Circular Shunt Research Articles

Circular shunt in a pulmonary artery to right atrial tunnel, an anomaly unreported so far.

While aortico-right atrial tunnels with left to right shunt from aorta to right atrium are reported widely, pulmonary artery to right atrial tunnels have not been described so far. Such a tunnel will lead to a circular shunt with a recirculation of blood in the right sided cardiac chambers repeatedly bypassing the pulmonary capillary bed. This newly described pulmonary artery to right atrial tunnel was closed nonsurgically with a duct occluder after angiographic delineation.

Absent Aortic Valve Associated with Double Outlet Right Ventricle and Aortopulmonary Window: Physiologic Implications of a Rare Malformation in both the Fetus and Neonate

Absence of the aortic valve is a rare congenital heart defect that is detectable in the prenatal period. In this condition, functional aortic valve leaflets are absent; in their place are rudimentary, immobile noncoapting plate-like structures at the level of the annulus resulting in severe aortic regurgitation. We report the fetal diagnosis and subsequent postnatal course of an infant with the novel association of absent aortic valve, double outlet right ventricle, and aortopulmonary window. This unique combination of defects resulted in an unusual pattern of circular shunting that produced evidence of fetal heart failure. Shortly after birth, the abnormal physiology led to compromised systemic perfusion, intestinal perforation and subsequent rapid demise of the patient. Abrupt postnatal deterioration typifies the vast majority of the absent aortic valve cases found in the literature. Our patient is unique in that it is the first female reported with absent aortic valve and the first reported with an aortopulmonary window. This report demonstrates that absent aortic valve is a condition that can be diagnosed prenatally by fetal echocardiogram; the highly abnormal physiology places these patients at risk for fetal heart failure. Given the potential for clinical instability and rapid deterioration after birth, such patients should undergo rapid postnatal assessment and immediate surgical intervention when deemed appropriate.

EComment. Two-stage repair of Ebstein's anormaly in a neonate

Ebstein's anomaly is a congenital heart disease, which rarely requires surgical intervention in the neonatal period. Therefore, the case involving surgical treatment for neonatal Ebstein's anomaly with circular shunting by Yohsuke Yanasa et al. is very interesting [1]. The clinical symptoms vary in severity depending on the anatomical malformation. Severe tricuspid regurgitation and right ventricular hypoplasia may produce a critical state in the neonate. Concomitant pulmonary regurgitation is rare, with the reversal of blood flow to the right ventricle, resulting in a 'circular shunt' and necessitating urgent surgical treatment for severe neonatal Ebstein's anomaly. Between 2006 and 2010, 107 patients (including one neonate and one infant) underwent surgery for Ebstein's anomaly at Bakoulev Scientific Center for Cardiovascular Surgery at the Russian Academy of Medical Sciences. In our practice, due to the decrease in pulmonary vascular resistance, minimal antegrade blood flow via pulmonary valve was restored but it was not sufficient to ensure adequate oxygen saturation. We performed a modified Blalock-Taussig shunt with a 4-mm graft. Postoperative oxygen saturation was 80% and the baby was discharged. Six months later, a successful one and a half surgical repair was performed. Surgery in the neonatal period has previously focused on palliation and conversion to single-ventricle physiology. Successful two-ventricle repair with good clinical results can safely be performed in the neonatal period but requires an individual approach in each case.

Surgical treatment for neonatal Ebstein's anomaly with circular shunting

We report a case of surgical treatment for neonatal Ebstein's anomaly with circular shunting. A prenatal diagnosis of Ebstein's anomaly was made at 30 weeks of gestation. In addition to severe tricuspid regurgitation, severe pulmonary regurgitation was also noted, resulting in a 'circular shunt'. At 38 weeks and 2 days of gestation, the baby was delivered by Caesarean section. A two-stage palliative operation was planned. As the first palliation, the pulmonary artery was ligated 1 h after birth to eliminate the circular shunt. Lipo-prostaglandin E(1) was administrated continuously to keep the ductus arteriosus patent. Four days after first operation, modified Starnes operation was performed as the second-stage palliation. The tricuspid valve was closed by an ePTFE patch with 3-mm fenestration. Pulmonary blood flow was supplied by a right modified Blalock-Taussig shunt with a 3.5-mm diameter ePTFE graft. The infant's postoperative haemodynamic status was stable. The patient is being followed up carefully and is scheduled to have a univentricular repair in the future.

Critical Ebstein Anomaly in a Fetus Successfully Managed by Elective Preterm Delivery and Surgical Intervention Without Delay After Birth

This report describes a case of Ebstein anomaly in a fetus with cardiomegaly, severe tricuspid regurgitation, pulmonary regurgitation, and retrograde ductal flow that showed a marked increase in the size of the right atrium with advancing gestational age. Elective preterm delivery was performed at 35 weeks gestation. The prostaglandin E1 infusion resulted in more pronounced systemic hypotension and acidosis secondary to circular shunt across the patent ductus arteriosus as well as pulmonary regurgitation and tricuspid regurgitation. Emergency surgical intervention consisting of main pulmonary artery ligation, ductus arteriosus ligation, central shunt creation, and plication of the right atrium without cardiopulmonary bypass was performed 4 h after birth. At the age of 16 days, the Starnes procedure was performed. The infant's postoperative course was uneventful. A fetus that has Ebstein anomaly associated with pulmonary regurgitation is at risk for circular shunt across the patent ductus arteriosus after delivery. Planned delivery and surgical intervention without delay after birth are useful for the treatment of such cases.

Neonatal Cyanosis: Diagnostic and Management Challenges

Neonatal central cyanosis is always a sign of serious pathological processes and may involve diverse organs and impose a significant diagnostic and therapeutic challenge. Here, we report an unusual presentation of Ebstein's anomaly, a rare congenital heart malformation, as the cause of central cyanosis in a one-week-old full-term infant. Initiation of PEG1 therapy in neonates with Ebstein's anomaly always needs a very careful consideration because of a high risk for the development of a “circular shunt” leading to severe deterioration of multiple organs perfusion.

Le shunt circulaire : complication de la maladie d’Ebstein de forme néonatale

We report a severe neonatal presentation of Ebstein anomaly with homodynamic aggravation at birth attributed to patent ductus arteriosus and circular shunt. Prenatal diagnosis of Ebstein anomaly of the tricuspid valve with functional pulmonary atresia was made at 37 weeks gestation by fetal two- and three-dimensional echocardiography. A cesarean section was performed in view of poor fetal tolerance. The newborn was born with hydrops and multivisceral failure. A post-natal echocardiography demonstrated a left-to-right shunt across the patent ductus arteriosus and functional pulmonary atresia with severe pulmonary insufficiency with absent forward flow. This created a circular shunt, where blood flowed through the ductus to the pulmonary arteries, retrograde through the pulmonary artery and Ebstein valve, across the patent foramen ovale and out the aorta. Prostaglandin E1 infusion was stopped, resulting in clinical and echocardiographic improvement. The management of the phenomenon of a circular shunt across a patent ductus arteriosus with Ebstein malformation involves promoting early ductal closure by stopping prostaglandin therapy.

Complete Right Heart Flow Reversal

Although the pathophysiologic mechanism of twin-twin transfusion syndrome (TTTS) remains incompletely understood, the process appears to involve abnormal vascular communications within the placenta, leading to characteristic hemodynamic changes in the recipient fetus. The recipient twin may have progressive volume and pressure overload, congestive heart failure, and hydrops. Recipient twin echocardiographic findings, which typically include valvar regurgitation/stenosis, ventricular hypertrophy, and diastolic/systolic dysfunction, tend to occur predominantly in the right heart, with relative sparing of the left. We describe a case of complete right heart flow reversal and preserved left ventricle (LV) function in a recipient twin, with complete resolution and normalization 1 month after successful selective fetoscopic laser photocoagulation (SFLP) of communicating vessels. We suggest that the circular shunt seen preoperatively through the right heart of the recipient twin represents a pathognomonic finding for TTTS. We speculate that the right ventricle (RV) may be particularly sensitive to the increase in afterload encountered by recipient twins in TTTS.

Contributions of intramyocardial sinusoids in pulmonary atresia and intact ventricular septum to a right-sided circular shunt.

Contributions of intramyocardial sinusoids in pulmonary atresia and intact ventricular septum to a right-sided circular shunt.