<p>Atrial septal defects are one of the most common forms of congenital heart disease, however sinus venosus communications, particularly pulmonary vein-type defects, are rare and are easily misdiagnosed. Patients with pulmonary vein-type sinus venosus defects often present earlier than those with ostium secundum defects with significant right heart dilation. Correct diagnosis has important implications for management. We discuss the clinical courses and review multimodality imaging of three patients correctly diagnosed with pulmonary vein-type defects after an initial diagnosis of an ostium secundum atrial septal defect, in order to promote understanding of the unique anatomy of this entity.</p>

<p><strong>Background</strong> Recent studies suggest that lymphatic congestion plays a role in development of late Fontan complications, such as protein-losing enteropathy. However, the role of the lymphatic circulation in early post-Fontan outcomes is not well defined.</p>

<p><strong>Methods and Results</strong> This was a retrospective, single-center study of patients undergoing first-time Fontan completion from 2012 to 2017. The primary outcome was ≤6&nbsp;months after surgery, a composite of death, Fontan takedown, extracorporeal membrane oxygenation, chest tube drainage &gt;14&nbsp;days, cardiac catheterization, readmission, or transplant. Complication causes were assigned to 1 of 4 groups: (1) Fontan circuit obstruction, (2) ventricular dysfunction or atrioventricular valve regurgitation, (3) persistent pleural effusions Fontan obstruction or ventricular dysfunction, and (4) chylothorax or plastic bronchitis. T2-weighted magnetic resonance imaging sequences were used to assess for lymphatic perfusion abnormality. The cohort consisted of 238 patients. Fifty-eight (24%) developed early complications: 20 of 58 (34.5%) in group 1, 8 of 58 (14%) in group 2, 18 of 58 (31%) in group 3, and 12 of 58 (20%) in group 4. Preoperative T2 imaging was available for 126 (53%) patients. Patients with high-grade lymphatic abnormalities had 6 times greater odds of developing early complications (=0.001).</p>

<p><strong>Conclusions </strong>There is substantial morbidity in the early post-Fontan period. Half of those who developed early complications had lymphatic failure or persistent effusions unrelated to structural or functional abnormalities. Preoperative T2 imaging demonstrated that patients with higher-grade lymphatic perfusion abnormalities were significantly more likely to develop early complications. This has implications for risk stratification and optimization of patients before Fontan palliation.</p>

<p><strong>BACKGROUND: </strong>Intramural ventricular septal defects (VSDs), residual interventricular communications occurring after repair of conotruncal defects, are associated with poor postoperative outcomes. The ability of intraoperative transesophageal echocardiography (TEE) to identify intramural VSDs has not yet been evaluated.</p>

<p><strong>METHODS: </strong>Intraoperative TEE and postoperative transthoracic echocardiography (TTE) data in all patients undergoing all biventricular repair of conotruncal anomalies in our hospital between January 1, 2006, and June 30, 2013, were reviewed. The ability of TEE to accurately identify residual defects was assessed using postoperative TTE as the reference imaging modality.</p>

<p><strong>RESULTS: </strong>Intramural VSDs occurred in 34 of 337 patients evaluated; 19 were identified by both TTE and TEE, and 15 were identified by TTE only. Sensitivity was 56% and specificity was 100% for TEE to identify intramural VSDs. Peripatch VSDs were identified in 90 patients by both TTE and TEE, in 53 by TTE only, and in 15 by TEE only, yielding a sensitivity of 63% and specificity of 92%. Of the VSDs requiring catheterization or surgical reintervention, 6 of 7 intramural VSDs and all 5 peripatch VSDs were identified by intraoperative TEE. TEE guided the intraoperative decision to return to cardiopulmonary bypass (CPB) in an attempt to close residual defects in 12 patients with intramural VSDs and in 4 patients with peripatch VSDs seen after initial CPB; of these, 10 intramural VSDs and all 4 peripatch VSDs resolved or became smaller on final intraoperative TEE.</p>

<p><strong>CONCLUSIONS: </strong>TEE has modest sensitivity but high specificity for identifying intramural VSDs and can detect most defects requiring reintervention. Repeat attempts at closure in the index operation may successfully correct intramural VSDs identified by TEE.</p>