Inferior Sinus Venosus Type Atrial Septal Defect Initially Presenting Pulmonary Hypertension on Transthoracic Echocardiography

Undiagnosed inferior vena cava type of sinus venosus atrial septal defect in a middle-aged woman: A rare case report

Sinus venosus atrial septal defect (ASD) accounts for 5% to 10% of ASDs. In contrast with the more common superior vena cava (SVC) type, the inferior vena cava (IVC) type of sinus venosus ASD with overriding IVC is extremely rare. The sinus venosus defect occur posterior to the fossa ovalis and is not regarded as true ASD. Transesophageal echocardiography (TEE) is a diagnostic procedure of choice due to close proximity of atrial septum to TEE transducer. However; it may not constantly yield detailed anatomical and functional characterization, and other imaging modalities such as cardiac magnetic resonance imaging (MRI) may be needed. We report the case of a 45-year-old woman with an undiagnosed hemodynamically significant IVC-type ASD without any anomalous drainage of pulmonary veins, who presented with progressive dyspnea.

Surgical repair of inferior sinus venosus defects: a novel approach with unsnared inferior vena cava

Background

Inferior sinus venosus defects (SVD) are very rare and difficult to image from transthoracic echocardiography. Surgical errors were occasionally reported in the repair of inferior SVDs.

Results

The authors have operated on 12 inferior SVD patients using bicaval cannulation with unsnared inferior vena cava (IVC) and proved successful.

Conclusion

This technique guaranteed a better exposure of surgical field and facilitate identifying the anatomical relationship between lower part of the SVD and IVC orifice, thus avoiding postoperative IVC - left atrial shunt and other surgical mistakes.