Use of the novel curved GOKU balloon catheter for acute-angled lesions in palliative surgery for congenital heart disease: comparison with a conventional straight balloon.

Obstruction develops commonly at the acute-angled portion of the vessels following palliative surgery, such as systemic-pulmonary shunt (SP shunt), right ventricle-to-pulmonary artery shunt (RV-PA shunt) in the Norwood-Sano procedure for hypoplastic left heart syndrome, and cavopulmonary (Glenn) anastomosis. Although balloon angioplasty is a treatment option, dilation with existing straight balloons is sometimes ineffective and technically complicated because of balloon slippage and target vessel distortion. In this study, we investigated the effectiveness of a curved GOKU balloon catheter for balloon angioplasty in postoperative acute-angled lesions associated with palliative surgery for congenital heart disease. We reviewed patients who underwent balloon angioplasty for angled lesions complicated by SP shunt, RV-PA shunt, or Glenn anastomosis, using the novel curved GOKU or a conventional balloon catheter, such as a Sterling balloon catheter. We evaluated patients' backgrounds, balloon specifications, target lesion anatomical features and angles, and short-term outcomes. We evaluated 45 procedures in 18 patients. A curved GOKU was used in 20 procedures, and a Sterling balloon in 25 procedures. The angulation of the lesions at maximum balloon inflation was significantly smaller using a curved GOKU vs a Sterling balloon [70-120 (mean ± standard deviation, 97 ± 40) degrees vs 110-180 (149 ± 46) degrees, respectively; p < 0.001], while the original angle was similar between the groups. Patients' short-term outcomes with the curved GOKU were excellent, with a significantly better percent increase in minimum lumen diameter of 0-220% (92% ± 66%) vs 0-46% (18% ± 15%) with the Sterling balloon (p < 00.1) and with less frequent balloon slippage. The curved GOKU was more effective in balloon angioplasty for acute-angled lesions compared with a conventional straight balloon, likely because of better conformability to the lesion angle and slip resistance.

Perforated posterior mitral leaflet aneurysm in an 8-month-old infant.

Mitral valve aneurysm not associated with infective endocarditis is rarely reported in children. We report a case of perforated posterior mitral leaflet aneurysm in an infant with reference to surgical and histopathological findings. Although its aetiology remains unclear, we suggest to include mitral valve aneurysm in differential diagnosis as a cause of mitral regurgitation in children.

Stent unzipping using an ultra-high-pressure balloon: in vitro and animal experiments.

As a child grows, limitations to the maximum dilatable stent diameter (MDD) will result in stenosis associated with size mismatch. If an implanted stent can be intentionally fractured along its length, a process called "unzipping," it may eventually be redilated to adult vessel size. Few studies have addressed how a stent can be unzipped using an ultra-high-pressure balloon (UHB) with the smallest balloon diameter. Eleven commercially available stents, three Liberté stents (LS), six genesis renal stents (GS), and two express vascular SD stents (ES), were tested for in vitro unzipping. In addition, using eight stents, we investigated whether a balloon that had unzipped the stent in vitro would work similarly in the vessel of a pig. Finally, we assessed the histological influence of the unzipped stent on the surrounding tissue. In a bench test, LS, GS, and ES were consistently unzipped by a balloon whose diameter was ≥ 1.5, 2.18, and 1.66 times that of MDD, respectively. In animal experiments, LS, GS, and ES were predictably unzipped with balloons of 1.50, 1.81, and 1.66 times the MDD, respectively. After unzipping, the unzipped strut did not damage the surrounding tissue histologically. Use of a UHB enabled unzipping of the stent with a balloon diameter less than two times the MDD enables implantation of a larger stent in the unzipped small stent by incremental steps.

Static balloon atrial septostomy for the purpose of left heart intervention in postoperative adult CHD.

Background and purposeStatic balloon atrial septostomy is a widely accepted intervention for children with CHD. Successful surgical palliation is creating increasing numbers of adult CHD patients who need subsequent left heart intervention requiring transseptal access. In these patients, the interatrial septum is usually thick and fibrotic because of a previous open heart surgery or catheter intervention, and conventional transseptal puncture may be unsuccessful. Static balloon atrial septostomy to access the left atrium may facilitate intervention via the interatrial septum in such situations. The purpose of this study was to investigate the usefulness and the safety of static balloon atrial septostomy, and the evolution of an iatrogenic atrial septal defect post procedure in adult CHD. METHODS: We retrospectively reviewed six procedures in five adults with CHD and collected demographic characteristics, details of the procedures, clinical outcome, and size changes of the iatrogenic atrial septal defect. RESULTS: The mean age at the time of the procedure was 35 years. The intended primary interventions were pulmonary vein isolation, stenting for pulmonary vein obstruction, and catheter ablation for focal atrial tachycardia. All static balloon atrial septostomies were effective, and the left heart interventions were successfully achieved via transseptal sheaths. There were no major complications associated with the static balloon atrial septostomy. There were no adverse clinical outcomes related to iatrogenic atrial septal defect, and the size of the defects regressed over time in all cases. CONCLUSIONS: Static balloon atrial septostomy can be a safe and useful technique in adult CHD patients needing left heart procedures. The thick interatrial septum found in postoperative patients may reduce the risk of persistent iatrogenic atrial septal defect.

[Tetralogy of Fallow with Total Anomalous Pulmonary Vein Return and Atrial Septal Defect;Successful Two-staged Surgical Management;Report of a Case].

A combination of tetralogy of Fallot( TOF) and total anomalous pulmonary venous return(TAPVR) is rare and results in chronic volume and pressure load of the right side of the heart and underfilling of the left heart. We report a successful 2-staged surgical correction of TOF associated with TAPVR and atrial septal defect. The patient was unsuitable for total primary intracardiac correction because the volume of the left ventricle was considered to be small. First, repair of anomalous pulmonary venous return and palliative right ventricle outflow tract reconstruction were simultaneously performed in 2 months of birth. One year after 1st operation, cardiac catheterization revealed that normalization of left ventricle volume, so 2nd operation was planned. Total correction of ventricular septal defect and right ventricle outflow reconstruction was performed and the patient was discharged on the 21st postoperative day with good hemodynamic status.

Usefulness of direct-conversion flat-panel detector system as a quality assurance tool for high-dose-rate 192Ir source.

The routine quality assurance (QA) procedure for a high-dose-rate (HDR) 192Ir radioactive source is an important task to provide appropriate brachytherapy. Traditionally, it has been difficult to obtain good quality images using the 192Ir source due to irradiation from the high-energy gamma rays. However, a direct-conversion flat-panel detector (d-FPD) has made it possible to confirm the localization and configuration of the 192Ir source. The purpose of the present study was to evaluate positional and temporal accuracy of the 192Ir source using a d-FPD system, and the usefulness of d-FPD as a QA tool. As a weekly verification of source positional accuracy test, we obtained 192Ir core imaging by single-shot radiography for three different positions (1300/1400/1500 mm) of a check ruler. To acquire images for measurement of the 192Ir source movement distance with varying interval steps (2.5/5.0/10.0 mm) and temporal accuracy, we used the high-speed image acquisition technique and digital subtraction. For accuracy of the 192Ir source dwell time, sequential images were obtained using various dwell times ranging from 0.5 to 30.0 sec, and the acquired number of image frames was assessed. Analysis of the data was performed using the measurement analysis function of the d-FPD system. Although there were slight weekly variations in source positional accuracy, the measured positional errors were less than 1.0 mm. For source temporal accuracy, the temporal errors were less than 1.0%, and the correlation between acquired frames and programmed time showed excellent linearity (R2 = 1). All 192Ir core images were acquired clearly without image halation, and the data were obtained quantitatively. All data were successfully stored in the picture archiving and communication system (PACS) for time-series analysis. The d-FPD is considered useful as the QA tool for the 192Ir source.

Monolayered mesenchymal stem cells repair scarred myocardium after myocardial infarction.

Mesenchymal stem cells are multipotent cells that can differentiate into cardiomyocytes and vascular endothelial cells. Here we show, using cell sheet technology, that monolayered mesenchymal stem cells have multipotent and self-propagating properties after transplantation into infarcted rat hearts. We cultured adipose tissue-derived mesenchymal stem cells characterized by flow cytometry using temperature-responsive culture dishes. Four weeks after coronary ligation, we transplanted the monolayered mesenchymal stem cells onto the scarred myocardium. After transplantation, the engrafted sheet gradually grew to form a thick stratum that included newly formed vessels, undifferentiated cells and few cardiomyocytes. The mesenchymal stem cell sheet also acted through paracrine pathways to trigger angiogenesis. Unlike a fibroblast cell sheet, the monolayered mesenchymal stem cells reversed wall thinning in the scar area and improved cardiac function in rats with myocardial infarction. Thus, transplantation of monolayered mesenchymal stem cells may be a new therapeutic strategy for cardiac tissue regeneration.

Risk Factors for Thromboembolic and Bleeding Events in Patients After the Fontan Operation (Insights from the National Database of Health Insurance Claims of Japan).

Risk stratification of thromboembolic events (TEs) and bleeding events is important for the appropriate selection of thromboprophylaxis in patients after the Fontan operation. Therefore, we clarified the risk factors for TEs and bleeding events in patients after the Fontan operation using the National Database of Health Insurance Claims and Specific Health Checkups of Japan. We conducted a retrospective cohort study including 2,515 patients who underwent the Fontan operation between June 2011 and September 2019. The end points were TEs and bleeding events within 1 year of the Fontan operation analysis. We analyzed the risk factors for these end points using a multivariate analysis. In total, 1,903 patients were included in the analysis. The median age at the time of the Fontan operation was 3 (1 to 22) years, and 1,067 patients (56%) were male. The incidence rates of TEs and bleeding events were 12% and 11%, respectively. Age (odds ratio [OR] 1.1 per 1 year older, p <0.05) was an independent risk factor for TEs. Thromboprophylaxis with aspirin after the Fontan operation significantly reduced TEs (OR 0.3, p <0.05). A history of postoperative hemorrhage (OR 1.5, p <0.05) and the use of a potassium channel blocker (OR 2.1, p <0.05) were independent risk factors for bleeding events. In conclusion, aspirin was found to reduce the risk of TEs within 1 year of the Fontan operation. The results of this study will be useful in selecting effective and safe thromboprophylaxis in patients after the Fontan operation.

[Accuracy of Classification of Cerebral Blood Flow Reduction Patterns Using Statistical Analysis Images Generated with Simulated SPECT Datasets via Deep Learning].

PURPOSE: The aim of this study was to evaluate the classification accuracy of specific blood flow reduction patterns in clinical images by deep learning using simulation data. METHODS: We obtained Z-score maps for 100 cases each of simulated Alzheimer's disease (AD), simulated dementia with Lewy bodies (DLB), and simulated normal cognition (NC) by performing statistical analysis of the simulation data that provided defects and healthy patient data. The clinical images were determined by reference to radiological reports, and Z-score maps of AD (n=33), DLB (n=20), and NC (n=28) were used. A network was constructed with reference to AlexNet, 4-fold cross-validation was performed using only simulation data, and classification accuracy was evaluated. We also trained the model using the simulation data and classified the clinical images. RESULTS: The accuracy rate of classification between simulations was 96.2% and that of the clinical images was 84.2%. CONCLUSION: Through deep learning using simulation data, clinical images may be classified with an accuracy of 84.2%.

Percutaneous pulmonary artery debanding.

BACKGROUND: There is a paucity of data on palliative or total percutaneous pulmonary artery debanding (p-debanding), particularly with use of a stent. METHODS: Twelve p-debandings in eight patients were included in this study. Age at pulmonary artery banding (PAB) ranged from 3 days to 1 year (median, 13 days), while p-debanding was performed at 2-157 (7) months. The body weight at the p-debanding ranged from 3.2 to 22.2 (7.3) kg. We chose the balloon diameter of 30-50% to the circumference of the band for palliative, and larger than 50% for total p-debanding, respectively. In either way, the balloon diameter did not exceed 1.5 times the reference vessel diameter. Stent was implanted for palliative p-debanding in 2 patients. RESULTS: 1. The circumference of the band ranged from 16 to 23 (20) mm, while the balloon diameter ranged from 20-60 (40)% to that, where larger than 50% was used for 2 procedures intended total p-debanding. 2. PAB diameter increased from 2.5-4.7 (3.0) mm to 2.8-9.5 (4.5) mm (p<0.01), however, there was no significant change in the diameter in 2 procedures. In one patient, p-debanding was the definitive treatment associated with spontaneous near closure of muscular ventricular septal defect, in another patient of congenitally corrected transposition of the great arteries, severely depressed left ventricular ejection fraction was recovered following p-debanding. 3. Arterial oxygen saturation (SaO2) increased from 64-97 (80)% to 66-95 (90)% (p<0.01), while in 10 procedures of 6 patients where the indication of p-debanding was hypoxia, SaO2 increased in 8 procedures. There was no significant pulmonary hypertension following p-debanding. CONCLUSION: Palliative or total p-debanding using balloon and/or stenting is generally feasible and effective. A balloon diameter 35-50% to the band circumference in palliative, and more than 50% in total p-debanding, while in either way less than 1.5 times the reference vessel diameter, is safe.

Transcatheter closure of perimembranous ventricular septal defects with Amplatzer® duct occluder I; The first case report in Japan.

We report the first case of transcatheter perimembranous ventricular septal defect (pmVSD) closure in Japan where none of existing devices for VSD closure has been approved. The pmVSD was successfully closed with first generation Amplatzer® duct occluder (ADO-I; St Jude Medical, St Paul, MN, USA). The procedure was performed under general anesthesia with transesophageal echocardiographic and fluoroscopic guidance. The left ventricular volume overload after the procedure was remarkably improved and no major complications occurred. ADO-I can be a safe and effective option for transcatheter pmVSD closure. The incidence of heart block may be less than reported with the original device. .

Transplantation of mesenchymal stem cells improves atrioventricular conduction in a rat model of complete atrioventricular block.

Mesenchymal stem cells (MSCs) are multipotent cells that differentiate into a variety of lineages including myocytes and vascular endothelial cells. However, little information is available regarding the therapeutic potential of MSCs in patients with atrioventricular block (AVB). We investigated whether local implantation of MSCs improves AV conduction in a rat model of complete AVB. Complete AVB was achieved by injection of ethanol into the AV nodal region of Lewis rats. Five days after ethanol injection, 2 x 10(6) of MSCs (MSC group) or vehicle (Control group) were injected into the AV nodal region. Animals were monitored by electrocardiograms for 14 days, and physiological and histological examinations were performed. The 1:1 AV conduction was recovered in 5 of 15 rats (33%) in the MSC group during the followup period, whereas no improvement was observed in the control group. MSC transplantation significantly decreased collagen deposition in the AV node, which was associated with a marked decrease in transforming growth factor-beta1 expression. In vitro experiments demonstrated that MSCs secreted a large amount of antifibrotic factors such as hepatocyte growth factor and interleukin-10, and MSC conditioned medium inhibited the growth of adult cardiac fibroblasts. In addition, local injection of MSC conditioned medium recovered AV conduction in 2 of 15 rats (13%). MSC transplantation improved AV conduction in a rat model of complete AVB, at least in part through antifibrotic paracrine effects.

Infusion of adrenomedullin improves acute myocarditis via attenuation of myocardial inflammation and edema.

OBJECTIVE: Our aim was to assess whether adrenomedullin (AM), a potent vasodilator peptide with a variety of cardioprotective effects, has a therapeutic potential for the treatment of acute myocarditis in a rat model. METHODS: One week after myosin injection, rats received a continuous infusion of AM or vehicle for 2 weeks, and pathological and physiological investigations were performed. RESULTS: AM treatment significantly reduced the infiltration of inflammatory cells in myocarditic hearts, and decreased the expressions of macrophage chemoattractant protein-1, matrix metalloproteinase-2 and transforming growth factor-beta. Myocardial edema indicated by increased heart weight to body weight ratio and wall thickness was attenuated by AM infusion (5.7+/-0.5 vs. 6.5+/-0.4 g/kg, and 1.9+/-0.3 vs. 2.8+/-0.5 mm, respectively). Infusion of AM significantly improved left ventricular maximum dP/dt and fractional shortening of myocarditic hearts (4203+/-640 vs. 3450+/-607 mm Hg/s, and 21.3+/-4.1 vs. 14.7+/-5.1%, respectively). CONCLUSION: Infusion of AM improved cardiac function and pathological findings in a rat model of acute myocarditis. Thus, infusion of AM may be a potent therapeutic strategy for acute myocarditis.

Percutaneous pulmonary debanding for an infant complicated by spontaneously closing muscular ventricular septal defect: A case report and in vitro study.

Pulmonary artery banding (PAB) is a standard operation for various congenital heart defects complicated by pulmonary hypertension (PH) and judged unsuitable for primary intracardiac repair. We report successful percutaneous pulmonary artery debanding in a baby complicated by muscular ventricular septal defect (VSD), that was initially large and multiple, but closed spontaneously later. The 5-month-old boy was referred to our hospital on day 3, diagnosed as having aortic coarctation (CoA), with multiple muscular VSDs and severe PH. On day 6, he underwent CoA repair and PAB using expanded polytetrafluoroethylene (ePTFE), while the muscular VSDs were left open. We planned percutaneous pulmonary debanding at the age of 5 months, as the muscular VSDs had become small. After dilation with a Mustang® (Boston Scientific, Marlborough, Massachusetts, United State) balloon (12 mm diameter) there was a persistent waist indicating a residual narrowing. Use of an extra-high pressure balloon, Conquest® (Medicon, Osaka, Japan) balloon of the same size, completely eliminated the waist. In in vitro experiments, the Mustang® partially tore the ePTFE, while a Conquest® of the same diameter completely opened the band. The mechanism of debanding was tearing of the ePTFE by the knot of the suture thread. Percutaneous pulmonary debanding to avoid unnecessary surgery is feasible in such a patient if the VSD becomes small. .

Performance evaluation of a direct-conversion flat-panel detector system in imaging and quality assurance for a high-dose-rate 192Ir source.

In high-dose-rate (HDR) brachytherapy, a direct-conversion flat-panel detector (d-FPD) clearly depicts a 192Ir source without image halation, even under the emission of high-energy gamma rays. However, it was unknown why iridium is visible when using a d-FPD. The purpose of this study was to clarify the reasons for visibility of the source core based on physical imaging characteristics, including the modulation transfer functions (MTF), noise power spectral (NPS), contrast transfer functions, and linearity of d-FPD to high-energy gamma rays. The acquired data included: x-rays, [X]; gamma rays, [γ]; dual rays (X + γ), [D], and subtracted data for depicting the source ([D] - [γ]). In the quality assurance (QA) test for the positional accuracy of a source core, the coordinates of each dwelling point were compared between the planned and actual source core positions using a CT/MR-compatible ovoid applicator and a Fletcher-Williamson applicator. The profile curves of [X] and ([D] - [γ]) matched well on MTF and NPS. The contrast resolutions of [D] and [X] were equivalent. A strongly positive linear correlation was found between the output data of [γ] and source strength (r 2 > 0.99). With regard to the accuracy of the source core position, the largest coordinate difference (3D distance) was noted at the maximum curvature of the CT/MR-compatible ovoid and Fletcher-Williamson applicators, showing 1.74 ± 0.02 mm and 1.01 ± 0.01 mm, respectively. A d-FPD system provides high-quality images of a source, even when high-energy gamma rays are emitted to the detector, and positional accuracy tests with clinical applicators are useful in identifying source positions (source movements) within the applicator for QA.

Transplantation of genetically engineered mesenchymal stem cells improves cardiac function in rats with myocardial infarction: benefit of a novel nonviral vector, cationized dextran.

It is expected that mesenchymal stem cells (MSCs) will be a cell source for cardiac reconstruction because of their differentiation potential and ability to supply growth factors. However, poor viability at the transplanted site often hinders the therapeutic potential of MSCs. Here, in a trial designed to address this problem, a non-viral carrier of cationized polysaccharide is introduced for genetic engineering of MSCs. Spermine-introduced dextran of cationized polysaccharide (spermine-dextran) was internalized into MSCs by way of a sugar-recognizable receptor to enhance the expression level of plasmid deoxyribonucleic acid (DNA). When genetically engineered by the spermine-dextran complex with plasmid DNA of adrenomedullin (AM), MSCs secreted a large amount of AM, an anti-apoptotic and angiogenic peptide. Transplantation of AM gene-engineered MSCs improved cardiac function after myocardial infarction significantly more than MSCs alone. Thus, this genetic engineering technology using the non-viral spermine-dextran is a promising strategy to improve MSC therapy for ischemic heart disease.

Transplantation of mesenchymal stem cells improves cardiac function in a rat model of dilated cardiomyopathy.

BACKGROUND: Pluripotent mesenchymal stem cells (MSCs) differentiate into a variety of cells, including cardiomyocytes and vascular endothelial cells. However, little information is available about the therapeutic potency of MSC transplantation in cases of dilated cardiomyopathy (DCM), an important cause of heart failure. METHODS AND RESULTS: We investigated whether transplanted MSCs induce myogenesis and angiogenesis and improve cardiac function in a rat model of DCM. MSCs were isolated from bone marrow aspirates of isogenic adult rats and expanded ex vivo. Cultured MSCs secreted large amounts of the angiogenic, antiapoptotic, and mitogenic factors vascular endothelial growth factor, hepatocyte growth factor, adrenomedullin, and insulin-like growth factor-1. Five weeks after immunization, MSCs or vehicle was injected into the myocardium. Some engrafted MSCs were positive for the cardiac markers desmin, cardiac troponin T, and connexin-43, whereas others formed vascular structures and were positive for von Willebrand factor or smooth muscle actin. Compared with vehicle injection, MSC transplantation significantly increased capillary density and decreased the collagen volume fraction in the myocardium, resulting in decreased left ventricular end-diastolic pressure (11+/-1 versus 16+/-1 mm Hg, P<0.05) and increased left ventricular maximum dP/dt (6767+/-323 versus 5138+/-280 mm Hg/s, P<0.05). CONCLUSIONS: MSC transplantation improved cardiac function in a rat model of DCM, possibly through induction of myogenesis and angiogenesis, as well as by inhibition of myocardial fibrosis. The beneficial effects of MSCs might be mediated not only by their differentiation into cardiomyocytes and vascular cells but also by their ability to supply large amounts of angiogenic, antiapoptotic, and mitogenic factors.

[Examination of retention index in brain tumor 201Tl scintigraphy using iNRT].

The retention index (R.I.) in Thalliun-201-chloride (201Tl-Cl) brain tumor single photon emission computed tomography (SPECT) imaging analysis is useful in assessing grades of malignancy. When the T/N ratio that influences the R.I. is calculated, it is ideal to draw an ROI on the same slices and coordinates of both early and delayed transaxial images. However, in many institutions, the image slice and ROI are determined manually by operators (i.e., by the conventional method). The Co-registration function within iNRT software enables an ROI to be automatically drawn. In this study, we obtained the R.I. from six brain tumor patients employing two different methods (i.e., Co-registration and the conventional method). Each R.I. was obtained from the same personal computer that was used to transfer the transaxial images. We then compared and evaluated the six R.I. values of seven operators. (2 radiologists and 5 radiological technologists). The results showed that the R.I. values did not differ significantly between the two methods, except in two cases. Furthermore, the coefficient of variation (CV) of the R.I. obtained from the Co-registration method was lower than the conventional method in all cases. The variations among operators were also smaller in the Co-registration method. These outcomes may have been due to the fact that in the conventional method it is difficult to identify the same slices of early and delayed images. Therefore, there were differences among operators in their ways of specifying positions of the ROI. This may have resulted in differences in the number of counts/pixel of the ROI. In conclusion, the R.I. obtained by using the Co-registration method would be more useful for improving diagnostic accuracy in (201)Tl-Cl brain tumor SPECT imaging than the conventional method.