Nakae S

Incidence and natural course of trabecular ventricular septal defect: Two-dimensional echocardiography and color Doppler flow imaging study

This study was designed to determine the prevalence of trabecular ventricular septal defect (t-VSD) in neonates and to evaluate the effects of its location, morphologic features, and size on its natural course during infancy. One thousand twenty-eight term newborn infants were examined by color Doppler flow imaging with orthogonal ultrasonographic views. Ten girls and 11 boys (2.0%) were found to have t-VSD. The natural course of the defect was examined in 42 consecutive cases, consisting of this group of 21 neonates and another group of 21 neonates with t-VSD. The morphologic features of the defect within the trabecular septum were classified as one or two defects (36 cases) and as a mesh-like defect (six cases). Reduction in size began from the right ventricular side or from within the trabecular septum. Spontaneous closure occurred most commonly during the first 6 months of life and was observed in 32 cases (76%) by 12 months of age: the frequency of closure was not related to the morphologic features and the initial size of the defect, but apical defects tended to have higher persistent patency than did defects in other locations (p less than 0.05). We conclude that the frequency of t-VSD in neonates and the frequency of spontaneous closure during early infancy are higher than previously believed. This information is important for predicting the natural course of t-VSD and deciding on its proper management.

Effect of suture closure of coronary artery fistula on aneurysmal coronary artery and myocardial ischemia

This study indicates the importance of coronary angiography and myocardial scintigraphy on long-term follow-up of patients after surgery for coronary arterial fistula in view of the progression to coronary artery obstruction and myocardial ischemia.

Correction of truncus arteriosus with autologous arterial flap in neonates and small infants.

BACKGROUND This study describes the results of techniques using the autologous truncal wall and part of the pulmonary artery for correction in anticipation of the growth of the pulmonary tract in patients with truncus arteriosus. METHODS Seven consecutive patients with truncus arteriosus were reviewed. The posterior wall of the pulmonary tract was obtained by anastomosing the lower edge of the truncal arteriotomy to the upper corner of the ventriculotomy from the truncus in types I and II. Anterior translocation of the pulmonary artery was performed in a type III. A pericardial patch with or without a monocusp was placed to complete the right ventricular outflow tract. RESULTS There were two hospital deaths, one of which was unrelated to a cardiac problem. Postoperative right-to-left ventricular peak pressure ratio was less than 0.55. There was one left pulmonary stenosis due to monocusp adherence in the late postoperative period. The sizes of the pulmonary tract at anastomosis were between 107% and 166% of the normal value between 7 months and 3.8 years of follow-up. CONCLUSIONS The use of autologous arterial wall instead of a conduit is recommended for the repair of truncus arteriosus to expect growth of the pulmonary tract.

Truncus arteriosus with interrupted aortic arch: Successful correction using autologous flap

A newborn baby with type II truncus arteriosus and type B interrupted aortic arch was successfully treated by creating a pulmonary tract using autologous flap made from truncal wall without excision of the pulmonary artery and by reconstructing the aortic arch with direct anastomosis. This method provided excellent hemodynamics with wide reconstruction of the pulmonary tract without conduit.

Assessment of left ventricular function before and after Fontan's operation for the correction of tricuspid atresia

SummaryFunctional change in the left ventricle was studied in the light of changes in the left ventricular (LV) volume preload before and after Fontans operation. Six cases with tricuspid atresia (TA) were studied, and they had either types Ib or IIb. The preoperative LV end-diastolic volume index (LVEDVI) was 123±44 ml/m2, which corresponds to 166%±45% of normal values. This suggests that in TA the preload of the LV volume is increased because of its peculiar hemodynamic situation. After Fontans operation, the LVEDV decreased by 24.6% to 119.6±87.7 ml (P=0.01), which corresponds to 120%±50.9% of normal values. Presenting a striking contrast to the decrease in LVEDV, the postoperative reduction in LV end-systolic volume (LVESV) was approximately 8%. Preoperative and postoperative values for LVESV were 67.1±50.8 ml and 62±45.6 ml, thus, the systolic volume was decreased. Because of the small change in LVESV, the ejection fraction (EF) of the left ventricle significantly decreased from 0.61±0.1 preoperatively to 0.48±0.1 postoperatively. The cardiac index (CI) remained in the range of 1.9–2.5 1/min/m2 with a mean of 2.2±0.2 1/min/m2 at 1 month after operation. But, later, improvement in EF was observed in one case, in which the CI increased from 2.5 to 3.2 1/min/m2. In cases with TA in which function of the left ventricle is damaged by chronic LV volume overload and longstanding hypoxemia, important factors for long-term survival after Fontans operation are the degree of postoperative improvement in LV function and the maximal limit of LV function, which could be affected by compromised function of the right heart.

Left ventricular characteristics during exercise in patients after Fontan's operation for tricuspid atresia

SummaryLeft ventricular function during supine bicycle exercise was studied using multigated blood pool imaging in ten patients with tricuspid atresia after Fontans operation and in 13 children and adults (control group). The mean age of the patients was 16 years and the mean interval between operation and study was 5 years. The peak work loads that the patients could perform were similar to those in the control group. Work loads and heart rates during radionuclide study in the operated group were also similar to those in the control group. The left ventricular ejection fraction at rest and during exercise in the operated group was less than in the control group, although the net increase during exercise was similar in the two groups. During exercise, left ventricular end-diastolic volume decreased significantly in the operated group. In the control group, this variable did not change significantly. Left ventricular stroke volume increased during exercise in the control group but it did not change significantly in the operated group. These data indicate that in patients after Fontans operation, left ventricular performance remains low during exercise, which is in part due to diminished left ventricular preload reserve, and this in turn may be caused by reduced reserve of right heart output.

Anterior pulmonary translocation without conduit for the repair of truncus arteriosus

A technique with autologous tissue for the correction of type III truncus arteriosus is described. The truncal root was excised as a cylinder that incorporated pulmonary arteries and that was translocated anterior to the ascending aorta. The proximal section of the cylinder was closed and the pulmonary tract was reconstructed with anastomosis of a widely opened distal section to the right ventricle. Autologous pericardium was sutured to the entire surface of the pulmonary tract.

Obstruction of the proximal pulmonary artery branches after banding of the pulmonary trunk.

Abstract Most of the pulmonary branch obstruction that occurs after banding may be the result of dislocation or placement of the band very near the bifurcation during surgery rather than progressive migration of the band. Two-dimensional and Doppler echocardiography are useful noninvasive techniques for evaluating pulmonary branch size and stenosis after banding.

Prospective echocardiographic analysis of progressive obstruction of the proximal pulmonary artery in congenital heart disease and obstructed pulmonary flow

BACKGROUND It is uncertain whether proximal pulmonary artery (PA) obstruction exists soon after birth and whether its progress relates directly to postnatal ductal constriction in congenital heart disease and obstructed pulmonary flow. METHODS Serial morphometric analyses of the PA branches by echocardiogram were performed in 28 patients (mean age at initial study 2.5 days) until severe constriction of the ductus occurred (mean age 47 days). These patients were divided into 2 groups by subsequent angiographic or postmortem confirmation; 10 with proximal PA obstruction (group 1) and 18 without obstruction (group 2). RESULTS At the time of initial examination, the mean indexed diameter of the proximal PA on the side of the ductus arteriosus in group 1 was significantly smaller than that on the contralateral side (5.2+/-0.7 versus 9.0+/-0.7 mm/BSA0.5, P < .001) or that in group 2 (8.0+/-0.4 mm/BSA0.5, P < .001). In group 1, 8 patients had a proximal PA index on the ductal side < or = 5.5 mm/BSA0.5, which was less than those of any group 2 patients. After severe constriction of the ductus, the proximal PA index on the ductal side further decreased only in group 1 (P < .01). CONCLUSIONS These data indicate that unilateral obstructive lesion of branch PA is present shortly after birth and its progression relates directly to ductal constriction. Neonates with branch PA obstruction can be identified on their initial echocardiogram as having a proximal PA index on the ductal side < or = 5.5 mm/BSA0.5.