A reappraisal of the sinus venosus defect

Abstract

OBJECTIVES The phenotypic features and morphogenesis of the ‘sinus venosus defect’ remain controversial. The phenotypic features are anomalous systemic connections of 1 or more pulmonary veins that retain their left atrial connection, usually associated with a biatrial connection of the superior caval vein. Cases with these features, however, have not always been described as sinus venosus defects. METHODS We reviewed the findings documented in the literature from 11 patients with a biatrial connection of the superior caval vein, most reported following an autopsy examination. We compared these findings with the anatomical details of 50 patients undergoing surgical correction in our centre, paying particular attention to the override of the superior caval vein. RESULTS In only two-thirds of those undergoing surgery did the superior caval vein override the rims of the oval fossa, with the degree of override >50% in only 2 individuals. It is only these latter 2 cases that are directly comparable to the reported cases of biatrial connection of the superior caval vein. CONCLUSIONS Our comparisons provide new insights into the developmental background and phenotypic features of the superior sinus venosus defect. The defects exist because of the anomalous systemic connection of the pulmonary veins that retain their left atrial connections but not always in association with a biatrial connection of the superior caval vein. In extreme cases, nonetheless, they can underscore the connection of the caval vein to the morphologically left atrium, frequently described previously as a ‘biatrial connection’. The sinus venosus defect is better considered a venovenous malformation than a septal defect.

Congenital heart disease: types, pathophysiology, diagnosis, and treatment options

“…Sinus venosus ASD is characterized by an anomalous systemic connection of one or more pulmonary veins, which is associated with a hemodynamically significant shunt. Surgery is the traditional therapeutic approach in these patients 136,137 . Recently, transcatheter closure via covered stent placement in the superior vena cava has been established as an alternative therapeutic option for some patients.…”

Three-Dimensional-Enabled Surgical Planning for the Correction of Right Partial Anomalous Pulmonary Venous Return

“…Partial anomalous pulmonary venous return (PAPVR) is a rare congenital cardiac disease characterized by abnormal drainage of at least one pulmonary vein (PV) into the systemic venous circulation [ 4 ]. This is usually associated with a sinus venosus defect (SVD) in almost 90% of cases [ 5 , 6 , 7 ]. PAPVR correction can be performed through several procedures, which can be mainly divided into [ 8 ]: the single patch technique (baffling of the PVs to the left atrium through the SVD), the double patch technique (baffling and enlargement of the superior vena cava (SVC)) and the Warden technique, that is already extensively described in the literature [ 9 , 10 ].…”

Venovenous Bridge Connecting Systemic and Pulmonary Venous Circulation: An Antecedent of the Sinus Venosus Defect

“…3,4 There is a growing consensus that the diagnostic morphological feature of the sinus venosus defect is a partially anomalous systemic drainage of the right pulmonary venous return, with the anomalously draining pulmonary vein retaining its connection to the left atrium. 1,2 Butts et al 1 demonstrated the presence of a similar configuration in 2 adult patients with an anomalous pulmonary venous drainage of right upper lobe pulmonary vein to the superior caval vein, associated with a bridging vein between the right upper lobe pulmonary vein and the right middle lobe pulmonary vein, which in turn was seen normally draining in the left atrium. The veno-venous bridge resulted in a pathophysiological state analogous to that observed in a classic sinus venosus defect, also evidenced by a positive transthoracic bubble contrast echocardiographic study.…”

“…It is now well accepted that, although previously misclassified as a sinus venosus atrial septal defect, the occurrence of sinus venosus defects are largely unrelated to deficient atrial septation. 1,2 Since it is often associated with partial anomalous pulmonary venous connection to the superior caval vein near the superior cavo-atrial junction, it was also hypothesized that unroofing of the wall separating the RUPV from the superior caval vein and the right atrium resulted in the defect. This concept was however abandoned based on the nonexistence of the said wall separating the 2 structures.…”

“…1 The classical sinus venosus defect simply appears to be an exaggerated version of the veno-venous connection observed in our case and also described previously by Butts et al With gradually accruing developmental and morphological evidence supporting the concept that sinus venosus defects are the result of persistent veno-venous bridges present in the fetus, the veno-venous connection identified in the present case may represent one end of the spectrum of the defect, with the classical sinus venosus defect with partial anomalous pulmonary venous connection at the other end. 1,2…”