Atrial septal defect sinus venosus


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Overview
During fetal development, the septal wall may fail to fuse causing an atrial septal defect to arise. A sinus venosus atrial septal defect is one such type of malformation arising from the irregular development of the septum and the superior vena cava or the inferior vena cava.

Sinus Venosus Atrial Septal Defect

 * In this type of atrial septal defect the common wall between the coronary sinus and the left atrium is not developed.


 * Some patients with coronary sinus atrial septal defects may also have a persistent left superior vena cava.


 * A sinus venosus ASD is a type of atrial septum defect in which the defect in the septum involves the venous inflow of either the superior vena cava or the inferior vena cava.


 * A sinus venosus ASD that involves the superior vena cava makes up 2 to 3% of all interatrial communication. It is located at the junction of the superior vena cava and the right atrium. It is frequently associated with anomalous drainage of the right-sided pulmonary veins into the right atrium (instead of the normal drainage of the pulmonary veins into the left atrium).

Surgical Closure
1) Sinus venosus ASD is commonly found to be associated with partial anomalous pulmonary venous return.

2) In presence of partial anomalous pulmonary venous return (pulmonary veins draining into the right atrium inplace of left atrium), atrial septal defect should be corrected by placement of patch over the defect. In larger defects, it is essential to ensure the usage of a synthetic patch to be placed strategically, to allow anomalous pulmonary venous drainage, to be diverted to the left atrium. 3)  In this case, anomalous pulmonary venous drainage must be carefully monitored and assessed as compromise of pulmonary venous return due to redirection could lead to [[Pulmonary hypertension|pulmonary venous hypertension

Prognosis
1) Good post-surgical prognosis irrespective of the patient's age at surgery.

2) Surgery for sinus venosus ASD is complex compared to other atrial septal defect and can cause stenosis of the superior vena cava or pulmonary veins, residual shunting and SA node dysfunction.