Obstructive Cor Triatriatum Sinister with Complete Balanced Atrioventricular Septal Defect and Raghib Complex

Cor triatriatum sinister associated with complete atrioventricular (AV) canal and Raghib complex is a very rare congenital anomaly. In cor triatriatum sinister, a membrane separates all the four pulmonary veins from the left-sided AV valve. Persistent left superior vena cava (LSVC) draining into the left atrium associated with an absent coronary sinus is termed as Raghib complex. Complete balanced AV septal defect (AVSD) along with cor triatriatum sinister and Raghib complex is a very rare anomaly and has not been reported in the literature.

A 7-month-old infant presented to our institute with a history of recurrent respiratory tract infections associated with intermittent episodes of central cyanosis. On echocardiography, a complete balanced AVSD, persistent LSVC with an unroofed coronary sinus, and an obstructive membrane separating the opening of pulmonary veins from the mitral valve were observed. There was severe AV valve regurgitation and elevated pulmonary artery pressure [Figure 1].

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Figure 1:

Pictorial representation of intracardiac anatomy. RA: Right atrium, CPVC: Common pulmonary venous channel, RtAVV: Right atrioventricular valve, LtAVV: Left atrioventricular valve, RV: Right ventricle, LV: Left ventricle, AVSD: Atrioventricular septal defect.

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The baby was taken up for surgical repair, standard median sternotomy, and left paramedian pericardiotomy was performed. Persistent LSVC and small intercommunicating vein were identified; LSVC is relatively larger in size compared to the right superior vena cava (RSVC). Standard aortic cannulation, LSVC, and inferior vena cava were cannulated and RSVC drainage was managed with a sucker. Right atriotomy was performed after cardioplegic arrest. The obstructive membrane in the left atrium is excised. A complete balanced AV canal defect is repaired with two patch technique using autologous unfixed pericardium; cleft in the left AV valve is also repaired. The LSVC opening into the left atrium is rerouted into the right atrium with a homologous pericardial patch [Figure 2].

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Figure 2:

Pictorial representation of anatomy after surgical repair of the defect. Obstructive cortriatriatum membrane resected, left superior venacava redirected to right atrium with pericardial patch, atrioventricular septal defect repaired with double patch technique. P: Patch. RA: Right atrium, CPVC: Common pulmonary venous channel, RtAVV: Right atrioventricular valve, LtAVV: Left atrioventricular valve, RV: Right ventricle, LV: Left ventricle, LSVC: Left superior vena cava, LAA: Left atrial appendage.

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The baby was shifted to the intensive care unit (ICU) with an open sternum, and peritoneal dialysis was also done in the immediate post-operative period. Sternal closure was done on the 3^rd post-operative day. The baby had a prolonged postoperative course in the ICU in view of severe right ventricular dysfunction. Tracheostomy was also performed in view of the need for prolonged ventilatory support. Tracheostomy was decannulated and the baby was discharged on the 50^th postoperative day.

Persistent LSVC is an anomaly associated with systemic venous drainage. LSVC is formed as a continuation of the left internal jugular vein and left brachiocephalic vein. It is observed in 2–5% of cases with congenital cardiac anomaly.^[1] Persistent LSVC is present due to the failure of regression of the left anterior cardinal vein. It usually drains into the coronary sinus.

An unroofed coronary sinus is an anomaly in which the separation between coronary sinus and the left atrium is partially or completely absent. Raghib complex is a combination of persistent LSVC with an unroofed coronary sinus.^[2] Persistent LSVC usually joins the coronary sinus between the left atrial appendage lying anteriorly and the opening of left pulmonary veins which form the posterior border.^[3] However, in this case, as there is an association of cor triatriatum with Raghib complex, opening of pulmonary veins is displaced superiorly into the proximal chamber.

Cor triatriatum sinister is a congenital cardiac anomaly that is associated with a membrane that separates the left atrium into two chambers; the membrane can have one or more restrictive ostia.^[4] It is observed that cor triatriatum and persistent LSVC are frequently associated with each other. One probable theory of the pathogenesis of cor triatriatum is compression of the persistent LSVC on the developing left atrium.^[5] Raghib complex associated with cor triatriatum is reported in the literature. Persistent LSVC with cor triatriatum is associated with AVSD in 3% of cases. The combination of Raghib complex with cor triatriatum and AVSD is rarely reported.

In this case, cor triatriatum membrane is resected and complete balanced AVSD is repaired with two patch technique using autologous unfixed pericardial patch, the opening of the persistent LSVC is located posterior to left atrial appendage opening in the distal left atrial chamber, the opening is baffled into right atrium using homologous pericardial patch as there was no sufficient autologous pericardium left after the AVSD repair. However, the persistent LSVC can be rerouted in different methods, isolated persistent LSVC can be rerouted to the right atrial appendage or on to right-sided superior vena cava. It can also be rerouted into the left pulmonary artery which results in left-sided bidirectional Glenn procedure. However, in this case, an intra-atrial baffle redirected the venous drainage of LSVC into the right atrium.

Raghib complex associated with obstructive cor triatriatum sinister and complete balanced AVSD is a rare association and the baby underwent repair of the complex cardiac anomaly. Surgical procedure done is unique only because three different congenital cardiac anomalies are present in an infant and the procedure demands a lot of patience and expertise.