Troubled Judging of Bronchus Compression Due to Contrast-Filled Balloon in Three-Dimensional Rotational Angiography.

Three-dimensional rotational angiography (3DRA) is a suitable technique to detect the risk of left main bronchus (LMB) compression during left pulmonary artery (LPA) stenting in partial cavopulmonary connection and total cavopulmonary connection (TCPC). We report on a case of a 4-year-old boy with hypoplastic left heart syndrome and TCPC in which 3DRA and bronchoscopy gave conflicting information on airway patency during balloon interrogation. The balloon with high contrast concentration created a severe artifact impeding visibility of the LMB. Simultaneous flexible bronchoscopy revealed an unobstructed LMB. Repeated 3DRAs with lower contrast concentration had no artifact and showed a patent airway in accordance with the bronchoscopy. Conventional LPA stenting was performed without indication for stent ovalization. The benefit of low contrast concentration in the interrogation balloon was demonstrated in a second case of an 11-year-old boy with TCPC. The margins of the LPA and LMB were clearly visible without blank-out artifact. Oval stent procedure was necessary to prevent LMB compression. When 3DRA is used for vessel-airway interrogation, the balloon contrast concentration should be low in order to avoid artifacts. When in doubt, simultaneous flexible bronchoscopy can overcome the dilemma in airway judgment.

Partially open stent after balloon catheter iatrogenic perforation. How to solve this complication using a novel technique? The Mij-Her technique.

Complications related to pulmonary artery stenting are potentially life-threatening. We reported a novel technique of how to achieve the introduction of a partial dilated stent into a long sheath using a snare in the event of a iatrogenic perforation of a balloon catheter.There are no publications of similar techniques describing successful resolution of this type of complication.

Pulmonary artery and lung parenchymal growth following early versus delayed stent interventions in a swine pulmonary artery stenosis model.

OBJECTIVES: Compare lung parenchymal and pulmonary artery (PA) growth and hemodynamics following early and delayed PA stent interventions for treatment of unilateral branch PA stenosis (PAS) in swine. BACKGROUND: How the pulmonary circulation remodels in response to different durations of hypoperfusion and how much growth and function can be recovered with catheter directed interventions at differing time periods of lung development is not understood. METHODS: A total of 18 swine were assigned to four groups: Sham (n = 4), untreated left PAS (LPAS) (n = 4), early intervention (EI) (n = 5), and delayed intervention (DI) (n = 5). EI had left pulmonary artery (LPA) stenting at 5 weeks (6 kg) with redilation at 10 weeks. DI had stenting at 10 weeks. All underwent right heart catheterization, computed tomography, magnetic resonance imaging, and histology at 20 weeks (55 kg). RESULTS: EI decreased the extent of histologic changes in the left lung as DI had marked alveolar septal and bronchovascular abnormalities (p = .05 and p < .05 vs. sham) that were less prevalent in EI. EI also increased left lung volumes and alveolar counts compared to DI. EI and DI equally restored LPA pulsatility, R heart pressures, and distal LPA growth. EI and DI improved, but did not normalize LPA stenosis diameter (LPA/DAo ratio: Sham 1.27 ± 0.11 mm/mm, DI 0.88 ± 0.10 mm/mm, EI 1.01 ± 0.09 mm/mm) and pulmonary blood flow distributions (LPA-flow%: Sham 52 ± 5%, LPAS 7 ± 2%, DI 44 ± 3%, EI 40 ± 2%). CONCLUSION: In this surgically created PAS model, EI was associated with improved lung parenchymal development compared to DI. Longer durations of L lung hypoperfusion did not detrimentally affect PA growth and R heart hemodynamics. Functional and anatomical discrepancies persist despite successful stent interventions that warrant additional investigation.

Consequences of an early catheter-based intervention on pulmonary artery growth and right ventricular myocardial function in a pig model of pulmonary artery stenosis.

OBJECTIVE: To determine the consequences of an early catheter-based intervention on pulmonary artery (PA) growth and right ventricular (RV) myocardial function in an animal model of branch PA stenosis. BACKGROUND: Acute results and safety profiles of deliberate stent fracture within the pulmonary vasculature have been demonstrated. The long-term impact of early stent intervention and deliberate stent fracture on PA growth and myocardial function is not understood. METHODS: Implantation of small diameter stents was performed in a pig model of left PA stenosis at 6 weeks (10 kg) followed by dilations at 10 (35 kg) and 18 weeks (65 kg) with intent to fracture and implant large diameter stents. Hemodynamics, RV contractility, and 2D/3D angiography were performed with each intervention. The heart and pulmonary vasculature were histologically assessed. RESULTS: Stent fracture occurred in 9/12 and implantation of large diameter stents was successful in 10/12 animals with no PA aneurysms or dissections. The final stented PA segment and distal left PA branch origins equaled the corresponding PA diameters of sham controls. Growth of left PA immediately beyond the stent was limited and there was diffuse fibro-intimal proliferation within the distal left and right PA. RV contractility was diminished in the intervention group and the response to dobutamine occurred uniquely via increases in heart rate. CONCLUSIONS: Early stent intervention in this surgically created PA stenosis model was associated with improved growth of the distal PA vasculature but additional investigation of PA vessel physiology and impact on the developing heart are needed.

Challenges for bilateral pulmonary artery stenting due to occluded femoral veins.

When the inferior caval vein is occluded or abnormal, jugular and hepatic veins provide alternative routes for interventions. For pulmonary artery stenting, transhepatic access may give a relatively straighter route than that from the jugular veins. We describe the challenges and strategies during transhepatic bilateral pulmonary artery stenting after arterial switch operation complicated by occluded inferior caval vein and congested hepatic veins.

Impact of preoperative left pulmonary artery stenting on the Fontan procedure: a retrospective multicentre study.

OBJECTIVES: Left pulmonary artery (LPA) or bifurcation stenoses at Fontan palliation can be very challenging to treat and may also require cardioplegia and aortic transection. Moreover, the low pressure of Fontan circulation and the bulkiness of the aorta increase the risk of a patch angioplasty collapse. Pre-Fontan LPA stenting of stenotic LPAs overcomes those drawbacks therefore the present study aimed to evaluate its advantageous impact on Fontan surgery. METHODS: A multicentre retrospective analysis was performed on 304 consecutive Fontan patients. The study population was divided into 2 groups (LPA stented, n = 62 vs not stented, n = 242); pre-and postoperative data were compared. RESULTS: LPA-stented patients had a higher prevalence of systemic right ventricle (P = 0.01), hypoplastic left heart syndrome (P = 0.042), complex neonatal palliations (Norwood/Damus-Kaye-Stansel) and surgical LPA patch repair at Glenn (P < 0.001). No differences were found in cross-clamp rates, early (P = 0.29) and late survival (94.6% vs 98.4, P = 0.2) or complications (P = 0.14). Complex palliations on ascending aorta/aortic arch (P = 0.013) and surgical LPA repair at Glenn (P < 0.001) proved to be risk factors for LPA stenting before Fontan at multivariable analysis. CONCLUSIONS: The LPA-stented group showed similar outcomes in terms of survival and complications rate compared to patients without LPA stenosis; however, they significantly differ in their higher preoperative risk profile and in their more complex anatomy. Complex neonatal palliations involving ascending aorta or aortic arch may increase the risk of pulmonary branches stenosis requiring stenting; therefore, preoperative stenting of LPA stenoses could help to reduce the surgical risk of complex Fontan procedure by avoiding the need for cross-clamp or complex mediastinal dissections to perform a high-risk surgical repair.

Preemptive stenting of the left pulmonary artery during comprehensive stage 2 procedure does not influence Fontan candidacy.

Objective: Pulmonary artery reconstruction during comprehensive stage 2 (CS2) procedure can be challenging. Since 2017, we have employed preemptive left pulmonary artery (LPA) stenting. We hypothesized that LPA stenting promotes adequate growth and without compromising Fontan candidacy. Herewith, we report our midterm results. Methods: From 2002 to 2020, 159 patients underwent CS2. Patients were divided as follows: no stent (n = 122; Group 1) and perioperative LPA stent (n = 37; Group 2). Group 2 was subdivided according to unplanned stent (n = 17; Group 2a) or preemptive stent (n = 20; Group 2b). Relevant perioperative data was reviewed. Nonparametric statistics were utilized. Results: Median age and weight at surgery and hospital length of stay after CS2 did not differ between groups. Median cardiopulmonary bypass and crossclamp times were significantly greater in Group 1 (265 vs 243 minutes [P = .021] and 46 vs 26 minutes [P = .008]). In-hospital mortality was similar between Groups 1 and 2 (9.0% vs 18.9%, respectively [P = .1348]). Group 2b demonstrated a superior survival compared to Group 2a (P = .0335) but not Group 1 (P > .9999). Preemptive stenting significantly increased median hilar LPA diameter at CS2 exit angiogram compared with no stenting (P < .0001). Groups 2a and 2b significantly increased the pre-Fontan diameter of the hilar LPA when compared with Group 1 (6.1 and 6.8 vs 5.7 mm, respectively [P < .0001]). A further 120 patients underwent Fontan operation (75%). Median follow-up for Groups 1 and 2 were 7.4 and 3.0 years, respectively. Conclusions: Perioperative LPA stenting during CS2 does not adversely affect pulmonary growth. Preemptive stenting seems advantageous for LPA growth in preparation for Fontan completion.

The application of simultaneous mainstem bronchus dilation with pulmonary artery stenting in the context of hypoplastic left heart syndrome.

Hypoplastic left heart syndrome (HLHS) is a congenital diagnosis that necessitates immediate intervention at the beginning of life to ensure survival past infancy and to optimize left-side cardiac function. Often, these required procedures can lead to deleterious side effects and resultant complications. In this case report, we present a 15-month-old patient with HLHS who underwent multiple procedures, including two aortic arch surgeries. After the interventions, the patient experienced left main pulmonary bronchus compression along with pulmonary artery stenosis. In this case, we outline an approach to performing vascular dilation without compromise of airway patency.

Use of Zephyr stent in congenital heart diseases: A single-center study.

Large vessel stenosis is currently successfully treated with percutaneous stent implantation. Zephyr stent is a cobalt-chromium peripheral stent specifically designed for large-vessel stenting. Its specific "S-" and "C-" shaped flexible polylinks prevent stent foreshortening and recoil. We report our experience of using Zephyr among the pediatric population and their medium-term outcome. The study included a total of 19 patients treated with 21 Zephyr stents. The indications for stenting included coarctation of the aorta (four patients), stenosed pulmonary artery (eight patients), stenosed right ventricular outflow tract (five patients) or conduit (one patient), and percutaneous Fontan (one patient). All the procedures were successful. None of the patients showed any stent-related complications. Stent fractures, foreshortening, or recoil were not seen during follow-up. Our medium-term (1-20 months) follow-up showed a favorable outcome. One patient developed restenosis. Zephyr stent is a good therapeutic option for large-vessel stenting. However, it needs large-scale studies for further confirmation.

Successful pulmonary artery stenting for occlusion at a constructed pericardial conduit after right upper double sleeve lobectomy.

The patient was a 53-year-old man. His chief complaint was a cough and dyspnea on exertion. Computed tomography (CT) showed a 3-cm-diameter tumor in the right upper lobe with invasion from hilar lymph nodes to the superior vena cava, right main bronchus, and pulmonary artery. After being diagnosed with non-small cell lung cancer, the patient underwent preoperative induction radiochemotherapy. At surgery, right upper double sleeve lobe lobectomy was performed. The right main pulmonary artery was reconstructed using a pericardial conduit. CT 1 week after surgery showed impaired blood flow in the right pulmonary artery. A metal vascular stent was inserted into the narrow part of the constructed pulmonary artery in the hybrid operating room because thrombectomy was unsuccessful. After surgery, contrast CT showed that blood flow was maintained. The patient is currently well without any recurrence 3 years after surgery.

Virtual Transcatheter Interventions for Peripheral Pulmonary Artery Stenosis in Williams and Alagille Syndromes.

Background Despite favorable outcomes of surgical pulmonary artery (PA) reconstruction, isolated proximal stenting of the central PAs is common clinical practice for patients with peripheral PA stenosis in association with Williams and Alagille syndromes. Given the technical challenges of PA reconstruction and the morbidities associated with transcatheter interventions, the hemodynamic consequences of all treatment strategies must be rigorously assessed. Our study aims to model, assess, and predict hemodynamic outcomes of transcatheter interventions in these patients. Methods and Results Isolated proximal and "extensive" interventions (stenting and/or balloon angioplasty of proximal and lobar vessels) were performed in silico on 6 patient-specific PA models. Autoregulatory adaptation of the cardiac output and downstream arterial resistance was modeled in response to intervention-induced hemodynamic perturbations. Postintervention computational fluid dynamics predictions were validated in 2 stented patients and quantitatively assessed in 4 surgical patients. Our computational methods accurately predicted postinterventional PA pressures, the primary indicators of success for treatment of peripheral PA stenosis. Proximal and extensive treatment achieved median reductions of 14% and 40% in main PA systolic pressure, 27% and 56% in pulmonary vascular resistance, and 10% and 45% in right ventricular stroke work, respectively. Conclusions In patients with Williams and Alagille syndromes, extensive transcatheter intervention is required to sufficiently reduce PA pressures and right ventricular stroke work. Transcatheter therapy was shown to be ineffective for long-segment stenosis and pales hemodynamically in comparison with published outcomes of surgical reconstruction. Regardless of the chosen strategy, a virtual treatment planning platform could identify lesions most critical for optimizing right ventricular afterload.

Non-invasive MRI Derived Hemodynamic Simulation to Predict Successful vs. Unsuccessful Catheter Interventions for Branch Pulmonary Artery Stenosis: Proof-of-Concept and Experimental Validation in Swine.

OBJECTIVE: This study assessed the ability of hemodynamic simulations to predict the success of catheter interventions in a swine model of branch pulmonary artery stenosis (bPAS). BACKGROUND: bPAS commonly occurs in congenital heart disease and is often managed with catheter based interventions. However, despite technical success, bPAS interventions do not lead to improved distal pulmonary blood flow (PBF) distribution in approximately 1/3rd of patients. New tools are needed to better identify which patients with bPAS would most benefit from catheter interventions. METHODS: For 13 catheter intervention cases in swine with surgically created left PAS (LPAS), PA pressures from right heart catheterization (RHC) and PBF distributions from MRI were measured before and after catheter interventions. Hemodynamic simulations with a reduced order computational fluid dynamics (CFD) model were performed using non-invasive PBF measurements derived from MRI, and then correlated with changes in invasive measures of hemodynamics and PBF distributions before and after catheter intervention to relieve bPAS. RESULTS: Compared to experimentally measured changes in left PBF distribution, simulations had a small bias (3.4 ± 11.1%), moderate agreement (ICC = 0.69 [0.24-0.90], 0.71 [0.23-0.91]), and good diagnostic capability to predict successful interventions (> 20% PBF increase) (AUC 0.83 [0.59-1.0]). Simulations had poorer prediction of changes in stenotic pressure gradient (ICC = 0.28 [- 0.33 to 0.73], r = 0.57 [- 0.04 to 0.87]) and MPA systolic pressure (ICC = 0.00 [- 0.52 to 0.53], r = 0.29 [- 0.32 to 0.72]). CONCLUSION: While there was only weak to moderate agreement between predicted and measured changes in PA pressures and pulmonary blood flow distributions, hemodynamic simulations did show good diagnostic value for predicting successful versus unsuccessful catheter based interventions to relieve bPAS. The results of this proof of concept study are promising and should encourage future development for using hemodynamic models in planning interventions for patients with bPAS.

Percutaneous salvage interventions in the Glenn circuit: a case series.

BACKGROUND: In majority of children bidirectional Glenn shunt is a safe and efficacious procedure with minimal post-operative issues. Rarely, there may be dysfunction in the Glenn pathway due loss of anatomical integrity or derangements in normal physiological or hemodynamic milieu. We report 4 cases in the last 3 years (2016-2019) where complications in the Glenn circuit led to serious consequences requiring transcatheter interventions. CASE PRESENTATION: Two of our patients presented with frank features of superior vena cava syndrome. One of them had right Glenn anastomotic site narrowing leading to severe obstruction along with significant left pulmonary artery origin stenosis. The other child had excessive antegrade flow impeding normal Glenn flow leading to superior vena cava syndrome. The next child in our series was initially lost to follow-up after bidirectional Glenn surgery. Later on, this child was noted to have discontinuous left pulmonary artery with perfusion only to the right lung from the Glenn. The remaining child described in this series had developed a large tortuous venous collateral post Glenn shunt leading to severe cyanosis. All the above children needed prompt percutaneous interventions to revert back to their basal state. On follow-up, the benefit was sustained in all. CONCLUSIONS: Percutaneous intervention procedures often provide a successful bailout option in various complicated situations post Glenn surgery with reasonable efficacy and safety.

Bronchial compression as adverse effect of right pulmonary artery stenting in a patient with truncus arteriosus communis and interrupted aortic arch.

Aortic arch obstruction and bronchial compression are possible postoperative complications in patients with truncus arteriosus communis (TAC) with interrupted aortic arch (IAA). We present a case of bronchial compression as adverse effect of right pulmonary artery (PA) stenting in an infant with TAC (Type 4A)-IAA (Type B) repair. Due to growth potential, self-expandable metal stent was applied for postoperative proximal right PA stenosis, which caused bronchial compression. Later, we found patient having bronchomalacia. Surgical removal was needed. Stent insertion might be an option for postoperative PA stenosis, but bronchial compression might be a potential risk, particularly in patients with bronchomalacia.

Bronchial compression following pulmonary artery stenting in single ventricle lesions: how to prevent, and how to decompress.

OBJECTIVES: To assess airway compression during pulmonary artery (PA) intervention in single ventricle (SV) palliation. BACKGROUND: SV lesions with a prominent neo-aortic root are considered a high risk for branch PA and/or bronchial stenosis. PA stenting is well established, but may result in ipsilateral bronchial compression. METHODS: Single-centre retrospective analysis of 19 palliated SV patients with branch PA stenosis and close proximity to the ipsilateral main bronchus who underwent cardiac catheterisation at a median age and weight of 8.5 years (0.5-25) and 16.5 kg (6-82) between 12/2011 and 05/2015. RESULTS: Two of the 19 patients suffered an almost-closed left-main bronchus (LMB) following PA stenting. Fortunately, LMB decompression succeeded in both those patients by re-shaping the PA stents by compressing the chest while splinting the LMB with an inflated balloon. To prevent the other 17 patients from suffering this serious complication, we adopted a thorough preparation strategy: 13 patients underwent safe simultaneous bronchoscopy and cardiac catheterisation; in the remaining 4 patients CT-angiography enabled accurate risk evaluation prior to re-catheterisation. CONCLUSIONS: In SV lesions accompanied by branch PA stenosis, thorough preparation via cross-sectional imaging is mandatory, including simultaneous bronchoscopy and cardiac catheterisation in selected cases, to rule out any airway compression before considering endovascular stent implantation. If a PA stent's compression has already caused severe bronchial obstruction, our balloon-splinted decompression technique should be considered.

Difficulty in Weaning from Cardio-Pulmonary Bypass due to Pulmonary Artery Extrinsic Stenosis Caused by a Hematoma—a Case of Ruptured Aortic Arch Aneurysm / 日本心臓血管外科学会雑誌

During aortic arch replacement in response to an aortic arch aneurysm sealed rupture, we experienced a case in which weaning from cardio-pulmonary bypass (CPB) became difficult, and pulmonary artery stenosis developed due to expanded hematoma. A 77-year-old man was raced to our hospital due to subjective symptom of chest/back pain. With a recognition of aortic arch aneurysm and hematoma around the aneurysm, it was diagnosed as an aortic arch aneurysm sealed rupture. Even though an elective aortic arch replacement was implemented using an open stent graft, reduction in blood pressure and poor oxygenation was observed at the process of CPB weaning. As a result of intraoperative pulmonary arteriography, severe stenosis was revealed on both left and right pulmonary arteries. With placement of a self-expanding stent, weaning from CPB was successfully completed. Being transferred to other hospital on day 60 after the surgery in order to continue rehabilitation, the man visits our hospital as an outpatient on his own as of now. As it is considered to be a rare case that weaning from CPB was successfully performed by pulmonary stenting in response to progressed intraoperative pulmonary artery stenosis caused by expanded hematoma after heparin administration, the details are reported here.