Results of the multicenter early feasibility study (EFS) of the Renata Minima stent as treatment for branch pulmonary artery stenosis and coarctation of aorta in infants.

BACKGROUND: Stent implantation has become standard of care in older children and adults for treatment of branch pulmonary artery stenosis (BPAS) and coarctation aorta (CoAo). There are no stents approved or available for infants that have the potential to be dilated to adult diameters. The Minima stent was designed to fulfill this unmet need. METHODS: Multicenter, prospective, nonrandomized early feasibility study evaluating safety and effectiveness of the Minima stent for treatment of BPAS and CoAo. Primary endpoints included: (1) successful deployment across lesion, (2) stenosis relief defined by an increase in angiographic diameter of >50% and (3) freedom from stent explant, embolization or migration at 30 days and 6 months. RESULTS: Between 2/2022 and 5/2022, 10 pts underwent Minima stent implantation with a median age and weight of 9 months (4-43 months) and 7.6 kg (5.1-16.9 kg). Procedural success and predefined stenosis relief was achieved in all cases (CoAo [n = 4], BPAS [n = 6]). Adverse events occurred in 3 pts: transient diminished lower extremity pulse (n = 2), distal stent on-balloon displacement successfully managed in the catheterization suite (n = 1). There were no deaths or major adverse events. All patients were free from stent explant and migration at 30 days and 6 months with no evidence for significant restenosis at latest follow-up. CONCLUSIONS: Implantation of the Renata Minima stent was safe and effective for the treatment of BPAS and CoAo in this small cohort of infants and young children during early follow-up. Based on these early results, an expanded study with longer follow-up is warranted.

The impact of unilateral pulmonary artery stenosis on right ventricular to pulmonary arterial coupling in patients with transposition of the great arteries.

BACKGROUND: Unilateral pulmonary artery (PA) stenosis is common in the transposition of the great arteries (TGA) after arterial switch operation (ASO) but the effects on the right ventricle (RV) remain unclear. AIMS: To assess the effects of unilateral PA stenosis on RV afterload and function in pediatric patients with TGA-ASO. METHODS: In this retrospective study, eight TGA patients with unilateral PA stenosis underwent heart catheterization and cardiac magnetic resonance (CMR) imaging. RV pressures, RV afterload (arterial elastance [Ea]), PA compliance, RV contractility (end-systolic elastance [Ees]), RV-to-PA (RV-PA) coupling (Ees/Ea), and RV diastolic stiffness (end-diastolic elastance [Eed]) were analyzed and compared to normal values from the literature. RESULTS: In all TGA patients (mean age 12 ± 3 years), RV afterload (Ea) and RV pressures were increased whereas PA compliance was reduced. RV contractility (Ees) was decreased resulting in RV-PA uncoupling. RV diastolic stiffness (Eed) was increased. CMR-derived RV volumes, mass, and ejection fraction were preserved. CONCLUSION: Unilateral PA stenosis results in an increased RV afterload in TGA patients after ASO. RV remodeling and function remain within normal limits when analyzed by CMR but RV pressure-volume loop analysis shows impaired RV diastolic stiffness and RV contractility leading to RV-PA uncoupling.

Sarcoidosis-associated pulmonary hypertension due to pulmonary arteries stenosis - a case report.

BACKGROUND: Sarcoidosis-associated pulmonary hypertension (SAPH) is listed in Group 5 of the clinical classification of pulmonary hypertension, due to its complex and multifactorial pathophysiology. The most common cause of SAPH development is advanced lung fibrosis with the associated destruction of the vascular bed, and/or alveolar hypoxia. However, a substantial proportion of SAPH patients (up to 30%) do not have significant fibrosis on chest imaging. In such cases, the development of pulmonary hypertension may be due to the lesions directly affecting the pulmonary vasculature, such as granulomatous angiitis, pulmonary veno-occlusive disease, chronic thromboembolism or external compression of vessels by enlarged lymph nodes. Based on the case of a 69-year-old female who developed SAPH due to pulmonary arteries stenosis, diagnostic difficulties and therapeutic management are discussed. CASE PRESENTATION: The patient, non-smoking female, diagnosed with stage II sarcoidosis twelve years earlier, presented with progressive dyspnoea on exertion, dry cough, minor haemoptysis and increasing oedema of the lower limbs. Computed tomography pulmonary angiography (CTPA) showed complete occlusion of the right upper lobe artery and narrowing of the left lower lobe artery, with post-stenotic dilatation of the arteries of the basal segments. The vascular pathology was caused by adjacent, enlarged lymph nodes with calcifications and fibrotic tissue surrounding the vessels. Pulmonary artery thrombi were not found. The patient was treated with systemic corticosteroid therapy and subsequently with balloon pulmonary angioplasty. Partial improvement in clinical status and hemodynamic parameters has been achieved. CONCLUSIONS: An appropriate screening strategy is required for early detection of pulmonary hypertension in sarcoidosis patients. Once SAPH diagnosis is confirmed, it is crucial to determine the appropriate phenotype of pulmonary hypertension and provide the most effective treatment plan. Although determining SAPH phenotype is challenging, one should remember about the possibility of pulmonary arteries occlusion.

The effects of percutaneous branch pulmonary artery interventions on exercise capacity, lung perfusion, and right ventricular function in biventricular CHD: a systematic review.

BACKGROUND: Branch pulmonary artery stenosis is common after surgical repair in patients with biventricular CHD and often requires reinterventions. However, (long-term) effects of percutaneous branch pulmonary artery interventions on exercise capacity, right ventricular function, and lung perfusion remain unclear. This review describes the (long-term) effects of percutaneous branch pulmonary artery interventions on exercise capacity, right ventricular function, and lung perfusion following PRISMA guidelines. METHODS: We performed a systematic search in PubMed, Embase, and Cochrane including studies about right ventricular function, exercise capacity, and lung perfusion after percutaneous branch pulmonary artery interventions. Study selection, data extraction, and quality assessment were performed by two researchers independently. RESULTS: In total, 7 eligible studies with low (n = 2) and moderate (n = 5) risk of bias with in total 330 patients reported on right ventricular function (n = 1), exercise capacity (n = 2), and lung perfusion (n = 7). Exercise capacity and lung perfusion seem to improve after a percutaneous intervention for branch pulmonary artery stenosis. No conclusions about right ventricular function or remodelling, differences between balloon and stent angioplasty or specific CHD populations could be made. CONCLUSION: Although pulmonary artery interventions are frequently performed in biventricular CHD, data on relevant outcome parameters such as exercise capacity, lung perfusion, and right ventricular function are largely lacking. An increase in exercise capacity and improvement of lung perfusion to the affected lung has been described in case of mild to more severe pulmonary artery stenosis during relatively short follow-up. However, there is need for future studies to evaluate the effect of pulmonary artery interventions in various CHD populations.

[Pulmonary artery stenosis after single lung transplantation: a case report and literature review].

Objective: To summarize and analyze the clinical features, treatment, and prognosis of pulmonary artery stenosis post-lung transplantation. Methods: A 62-year-old male patient was admitted to the hospital with a cough and chest tightness of over a year's duration, which had worsened in the last two months, leading to the diagnosis of idiopathic pulmonary fibrosis. The clinical data were observed and reviewed post-left allograft single lung transplantation. Literature searches were conducted using the keywords "lung transplantation" "stenosis, pulmonary artery" and "postoperative complications" in CNKI, Wanfang Medical Network, and PubMed databases up to December 2022. Results: On January 26, 2022, a left allograft single lung transplantation was performed under general anesthesia. Postoperatively, extracorporeal membrane oxygenation and mechanical ventilation were successfully weaned off at 22 hours and 2 days, respectively, with transfer from the intensive care unit 12 days after surgery. PaO2 and PaCO2 were 50 mmHg and 40 mmHg after deoxygenation. Both pulmonary CT angiography and ventilatory-perfusion imaging indicated stenosis of the left pulmonary anastomosis. Balloon dilation and pulmonary artery stenting were performed, with PaO2 and PaCO2 improving to 87 mmHg and 42 mmHg, respectively. The patient was discharged 102 days post-surgery, and was followed up for 1 year, with a good prognosis. Additionally, 36 related articles were retrieved, encompassing 69 cases with a median age of 53 years (38.5-59.0 years). Of these, 27.54% (19/69) were diagnosed with idiopathic pulmonary fibrosis, 46.38% (32/69) underwent single lung transplantation, with the primary clinical symptom being hypoxemia in 71.01% (49/69) cases. Left pulmonary artery anastomotic stenosis was observed in 43.48% (30/69), with 65.22% (45/69) being diagnosed in the late postoperative period. Interventional therapy was performed to 44.93% (31/69), with a mortality rate of 21.74% (15/69). Conclusions: The primary clinical manifestation of post-lung transplantation pulmonary artery stenosis is hypoxemia and can be diagnosed by pulmonary artery CT angiography, transesophageal echocardiography, and pulmonary angiography. Early diagnosis can significantly reduce mortality, and interventional therapy is an effective treatment for severe pulmonary artery stenosis post-lung transplantation.

Adult-onset idiopathic peripheral pulmonary artery stenosis.

BACKGROUND: Peripheral pulmonary artery stenosis (PPS) refers to stenosis of the pulmonary artery from the trunk to the peripheral arteries. Although paediatric PPS is well described, the clinical characteristics of adult-onset idiopathic PPS have not been established. Our objectives in this study were to characterise the disease profile of adult-onset PPS. METHODS: We collected data in Japanese centres. This cohort included patients who underwent pulmonary angiography (PAG) and excluded patients with chronic thromboembolic pulmonary hypertension or Takayasu arteritis. Patient backgrounds, right heart catheterisation (RHC) findings, imaging findings and treatment profiles were collected. RESULTS: 44 patients (median (interquartile range) age 39 (29-57) years; 29 females (65.9%)) with PPS were enrolled from 20 centres. In PAG, stenosis of segmental and peripheral pulmonary arteries was observed in 41 (93.2%) and 36 patients (81.8%), respectively. 35 patients (79.5%) received medications approved for pulmonary arterial hypertension (PAH) and 22 patients (50.0%) received combination therapy. 25 patients (56.8%) underwent transcatheter pulmonary angioplasty. RHC data showed improvements in both mean pulmonary arterial pressure (44 versus 40 mmHg; p<0.001) and pulmonary vascular resistance (760 versus 514 dyn·s·cm-5; p<0.001) from baseline to final follow-up. The 3-, 5- and 10-year survival rates of patients with PPS were 97.5% (95% CI 83.5-99.6%), 89.0% (95% CI 68.9-96.4%) and 67.0% (95% CI 41.4-83.3%), respectively. CONCLUSIONS: In this study, patients with adult-onset idiopathic PPS presented with segmental and peripheral pulmonary artery stenosis. Although patients had severe pulmonary hypertension at baseline, they showed a favourable treatment response to PAH drugs combined with transcatheter pulmonary angioplasty.

Comparison of long-term survival after endovascular treatment versus medical therapy in patients with Takayasu's arteritis and pulmonary artery stenosis.

OBJECTIVES: There is currently no unanimous consensus on the treatment of Takayasu's arteritis (TAK) involving the pulmonary artery, and there are very few related studies that compare the efficacies of drug-based therapy and revascularization. This study aimed to compare the long-term survival outcomes after endovascular treatment and medical therapy in TAK patients with pulmonary artery stenosis (PAS) and pulmonary hypertension (PH). METHODS: A total of 129 TAK patients with PAS and PH (women, 101; men, 28; mean age, 40.5 years) were retrospectively enrolled in this study. Data on clinical features, treatment regimens, and mortality, were collected. Patients were categorised into medical treatment (n=75) and percutaneous transluminal pulmonary angioplasty (PTPA; n=54: 52 with PTPA and 2 with stent implantation) groups. The primary endpoint was cardiac mortality. The median follow-up time was 54 (40.5, 58.5) months. RESULTS: There were no significant differences in sex, age, comorbidities, disease activity, World Health Organization (WHO) function classification, and 6-min walk distance (6MWD) between the two groups at baseline. Compared with the conservative treatment group, cardiac mortality, WHO functional class, and 6MWD were significantly improved in the PTPA group (p=0.031, p<0.001, and p=0.004, respectively). CONCLUSIONS: Under basic medicine, PTPA therapy improves the long-term survival of TAK patients with PAS and PH compared to medical treatment alone. PTPA may be a promising modality for the TAK patients with PAS and PH.

Stenting of branch pulmonary artery stenosis in children: initial experience and mid-term follow-up of the pul-stent.

Not all stents are suitable for children. For instance, premounted stents can be used in infants and small children but cannot dilate with age to accommodate adult-sized pulmonary arteries. Conversely, the Pul-Stent adapts to somatic growth. Thus, our hospital implemented the Pul-Stent in pediatric patients with branch pulmonary artery stenosis. This study summarizes our initial experience with Pul-Stents in this patient population, including the efficacy and safety. We implanted 37 Pul-Stents in 35 patients between August 2014 and June 2015. The patients' mean age and weight at stent implantation were 6.7 ± 3.0 years and 20.9 ± 8.7 kg, respectively. Bench testing revealed that axial shortening of the Pul-Stent was minimal with further dilation, and the radial strength did not change. The stents were successfully deployed in all cases, except two with minor malpositioning. Primarily, 8-12 mm mounting balloons were used for the initial implantation, and a long sheath (8-10 F) was used for delivery. After stent implantation, the minimal lumen diameter in the stenosed segment increased by 50% in 97% (34/35) of patients. Furthermore, the pressure gradient across the stenosed segment decreased by 50% in 77% (23/30) of biventricular patients. One stent fracture and one stent restenosis were noted during the follow-up visits (mean follow-up time: 4.6 ± 1.7 years). Eighteen patients (51%) underwent repeat catheterization; ten had successful redilation. No aneurysms or stent fractures were observed. Our initial results indicate that the Pul-Stent is safe and effective in pediatric patients and can be further dilated over time to accommodate somatic growth. Moreover, the Pul-Stent has good compliance and adequate radial strength to treat pulmonary artery stenosis effectively.

Clinical characteristics of tetralogy of Fallot with left pulmonary artery acute angulation on computed tomography.

Left pulmonary artery (LPA) stenosis with acute angulation commonly necessitates surgical revision in the treatment of tetralogy of Fallot (TOF). We investigated the clinical characteristics of acute angulation of the LPA in patients with TOF via computed tomography (CT). Between 2011 and 2022, 160 patients were diagnosed with TOF using CT. After excluding 28 patients due to insufficient records or age, 132 patients were included in the present analysis. The patients were divided into two groups according to the presence or absence of acute angulation of the LPA: group I (TOF with an acute angle of the LPA, n = 53) and group II (TOF without an acute angle of the LPA, n = 79). We retrospectively collected clinical data from electronic medical records. T-tests were used to analyze continuous variables (i.e., age, sex, weight, right ventricular outflow tract [RVOT] pressure on echocardiography, and distance to bifurcation), and Fisher's exact and chi-square tests were used to analyze categorical data (i.e., presence of the right aortic arch, pulmonary arterial atresia/hypoplasia, atrial septal defect [ASD], patent ductus arteriosus [PDA], and pulmonary valve). The groups did not differ significantly in terms of sex, weight, presence of the right aortic arch, pulmonary arterial atresia/hypoplasia, ASD, or distance to the bifurcation. Moreover, there was no significant difference between the presence and absence of PDA (P = 0.057); however, patients in group I were significantly older (143.2 ± 97.8 days) than those in group II (91.1 ± 76.0 days, P = 0.002). Furthermore, RVOT pressure was significantly higher among patients in group I (45.1 ± 22.5 mmHg) than in group II (25.0 ± 12.4 mmHg, P < 0.001). In the current study, acute angulation of the LPA in patients with TOF, as observed on CT, was associated with older age and higher RVOT pressure on echocardiography.

Novel mutation in ELN gene causes cardiac abnormalities and inguinal hernia: case report.

BACKGROUND: Elastin-driven genetic diseases are a group of complex diseases driven by elastin protein insufficiency and dominant-negative production of aberrant protein, including supravalvular aortic stenosis (SVAS) and autosomal dominant cutis laxa. Here, a Chinese boy with a novel nonsense mutation in the ELN gene is reported. CASE PRESENTATION: We report a 1-year-old boy who presented with exercise intolerance, weight growth restriction with age, a 1-year history of heart murmur, and inguinal hernia. Gene sequencing revealed a novel nonsense mutation in the ELN gene (c.757 C > T (p.Gln253Ter), NM_000501.4). Due to severe branch pulmonary artery stenosis, the reconstruction of the branch pulmonary artery with autologous pericardium was performed. The inguinal hernia repair was performed 3 months postoperatively. After six months of outpatient follow-up, the child recovered well, gained weight with age, and had no special clinical symptoms. CONCLUSION: We identified a de novo nonsense mutation in the ELN gene leading to mild SVAS and severe branch pulmonary artery stenosis. A new phenotype of inguinal hernia was also needed to be considered for possible association with the ELN gene. Still, further confirmation will be necessary.

Association between RNF213 c.14576G>A Variant (rs112735431) and Peripheral Pulmonary Artery Stenosis in Moyamoya Disease.

BACKGROUND: Moyamoya disease (MMD) and peripheral pulmonary artery stenosis (PPAS) are relatively rare and demonstrate steno-occlusive vascular lesions in different organs. Genetic studies identified RNF213 polymorphism c.14576G>A (rs112735431) as a susceptibility variant for East Asian MMD. RNF213 polymorphism c.14576G>A is further associated with various vascular lesions of other organs. In this study, we aimed to clarify the incidence and clinical manifestations of PPAS in MMD patients and analyze the correlation between RNF213 genotype and PPAS. METHODS: This retrospective case-control study investigated the association between RNF213 polymorphism and PPAS in 306 MMD/quasi-MMD patients, reviewing the medical charts and imaging records of consecutive patients with MMD admitted from January 2015 to December 2020. RESULTS: PPAS was observed in 3 MMD/quasi-MMD patients (0.98%, 3/306). RNF213 polymorphism c.14576G>A was determined for all 306 MMD/quasi-MMD patients. The incidence of PPAS in RNF213-wildtype, RNF213-heterozygote, and RNF213-homozygote MMD/quasi-MMD patients was 0% (0/101), 0.5% (1/200), and 40% (2/5), respectively. The association between PPAS and homozygote polymorphism of RNF213 c.14576G>A was statistically significant in MMD/quasi-MMD patients (p = 0.0018). In all cases, pulmonary artery hypertension due to PPAS was evident during their childhood and young adolescent stages. Surgical indications for MMD were discouraged in 1 case due to her severe cardiopulmonary dysfunction. CONCLUSIONS: The homozygote variant of RNF213 polymorphism c.14576G>A can be a potential predisposing factor for PPAS in MMD/quasi-MMD patients. Despite the relatively rare entity, PPAS should be noted to determine surgical indications for MMD/quasi-MMD patients.

Echocardiographic Predictors of Ductal Tissue-Related Branch Pulmonary Artery Stenosis in Pulmonary Atresia.

Branch pulmonary artery (PA) stenosis due to ductus arteriosus (DA) tissue (DA-PS) contributes to the morbidity associated with pulmonary atresia (PAtr). We sought to identify preoperative echocardiographic features predictive of DA-PS. Patients consecutively encountered with PAtr and a DA-dependent pulmonary circulation at birth who underwent intervention in our program over a 5-year period were identified and records reviewed. Preoperative echocardiograms were reviewed to identify features that predicted postoperative DA-PS. Seventy patients with PAtr met inclusion criteria and 36 (51%) had DA-PS. At preoperative echocardiography, the proximal diameter of the PA ipsilateral to the DA was smaller in those with versus without DA-PS (Z-score - 4.8 ± 1.7 vs - 1.1 ± 1.7, respectively p < 0.001). PA origins could not be imaged on the same axial plane in 21/36 (58%) with versus 2/34 (6%) without DA-PS. Patients with DA-PS had an obtuse posterior angle of the PA bifurcation compared to those without (128 ± 17° and 87 ± 21°, p < 0.001), and a posterior angle of > 100° best predicted DA-PS with a sensitivity of 97% and specificity of 76%. An abnormal PA relationship and/or an obtuse posterior bifurcation angle had a sensitivity, specificity, positive and negative predictive value for DA-PS of 78%, 94%, 90% and 86%, respectively. Finally, DA insertion was into the ipsilateral PA in 26/36 (72%) of cases with DA-PS. A smaller proximal ipsilateral PA diameter, inability to image the PAs in the same plane, a posterior PA bifurcation angle of > 100°, and insertion of the DA in the ipsilateral PA demonstrated by echo are useful in identifying patients at risk for DA-PS.

Doppler Echocardiographic Indices Are Specific But Not Sensitive to Predict Pulmonary Artery Occlusion Pressure in Critically Ill Patients Under Mechanical Ventilation.

OBJECTIVES: The objective of this study was to prospectively evaluate the ability of transthoracic echocardiography to assess pulmonary artery occlusion pressure in mechanically ventilated critically ill patients. DESIGN: In a prospective observational study. SETTING: Amiens University Hospital Medical ICU. PATIENTS: Fifty-three mechanically ventilated patients in sinus rhythm admitted to our ICU. INTERVENTION: Transthoracic echocardiography was performed simultaneously to pulmonary artery catheter. MEASUREMENTS AND MAIN RESULTS: Transmitral early velocity wave recorded using pulsed wave Doppler (E), late transmitral velocity wave recorded using pulsed wave Doppler (A), and deceleration time of E wave were recorded using pulsed Doppler as well as early mitral annulus velocity wave recorded using tissue Doppler imaging (E'). Pulmonary artery occlusion pressure was measured simultaneously using pulmonary artery catheter. There was a significant correlation between pulmonary artery occlusion pressure and lateral ratio between E wave and E' (E/E' ratio) (r = 0.35; p < 0.01), ratio between E wave and A wave (E/A ratio) (r = 0.41; p < 0.002), and deceleration time of E wave (r = -0.34; p < 0.02). E/E' greater than 15 was predictive of pulmonary artery occlusion pressure greater than or equal to 18 mm Hg with a sensitivity of 25% and a specificity of 95%, whereas E/E' less than 7 was predictive of pulmonary artery occlusion pressure less than 18 mm Hg with a sensitivity of 32% and a specificity of 81%. E/A greater than 1.8 yielded a sensitivity of 44% and a specificity of 95% to predict pulmonary artery occlusion pressure greater than or equal to 18 mm Hg, whereas E/A less than 0.7 was predictive of pulmonary artery occlusion pressure less than 18 mm Hg with a sensitivity of 19% and a specificity of 94%. A similar predictive capacity was observed when the analysis was confined to patients with EF less than 50%. A large proportion of E/E' measurements 32 (60%) were situated between the two cut-off values obtained by the receiver operating characteristic curves: E/E' greater than 15 and E/E' less than 7. CONCLUSIONS: In mechanically ventilated critically ill patients, Doppler transthoracic echocardiography indices are highly specific but not sensitive to estimate pulmonary artery occlusion pressure.

Cutting balloon angioplasty on branch pulmonary artery stenosis in pediatric patients.

OBJECTIVES: To identify medium-term results following cutting balloon angioplasty (CBA) for branch pulmonary artery stenosis (PAS) and predictors of successful intervention. BACKGROUND: CBA has emerged as a successful alternative therapy for PAS resistant to conventional balloon angioplasty techniques but there is little information on medium and long-term outcomes. METHODS: This is a descriptive, single center, retrospective chart review of pediatric patients who underwent CBA for PAS at Arkansas Children's Hospital between May 2005 and December 2020. We reviewed demographics, procedural specifics, and 30-day complications. RESULTS: Forty-four patients underwent pulmonary artery CBA on 114 pulmonary artery segments through 126 catheterization cases, totaling 148 CBA events. Thirty-three individual pulmonary arteries underwent repeat intervention. Average minimal luminal diameter increase from pre-CBA to end of follow-up was 57% (CI, 38%-75%). Absence of Tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries (TOF/PA/MAPCAs) and the absence of Alagille Syndrome, Williams Syndrome, or Arterial Tortuosity Syndrome (ATS) were associated with increased odds of sustained success by 70% (CI, 0.11-0.79) and 91% (CI, 0.02-0.56), respectively. Increasing the cutting balloon diameter-to-minimal luminal diameter ratio by 0.5 increased odds of successful intervention by 2.37-fold (CI, 1.7-3.3). Seven patients had 30-day complications including one death. CONCLUSIONS: In the longest follow-up to date of children and adolescents who underwent CBA for branch PAS, we found that there was moderate medium-term success. Additionally, absence of TOF/PA/MAPCAs, absence of Alagille Syndrome, Williams Syndrome, or ATS, and high cutting balloon diameter-to-minimal luminal diameter ratio are predictors of sustained results.

Stent interventions for pulmonary artery stenosis improve bi-ventricular flow efficiency in a swine model.

BACKGROUND: Branch pulmonary artery (PA) stenosis (PAS) commonly occurs in patients with congenital heart disease (CHD). Prior studies have documented technical success and clinical outcomes of PA stent interventions for PAS but the impact of PA stent interventions on ventricular function is unknown. The objective of this study was to utilize 4D flow cardiovascular magnetic resonance (CMR) to better understand the impact of PAS and PA stenting on ventricular contraction and ventricular flow in a swine model of unilateral branch PA stenosis. METHODS: 18 swine (4 sham, 4 untreated left PAS, 10 PAS stent intervention) underwent right heart catheterization and CMR at 20 weeks age (55 kg). CMR included ventricular strain analysis and 4D flow CMR. RESULTS: 4D flow CMR measured inefficient right ventricular (RV) and left ventricular (LV) flow patterns in the PAS group (RV non-dimensional (n.d.) vorticity: sham 82 ± 47, PAS 120 ± 47; LV n.d. vorticity: sham 57 ± 5, PAS 78 ± 15 p < 0.01) despite the PAS group having normal heart rate, ejection fraction and end-diastolic volume. The intervention group demonstrated increased ejection fraction that resulted in more efficient ventricular flow compared to untreated PAS (RV n.d. vorticity: 59 ± 12 p < 0.01; LV n.d. vorticity: 41 ± 7 p < 0.001). CONCLUSION: These results describe previously unknown consequences of PAS on ventricular function in an animal model of unilateral PA stenosis and show that PA stent interventions improve ventricular flow efficiency. This study also highlights the sensitivity of 4D flow CMR biomarkers to detect earlier ventricular dysfunction assisting in identification of patients who may benefit from PAS interventions.

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.

Novel arterioplasty of severe left pulmonary artery stenosis using native main pulmonary artery.

There are multiple approaches described for the repair of stenosed branch pulmonary arteries. Regardless of the technique used, restenosis is common. We describe a case of severe left pulmonary artery stenosis repaired with a novel technique using the native main pulmonary artery which was transected and turned down to create a direct anastomosis with the left pulmonary artery. This tension-free tissue to tissue anastomosis resulted in hemodynamically gratifying results with the potential for growth.

Relationship between a Tracheal and Left Pulmonary Artery Stenosis Index and the Prognosis of Pulmonary Artery Sling with Tracheal Stenosis.

Pulmonary artery sling is a rare congenital pulmonary vascular malformation, often associated with tracheal or bronchial stenosis. Surgical treatment of pulmonary artery sling with tracheal stenosis (T) has a high risk of death and a relatively poor prognosis. This study explored the relationship between the T and left pulmonary artery stenosis (P) ratio and the effects of surgery for pulmonary artery sling with tracheal stenosis. Patients undergoing surgery for pulmonary artery sling in our center from January 2010 to December 2018 were retrospectively analyzed. Routine cardiac-enhanced computed tomography (CT) was performed preoperatively, and the P and T diameters were measured on the CT image. The T/P ratio was then calculated and analyzed. Thirty cases of pulmonary artery sling combined with tracheal stenosis were operated under cardiopulmonary bypass. The mean age at operation was 13.8 ± 13.6 months (1.2-57.1 months, Q1-Q3: 5-17 months), and the mean body weight was 8.8 ± 3.5 kg (3.8-17.3 kg, Q1-Q3: 5.8-11.5 kg). Twenty-three patients survived, and seven died, with an overall survival rate of 76.7%. Twenty-four patients underwent left pulmonary artery re-implantation, six patients underwent simultaneous left pulmonary artery re-implantation and slide tracheoplasty, and patients with intracardiac malformations (ventricular septal defect (n = 6) and atrial septal defect (n = 4)) underwent concurrent repair of the intracardiac defect. All cases had different degrees of tracheal stenosis, and the most narrowed trachea occurred with compression by the left pulmonary artery sling. The T/P ratio in the tracheoplasty group was significantly higher than that in the non-tracheoplasty group. The mortality rate in the T/P ≤ 1.15 group was significantly lower than that in the T/P > 1.15 group. Pulmonary artery sling treatment has a high risk of death. Left pulmonary artery re-implantation is an effective and safe surgical method for treating pulmonary artery sling, and slide tracheoplasty is an effective surgical method to correct tracheal stenosis. Children with T > 78.4% should receive active intervention for the tracheal stenosis, and these children have a considerable postoperative survival rate. The T/P ratio can be used to compare the relative superiority of the two compressions. A T/P ratio > 1.15 can be used as a reference index for intervention in tracheal stenosis and is a risk factor for postoperative death.

Fate of the Left Pulmonary Artery and Thoracic Aorta After Transcatheter Patent Ductus Arteriosus Closure in Low Birth Weight Premature Infants.

Transcatheter patent ductus arteriosus closure (TCPC) is an emerging treatment for low birth weight extremely premature neonates (EPNs). Left pulmonary artery (LPA) and descending aorta (DAO) obstruction are described device-related complications, however, data on mid- and long-term vascular outcomes are lacking. A retrospective analysis of EPNs who underwent successful TCPC at our institution from 03/2013 to 12/2018 was performed. Two-dimensional echocardiography and spectral Doppler velocities from various time points before and after TCPC were used to identify LPA and DAO flow disturbances. A total of 44 EPNs underwent successful TCPC at a median (range) procedural weight of 1150 g (755-2500 g). Thirty-two (73%) patients were closed with the AVP II and 12 (27%) with the Amplatzer Piccolo device. LPA and DAO velocities on average remained within normal limits and improved spontaneously in long-term follow up (26.1 months, range 1-75 months). One patient, who had concerning LPA flow characteristics immediately after device implant (peak velocity 2.6 m/s) developed progressive LPA stenosis requiring stent placement 3 months post-procedure. In the remaining infants, including 7 (16%) who developed LPA and 3 (7%) who developed DAO flow disturbances (range 2-2.4 m/s), all had progressive normalization of flow velocities over time. TCPC can be performed safely in EPNs with a low incidence of LPA and DAO obstruction. In the absence of significant progressive vascular obstruction in the early post-procedure period, mild increases in LPA and DAO flow velocities tend to improve spontaneously and normalize in long-term follow-up.

Hybrid Subxiphoid Perventricular Approach as an Alternative Access in Neonates and Small Children Undergoing Complex Congenital Heart Interventions.

The hybrid subxiphoid perventricular approach provides direct access through the heart and may alleviate the technical limitations of complex percutaneous interventions particularly in infants with low body weight. We present the outcomes from a tertiary cardiology center using this approach. We performed a retrospective review of all patients less than 15 kg who underwent a hybrid perventricular approach via a small subxiphoid incision. Medical records were reviewed to obtain clinical, demographic and outcome data. Seventeen patients underwent 18 hybrid perventricular procedures using a subxiphoid approach. Median age at time of procedure was 4.6 months (IQR = 1.6 to 18 months) and median weight was 6.2 kgs (IQR = 3.4 to 8.6 kgs). Six patients underwent hybrid pulmonary valve replacement (PVR), 5 patients underwent pulmonary outflow stenting, and 5 infants underwent hybrid ventricular septal defect (VSD) device closure. One patient with a single ventricle who did not tolerate a percutaneous approach underwent left pulmonary artery (LPA) stenting for severe LPA coarctation with subsequent right ventricular outflow tract (RVOT) stenting. One further patient underwent implantation of a larger diameter stent for pulmonary artery bifurcation stenosis. Procedure success rate was 89% with two of the VSD cases reverted to open surgical repair. There were no intra-procedural complications; however, one patient died within 72 h. Minor adverse events occurred in 2 patients including a wound infection in one patient with an immunodeficiency syndrome. Hybrid subxiphoid perventricular approach provides an excellent alternative access to the heart especially in low birth weight infants to prevent hemodynamic instability or in small children requiring large delivery sheaths.