likely that many cases go unnoticed or misdiagnosed. The pathological findings are briefly reviewed to provide an adequate post mortem diagnosis of acardiac fetus and placental examination.

Acardiac syndrome coexisting with complex skeletal dysplasia in the co‐twin: 3D sonographic findings

We present a case of twin reversed arterial perfusion syndrome complicated by an acardius acephalus fetus and complex skeletal dysplasia in the co-twin, including a reduction of the right arm and absence of the right scapula and 4 ribs, as evaluated with three-dimensional sonography and MRI.

-Interruption of umbilical blood flow in an acardiac twin by endoscopic laser coagulation-.

We report on the successful intrauterine surgical treatment of a twin pregnancy with an acardiac fetus. At 18 weeks of gestation the patient presented with polyhydramnios and a hydropic acardius acephalus and the donor twin showed signs of congestive heart failure. Colour Doppler ultrasound allowed localisation of the communicating vessels running on the placental surface towards the umbilicus of the acardiac twin. At 20 weeks we performed endoscopic laser coagulation of the umbilical vessels of the acardiac twin. A sheath (9.8 Charriere) with a 1.9 mm diameter rigid fetoscope (field of vision 60 degrees) was introduced percutaneously under local anesthesia into the amniotic cavity of the "pump" twin. Under sonographic control the fetoscope was directed towards the communicating vessels on the placental surface. A Nd-YAG laser (0.4 mm diameter fiber) was used to coagulate two vessels, artery and vein, until interruption of the reversed arterial perfusion was accomplished. Tricuspid regurgitation of the normal twin disappeared throughout the following two weeks and no further complications occurred throughout pregnancy. At 39 weeks a healthy girl was delivered vaginally. No at the age of 3 months she is developing normally. Minimal invasive endoscopic laser coagulation of the umbilical vessels of the acardiac twin appears to be the optimal currently available treatment for the normal twin, for which otherwise a high mortality ( > 50%) and morbidity must be expected.

Acardius acephalus after ovulation induction by clomiphene

Acardius acephalus after ovulation induction by clomiphene

Antenatal Diagnosis of a Rare Combined Fetal Malformation: Acardius Acephalus and Single Ventricle of the Twin

The development of an acardius in a monozygotic multiple pregnancy has been reported in more than 200 cases. We present the case of an acardius acephalus in a twin pregnancy additionally complicated by a serious cardiac malformation of the donor twin (single ventricle). Antenatal diagnosis and development as well as intrauterine treatment of the donor twin from 26 to 34 weeks of gestation are described.

Acardiac twins: an analysis of 10 cases

The pathological characteristics of the acardiac fetus were studied based on 10 autopsy cases. These cases were collected during a 13-year period at Seoul National University Hospital. All 10 fetuses were monochorionic twins, and six of them were male. Externally normal co-twins survived in five cases and died perinatally in three cases. The gestational period of these acardiacs ranged from 20 to 33 weeks. All of them showed a growth arrest of a fairly wide spectrum. Four cases belonged to acardius anceps, five were acardius acephalus, and one was acardius amorphus. Nine out of 10 cases were holoacardius, whereas one was hemiacardius with a vestigial heart tube present. Characteristic artery-to-artery anastomoses were demonstrated in all cases where examination was possible. The umbilical cords of the acardiacs often consisted of only two vessels, i.e., one umbilical artery and one umbilical vein, and these vessels were directly attached to the arteries and veins of the normal co-twins on the placental surface. The vascular system of the acardiac fetuses was simplified, providing only inflow and outflow pathways through common iliac vessels and vitelline vessels. When the head part was preserved (acardius anceps), the facial features were indistinguishable, particularly in the midfacial region, which resulted in a characteristic holoprosencephalic malformation of the brain in two out of four cases. Normal eyeball structure was not noted in any of these cases. The oral cavity and tongue were rarely recognized. Once the head part was absent (acardius acephalus) there was a wide variation of thoracic organ development. Hypoplastic lungs were seen in three cases, and they were connected to the trachea. A tracheoesophageal fistula was seen twice. The gastrointestinal tract was the most common feature of these acardiac monsters. However, it often lacked some portions, such as a stomach, midgut or part of a large intestine. The kidneys, testes and other parts of the urinary system were other common constituents of the acardiacs.

A Case of Acardiac Anomaly in the Cynomolgus Monkey (Macaca fascicularis): A Complication of Monozygotic Monochorial Twinning

A case of acardius acephalus in a Macaca fascicularis is reported. This congenital anomaly occurs only in multiple-birth gestations (most commonly monozygotic twins). Artery-to-artery and vein-to-vein anastomoses appear to be a constant feature. This condition is very rare in man and probably even more so in monkeys. Classification and theories on etiology are discussed.

Two autopsy case of human fetuses with acardius acephalus from mother using female sex horomones

Two autopsy case of human fetuses with acardius acephalus from mother using female sex horomones