Computational Fluid Dynamics Support for Fontan Planning in Minutes, Not Hours: The Next Step in Clinical Pre-Interventional Simulations

Computational fluid dynamics (CFD) modeling may aid in planning of invasive interventions in Fontan patients. Clinical application of current CFD techniques is however limited by complexity and long computation times. Therefore, we validated a “lean” CFD method to magnetic resonance imaging (MRI) and an “established” CFD method, ultimately aiming to reduce complexity to enable predictive CFD during ongoing interventions. Fifteen Fontan patients underwent MRI for CFD modeling. The differences between lean and established approach, in hepatic and total flow percentage to the left pulmonary artery (%LPA), power loss and relative wall shear stress area were 1.5 ± 4.0%, -0.17 ± 1.1%, -0.055 ± 0.092 mW and 1.1 ± 1.4%. Compared with MRI, the lean and established method showed a bias in %LPA of -1.9 ± 3.4% and -1.8 ± 3.1%. Computation time was for the lean and established approach 3.0 ± 2.0 min and 7.0 ± 3.4 h, respectively. We conclude that the proposed lean method provides fast and reliable results for future CFD support during interventions. Graphical abstract

Pulmonary Artery Sling with Tracheal Stenosis Combined with A Large Ventricular Septal Defect in A Two-Month-Old Boy: A Case Report

Pulmonary artery sling (PAS) is a rare congenital cardiovascular abnormality. In typical PAS patients, the left pulmonary artery (LPA) arises from the right pulmonary artery and passes between the trachea and esophagus, which possibly causes tracheal stenosis and some respiratory symptoms. PAS typically associates with other cardiovascular anomalies, which may cause difficulties to the treatment of patients. This report described a rare case of a two-month-old boy with PAS, VSD, and tracheal stenosis simultaneously and underwent procedures without tracheoplasty.

Left Pulmonary Artery Coarctation Associated with Pneumonia and Pulmonary Hypertension in a Cat

A five-month-old European shorthair female kitten was referred because of recurrent episodes of respiratory distress. Results of physical examination, thoracic radiography, and echocardiography led to a presumptive diagnosis of severe precapillary pulmonary hypertension (PH) and interstitial pneumonia associated with right-sided cardiac remodeling. The cat rapidly died because of respiratory insufficiency. Pulmonary and cardiovascular pathological findings evidenced left pulmonary artery coarctation, severe right-sided cardiac hypertrophy, and bilateral pneumonia. This is the first report of pulmonary artery coarctation associated with pneumonia and PH in a cat.

Bilateral Pulmonary Arteries Reconstruction for Correction of Tetralogy of Fallot with Unilateral Absence of the Pulmonary Artery

Background: Tetralogy of Fallot (TOF) is the most common combined the deformity of unilateral absence of the pulmonary artery (UAPA). The treatment strategy of TOF combined with UAPA is still very controversial. In this study, we analyzed the effect of the bilateral pulmonary reconstruction for patients with TOF combined with UAPA. Methods: A single-institution, retrospective review of all 1713 patients with TOF between January 2009 to November 2021. Eight patients were diagnosed with TOF combined with UAPA, and 7 patients underwent the surgery. Three patients underwent one-stage TOF correction with bilateral pulmonary artery reconstruction. Three patients underwent bilateral pulmonary artery reconstruction, followed by two-stage TOF correction after several months. One patient underwent 2 procedures of left pulmonary artery reconstruction, and the VSD remained open. Results: All 7 patients survived during the postoperative follow-up and showed good cardiac function and normal oxygen saturation >97%. During the follow-up with echocardiograms, it was found that the left pulmonary arteries that were reconstructed with Goretex vessel or direct anastomosis had thrombosis or stenosis. The left pulmonary artery reconstructed with the modified autologous tissue extension technique was unobstructed. Conclusions: In patients with TOF and UAPA, if there is a pulmonary confluence in the affected hilum, it is feasible to implement bilateral pulmonary artery reconstruction for one-stage TOF correction. The use of pulmonary artery extension technique and autologous tissue to bilateral pulmonary reconstruct could reduce the incidence of anastomotic stenosis.

Left Pulmonary Artery Sling: Postoperative Outcomes for Patients at a Single Center

Background Left pulmonary artery (LPA) sling is a rare anomaly characterized by the origin of the LPA from the right pulmonary artery with a course between the trachea and esophagus. It is often associated with airway and cardiac anomalies. Methods This is a retrospective case series of consecutive patients who underwent LPA sling repair (LPASR) at a tertiary care center over a 35-year period with a focus on tracheal and/or LPA reinterventions and survival. Results Between June 1983 and July 2018, 42 patients were identified: isolated LPASR was performed in 16 (38%), LPASR/intracardiac repair in 10 (24%), and LPASR/tracheal repair in 16 (38%). There were 5 (12%) in-hospital and 4 (10%) late deaths. Survival rates (15 years) were as follows: 100% (isolated LPASR), 65% (concomitant intracardiac repair), and 52% (concomitant tracheal surgery). Preoperative intensive care unit (ICU) hospitalization was associated with future intervention on the LPA/trachea (61%, 11/18). The median distribution of blood flow to the left lung post-index surgery was 38%. Freedom from isolated LPA intervention was 100% after isolated LPASR, 93% after LPASR/tracheal surgery, and 69% after LPASR/intracardiac repair. Freedom from isolated tracheal intervention was 92% after isolated LPASR, 73% after LPASR/tracheal surgery, and 78% after LPASR/intracardiac repair. Conclusions ICU hospitalization prior to index surgery may indicate the severity of associated cardiac/tracheal abnormalities as this is associated with increased morbidity and mortality. Patients who underwent LPASR/intracardiac surgery were more likely to undergo isolated LPA intervention and those who underwent LPASR/tracheal surgery were more likely to undergo isolated tracheal intervention.

A Delayed Anatomic Diagnosis and Management Challenge in an Initially Asymptomatic Infant With Type II Pulmonary Artery Sling: A Case Report

Pulmonary artery sling (PAS) is a rare but fatal malformation. Patients with PAS tend to develop obstructive symptoms in few weeks of life. Conversely, some patients may be otherwise mild or asymptomatic in their early life. Currently, no consensus on the intervention timing and treatment strategy for asymptomatic and mild cases has been reached. Moreover, the extent of tracheal stenosis is another determining factor for the choice of intervention timing since clinical symptoms might not correspond well with the degree of stenosis. Lack of comprehensive assessment of entire airways confer underestimation of disease severity and in turn improper choice of treatment regimens and poor outcomes. Herein, we described an infantile case of PAS, who was scheduled initially for periodic outpatient follow-up on account of the absence of symptoms and inadequate imaging assessment at diagnosis. The patient developed recurrent wheezing and progressive respiratory distress at 7 months of age. After left pulmonary artery (LPA) reimplantation without tracheal intervention, bronchoscopy was performed due to failure to wean from mechanical ventilation, which demonstrated complete tracheal cartilage rings, a long segment tracheal stenosis, a low tracheal bifurcation at T6, and the absence of a separate right middle lobe bronchus. The patient was finally diagnosed with type IIb PAS and extubated successfully following conservative treatment. Miserably, neurological sequelae were devastating, leading to poor outcomes. Comprehensive airway evaluation using bronchoscopy is substantial to early identification of all components responsible for airway compromise in PAS anatomic subtypes. Considering severe concomitant maldevelopment of the bronchial tree in children with type IIb PAS, early and complete correction by surgery might decrease perioperative morbidities and mortalities of these patients.

Anomalous Origin of Left Pulmonary Artery From Ascending Aorta: Embryological Model

Background Anomalous origin of the left pulmonary artery (ALPA) from the ascending aorta (AA) is a rare congenital heart malformation. Aim To give some of our embryological considerations of ALPA from the AA. Methods We present a patient with ALPA from the AA, right-sided aortic arch, right-sided ductus arteriosus (DA), and aberrant left subclavian artery (LSCA). Results The distal end of ALPA was cut off, the proximal end was sutured, and the distal end was directly anastomosed to the left wall of the main pulmonary artery (MPA). Conclusion The failure of migration and differentiation of cardiac neural crest cells at the fourth and sixth archs result in unilateral arch agenesis or failure of detachment of the left sixth arch from the aortic sac, which form ALPA the AA.

Outcome of ductus arteriosus stenting including vertical tubular and convoluted tortuous ducts with emphasis on technical considerations

Background Ductal stenting is the preferred method of securing adequate pulmonary blood flow in patients with duct-dependent pulmonary circulation. The main limitation in most centers is the difficult vertical tubular or convoluted ducts that represent real challenges to interventional pediatric cardiologists. We present our experience in patent ductus arteriosus (PDA) stenting with some technical tips to overcome difficulties, especially in stenting tortuous or long tubular ducts. This study was conducted on all patients with cyanotic congenital heart disease who underwent PDA stenting between January 2011 and December 2018. Results We attempted to stent the PDA in 43 patients, with a success rate of 93% (40 patients) and only one procedural mortality. There was also one stent migration that needed to be treated with urgent surgery. Three-fourths of the patients had difficult ductal morphology and origin. One stent was used to cover the PDA in 27 patients (62.8%), two stents were used in 13 (30.2%), and three stents were used in 2 patients (4.6%). In-stent stenosis rate was 12.5% (5 patients) and the development of progressive left pulmonary artery stenosis was seen in two patients (5%). Pulmonary artery growth was adequate in all patients. Conclusions PDA stenting is an effective method of palliation for patients with duct-dependent pulmonary circulation. It has low morbidity and mortality rates. Stenting difficult ducts have become more feasible with evolving materials and techniques.