2024 Statement from Asia expert operators on transcatheter pulmonary valve replacement.

Transcatheter pulmonary valve replacement (TPVR), also known as percutaneous pulmonary valve implantation, refers to a minimally invasive technique that replaces the pulmonary valve by delivering an artificial pulmonary prosthesis through a catheter into the diseased pulmonary valve under the guidance of X-ray and/or echocardiogram while the heart is still beating not arrested. In recent years, TPVR has achieved remarkable progress in device development, evidence-based medicine proof and clinical experience. To update the knowledge of TPVR in a timely fashion, and according to the latest research and further facilitate the standardized and healthy development of TPVR in Asia, we have updated this consensus statement. After systematical review of the relevant literature with an in-depth analysis of eight main issues, we finally established eight core viewpoints, including indication recommendation, device selection, perioperative evaluation, procedure precautions, and prevention and treatment of complications.

Repair of iatrogenic left pulmonary artery to left atrial appendage fistula using a covered CP stent: a case report.

We report a case of iatrogenic left pulmonary artery-left atrial appendage fistula following percutaneous transluminal angioplasty for residual pulmonary artery stenosis in an 11-year-old boy. This rare complication could have been predicted by understanding the anatomical relationship of these structures. In this study, simulation using three-dimensional printing greatly contributed to successful stent placement.

Epidemiologic study of patients after Fontan operation based on Medical Aid Program for Chronic Pediatric Diseases of Specified Categories cohort.

Nationwide registry data of patients with single-ventricle physiology have been rarely reported. The Medical Aid Program for Chronic Pediatric Diseases of Specified Categories (Japan) has contributed to the financial support of medical expense for patients younger than 20 years with chronic paediatric disease, and almost all children in Japan who require disease-specific treatment voluntarily apply to this programme. The epidemiology and medium- to long-term outcome of patients following a Fontan procedure were investigated using the database. The usefulness of this epidemiologic investigation in identifying real-world objectives and clinical applications was also examined. A total of 2862 patients who underwent a Fontan operation were identified from 18,589 patients with chronic heart disease registered to the medical aid programme. The details of symptoms, treatment, and somatic growth were evaluated, from which we were able to clarify the nationwide data regarding the current status of post-Fontan patients younger than 20 years. This study elucidated the current status of post-Fontan patients under 20 years of age in Japan. Data analysis of the Medical Aid Program for Chronic Pediatric Diseases of Specified Categories cohort provided useful information towards understanding the comprehensive status of patients with chronic heart disease and contributed to improved disease management.

Practice and Safety of Static Balloon Atrial Septostomy Based on a Nationwide Registry Data.

BACKGROUND: Balloon atrial septostomy (BAS) is an essential catheterization procedure for congenital heart lesions. Recently, a balloon catheter for static BAS was approved for the first time in Japan as an alternative to the conventional pull-through BAS. Despite the expected increase in the use of static BAS, reports on its safety are scarce worldwide.Methods and Results: Data on static and pull-through BAS registered in a national registry between 2016 and 2018 were collected. During the study period, 247 sessions of static BAS and 588 sessions of pull-through BAS were performed on a total of 674 patients. Patients who underwent static BAS were older (P<0.001). The incidence of serious adverse events (4.3% vs. 0.9%, P=0.03) and the overall incidence of adverse events (8.1% vs. 3.2%, P=0.03) were higher in static BAS than in pull-through BAS. Among patients who underwent static BAS, the risk factor for adverse events was a body weight <3 kg at the time of the procedure (odds ratio: 4.3 [confidence interval: 1.7-11], P=0.003). CONCLUSIONS: This nationwide study revealed differences in patient background between static and pull-through BAS, as well as a higher incidence of adverse events related to static BAS. Patients weighing <3 kg are at high risk for adverse events after static BAS and may require surgical and circulatory support backup.

"Half-uncovered technique" to secure larger stents for postoperative pulmonary vein stenosis.

Although larger stent placement could be effective for pulmonary vein stenosis, stents extrusion tends to occur due to caliber narrowing, small landing area, and the slippery nature. We placed stents with diameter ≧8 mm for four stenotic lesions using the "half-uncovered technique". All stents were precisely placed and successfully resolved the stenosis. This technique allows us to avoid extrusion and to perform safe and effective dilatation when placing larger stents for pulmonary vein stenosis.

Stent Implantation for Congenital Heart Diseases in Japan　- Comprehensive Analysis From the Japanese Society of Congenital Interventional Cardiology Registry.

BACKGROUND: Stent implantation for vascular stenosis associated with congenital heart diseases is commonly performed as an off-label procedure in Japan because there is no officially approved stent for any congenital heart disease.Methods and Results:We analyzed data from the Japanese Society of Congenital Interventional Cardiology Registry collected from January 2016 to December 2018. Patients who underwent stent implantation were enrolled in the present analysis. During the study period, there were 470 procedures, 443 sessions, and 391 cases. Of 443 sessions, 427 (96.4%) succeeded procedurally. There were no differences in the procedural success rates among age groups. In all, 416 sessions (367 patients; 94%) resulted in survival to 30 days after catheter intervention. Of 392 admissions, 357 patients (91%) survived to discharge. Only 4 deaths were directly related to stent implantation. Some in-hospital complications were observed during 55 of 443 sessions. Both hospital deaths and serious complications were significantly more frequent in the group with various preoperative risk factors. CONCLUSIONS: Although not officially approved for congenital heart diseases in Japan, stent implantation in congenital heart diseases has been widely and routinely performed for many years with safety and efficacy. The aim of stenting was variable and broad because of many different applications and morphological variations. These data may facilitate approval of such an important device in Japan.

Clinical trial of the CP stent for pulmonary artery stenosis: the first investigator-initiated clinical trial for pediatric interventional cardiology in Japan.

Stenting is an important treatment option for pulmonary artery stenosis (PS) associated with congenital heart disease (CHD). However, no stent has been approved for this indication in Japan, despite negotiation between academia and the regulatory bodies for longer than 20 years. To evaluate efficacy and safety of the CP stent, we performed the first investigator-initiated clinical trial for pediatric interventional cardiology in Japan. This trial was designed as a single-arm, prospective, clinical trial. Patients who had postoperative PS associated with CHD were included. Stenting was attempted in 24 cases and succeeded in 22 cases. The median age of the patients was 11 years (3-36 years) and weight was 38 kg (12-69 kg), while follow-up for 12 months was completed. In all 22 cases, stenting was successful, with a 50% increase in the minimum lumen diameter (MLD) in 86.4% of patients (90% confidence interval, 68.4-96.2%). The mean percent change in MLD was 119.3 ± 52.5%. In two-ventricle repair, the mean percent change in systolic right ventricular/aortic pressure was - 8.5 ± 16.1%, while that of pressure gradient was - 55.9 ± 41.7%. In single-ventricle repair, the percent change in the mean pressure gradient was - 100.0 ± 0%, while that of SaO2 was 1.4 ± 1.7%. No serious adverse events or significant restenosis was reported. The CP stent is highly effective and safe for PS associated with CHD. This study has significant importance in not only scientific but also social considerations.

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.

Partnership Between Japan and the United States for Early Development of Pediatric Medical Devices　- Harmonization By Doing for Children.

BACKGROUND: The Harmonization By Doing (HBD) program was established in 2003 as a partnership among stakeholders of academia, industry and regulatory agencies in Japan and the United States, with a primary focus on streamlining processes of global medical device development for cardiovascular medical devices. While HBD has traditionally focused on development of devices intended to treat conditions prevalent in adults, in 2016, HBD established the "HBD-for-Children" program, which focuses on the development of pediatric devices as the development of medical devices for pediatric use lags behind that of medical devices for adults in both countries.Methods and Results:Activities of the program have included: (1) conducting a survey with industry to better understand the challenges that constrain the development of pediatric medical devices; (2) categorizing pediatric medical devices into five categories based on global availability and exploring concrete solutions for the early application and regulatory approval in both geographies; and (3) facilitating global clinical trials of pediatric medical devices in both countries. CONCLUSIONS: The establishment of the HBD-for-Children program is significant because it represents a global initiative for the introduction of pediatric medical devices for patients in a timely manner. Through the program, academia, industry and regulatory agencies can work together to facilitate innovative pediatric device development from a multi-stakeholder perspective. This activity could also encourage industry partners to pursue the development of pediatric medical devices.

Risk Factors and Predictors of Cardiac Erosion Discovered from 12 Japanese Patients Who Developed Erosion After Atrial Septal Defect Closure Using Amplatzer Septal Occluder.

Cardiac erosion is a rare serious complication following Amplatzer septal occluder (ASO) placement for atrial septal defect. Although multiple risk factors have been found, a useful predictor to prevent it has not been established yet. In 12 patients who developed erosion between 2005 and 2016 in Japan, we retrospectively observed patients' characteristics and transesophageal echocardiography findings immediately before and after ASO placement and at erosion onset. We compared risk factors of erosion, including absent aortic rim, device size/body weight ratio, device shape, or Valsalva sinus wall deformation pressed by either disk-edge, the maximum depth of which from the standard curve of the Valsalva wall was defined as Dent, between the 12 patients and 95 patients with Valsalva sinus wall deformation immediately after placement who did not develop erosion for 5 ± 3 years. Of the 12 patients, nine developed pericardial effusion with eight cardiac tamponade and three aorta-atrium fistula; all were surgically rescued. Surgical findings revealed that erosion in all patients occurred at the right and/or left atrial roof beside the Valsalva in the non-coronary cusp on which the disk-edge seemed to be pressing. The mean Dent immediately after the placement in patients with erosion was significantly deeper than without (2.48 ± 0.32 vs. 1.28 ± 0.38; p < 0.001). There were no differences in the other risk factors between the two groups. Dent is believed to be a useful indicator of erosion development after ASO placement. If Dent is > 2.0 mm, it is desirable to change the size or to replace the device.

Successful everolimus-eluting stent implantation into the left main trunk stenosis in the anomalous coronary artery after neo-aortic valve replacement in a 6-year-old boy.

CHDs occasionally have coronary complications; however, stent implantation is technically difficult in small children. We reported a successful drug-eluting stent implantation into the congenital anomalous coronary artery in a 6-year-old boy. This treatment is useful for rescuing coronary stenosis, and dual antiplatelet therapy is important to prevent stent restenosis.

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.

Successful simultaneous transcatheter treatment for a secundum atrial septal defect complicated by valvular pulmonary stenosis in an infant.

Only few reports have described successful simultaneous transcatheter intervention for CHD in infants. We present an infant with secundum atrial septal defect complicated by valvular pulmonary stenosis. Percutaneous transcatheter pulmonary valvuloplasty was performed first, followed by transcatheter closure of the secundum atrial septal defect uneventfully. Simultaneous transcatheter correction is an effective therapeutic option even in infants.

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.

Transcatheter occlusion of gigantic persistent ductus arteriosus (PDA) using a custom-made persistent ductus arteriosus occluder.

We reported transcatheter closure of gigantic persistent ductus arteriosus (PDA) complicated by severe pulmonary hypertension (PH) using a custom-made PDA occluder. A 19-year-old lady weighing 45 kg visited to our Heart Saving Project in Mongolia with a chief complaint of shortness of breath. Contrast CT scan showed ellipsoidal section of PDA whose long axis being 28 mm, and the short axis of 21 mm. A custom-made PDA occluder, whose retention skirt, the aortic side, and the pulmonic side diameter of the body were 54, 36, 34 mm, respectively, was successfully deployed using 14-Fr sheath. Pulmonary pressure decreased around a half compared to before closure. A custom-made duct occluder could be a reasonable and cost-effective choice for transcatheter closure of gigantic PDA complicated by severe PH. © 2015 Wiley Periodicals, Inc.

Morphological and Hemodynamic Effectiveness of Stenting for Pulmonary Artery Stenosis　- Subanalysis of JPIC Stent Survey.

BACKGROUND: Percutaneous stenting for branch pulmonary artery stenosis is an established interventional choice in congenital heart disease. The apparent morphologic change in the vessel diameter often differs from the hemodynamic result. METHODS AND RESULTS: We performed a subanalysis of the data from the Japanese Society of Pediatric Interventional Cardiology (JPIC) stent survey. The factors that may have contributed to morphologic effectiveness included reference vessel diameter (RVD), minimum lumen diameter (MLD) and percent diameter stenosis (%DS) and the relation between morphologic and hemodynamic effectiveness was evaluated in 206 lesions treated with stenting. We defined a "50% increase in MLD" as "morphologically effective", while "achievement of either a reduced pressure gradient greater than 50% or an increase of perfusion ratio to the affected side to the contralateral side greater than 20%" as "hemodynamically effective". Morphologic effectiveness was achieved in 84% of patients. Before stenting, %DS was significantly larger, while RVD was smaller in the "effective" group than in the "non-effective" group. The cutoff value for effective stenting was 51% for %DS and 14.7 mm for RVD before stenting. Hemodynamic effectiveness was obtained more often in the "morphologic effective" group. CONCLUSIONS: RVD and %DS were the 2 main contributors to acute morphologic effectiveness. There was a significant relationship between "morphologic effectiveness" and "hemodynamic effectiveness", judging from increased perfusion of the affected lung and/or decreased pressure gradient. (Circ J 2016; 80: 1852-1856).

Current trends in stenting for aortic coarctation in Japan: Subanalysis of Japanese Society of Pediatric Interventional Cardiology (JPIC) stent survey.

BACKGROUND: Stenting for aortic coarctation (CoA) has been accepted as an alternative to surgery for adolescents and adults, but only a few case have been reported in Japan. The purpose of this study was to provide a detailed review of Japanese national data on stenting of CoA. METHODS: In a subanalysis of the data of the Japanese Society of Pediatric Interventional Cardiology (JPIC), we identified 35 patients with CoA who underwent stenting. We analyzed procedural characteristics including factors that may have contributed to hemodynamic effectiveness, and we compared these parameters between the patients under and over 15 years of age. RESULTS: The mean ratio of balloon diameter/minimum lumen diameter (MLD) before stenting was 1.7 (range, 1.2-4.0), and the mean difference between the balloon diameter and the reference vessel diameter was -0.7 mm (range, -5.0 to +3.0 mm). %MLD/balloon diameter, which was defined as [(balloon diameter - MLD after dilation)/balloon diameter] × 100 predicted achievement of <10 mmHg pressure gradient after stenting. The sensitivity and the specificity of its cut-off of 7% were 93% and 47% (AUC, 0.7), respectively. There was no statistical difference between the two age groups under and over 15 years of age, in terms of selection criteria of stent size, balloon type used for deployment and immediate angiographic and hemodynamic result. CONCLUSIONS: Stenting for CoA was clinically effective with few complications in Japan, even in patients not fully grown.

Impact of novel balloon catheter on static balloon atrial septostomy with double balloon technique in infants with congenital heart disease.

BACKGROUND: The aim of this study was to investigate the feasibility of static balloon atrial septostomy (BAS) with the double balloon technique for infants. TMP PED balloon catheter, newly designed for static BAS in small children, was used in 3 infants. The balloon catheter has a low profile, short and round shoulder, and smooth deflation without slippage. METHODS AND RESULTS: Three infants (transposition of the great arteries, n=2; pulmonary atresia with intact ventricular septum, n=1) underwent static BAS with double balloon for restrictive interatrial communication between December 2014 and March 2015. Hemodynamic and echocardiographic assessment was done before and after the procedure. Pressure gradient between left and right atrium decreased from 6, 7 and 9 mmHg to 2, 2 and 1 mmHg, respectively. Oxygen saturation in systemic artery increased from 72, 68 and 73% to 78, 70 and 79%, respectively. Maximum defect diameter increased from 3.5, 3.0 and 3.3 mm to 6.6×5.2, 9.0×6.2 and 8.1×5.1 mm, respectively. No complication was recorded. CONCLUSIONS: Static BAS with double balloon technique using the novel TMP PED balloon catheter was safe and effective in producing sufficient interatrial communication for 8-20 weeks in infants. Static BAS is a promising procedure to create interatrial communication in infants.

Percutaneous catheter aspiration thrombectomy for the occluded stents of pulmonary artery in children with single ventricle physiology after fontan surgery.

Successful surgical palliation with the Fontan procedure allows survival into adulthood for many patients born with single ventricle (SV) physiology, but the limited studies reported incidence of perioperative and long-term complications including thromboembolic events. Chronic pulmonary embolism is a common complication in patients with Fontan circulation, and may have serious consequences. Percutaneous intervention may be less invasive option for such a high-risk population than surgery is. We described two patients who developed complete thrombosis of the left pulmonary artery following catheter placement of a stent in this vessel shortly after Fontan surgery. Percutaneous catheter aspiration thrombectomy was successfully performed. Percutaneous catheter aspiration thrombectomy may be considered as a viable option in acute thrombus in children with SV physiology after Fontan surgery.

Novel curved balloon catheter for dilating postoperative angled lesions associated with congenital heart disease.

OBJECTIVES: This study aimed to analyze the surface stress generated by a novel curved balloon and assess its efficacy for treating angular lesions associated with congenital heart disease. BACKGROUND: Obstructions at the anastomosis of aortopulmonary shunts and cavopulmonary connections may occur postoperatively. Catheter interventions are often performed for such lesions; however, acute angulation may cause balloon slippage or inappropriate stress on the vessel wall. METHODS: We dilated the curved balloon in a curved vessel model and measured the resultant wall stress and its distribution. Clinical evaluations were performed using this balloon in angled lesions. RESULTS: In the curved vessel model, curved balloons generated uniform stress on the lesser and greater curvatures (curved type, lesser/greater = 0.343 MPa/0.327 MPa; P = 0.61), whereas straight balloons caused disproportionate stress (straight type, lesser/greater = 0.358 MPa/0.254 MPa; P = 0.19). However, the difference in average stress was not statistically significant. Furthermore, the stress was uniform along the entire length of the curved balloon, but differed between the mid and end portions of the straight balloon. Curved balloon dilations were performed for 10 lesions in 7 patients. The curved balloon conformed well to the angulated lesion without slipping. The median percent change in the minimal lumen diameter (MLD) was 64% (range, 0-206%). In 5 lesions, MLD increased by ≥50%. Oxygen saturation increased by 5% (0-9%). CONCLUSIONS: Although further clinical evaluation is necessary, this novel curved balloon may be a reasonable alternative in angled lesions, providing better conformability and preventing excessive stress to the vessel wall adjacent to the stenosis.