A geometrical pitfall of Area-Length method; -Is left ventricle volume evaluation of repaired Tetralogy of Fallot by angiocardiography accurate?

Biplane Area-Length (AL) method by left ventriculography (LVG) has been widely adopted as a standard method to estimate left ventricular volume. However, we have experienced difficulties in adopting the value by AL method for the children with Tetralogy of Fallot (TOF) due to the discrepancy among volumetric modalities. This study validated some limitations of AL method, considering the basic principles of its formulation. A single center retrospective cohort study was conducted for 1 year. The confirmed 22 cases with repaired TOF at our hospital were enrolled. The clinical characteristics, some cardiac MRI analyses, and all the cardiac catheterization studies were collected. Angiographic data were compared with historic cohorts of Kawasaki disease without any coronary artery lesions by using AL method. Cardiac MRI analyses of ten TOF patients were additionally available. LVG studies showed that the length of the long axis on anteroposterior view (AP) was not equal to that on lateral view (LT) due to anatomically apical elevation in TOF, followed by a significant difference found in the sagittal lengths of the LV long axis between AP and LT (P = 0.003). Because the difference critically affected the formula depending on biplane AL method, the calculated LVEDV of TOF group appeared overestimated, compared with the control group (TOF vs control group: 119.5% ± 6.3% vs 96.4 ± 3.5% of Normal, P = 0.006). Available cardiac MRI analyses of some patients in TOF group revealed 55% increase of LVEDV by AL method (angiocardiography 116 ± 7.0 vs CMR 75 ± 3.7 ml/m2, P = 0.0025). A pitfall exists when applying biplane AL method to measure LV volume especially for TOF patients, because the long axis on AP view is not always identical to that on LT view.

Significance of right atrial tension for the development of complications in patients after atriopulmonary connection Fontan procedure: potential indicator for Fontan conversion.

Elevated right atrial (RA) pressure and progressive RA dilation are thought to play pivotal roles in the development of late complications after atriopulmonary connection (APC) Fontan surgery. However, no clear cut-off value for RA pressure or RA volume has been determined for stratifying the risk of developing Fontan complications. We hypothesized that RA tension, which incorporates information about both RA pressure and volume, might help predict the risk of developing complications. We retrospectively studied 51 consecutive APC Fontan patients (median postoperative period 14 years). RA tension was computed from the RA pressure and RA radius, which was calculated from RA volume measured by RA angiography. The correlation between the cardiac catheterization hemodynamic data and the complications of APC Fontan was investigated. Of the 51 patients, 28 had complications, including liver fibrosis (n = 28), arrhythmia (n = 8), protein-losing enteropathy (n = 1), and RA thrombosis (n = 1). Among the hemodynamic data, RA volume and RA tension, but not RA pressure, were significantly higher in patients with complications than in those without (P = 0.004 and P = 0.001, respectively). The cut-off level for RA tension to predict Fontan complications was 26,131 dyne/cm by receiver operating characteristic curve (area under the curve 0.79, sensitivity 71.4%, and specificity 73.9%). The present study demonstrated the significance of RA tension rather than high venous pressure for the development of Fontan complications. Amid the uncertainty about clinical outcomes, the present results, subject to further validation, may contribute to the indications for Fontan conversion.

Aortopexy for tracheomalacia with dextrocardia, pulmonary artery sling, and congenital tracheal stenosis.

We report a rare case of coexisting pulmonary artery sling, congenital tracheal stenosis, and dextrocardia caused by right lung hypoplasia. Successful treatment of severe postoperative tracheomalacia was achieved by aortopexy, aiming displacement of the aortic arch across orthogonally in front of the trachea due to dextrocardia. The aim of this surgery was different from the usual aortopexy for tracheomalacia, which lifts the tracheal wall with the aorta. The three-dimensional evaluation considering the patient's associated malformations led to a successful result.