Hyungtae Kim

Efficacy of veno-arterial extracorporeal membrane oxygenation in acute myocardial infarction with cardiogenic shock

AIM We analyzed the results of acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) necessitating extracorporeal membrane oxygenation (ECMO), and investigated for the associated risk factors for poor clinical outcomes. METHODS We retrospectively reviewed the medical records of 27 patients who required ECMO for AMI associated with CS between April 2006 and July 2010. Mean age was 63.7 ± 11.0 (range: 45-81) years, and there were 16 males (59.3%). RESULTS The mean duration of ECMO support was 30.2 ± 30.1 (range: 1-141)h. Cardiopulmonary resuscitations (CPR) were performed in 21 patients (77.8%) before ECMO initiation. Twenty-two patients (81.5%) were successfully weaned off ECMO, and 16 patients (59.3%) survived to discharge. The 30-day mortality was 37.0% (10/27 patients). Complications developed in 17 patients (63.0%: pneumonia in 10 patients, acute renal failure in 10 patients, massive bleeding in 4 patients, and thromboembolic event in 1 patient). The period between CPR initiation and ECMO commencement was a significant risk factor for ECMO weaning failure. High pre-ECMO serum lactate level was identified as a significant risk factor for poor survival on univariated and multivariated analysis. CONCLUSION ECMO support could improve survival in patients who suffer AMI associated with CS, and early ECMO initiation yields better outcomes (successful ECMO weaning).

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.

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.

Early and midterm outcomes of left pulmonary artery angioplasty using an anterior wall flap of the main pulmonary artery in tetralogy of Fallot repair.

OBJECTIVES Postoperative left pulmonary artery (LPA) kinking is problematic in repair of tetralogy of Fallot (TOF). We used angioplasty of the proximal LPA with an anterior wall flap of the main pulmonary artery (MPA) to prevent this problem. METHODS We have used an anterior wall of the MPA as a flap for LPA angioplasty in 42 patients with TOF and pulmonary stenosis (26 males and 16 females) since February 2007. During the same period, 116 patients underwent total repair of TOF with pulmonary stenosis. The median age was 7.1 months (range, 3-88.8), and the median weight was 8.4 kg (range, 5-27). The indications for LPA angioplasty were acute-angle proximal LPA in 17 (40.5%), proximal LPA stenosis in 6 (14.3%), acute-angle and stenotic proximal LPA in 18 (43%), and short and small distal MPA in 1 patient. The patches used for MPA and LPA reconstruction were glutaraldehyde-treated autologous pericardium in 34 and bovine pericardium in 8 patients. RESULTS No operative or late death occurred. The mean follow-up duration after surgery was 26.4 ± 18.6 months (range, 0.5-67). During the follow-up period, reoperation for LPA stenosis or kinking was not required in any patient; however, balloon angioplasty was performed with good results in 4 patients (9.5%). No postoperative kinking of the proximal LPA occurred. Echocardiography or computed tomography angiography at the recent follow-up visit demonstrated good branch pulmonary arteries in all patients. CONCLUSIONS Angioplasty of the proximal LPA using an anterior wall flap of the MPA in the patients with TOF and pulmonary stenosis is an effective method in the management of acute angle and/or stenosis of LPA without postoperative kinking.

A New Simplified Technique for Making Tricuspid Expanded Polytetrafluoroethylene Valved Conduit for Right Ventricular Outflow Reconstruction

Several methods of making expanded polytetrafluoroethylene valved conduit have been reported, but these techniques are complicated and less reproducible. We have developed a new simplified technique for making a tricuspid expanded polytetrafluoroethylene valved conduit for right ventricular outflow tract reconstruction and have been using this conduit for approximately 3 years with excellent results. Our technique is straightforward and reproducible, and the cusps in the conduit are durable due to the use of a specialized suturing technique.

Anterior Translocation of the Right Pulmonary Artery for Relief of Airway Compression in the Repair of Distal Aortopulmonary Window and Interrupted Aortic Arch

Airway compression by dilated right pulmonary artery (RPA) in infants with congenital heart disease can cause severe respiratory insufficiency and increase postoperative morbidity. Anterior aortopexy can be a good solution. However, in a case in which aortic arch repair is required, anterior aortopexy might not be effective or can be dangerous. Anterior translocation of the RPA can be a good option to avoid postoperative airway obstruction. We adopted this technique in a one-stage complete repair of distal aortopulmonary window, aortic origin of the RPA, interrupted aortic arch, and ventricular septal defect in a neonate with compression of both main bronchi. After 37 months of follow-up, no problem was encountered with her airway or RPA. We describe the technique used and the results obtained.

Temporary Fenestration Using Venoatrial Extracorporeal Membrane Oxygenation After the Fontan Operation

A 28.7-month-old male child who had undergone a Norwood operation and bidirectional cavopulmonary shunt at the age of 5 days and 6.6 months, respectively, underwent the extracardiac conduit Fontan operation. After the operation, high-volume resuscitation was needed, which led to high central venous pressure (CVP) and low arterial oxygen saturation. Venoatrial extracorporeal membrane oxygenation (ECMO) was initiated between the superior vena cava and the right atrium with one third of the expected normal cardiac output. This low-flow venoatrial ECMO immediately terminated the vicious cycle caused by high venous pressure in the Fontan circulation. He was weaned from ECMO and discharged home.

Combination Therapy of BRAF Inhibitors for Advanced Melanoma with BRAF V600 Mutation: A Systematic Review and Meta-Analysis

Abstract Background: Although BRAF inhibitors have been used to treat advanced melanoma with BRAF mutation, combination strategies are suggested due to acquired resistance to BRAF inhibitors. Objective: To assess the efficacy of BRAF inhibitor-based combination therapy for the treatment of advanced melanoma with BRAF mutation. Methods: We conducted a systematic review and meta-analysis of studies that compared BRAF inhibitor-based combination therapy with BRAF inhibitor monotherapy. We searched MEDLINE, EMBASE, the Cochrane Library and relevant conference proceedings. The random-effects inverse variance and Mantel–Haenszel methods were used to pool the results. Results: Four randomized controlled trials and one cohort study were identified. A combination therapy with BRAF inhibitors and MEK inhibitors was used in all studies. The combined hazard ratios of overall survival (OS) and progression-free survival (PFS) comparing combination therapy with monotherapy were 0.70 [95% confidence interval (CI) 0.62–0.78] and 0.59 (95% CI 0.55–0.63), respectively. The combined risk ratio of objective response rate (ORR) was 1.30 (95% CI 1.20–1.40), which meant more patients achieved complete/partial responses in combination therapy group than those in the monotherapy group. Conclusions: Combination therapy with BRAF inhibitors and MEK inhibitors significantly improved OS, PFS, and ORR in patients with advanced melanoma with BRAF mutation.