The use of cardiopulmonary bypass during surgery is the most challenging procedure in all the possible fetal cardiac interventions. Catheter-based fetal cardiac interventions have recently been developed and applied in the clinical setting for a particular category of congenital heart diseases. The intention was to improve long-term results by allowing the heart to grow normally before birth. However, the procedures that can be performed using catheter intervention are very limited, the primary examples of which are atrial septostomy, aortic valvotomy, and pulmonary valvotomy. There is still a group of congenital heart diseases, such as total anomalous pulmonary venous connection, hypoplastic left heart syndrome, pulmonary atresia with intact ventricular septum, and Ebstein’s anomaly, for which long-term results could be improved or Fontan circulation could be avoided using fetal surgical cardiac intervention but may not be achieved using catheter intervention. In 1985, Richter et al first reported an animal study on fetal cardiopulmonary bypass. Since this report, which was over 30 years ago, several developments in this field have been achieved; however, there are no case reports on successful fetal cardiopulmonary bypass in humans. The aim of this study was to determine the current status of developments in fetal surgical intervention using cardiopulmonary bypass.

View full abstract

In biventricular physiology, transcatheter right ventricular outflow tract (RVOT) stenting is indicated as an initial palliative alternative to a modified Blalock-Taussig shunt or to delay surgery for obstructed RVOT conduit. RVOT conduits may eventually need replacing because of luminal narrowing, regurgitation, or size mismatch associated with somatic growth. During the 2000s, reports from North America described acutely improved hemodynamics and the ability to postpone surgical replacement for 2.1–3.9 years with endovascular stenting for conduit stenosis. However, common complications of stenting RVOT conduits are free pulmonary regurgitation and frequent stent fracture. In addition, the potential risk of proximal coronary artery compression also limits its use when the anatomy is unfavorable. Recently, transcatheter pulmonary valve implants (TPVI), intended for treating RVOT conduit dysfunction, have become available in Europe and the US. However, size considerations may limit their use to smaller sized RVOT conduits. These uncertainties mean that stenting and surgery will remain necessary therapeutic options for conduit pathology, particularly in Japan where TPVI is unavailable. Given the likelihood of its continued use, we reviewed current trends in stenting for RVOT conduits in Japan and their potential risks and benefits.

View full abstract

Background: Various grades of sinusoidal communications (SC) occur in patients with pulmonary atresia (PA) with intact ventricular septum (IVS). The aim of this study was to classify patients with PA/IVS according to the SC grade and to investigate the relationship between the SC grade and long-term outcome.
Methods: Fifty six patients with a diagnosis of PA/IVS, admitted to our institution from 1995 to 2014, were retrospectively reviewed. SC was classified into five grades, and all the angiographic imaging studies in the neonatal period and the follow-up information were reviewed. Changes in SC and the relationships between SC grade and coronary event, exercise electrocardiography (EKG) and ST changes, cardiac function, brain natriuretic peptide (BNP), right ventricular (RV) pressure, and RV end-diastolic volume (RVEDV) were analyzed.
Results: SC grades of 0, 1, 2, 3, and 4 were present in 30, 5, 11, 10, and 0 patients, respectively. Two patients with SC grade 3 died because of coronary events. No deaths were seen after Glenn operations. Significant differences were observed between patients with and without SC in terms of coronary events (p＝0.025) and EKG ST changes (p＝0.0025). On the other hand, no relationship was seen between SC grade and cardiac function, BNP, and RV pressure. Six patients underwent surgical intervention. Three patients showed natural SC regression and none showed progressive obstruction.
Conclusion: The presence of interrupted coronary arteries (SC grade 3 or 4) appears to be related to increased frequency of coronary events and a high mortality rate. In the neonatal period, the accurate assessment of SC grade is important and attention should be paid to the risk of sudden death, particularly before the Glenn operation.

View full abstract

Our lab has identified the mutated genes responsible for congenital heart defects (CHD) using immortalized B cell lines established from the patient’s blood. Using animal models, we have investigated how the mutations cause disease. However, because of the progress in induced pluripotent stem (iPS) cell technology, it would be better for us to use iPS cell-derived cardiac cells instead of mouse models. Therefore, we have established iPS cells from patients with long QT syndrome (LQTS) and sick sinus syndrome (SSS) and from normal controls. All established iPS cells expressed octamer-binding transcription factor-4 (Oct4), T-cell receptor alpha-1-60 (TRA-1-60), stage-specific embryonic antigen-4 (SSEA4), and Nanog genes and proteins and were alkaline phosphatase-positive. The mutated genes were not altered after reprogramming. Moreover, Epstein–Barr (EB) viral genes were not expressed after reprogramming. These results suggest that cardiac cells, such as cardiomyocytes, derived from iPS cells reflect the mutations of specific diseases and have no artifacts from the EB virus. Therefore, iPS cell-derived cardiac cells can be used as a powerful tool in in vitro disease models.

View full abstract

Background: Increasing number of automated external defibrillators (AED) has been installed in public institutions nationwide. Therefore, there is increasing interest in the prognosis of patients who survived after incidences of ventricular fibrillation (VF) and were resuscitated using AEDs. However, little information is available about VF survivors with congenital heart disease (CHD).
Methods: Six CHD patients (median age: 17.1 years), who were resuscitated using an AED and subsequently underwent implantable cardioverter defibrillator (ICD) implantation in our hospital between November 2006 and October 2012, were reviewed. Patient demographics and periprocedural data of the ICD were analyzed.
Results: Underlying diseases consisted of two patients with tetralogy of Fallot and one each of corrected transposition of the great arteries, subaortic stenosis, myocardial infarction post-surgery for congenital mitral regurgitation, and anomalous origin of the coronary artery. In five patients, repair of the cardiac abnormality was simultaneously performed with the ICD implantation. During a median follow-up period of 3.9 years, one patient received appropriate therapy (once) and three patients received inappropriate therapies (eight times in total).
Conclusions: Here we reported on our strategy and the clinical outcome of VF survivors with CHD who underwent ICD implantation at our hospital. Our treatment policy for ventricular tachycardia/VF includes aggressive intervention of the underlying cardiac abnormality and jeopardized hemodynamics using cardiac medications and surgery in addition to ICD implantation. As a result of this useful strategy, all patients are still alive without residual disability.

View full abstract

Objective: The purpose of this study was to evaluate the indications and surgical outcomes of aortic valve repair (AVP) using glutaraldehyde-treated autologous pericardial patch in children with aortic valve disease.
Patients and Methods: From September 2004 to December 2012, five children underwent AVP using glutaraldehyde treated autologous pericardium at our institution. The median age at surgery was 5.0 years (range: 2.6 to 11.6 years). The primary diagnoses were truncus arteriosus, ventricular septal defect, coarctation complex, complete transposition of the great arteries, and congenital aortic valve insufficiency. The criteria for this procedure included aortic insufficiency (AI), tricuspid aortic valve, cusp dysplasia limited to one or two cusps, and truncal valve insufficiency. The median follow-up time was 5.0 years (range: 2.0 to 6.6 years).
Results: There were no early or late deaths. Preoperatively, the degree of AI was severe in four patients and moderate in one patient. After AVP, AI was improved to mild in four and mild to moderate in one patient. One patient, who had undergone two previous surgeries, underwent the Ross-Konno operation 4 years and 11 months after AVP because of progression of AI and aortic valve stenosis. Except this case, the degree of AI was mild in two and moderate in two patients, and the flow velocity of the aortic valve was less than 2.5 m/s at the latest follow-up. During follow up, the diameters of the aortic annulus had grown in all patients along the normal average curve (mean diameter was 18.8±4.3 mm preoperatively and 21.2±2.6 mm at the latest follow up).
Conclusion: AVP using a glutaraldehyde-treated autologous pericardial patch is an effective surgical option that can postpone aortic valve replacement or Ross procedure in patients with aortic or truncal valve insufficiency. Careful follow-up is necessary, particularly in patients with multiple previous surgeries.

View full abstract

Background: In small children, conduits for right ventricular outflow tract reconstruction are limited because of patient size and conduit resources, particularly in Japan.
Methods: Since 2007, we have performed the Rastelli-type procedure using 16-mm hand-made trileaflet expanded polytetrafluoroethylene (ePTFE) conduits in nine approximately 1-year-old children. The median age and body weight at surgery was 17.3 months (range: 10～22 months) and 8.9 kg (range: 6.8～11 kg), respectively. The patient diagnoses were double-outlet right ventricle (DORV) with pulmonary stenosis (PS) in four, pulmonary atresia with ventricular septal defect (PA/VSD) and major aortopulmonary collateral arteries (MAPCA) in four, and PA/VSD in one patient. All patients had undergone previous surgical procedures, including modified Blalock shunt in five and unifocalization of MAPCA and modified Blalock shunt in four patients. Conduit function, re-intervention, and right ventricular function were retrospectively investigated.
Results: There was no early or late mortality. During the median follow-up of 45 months (range: 18～79 months), balloon dilation for conduit stenosis was performed in two patients at 47 and 51 months post surgery, respectively. One of these patients required conduit replacement 27 months after balloon dilation. Excluding this patient, the most recent echocardiographic pressure gradients of the conduits were 0～20 mmHg in four, 21～40 mmHg in four, and no patient had conduit stenosis with the pressure gradients over 41 mmHg. Conduit regurgitation was trivial in four, mild in two, and moderate in two patients.
Conclusion: The Rastelli-type procedure using 16-mm hand-made trileaflet ePTFE conduits in approximately 1-year-old infants showed acceptable mid-term results. Conduit stenosis gradually developed over 5～6 years. Balloon dilation for conduit stenosis has the potential to delay conduit replacement without increasing conduit regurgitation.

View full abstract

Semans and Taussig first described congenital left atrial appendage aneurysm (LAAA) in 1938. However, it is very rare and has seldom been reported. The congenital reasons for its development are unknown. Although it is asymptomatic during the infantile period, it is usually resected in order to prevent symptoms that are commonly associated with it, including supraventricular arrhythmia, compression of the coronary arteries, dyspnea, intracardiac thrombus, and pulmonary venous stenosis. Here we report on the surgical management of an asymptomatic 2-year-old girl with this anomaly. Transthoracic and transesophageal echocardiography did not reveal thrombosis in the left appendage, and contrast-enhanced computed tomography of the LAAA demonstrated no abnormal structures. After median sternotomy, aneurysmectomy was performed under cardiopulmonary bypass without cross-clamping. The patient underwent successful surgical resection of the aneurysm.
Pathological examination revealed the three levels of atrial structure epicardial, myocardial, and endocardial layers; thinning of the muscular layer; and mucous degeneration, classifying the LAAA into an intrapericardial aneurysm of the left atrial appendage. Tissue destruction and the inability to maintain tissue homeostasis may have contributed to the formation of the LAAA.

View full abstract

We report the case of a 14-year-old girl with diffuse pulmonary arteriovenous malformations (PAVM) associated with mutations of the endoglin (ENG) gene (p. Ala160del, c.479_481 delCTG; ex4). She was diagnosed at 9 years of age and had undergone percutaneous transcatheter embolization (TCE) five times since the diagnosis. However, the effects were limited. Initial oxygen saturation after coil embolization was over 90％, gradually falling to 80％ after every treatment. With diffuse PAVM, embolization of the fistulas or feeding vessels still leaves a chance for enlargement of another feeding vessel. Enlarged feeding vessels increase fistula inflow and consequently induce PAVM development and hypoxia. We considered this as the cause of the repeated hypoxemia. Because embolization of the fistulas alone did not seem sufficient to interrupt the blood supply, we decided to perform coil embolizations and sacrifice normal pulmonary artery trees. Occluding normal pulmonary arteries is known to reduce pulmonary capillary beds and can induce pulmonary arterial hypertension. However, to improve hypoxemia, we considered that TCE with sacrifice of normal pulmonary arteries would be necessary. Repeated TCE brought about a good clinical course without pulmonary artery pressure elevation. TCE with sacrifice of normal pulmonary arteries may offer a promising and effective choice of treatment in some cases of PAVM. It is necessary to pay close attention to the development of pulmonary arterial hypertension in long-term follow-up.

View full abstract