Fetal therapy in utero by blockage of the umbilical blood flow of acardiac monster in twin pregnancy

We studied a life-saving method for the unaffected twin in two recent patients who had acardiac monster in twin pregnancy. We succeeded in blocking the umbilical blood flow of the acardiac monster in utero as radical treatment for this abnormality in one of the patients. In case 1, tocolysis and amniocentesis with puncture to the cyst of the acardiac monster were performed to prevent premature labor. However, the patient underwent premature labor at 27 weeks of gestation, and the newborn died. In case 2, fetal treatment was given: A steel coil was placed in the umbilical cord close to the abdominal wall of the acardiac monster under ultrasonographic guidance at 23 weeks of gestation to block blood flow. As a result, no enlargement of the acardiac monster was observed, and the cardiac function of the unaffected fetus improved. At 38 weeks of gestation, the patient delivered a normal baby weighing 2,237g and an acardiac monster weighing 110g. There were no complications in either the mother or newborn. There has been no report describing blockage of the umbilical blood flow of an acardiac monster in utero. Our method is considered efficient and less risky to the mother and the unaffected twin.     

Acardiac acephalic monster extremely larger than its co-twin. A case report.

The acardiac monster represents a rare but one of the severest congenital anomalies which occur only in multiple pregnancy. The affected fetus is sustained by a parasitic anastomosis to the umbilical blood vessels of the normal fetus. We report an interesting case of a macrosomic acardiac acephalic fetus weighing 4.5-fold of another variable donor fetus (approximately 6 kg) in a twin pregnancy.     

Intrauterine treatment for an acardiac twin with alcohol injection into the umbilical artery

An acardiac twin is a unique complication of monochorionic twinning, in which a normal pump twin perfuses the acardiac twin. The mortality rate of the pump twin is greater than 50%. Herein we present the successful treatment of an acardiac twin with alcoholization as follows. An acardiac twin was diagnosed at 24 weeks gestation. Circulation interruption of the acardiac twin was successfully achieved by injection of absolute alcohol (5 mL) into the intra-abdominal umbilical artery. Serial ultrasound after the procedure revealed normal growth of the pump twin, whereas the acardiac twin was shrinking. Spontaneous premature delivery at 34 weeks gestation resulted in a normal surviving female baby weighing 2410g and an acardiac female fetus weighing 300g. This experience suggests that this simple technique may be an alternative treatment for an acardiac twin.     

Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy

ObjectiveTwin-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 reportThis 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.ConclusionAntenatal sonography is an important tool to evaluate the fetus status. Under special condition, term pregnancy is still possible without any treatment.Case reportTwin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.     

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

Summary: The twin reversed-arterial-perfusion (TRAP) sequence found in monozygotic twins is a consequence of primary or secondary cardiac development disruption and direct arterioarterial and venovenous placental anastomoses. Associated findings include the presence of a single umbilical artery (66%) and chromosomal abnormalities in the acardiac twin (33%). Morphological abnormalities in the acardiac twin are consistent with perfusion of tissues supplied by the common iliac and lower branches of the aorta with deoxygenated blood. The pump or donor twin may develop cardiac failure because of the anomalous perfusion circuit. Polyhydramnios is significantly associated with the presence of renal tissue in the acardiac twin. An acardiac pump twin weight ratio (>50%) is associated with the development of polyhydramnios and preterm labour. Identified high-risk factors for poor obstetrical outcome include: acardiac anceps, polyhydramnios, acardiac twin with ears, and pump twin cardiac failure. Management options include elective termination, observation (serial cardiotocography (CTG), ultrasonography and echocardiography) and selective nonsurgical interventions (indomethacin, digitalis, tocolysis). Additionally, surgical interventions (hysterotomy with selective delivery of the acardiac twin or ligation of the acardiac twin's umbilical cord), and ultrasound-guided embolization of the acardiac twin's umbilical artery with absolute alcohol, platinum coils, or thrombogenic coils have been reported. The most appropriate interventions for the varous clinical presentations of this disorder are as yet undetermined, and conservative nonintervention is often appropriate. Long-term follow-up data on surviving pump twins are lacking. It is anticipated that centres with active study protocols for these conditions will best serve patient care and clinical research needs.     

Acardiac anomaly: current issues in prenatal assessment and treatment

Acardiac anomaly is a rare condition affecting monochorionic multiple pregnancies. We review this condition with emphasis on its prenatal diagnostic features and treatment options. Due to the parasitic hemodynamic dependence of the acardiac twin on the pump twin, it is important to monitor the pump twin for signs of decompensation and, if indicated, intervene by interrupting vascular supply to the acardiac twin. The goal of treatment is to maximize the pump-twin's chance of survival. To assist with the decision of when to treat, we suggest a new classification system based on prognostic factors, specifically the size and growth of the acardiac twin and the cardiovascular condition of the pump twin. When the acardiac twin is small and no signs of cardiovascular impairment in the pump twin are present, we suggest serial ultrasound surveillance to detect any worsening of the condition. In cases with a large acardiac twin or rapid growth of the acardiac mass, we recommend prompt intervention. Once treatment is indicated, the intrafetal approach to interrupt the vascular supply to the acardiac twin appears to be superior to cord occlusion techniques as it is simpler, safer and more effective. The first line of treatment, if available, should be ultrasound-guided laser coagulation or radiofrequency ablation of the intrafetal vessels.     

Acardiac twin with preserved brain

The fatal acardiac syndrome is a rare complication of monochorionic twinning and is reported in 1 of 35,000 births. It is caused by arterioarterial and venovenous placental anastomoses leading to circulatory predominance of 1 twin. The donor 'pump' twin provides circulation for itself and for the recipient acardiac twin. The acardiac twin is usually grossly abnormal with severe reduction anomalies of the upper part of the body. We report a twin pregnancy, where a recipient twin initially by ultrasound was misdiagnosed as dead. In the third trimester the supposedly dead twin presented as an edematous acardiac twin without peripheral reduction defects and a nearly normally developed brain. An acardiac twin with a nearly normal external appearance and an almost normally developed brain, nourished by a surviving twin brother, has not previously been described in the literature.     

Successful intrauterine treatment with alcohol ablation in a case of acardiac twin pregnancy.

Acardiac twinning is a rare obstetric condition unique to monochorionic twin gestation and the pump twin has high perinatal mortality. We report an acardiac twin pregnancy, in which the pump twin presented with intrauterine growth restriction and oligohydramnios, and grossly hydropic acardiac fetus measured 12 x 14 x 18 cm, and with no cardiac activity at 27 weeks of gestation. We treated the acardiac fetus with 1 ml alcohol ablation in utero, and delivered a live male baby weighing 1750 g at 36 weeks' gestation.     

Term birth after midtrimester hysterotomy and selective delivery of an acardiac twin.

OBJECTIVE: Our aim was to determine whether hysterotomy and selective removal of an acardiac twin could improve the outcome of the "pump" twin. STUDY DESIGN: A literature and case review of the outcome of the acardiac twin malformation was performed. When an acardiac malformation was diagnosed at 19 weeks' gestation the patient was monitored with weekly ultrasonographic examinations. At 23 weeks' gestation, no blood flow could be demonstrated to the acardiac twin and it was thought that the continued presence of the acardiac twin posed a risk to the "pump" twin. A midtrimester hysterotomy was performed and the acardiac twin was delivered. RESULTS: After the midtrimester hysterotomy, the pregnancy progressed to term and a healthy female infant was delivered by elective cesarean section at 37 weeks' gestation. CONCLUSION: Midtrimester hysterotomy may be a useful intervention in cases of twinning when one fetus is a threat to the health of the other.     

The management of acardiac twins: a conservative approach

OBJECTIVE: Optimal management of acardiac twin pregnancies is controversial. Data suggest a 50% mortality rate in the "pump" twin when the pregnancy is managed expectantly. Because of increased antenatal diagnosis, outcomes in expectantly managed cases may be better than reported. Our objective was to determine the outcome of expectantly managed acardiac twin pregnancies. STUDY DESIGN: All cases of antenatally diagnosed acardiac twins delivered in our community between 1994 and 2001 were ascertained. All were managed expectantly. Perinatal outcome of pump twins was the primary outcome variable. RESULTS: Ten cases were identified. Nine women were delivered of healthy pump twins. There was one neonatal death. The mean gestational age at delivery was 34.2 weeks. The mean weights of the pump and acardiac twins were 2279 g and 1372 g, respectively. CONCLUSION: Neonatal mortality of pump twins in antenatally diagnosed acardiac twin pregnancies may be considerably less than reported. Expectant management with close antepartum surveillance deserves consideration.     

Spontaneous cessation of umbilical blood flow in the acardiac fetus of a twin pregnancy.

The acardiac fetus is a rare entity found only in monozygotic multiple pregnancy. Although the acardiac fetus is non-viable, the perinatal mortality rate for the normal fetus may be as high as 50 per cent, and is usually associated with fetal heart failure and hydrops fetalis, or as the result of prematurity. In this communication, we describe a case of spontaneous cessation of blood flow to an acardiac fetus and discuss the management of this condition with special reference to optimizing the outcome for the normal fetus.     

Perinatal outcome of forty-nine pregnancies complicated by acardiac twinning

Acardiac twinning affects 1 in 100 monozygotic twin pregnancies and 1 in 35,000 pregnancies overall. The presence of an acadiac twin requires the normal (or "pump") twin to provide circulation for itself, as well as the acardiac sibling. In many cases the acardiac twin is almost equal to the normal twin. The principal perinatal problems associated with acardiac twinning are pump-twin congestive heart failure, maternal hydramnios, and preterm delivery. We reviewed the perinatal courses of 49 acardiac twin pregnancies to identify factors prognostic of favorable outcome. The overall perinatal mortality was 55%, primarily associated with prematurity. Mean (+/- SD) gestational age at delivery was 29 +/- 7.3 weeks, with a mean (+/- SD) normal twin weight of 1378 +/- 1047 gm. The acardiac weight averaged 651 +/- 571 gm. However, the occurrence of hydramnios, the occurrence of preterm labor, and perinatal outcome were strongly related to the ratio of the acardiac and pump-twin's weight. The mean overall ratio of the twin weights was 52% +/- 42%. However, the mean weight ratio for patients delivered before 34 weeks was 60% versus 29% (p less than 0.04). Preterm delivery was strongly associated with the development of hydramnios and congestive heart failure in the pump twin (p less than 0.01). If the twin-weight ratio was above 70% (25% of cases), the incidence of preterm delivery was 90%; hydramnios, 40%; and pump-twin congestive heart failure, 30% compared with 75%, 30%, and 10%, respectively, when the ratio was less (p less than 0.05). Regression of the weight of the acardiac twin against its longest dimension (L) resulted in this equation for prediction of acardiac weight: Weight (grams) = 1.2 L2-1.7L; r = 0.79, p less than 0.01. These data suggest that estimation of the relative weights in acardiac twins provides prognostic information regarding outcome. Poor outcome occurs with congestive heart failure and hydramnios in the normal twin. Use of the above data may assist in counseling patients and determining optimal management.     

Twin reversed arterial perfusion sequence

An acardiac twin is probably the most severe malformation found in humans and is found in 1:100 of all monozygotic twin pregnancies and in about 1:30 of all monozygotic triplets. There are several types of acardiac fetuses; in fact, two major theories exist on their origin. Arterio-arterial anastomoses between the umbilical cord of the normal and the acardiac twin are responsible for the clinical presentation of a Twin Reversed Arterial Perfusion or TRAP sequence. Possible complications for the healthy twin are circulatory overload, which can lead to congestive heart failure, polyhydramnios (and, thus, preterm labor), and eventually intra-uterine demise. Furthermore, perinatal complications can occur due to the acardiac mass itself and hypoxia and intra-uterine growth retardation of the normal twin. Several risk factors to estimate the severity of the anomaly and the consequences for the healthy ‘pump’ twin have been identified. Using several ultrasonographic features, a distinction between TRAP sequence and twin-to-twin transfusion syndrome and other anomalies must be made. Treatment of the anomaly can either be conservative (reducing the polyhydramnios) or invasive. The latter consists of umbilical cord occlusion or interstitial vessel obliteration of the acardiac twin. Literature review has pointed out the benefits of the second option.     

Selective reduction of acardiac twin by radiofrequency ablation

OBJECTIVE: Acardiac/acephalic twinning is a rare anomaly in which a normal "pump" twin perfuses an acardiac twin, which results in twin reversed arterial perfusion sequence. A novel technique for selective reduction and obliteration of blood flow in the acardiac twin is described. STUDY DESIGN: Thirteen consecutive cases of monochorionic twin gestation with twin reversed arterial perfusion sequence underwent selective reduction of the abnormal twin with the use of radiofrequency ablation. Under direct real-time sonographic guidance, a 3-mm (14-gauge) radiofrequency ablation needle was percutaneously inserted through the maternal abdominal wall into the intrauterine fetal abdomen at the level of the cord insertion site of the acardiac twin. Energy was applied until termination of blood flow to the acardiac fetus was documented by Doppler ultrasound scanning. RESULTS: All 13 mothers tolerated the procedure without major complications. All 13 "pump" fetuses have been delivered. Twelve of 13 infants are alive and well. The first patient in this series was delivered at 24.4 weeks and the infant subsequently died from complications of prematurity. Average gestational age at intervention was 20.7 weeks, and the average gestational age at delivery was 36.2 weeks. CONCLUSION: 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.     

Placental teratoma: differential diagnosis with fetal acardia

The acardiac fetus is a rare congenital malformation observed only in monozygotic twin pregnancies (1/35.000 pregnancies). Placental teratoma is extremely rare (less than 20 cases have been reported in the literature since 1925). A case of placental teratoma, misdiagnosed as fetus acardius amorphus, is presented with ultra-sound follow-up, delivery and outcome of the normal fetus. Pathological findings, histogenesis, differential diagnosis with the acardiac fetus and finally review of the literature will be discussed.     

The normal fetus of an acardiac twin pregnancy: perinatal management based on echocardiographic and sonographic evaluation

Experience with three prenatally diagnosed pregnancies complicated by an acardiac twin reveals that ultrasonography and echocardiography are helpful in detecting early signs of in-utero congestive heart failure in the normal twin. The use of Doppler blood flow analysis to determine direction of blood flow, post-mortem placental and fetal angiography, and umbilical cord blood gas determination provided proof that retrograde arterial perfusion occurs in the acardiac fetus. In a fourth pregnancy, an experimental approach to occlude the acardiac twin's umbilical cord was attempted, but was unsuccessful.     

Documentation of paradoxical umbilical blood supply of an acardiac twin in the antepartum state

In a case with one acardiac twin, color Doppler examination revealed retrograde umbilical circulation to this fetus. This pulsatile flow in the umbilical vessel of the acardiac fetus was supported by the cardiac function of the co-existing healthy twin.     

The acardiac twin. A case report

The acardiac twin is a rare consequence of monozygotic twinning and occurs in 1 per 35,000 deliveries. One percent of all monozygotic twins is affected. Prenatal diagnosis is possible with ultrasonography. Complications associated with the presence of an acardiac twin include sequelae from the twin-to-twin transfusion syndrome, polyhydramnios, dystocia, ruptured uterus and congestive heart failure in the normal twin. In utero fetal therapy is possible in some instances.     

Sirenomelia sequence: early prenatal diagnosis of one rare case associated with acardiac malformation

Sirenomelia sequence is a very rare congenital malformation, with incidence of around 1.5–4.2 per 100,000 births. Prenatal diagnosis of sirenomelia in the first trimester is rare; there are only five cases reported for the present, and the association of sirenomelia with acardiac malformation is even rarer. We present a rare case of sirenomelia associated with acardiac malformation detected in the first trimester through combined two-dimensional, three-dimensional and color Doppler sonographies.