Hyoung Doo Lee

Multidetector CT evaluation of total anomalous pulmonary venous connections: comparison with echocardiography

BackgroundAlthough echocardiography is the first-line imaging modality in the diagnosis of total anomalous pulmonary venous connection (TAPVC), multidetector CT (MDCT) could have advantages in the diagnosis of TAPVC in certain cases.ObjectiveTo compare MDCT with echocardiography in the evaluation of TAPVC.Materials and methodsEnrolled in the study were 23 patients with surgically proven TAPVC. The echocardiography and MDCT findings were independently interpreted by a paediatric cardiologist and cardiac radiologist in terms of: (1) the drainage site of the common pulmonary vein, (2) stenosis of the vertical vein, and (3) the course of the atypical vessel into the systemic vein in the case of vertical vein stenosis. The findings from both modalities were correlated with the results obtained at surgery (n=22) or autopsy (n=1).ResultsIn all patients, MDCT correctly depicted the drainage site of the common pulmonary vein, stenosis of the vertical vein and the course of the atypical vessel into the systemic vein (sensitivity 100%, specificity 100%). The specificity of echocardiography was 100% for the three defined findings. The sensitivity of echocardiography, however, was 87%, 71% and 0%, respectively.ConclusionMDCT can facilitate the diagnosis of TAPVC in certain cases.

Identification of KCNN2 as a susceptibility locus for coronary artery aneurysms in Kawasaki disease using genome-wide association analysis.

Kawasaki disease (KD) is often complicated by coronary artery lesions (CALs), including aneurysms. Because of the complications associated with KD, this disorder is the leading cause of acquired heart disease in children from developed countries. To identify genetic loci that confer a higher risk of developing CALs, we performed a case–control association study using previous genome-wide association study data for samples from KD cases only (n=186) by grouping KD patients without CALs (control: n=123) vs KD patients with extremely large aneurysms (diameter>5 mm) (case: n=17). Twelve loci with one or more sequence variants were found to be significantly associated with CALs (P<1 × 10−5). Of these, an SNP (rs17136627) in the potassium intermediate/small conductance calcium-activated channel, subfamily N, member 2 (KCNN2) at 5q22.3 was validated in 32 KD patients with large aneurysms (diameter>5 mm) and 191 KD patients without CALs (odds ratio (OR)=12.6, Pcombined=1.96 × 10−8). This result indicates that the KCNN2 gene can have an important role in the development of coronary artery aneurysms in KD.

Early and late outcomes of total repair of tetralogy of Fallot: risk factors for late right ventricular dilatation

OBJECTIVES This study was undertaken to assess the early and long-term results of total repair of tetralogy of Fallot (TOF) and to identify the risk factors associated with late right ventricular (RV) dilatation. METHODS The medical records of 326 patients (male:female = 192:134) who underwent total repair of TOF at Pusan National and Dong-A University Hospitals between July 1991 and May 2011 were retrospectively reviewed. Median age and weight at the time of operation were 13.0 months and 8.7 kg, respectively. Right ventricular end-diastolic dimensions and left ventricular end-diastolic dimensions were obtained during follow-up echocardiography to identify the risk factors associated with late RV dilatation. RESULTS There were one operative death (0.3%) and 8 late deaths (2.5%). Of late deaths, two were related to operation-related cardiac problems. Overall survival rates at 5, 10, and 15 years were 97.0%, 95.4%, and 95.4%, and the corresponding freedom from cardiac death were 98.8%, 98.8%, and 98.8%, respectively. Freedom from re-operation and re-intervention were 84.4%, 74.2% and 74.2%. Six patients underwent pulmonary valve replacement during the follow-up period. Transannular patch (P = 0.036) and postoperative ventilator support period (P < 0.001) were found to be significant risk factors of late RV dilatation in multivariate analysis. CONCLUSIONS Total correction of TOF can be performed with a very low mortality rate. However, the postoperative re-operation or re-intervention rates remain relatively high. Late RV dilatation after total repair of TOF was found to be associated with transannular patch enlargement and a longer postoperative ventilator support period.

Clinical features and short-term outcomes of pediatric acute fulminant myocarditis in a single center

Purpose The aims of this study were to document our single-center experience with pediatric acute fulminant myocarditis (AFM) and to investigate its clinical features and short-term outcomes. Methods We performed a retrospective chart review of all children <18 years old who were diagnosed with AFM between October 2008 and February 2013. Data about patient demographics, initial symptoms, investigation results, management, and outcomes between survivors and nonsurvivors were collected. Results Seventeen of 21 patients (80.9%) with myocarditis were diagnosed with AFM. Eleven patients (64.7%) survived to discharge, and 6 (35.3%) died. Electrocardiography on admission revealed dysrhythmia in 10 patients (58.8%); of these, all 7 patients with a complete atrioventricular block survived. Fractional shortening upon admission was significantly different between the survivors (16%) and nonsurvivors (8.5%) (P=0.01). Of the serial biochemical markers, only the initial brain natriuretic peptide (P=0.03) and peak blood urea nitrogen levels (P=0.02) were significantly different. Of 17 patients, 4 (23.5%) required medical treatment only. Extracorporeal membrane oxygenation (ECMO) was performed in 13 patients (76.5%); the survival rate in these patients was 53.8%. ECMO support was initiated >24 hours after admission in 4 of the 13 patients (30.7%), and 3 of those 4 patients (75%) died. Conclusion AFM outcomes may be associated with complete atrioventricular block upon hospital admission, left ventricular fractional shortening at admission, time from admission to the initiation of ECMO support, initial brain natriuretic peptide level, and peak blood urea nitrogen level.

A central shunt to rehabilitate diminutive pulmonary arteries in patients with pulmonary atresia with ventricular septal defect

OBJECTIVES We evaluated our clinical experiences on rehabilitation of native pulmonary arteries (PAs) with a central shunt using an expanded polytetrafluoroethylene (ePTFE) tube graft in management of pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (MAPCAs) with diminutive PAs. METHODS From March 1993 to June 2013, a total of 28 consecutive patients underwent surgery for pulmonary atresia with VSD and MAPCAs. We identified 15 patients who underwent a central shunt procedure using an ePTFE tube graft. Median age and weight at the initial operation were 1.91 months and 5.22 kg, respectively. Ligation of MAPCAs was performed in 3 patients concomitantly. The techniques used were a U-shaped central shunt in 13 patients, and a side-to-side aorto-ePTFE tube graft anastomosis in 2 patients. RESULTS There was no surgical mortality, and no shunt occlusion. The mean follow-up duration was 70.7 ± 67.1 months. Complete repair was achieved in 13 patients (13 of 14 of the follow-up patients; 92.9%), and the remaining patient is waiting for complete repair. The median age at complete repair was 19.4 months. The mean PA index before the initial central shunt procedure was 22.7 ± 13.2 mm(2)/m(2), which increased to 149.4 ± 86.6 mm(2)/m(2) at the final recordings before shunt division, and 185.9 ± 84.0 mm(2)/m(2) before complete repair. There were 2 late mortality cases. The overall survival rates were 92.9%, 82.5%, and 82.5%, at 1, 5, and 10 years, respectively. CONCLUSIONS A central shunt, using an ePTFE tube graft, is an effective initial palliative procedure for rehabilitation of the diminutive PAs in patients with pulmonary atresia with VSD and MAPCAs.

Arterial Switch Operation in Patients with Intramural Coronary Artery: Early and Mid-term Results

Background The intramural coronary artery has been known as a risk factor for early death after an arterial switch operation (ASO). We reviewed the morphological characteristics and evaluated the early and mid-term results of ASO for patients with an intramural coronary artery. Materials and Methods From March 1994 to September 15th 2010, 158 patients underwent ASO at Dong-A and Pusan National University Hospitals for repair of transposition of the great arteries and double outlet right ventricle. Among these patients, 14 patients (8.9%) had an intramural coronary artery. Mean age at operation was 13.4±10.2 days (4 to 39 days) and mean body weight was 3.48±0.33 kg (2.88 to 3.88 kg). All patients except one were male. Eight patients had TGA/IVS and 4 patients had an aortic arch anomaly. Two patients (14.3%) had side-by-side great artery relation, of whom one had an intramural right coronary artery and the other had an intramural left anterior descending coronary artery. Twelve patients had anterior-posterior relation, all of whom had an intramural left coronary artery (LCA). The aortocoronary flap technique was used in coronary transfer in 8 patients, of whom one patient required a switch to the individual coronary button technique 2 days after operation because of myocardial ischemia. An individual coronary button implantation technique was adopted in 6, of whom 2 patients required left subclavian artery free graft to LCA during the same operation due to LCA injury during coronary button mobilization and LCA torsion. Results There was 1 operative death (7.1%), which occurred in the first patient in our series. This patient underwent an aortocoronary flap procedure for coronary transfer combining aortic arch repair. Overall operative mortality for 144 patients without an intramural coronary artery was 13.2% (19/144). There was no statistical difference in operative mortality between the patients with and without an intramural coronary artery (p>0.1). There was no late death. The mean follow-up duration was 52.1±43.0 months (0.5 to 132 months). One patient who had a subclavian artery free graft required LCA stenting 6.5 years after surgery for LCA anastomotic site stenosis. No other surviving patient needed any intervention for coronary problems. All patients had normal ventricular function at latest echocardiography and were in NYHA class 1. Conclusion The arterial switch operation in Transposition of Great Arteries or Double Outlet Right Ventricle patients with intramural coronary can be performed with low mortality; however, there is a high incidence of intraoperative or postoperative coronary problems, which can be managed with conversion to the individual coronary button technique and a bypass procedure using a left subclavian free graft. Both aortocoronary flap and individual coronary button implantation techniques for coronary transfer have excellent mid-term results.

Congenital left atrial appendage aneurysm diagnosed by fetal echocardiography

A newborn infant was evaluated because of a large cystic mass adjacent to the left atrium on prenatal ultrasound. The diagnosis was an aneurysm of the left atrial appendage. Most cases of this rare lesion are recognized between the 2nd and 4th decades of life. The present case, however, was detected on fetal echocardiography. The patient showed significant mitral regurgitation caused by the compression of the left atrioventricular groove. Simple aneurysmectomy without mitral valvuloplasty was sufficient to relieve significant mitral regurgitation in this case.

A Novel Technique of Supra-Annular Mitral Valve Replacement

We describe a new technique of mitral valve replacement in an 11.5-month-old, 5.5 kg baby whose native mitral annulus was only 14 mm. We successfully implanted a 16-mm mechanical valve in the supra-annular position by sewing it into a short polytetrafluoroethylene graft that was then sutured to the native annulus.

Outcome of Staged Repair of Tetralogy of Fallot with Pulmonary Atresia and a Ductus-dependent Pulmonary Circulation: Should Primary Repair Be Considered?

Background The tetralogy of Fallot (TOF) with pulmonary atresia (PA) and a ductus-dependent pulmonary circulation (no major aorto-pulmonary collateral arteries (MAPCAs)) has been treated with staged repair or primary repair depending on the preference of surgeons or institutions. We evaluated the 19-year outcome of staged repair for this anomaly to find out whether our surgical strategy should be changed. Materials and Methods Forty-four patients with TOF/PA with patent ductus arteriosus (PDA) who underwent staged repair from June 1991 to October 2010 were included in this retrospective study. The patients with MAPCAs were excluded. The average age at the first palliative shunt surgery was 40.8±67.5 days (range: 0~332 days). Thirty-one patients (31/44, 70%) were neonates. The average weight was 3.5±1.6 kg (range: 1.6~8.7 kg). A modified Blalock-Taussig (BT) shunt was performed in 38 patients, classic BT shunt in 4 patients, and central shunt in 2 patients. Six patients required concomitant procedures: pulmonary artery angioplasty was performed in 4 patients, pulmonary artery reconstruction in one patient, and re-implantation of the left pulmonary artery to the main pulmonary artery in one patient. Four patients required a second shunt operation before the definitive repair was performed. Thirty-three patients underwent definitive repair at 24.2±13.3 months (range: 7.3~68 months) after the first palliative operation. The average age at the time of definitive repair was 25.4±13.5 months (range: 7.6~68.6 months) and their average weight was 11.0±2.1 kg. For definitive repair, 3 types of right ventricular outflow procedures were used: extra-cardiac conduit was performed in 30 patients, trans-annular patch in 2 patients, and REV operation in 1 patient. One patient was lost to follow-up after hospital discharge. The mean follow-up duration for the rest of the patients was 72±37 months (range: 4~160 months). Results Ten patients (10/44, 22.7%) died before the definitive repair was performed. Four of them died during hospitalization after the shunt operation. Six deaths were thought to be shunt-related. The average time of shunt-related deaths after shunt procedures was 8.7 months (range: 2 days~25.3 months). There was no operative mortality after the definitive repair, but one patient died from dilated cardiomyopathy caused by myocarditis 8 years and 3 months after the definitive repair. Five-year and 10-year survival rates after the first palliative operation were 76.8% and 69.1%, respectively. Conclusion There was a high overall mortality rate in staged repair for the patients with TOF/PA with PDA. Majority of deaths occurred before the definitive repair was performed. Therefore, primary repair or early second stage definitive repair should be considered to enhance the survival rate for patients with TOF/PA with PDA.

A genome-wide association analysis identifies NMNAT2 and HCP5 as susceptibility loci for Kawasaki disease

Kawasaki disease (KD), a systemic vasculitis of infants and children, manifests as fever and mucocutaneous inflammation. Although its etiology is largely unknown, the epidemiological data suggest that genetic factors are important in KD susceptibility. To identify genetic variants influencing KD susceptibility, we performed a genome-wide association study (GWAS) and replication study using a total of 915 children with KD and 4553 controls in the Korean population. Six single-nucleotide polymorphisms (SNPs) in three loci were associated significantly with KD susceptibility (P<1.0 × 10−5), including the previously reported BLK locus (rs6993775, odds ratio (OR)=1.52, P=2.52 × 10−11). The other two loci were newly identified: NMNAT2 on chromosome 1q25.3 (rs2078087, OR=1.33, P=1.15 × 10−6) and the human leukocyte antigen (HLA) region on chromosome 6p21.3 (HLA-C, HLA-B, MICA and HCP5) (rs9380242, rs9378199, rs9266669 and rs6938467; OR=1.33–1.51, P=8.93 × 10−6 to 5.24 × 10−8). Additionally, SNP rs17280682 in NLRP14 was associated significantly with KD with a family history (18 cases vs 4553 controls, OR=6.76, P=5.46 × 10−6). These results provide new insights into the pathogenesis and pathophysiology of KD.