The association between cardiac magnetic resonance-derived aortic stiffness parameters and aortic dilation in young adults with bicuspid aortic valve: With and without coarctation of aorta

Background

Bicuspid aortic valve (BAV) is associated with progressive aortic dilation. Studies in aortopathies have shown a correlation between increased aortic stiffness and aortic dilation. We aimed to evaluate aortic stiffness measures as predictors of progressive aortic dilation by cardiac magnetic resonance (CMR) in BAV patients.

Methods

This is a retrospective study of 49 patients with BAV (median age 21.1 years at first CMR visit) with ≥2 CMR at the Wisconsin Adult Congenital Heart Disease Program (WAtCH). Circumferential aortic strain, distensibility, and β-stiffness index were obtained from CMR-derived aortic root cine imaging, and aortic dimensions were measured at aortic root and ascending aorta. A linear mixed-model and logistic regression were used to identify important predictors of progressive aortic dilation.

Results

Over a median of 3.8 years follow-up, the annual growth rates of aortic root and ascending aorta dimensions were 0.25 and 0.16 mm/year, respectively. Aortic strain and distensibility decreased while β-stiffness index increased with age. Aortic root strain and distensibility were associated with progressive dilation of the ascending aorta. Baseline aortic root diameter was an independent predictor of >1 mm/year growth rate of the aortic root (adjusted OR 1.34, 95 % CI 1.03-1.74, p = 0.028). Most patients (61 %) had coexisting coarctation of aorta. Despite the higher prevalence of hypertension in patients with aortic coarctation, hypertension or coarctation had no effect on baseline aorta dimensions, stiffness, or progressive aortic dilation.

Conclusion

Some CMR-derived aortic stiffness parameters correlated with progressive aortic dilation in BAV and should be further investigated in larger and older BAV cohorts.

Outcomes of one-staged procedures to treat aortic coarctation complicated by cardiac anomalies

OBJECTIVE

One-staged surgical treatment of aortic coarctation combined with cardiac anomalies is challenging. We aim to evaluate the feasibility of bilateral aortofemoral bypass technique in one-staged surgery treating coractation by comparing surgical outcomes with catheter intervention plus stent (hybrid).

METHODS

Between January 2012 and December 2017, 50 patients underwent one-staged surgical procedures to treat coarctation and repair concomitant cardiac anomalies, like aortic root dilatation, cardiac valvular disease and so on. Among them, 30 patients underwent bilateral aortofemoral bypass and 20 patients underwent hybrid procedure to treat coarctation. We retrospectively analyzed the data of these patients and compared the early and late results.

RESULTS

All the baseline clinical characteristics were comparable between groups except that the mean age of bypass group was 39.5 ± 14.0 years which was older than hybrid group (27.9 ± 8.5 years, P = 0.002). Technical success was achieved in all patients, with no hospital death or other severe complications. Immediately after surgery, in bypass and hybrid group, the mean upper-limb systolic blood pressure decreased from 159.4 to 119.7 mmHg and 148.4 to 111.6 mmHg, the median peak systolic gradient decreased from 68.0 to 10 mmHg and 46.5 to 10 mmHg respectively (P = 0.09). And the mean upper-lower limbs gradient decreased from 21.7 to 5.9 mmHg and 21.0 to 2.7 mmHg respectively (P = 0.104). The mean follow-up time was 76.92 ± 18.7 in bypass group and 85.4 ± 20.6 months in hybrid group. There were 4 late deaths in bypass group (one died of gastrointestinal bleeding, one died of pulmonary embolism and the other two died of heart failure caused by mechanical prosthetic valve dysfunction). The follow-up peak systolic gradient and other blood pressure parameters showed stable and no differences between two groups.

CONCLUSIONS

The bilateral aortofemoral bypass surgery is a safe and effective method which can be used in one-staged surgical strategy to treat coarctation complicated by cardiac anomalies and can be an alternative to the hybrid method.

Surgical and endovascular treatment of late post-coarctation repair aortic aneurysms: results from an international multicenter study

OBJECTIVE

Formation of post-aortic coarctation aneurysms (pCoAA) is well described in the literature and carries a significant risk of rupture and death. Treatment strategies include open surgical, hybrid, and endovascular repair dependent on clinical presentation, risk assessment, and anatomy. The aim of this study is to report early and mid-term results of open surgical and endovascular repair of pCoAA.

METHODS

This is an international multicenter retrospective study including patients who underwent open surgical or endovascular repair for pCoAA between 2000 and 2021 at 14 highly specialized academic cardiovascular centers. The pre-, intra-, and postoperative data were recorded and analyzed.

RESULTS

A total of 74 patients [46 male, median age 44 years-old (IQR, 35-53)] underwent pCoAA repair. All patients had previously undergone surgical repair of aortic coarctation (CoA) at a median age of 11 years-old for the index procedure (IQR, 7-17). The most common first surgical correction was synthetic patch aortoplasty in 48 patients, followed by graft interposition in 11. Median pCoAA diameter was 54 mm (IQR, 44-63). The median time from the CoA repair to the pCoAA diagnosis was 33 years (IQR, 25-40). A total of 33 patients had symptoms at presentation, including thoracic or back pain in eight. Open surgical repair was performed in 28 patients, including four frozen elephant trunk (FET) procedures and one Bentall. The remaining 46 patients underwent endovascular repair of the pCoAA. Two in-hospital deaths were observed (one FET and one endovascular). After a median follow-up of 50 months (IQR, 14-127), there was a total of seven reinterventions.

CONCLUSIONS

This international multicenter study demonstrates that patients with pCoAA can be safely treated with either open surgical or endovascular interventions. Since the median time between the coarctation repair and the aneurysm formation was over 30 years, life-long surveillance of these patients is warranted.

Difference and similarity between type A interrupted aortic arch and aortic coarctation in adults: Two case reports

BACKGROUND

Aortic coarctation (CoA) is usually confused with interrupted aortic arch (IAA), especially adult type A interrupted aortic arch, due to their similar anatomical location. Although the main difference between them is whether arterial lumen exhibits continuity or not, the clinical manifestations are similar and connection exists between them. Adult type A IAA is considered as an extreme form of CoA, which is complete discontinuity of aortic function and lumen caused by degenerative arterial coarctation. This paper reports two cases (interrupted aortic arch and severe aortic coarctation) to analyze the difference and similarity between them.

CASE SUMMARY

The two cases of patients presented with hypertension for many years. Computed tomography angiography showed that the aortic arch and descending aorta were discontinuous or significantly narrowed with extensive collateral flow. The IAA patient refused surgical treatment and blood pressure could be controlled with drugs. While the CoA patient underwent stent implantation because of uncontrollable hypertension, the blood flow recovered smoothly and the blood pressures at both ends of the stenosis returned to normal after surgery.

CONCLUSION

Adult type A IAA and CoA have difference and similarity, and type A IAA is associated with CoA to a certain extent. The treatment method should be chosen based on the patient's clinical symptoms rather than the severity of the lesion.

Echocardiographic findings for improved prenatal diagnosis of aortic coarctation with ventricular septal defect

Accurate prenatal diagnosis of coarctation of the aorta (CoA) associated with ventricular septal defect (VSD) remains challenging. The objective of the study was to identify which Doppler and/or two-dimensional sonographic findings are most useful for predicting fetal CoA/VSD. A retrospective cohort study identified 35 fetuses with suspected CoA/VSD. Prenatal imaging characteristics included the right ventricular/left ventricular, pulmonary artery (PA)/aorta ratio, aortic isthmus (AOI) Z score, diastolic velocity-time integral (VTID), and systolic velocity-time integral (VTIS) at the AOI. The area under the receiver operating characteristic curve (AUC), integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were calculated. Significant differences in the PA/AO, VTID, VTID/VTIS, VTID/VTIS, VTID/(VTID + VTIS), and AOI Z score between the true CoA group and false positives were found. When associated with VSD, the VTID/VTIS and VTID/(VTID + VTIS) had the highest AUC (0.97, 95% confidence interval: 0.84-1.00), with 88.46% sensitivity and 100.00% specificity for predicting the true CoA. The AOI Z score had the highest sensitivity (92.31%). Adding the VTID/VTIS to the AOI Z score significantly improved the performance (IDI, 50%; NRI, 82%; P < 0.05), with an improvement in specificity (77.78% vs. 55.56%; non-Event P = 0.008) without sacrificing sensitivity (96.15% vs. 92.31%; Event P = 0.564). In fetuses with suspected CoA associated with VSD, the quantitative spectral Doppler metric aided accurate detection of the fetal CoA, with reduced false positives. The conventional AOI Z score plus spectral Doppler metric may improve the overall diagnostic accuracy of CoA/VSD.

Personalized Pre- and Post-Operative Hemodynamic Assessment of Aortic Coarctation from 3D Rotational Angiography

PURPOSE

Coarctation of Aorta (CoA) is a congenital disease consisting of a narrowing that obstructs the systemic blood flow. This proof-of-concept study aimed to develop a framework for automatically and robustly personalizing aortic hemodynamic computations for the assessment of pre- and post-intervention CoA patients from 3D rotational angiography (3DRA) data.

METHODS

We propose a framework that combines hemodynamic modelling and machine learning (ML) based techniques, and rely on 3DRA data for non-invasive pressure computation in CoA patients. The key features of our framework are a parameter estimation method for calibrating inlet and outlet boundary conditions, and regional mechanical wall properties, to ensure that the computational results match the patient-specific measurements, and an improved ML based pressure drop model capable of predicting the instantaneous pressure drop for a wide range of flow conditions and anatomical CoA variations.

RESULTS

We evaluated the framework by investigating 6 patient datasets, under pre- and post-operative setting, and, since all calibration procedures converged successfully, the proposed approach is deemed robust. We compared the peak-to-peak and the cycle-averaged pressure drop computed using the reduced-order hemodynamic model with the catheter based measurements, before and after virtual and actual stenting. The mean absolute error for the peak-to-peak pressure drop, which is the most relevant measure for clinical decision making, was 2.98 mmHg for the pre- and 2.11 mmHg for the post-operative setting. Moreover, the proposed method is computationally efficient: the average execution time was of only [Formula: see text] minutes on a standard hardware configuration.

CONCLUSION

The use of 3DRA for hemodynamic modelling could allow for a complete hemodynamic assessment, as well as virtual interventions or surgeries and predictive modeling. However, before such an approach can be used routinely, significant advancements are required for automating the workflow.

Angioplasty of Native Coarctation in a Very Low Birth Weight, Donor of Twin-Twin Transfusion Infant

We present a case of successful balloon angioplasty of native aortic coarctation in a preterm infant, a donor of twin-twin transfusion syndrome with low birth weight. Angioplasty was done at the age of 15 days and weight of 480 g, using umbilical artery approach. Follow-up at 4 months of age showed no recurrence of coarctation.

Left heart bypass for repair of aortic coarctation in children: Technical tips and pitfalls

Spinal cord injury secondary to coarctation repair in children is a serious, though relatively uncommon, complication. Several measures have been proposed to minimize this risk, which seems to affect more older children than neonates and those with inadequate collateral circulation. Left heart bypass has been proposed as a protective strategy.

Effectiveness of Repair of Aortic Coarctation in Neonates: A Long-Term experience

To evaluate early and long-term results of surgical treatment of aortic coarctation (CoAo) in neonates. This is a retrospective clinical review of neonates with CoAo, who underwent surgery between 1995 and 2019. Data were retrieved from our institutional database, to identify preoperative and postoperative characteristics. Statistical analysis was performed by means of relative risk ratio and Cox and logistic multivariate analysis. 218 consecutive neonates (M/F: 129/89, median age 11 days, IQR 7-17 days) were included; 202 (92.7%) had a left thoracotomy; 178 underwent extended end-to-end anastomosis (EEEA, 81.6%). Hypoplastic aortic arch (HAA) was present in 102 patients (46.8%); complex cardiac anomalies in 85 (39%). Significant postoperative complications occurred in 20 (9.2%). Thirty-day mortality was 2.3% (most in complex types). At a median follow-up of 10.4 years (IQR 5.6-15.0 years; FU completeness 95.9%), there were 8 late deaths (3.7%), all associated to complex CoAo. Among 196 survivors, 177 (93.2%) were in NYHA class I; re-interventions on aortic arch occurred in 9.2% (2.0% were surgical). Freedom from mortality and re-intervention on aorta at 10 years were 94.3% and 96.7%, respectively. Surgical repair of CoAo in newborns without CPB in our series was safe and low-risk, with excellent early and late outcomes.

Effect of coarctation of aorta anatomy and balloon profile on the outcome of balloon angioplasty in infantile coarctation

OBJECTIVE

Coarctation of the Aorta (CoA) is a relatively common cardiovascular disorder. The present study aimed to evaluate the effect of COA anatomy and high versus low-pressure balloons on the outcome of balloon angioplasty among neonates and infants.

METHODS

In this retrospective study, the neonates and infants undergoing balloon angioplasty at Namazi hospital were enrolled. After balloon angioplasty, immediate data results were promptly recorded.Moreover, midterm echocardiographic information was collected via electronic cardiac records of pediatric wards and clinical and echocardiographic data at least 12 months after balloon angioplasty. Finally, data were analyzed using SPSS-20.

RESULTS

In this study, 42 infants were included. The median age at the time of balloon angioplasty was 1.55 (range 0.1-12) months and 66.7% of the patients were male. The mean pressure gradient of coarctation was 38.49 ± 24.97 mmHg, which decreased to 7.61 ± 8.00 mmHg (P < 0.001). A high-pressure balloon was used in 27, and a low-pressure balloon was used in 15 patients. COA's pressure gradient changed 30.89 ± 18.06 in the high-pressure group and 24.53 ± 20.79 in the low-pressure balloon group (P = 0.282). In the high-pressure balloon group, 14.81% and in the low-pressure group, 33.33% had recoarctation and need second balloon angioplasty (p < 0.021). The infant with discrete coarctation had a higher decrease in gradient and lower recoarctation.

CONCLUSION

Recoarctation rate was lower in the high-pressure balloon. The infant with discrete COA had a better response to the balloon with more decrease in gradient and lower recoarctation rate. Therefore, the stenotic segment anatomy needs to be considered in the selection of treatment methods.

Prenatal Diagnosis of Aortic Coarctation: Prediction Algorithm according to Gestational Age

OBJECTIVES

The aim of the study was first to quantify the diagnostic accuracy of predictive anatomical factors of aortic coarctation (CoA) and second to design a postnatal CoA probability algorithm according to gestational age (GA) in prenatal period.

METHODS

Global and according to GA diagnostic performance of cardiac anatomical variables using the ROC curve were evaluated in a retrospective cohort of fetuses with suspicion of CoA (2004-2020). A serial testing strategy to predict postnatal CoA by fetal echocardiography was designed.

RESULTS

114 fetuses were included. Isthmus-to-ductal (I/D) ratio provided the best discrimination between healthy fetuses and those with CoA (AUC 0.91, 95% CI: 0.86-0.96, I/D < 0.74 sensitivity 96.3%, I/D < 0.6, specificity 92.5%) with good classification capacity in both the second and third trimesters of gestation. Isthmus z-score and pulmonary/aortic valve ratio increased accuracy in fetuses >28 and tricuspid/mitral valve ratio (TV/MV) in fetuses ≤28 weeks. Study of I/D plus TV/MV ratio in fetuses ≤28 and I/D ratio plus isthmus z-scores in fetuses >28 weeks allowed to correctly classify 91.8% of fetuses as high or low probability of postnatal CoA.

CONCLUSIONS

Diagnostic discrimination of anatomic predictive factors for CoA varies according to GA. Specific algorithms according to GA increase accuracy in CoA's prenatal prediction.

The clinical presentation and outcome of aortic coarctation associated with left ventricular inflow and outflow tract lesion in adult patients: Shone syndrome and beyond

BACKGROUND

Aortic coarctation (AoCoa) is a congenital stenosis of aorta, which often co-exists with other congenital heart defects. Many studies have shown the importance of regular follow-up in these patients however there is scarcity of knowledge relating to the impact of left ventricle inflow lesions (LVIT) and left ventricle outflow track lesions (LVOT). The aim of this study is to evaluate the impact of isolated AoCoa with LVIT and/or LVOT on haemodynamic, morbidity and mortality.

METHODS

We have retrospectively analysed clinical data of all adult AoCoa patients who underwent echocardiography between 2010-2018 in our centre. Outcome measures included death, number of hospitalisations for cardiac causes, development of cardiac arrhythmia, new prescription of HF medication.

RESULTS

A total of 406 AoCoa patients were included and were followed for a median 4.2 years. At baseline, 38% patients had AoCoa alone, 54% patients had LVOT, 3% patients had LVIT, and 5% patients had mixed LVIT and LVOT, including patients with Shone syndrome. Patients with mixed LVIT and LVOT had the highest mortality of the four groups and the highest heart failure-related morbidity. Moreover, they were the most prone to have a higher indexed LA volume compared to patients with no LVOT (p=0.0001). During follow-up, 13 patients died, of which 21% patients were from the mixed LVIT and LVOT group.

CONCLUSIONS

AoCoa patients with a combination of LVIT and LVOT including Shone complex are associated with a significantly higher morbidity and mortality compared to AoCoa alone.

Equal cerebral perfusion during extended aortic coarctation repair

OBJECTIVES

Aortic coarctation with distal aortic arch hypoplasia can be effectively addressed by coarctation resection with extended end-to-end-anastomosis (REEEA). Particularly, when unilateral cerebral perfusion (UCP) is established by clamping of left-sided supra-aortic vessels, the extent of cerebral blood flow distribution during repair remains undetermined, so far. Transfontanellar contrast-enhanced ultrasound (T-CEUS) can be utilized for real-time visualization and quantitative evaluation of cerebral blood flow. This study quantitatively evaluates cerebral perfusion during REEEA by using intraoperative T-CEUS.

METHODS

In a prospective study, 9 infants with open fontanelle undergoing REEEA [median age: 13 days (range 1-34) and median weight 3.1 kg (range 2.2-4.4)] were intraoperatively examined with T-CEUS at 3 consecutive time-points: before skin incision, during UCP and after skin suture. A software-based analysis of 11 parameters was used for data evaluation. Absolute and relative blood flow in contralateral hemispheres was measured in side-by-side comparison, and referenced to baseline measurements.

RESULTS

No side-depend absolute or relative cerebral perfusion differences were found during REEEA, except for an increased relative 'wash-out-rate' (P = 0.0013) in favour of the right hemisphere after surgery. Compared to ipsilateral baseline levels, 'rise time' was transiently increased in right (P = 0.0277) and 'time-to-peak' in both hemispheres (right: P = 0.0403 and left: P = 0.0286), all during UCP.

CONCLUSIONS

The use of T-CEUS provided evidence for homogenous distribution of contrast agent in both hemispheres during UCP. T-CEUS can be utilized for the postprocedural evaluation of cerebral perfusion during congenital cardiac surgery.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov Unique, Identifier: NCT03215628.

Combined endovascular and open treatment to prevent increase in afterload in anastomotic pseudoaneurysm and aortobronchial fistula after surgery for aortic coarctation

We report the treatment of a patient who had presented with hemoptysis due to an aortobronchial fistula from an anastomotic pseudoaneurysm after extra-anatomic bypass for aortic coarctation. An aortobronchial fistula can often result from an aortic pseudoaneurysm and is associated with high mortality if not treated. We decided to use combined endovascular and open surgical treatment and obtained a satisfactory intraoperative result. The perioperative outcome and first follow-up visit were favorable. In recent years, endovascular repair of pathologic aortic conditions has increased; thus, we have placed the present case within the context of the relevant medical literature.

Carotid atherosclerosis, changes in tissue remodeling and repair in patients with aortic coarctation

BACKGROUND AND AIMS

After aortic coarctation (CoA) repair, patients still suffer from cardiovascular complications. The aim of this study was to measure cardiovascular markers, intima-media thickness (IMT) and plaques in controls and patients with CoA.

METHODS

Sixty-four patients with CoA (66% male, mean age 48 ± 15 years) and controls (54% men, mean age 47 ± 16 years) underwent ultrasound of their arteries. A multiplex platform to analyze circulating blood levels biomarkers reflecting inflammation, tissue remodeling and repair was used.

RESULTS

In men following CoA repair, a significantly increased carotid bulb IMT was observed in comparison to the control group (1.05 [0.72-1.24] vs. 0.67 [0.59-0.95] mm; p = 0.003). Median common carotid artery (CCA) IMT was increased in men compared to controls (0.82 [0.61-0.97] mm vs. 0.58 [0.53-0.76] mm, p < 0.003) and in women compared to controls (0.83 [0.70-0.92] vs. 0.60 [0.55-0.69], p < 0.004). CoA demonstrated an independent association with IMT in both men and women. Men with CoA were also more likely to have a plaque in their carotid arteries (p = 0.010). In women with CoA, we observed significantly lower levels of stem cell factor (SCF, p = 0.004) while in men with CoA we observed significantly lower levels of matrix metalloproteinase-3 (MMP-3, p = 0.048), tumor necrosis factor receptor 1 (TNF-R1, p = 0.032), tumor necrosis factor receptor superfamily member 10B (TRAIL-R2, p = 0.019) and monocyte chemotactic protein 1 (MCP-1, p = 0.015).

CONCLUSIONS

This is the first study to show that despite successful CoA repair, patients have more carotid atherosclerosis than can be explained by changes in tissue remodeling and repair.

Delayed presentation of massive haemoptysis from aortic aneurysm after aortic coarctation repair (a case report)

Introduction

Massive haemoptysis refers to coughing and losing a huge amount of blood in a 24-hour period. It's a life-threatening condition with high mortality rate.

Case presentation

We report a rare case of massive haemoptysis in a 60-year-old female patient who had aortic coarctation repair 30 years ago. Her Computed tomography (CT) angiography showed huge aneurysmal dilatation and dissection of the descending thoracic aorta at the site of the repair. Thoracic endovascular aortic repair (TEVAR) was done, but the patient had recurrent massive haemoptysis due to extension of the aneurysm to the aortic arch. The patient then underwent one stage surgical right to left carotid artery shunt followed by TEVAR to the aortic arch covering the left common carotid artery. The procedure was successful, and haemoptysis was controlled without any complications.

Discussion

In this case the high index of suspicion for thoracic aortic aneurysm in patients presenting with haemoptysis and prior history of coarctation repair were demonstrated.

Conclusion

massive haemoptysis in patients who had aortic coarctation repair is an alarming sign, and surgical intervention is required. TEVAR has become one of the best approaches for managing aortic aneurysm and has replaced open repair.

•

Thoracic aortic aneurysms must be ruled out in those patients who present with massive hemoptysis.

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In case of aortic coarctation repair, thoracic aortic aneurysms should be considered.

•

Thoracic endovascular aortic repair (TEVAR) has become one of the best approaches for managing thoracic aortic pathology.

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In patients who present with massive hemoptysis post TEVAR, aneurysms and endoleak must be ruled out.

Giant descending aortic pseudo-aneurysm in an adult man with uncorrected aortic coarctation

Background

Aortic coarctation (CoAo) accounts for 6 to 8% of all congenital heart diseases and occurs two to five times more often in males. The uncorrected aortic coarctation is complicated by hypertension, ascending and descending aortic aneurysms, endarteritis, and heart failure. The aortic pseudo-aneurysm (APD) usually occurs in patients with endarteritis. We report an adult man with bicuspid aortic valve, perimembranous ventricular septal defect, and uncorrected aortic coarctation complicated by descending aortic pseudo-aneurysm without aortic endarteritis.

Case presentation

A 40-year-old man was referred to our division for hemoptysis and severe aortic coarctation. Echocardiography confirmed the aortic coarctation diagnosis and showed a large aortic pseudo-aneurysm at the coarctation site with intra-cavity mural thrombus. Subsequently, the patient underwent contrast-enhanced computed tomography angiography, and diagnosis of coarctation and APD was confirmed. Due to various malformations and considering that the patient had become unstable due to hemoptysis, it was discussed in the heart team, and it was decided that the patient would undergo staged surgery.

Conclusions

The aortic pseudo-aneurysm is a rare complication in patients with untreated coarctation that requires prompt surgery, and this complication should be considered in patients with untreated aortic coarctation who present with hemoptysis.

Effects of Uncertainty of Outlet Boundary Conditions in a Patient-Specific Case of Aortic Coarctation

Computational Fluid Dynamics (CFD) simulations of blood flow are widely used to compute a variety of hemodynamic indicators such as velocity, time-varying wall shear stress, pressure drop, and energy losses. One of the major advances of this approach is that it is non-invasive. The accuracy of the cardiovascular simulations depends directly on the level of certainty on input parameters due to the modelling assumptions or computational settings. Physiologically suitable boundary conditions at the inlet and outlet of the computational domain are needed to perform a patient-specific CFD analysis. These conditions are often affected by uncertainties, whose impact can be quantified through a stochastic approach. A methodology based on a full propagation of the uncertainty from clinical data to model results is proposed here. It was possible to estimate the confidence associated with model predictions, differently than by deterministic simulations. We evaluated the effect of using three-element Windkessel models as the outflow boundary conditions of a patient-specific aortic coarctation model. A parameter was introduced to calibrate the resistances of the Windkessel model at the outlets. The generalized Polynomial Chaos method was adopted to perform the stochastic analysis, starting from a few deterministic simulations. Our results show that the uncertainty of the input parameter gave a remarkable variability on the volume flow rate waveform at the systolic peak simulating the conditions before the treatment. The same uncertain parameter had a slighter effect on other quantities of interest, such as the pressure gradient. Furthermore, the results highlight that the fine-tuning of Windkessel resistances is not necessary to simulate the post-stenting scenario.

"Undiagnosed aortic coarctation with 2 simultaneous acute aortic syndromes: Intramural hematoma and mycotic aneurysm"

Acute aortic syndrome can be a fatal pathology if not diagnosed and managed early. Although acute aortic syndrome is more often a diagnosis of adulthood, it may occasionally afflict the pediatric patients. We herein present a case of a 5-year-old female that was discovered to have multiple acute and congenital aortic abnormalities after presenting to the emergency department with infectious symptoms and lower extremity pain. Acute aortic syndrome may not be a top differential consideration in children with acute chest pain; however, it is important to consider because delayed diagnosis and management can have fatal implications.

Heating of an Aortic Stent for Coarctation Treatment During Magnetic Particle Imaging and Magnetic Resonance Imaging-A Comparative In Vitro Study

PURPOSE

To evaluate heating of a redilatable stent for the treatment of aortic coarctation in neonates and small children in the new imaging modality magnetic particle imaging and established magnetic resonance imaging.

MATERIALS AND METHODS

The cobalt-chromium stent (BabyStent, OSYPKA AG, Rheinfelden, Germany) has a stent design which allows for redilatation and adjustment of the diameter from 6 to 16 mm for a use in aortic coarctation. The stent loses its radial integrity while opening at predetermined breaking points at a diameter of 14 mm or 16 mm, respectively. We measured the temperature increase in the stent at different diameters during 7-min magnetic particle imaging and magnetic resonance imaging scans with fiber optic thermometers under static conditions surrounded by air. In magnetic particle imaging, stents with diameters from 6 to 16 mm were tested while in magnetic resonance imaging only stents with diameters of 6 mm and 14 mm were investigated exemplarily.

RESULT

In magnetic particle imaging, the measured temperature differences increased up to 4.7 K with growing diameters, whereas the opened stents with discontinuous struts at 14 and 16 mm showed only minimal heating of max. 0.5 K. In contrast to magnetic particle imaging, our measurements showed no heating of the stents during magnetic resonance imaging under identical conditions.

CONCLUSION

The BabyStent did show only slight heating in magnetic particle imaging and no detectable temperature increase in magnetic resonance imaging.

Acute Stanford type A aortic dissection associated with aortic coarctation repaired by Tirone E. David & debranching techniques with combined axillar and femoral perfusion: a case report

We present the case of a 38-year-old male with a diagnosis of Stanford A aortic dissection and associated coarctation of the thoracic aorta. Acute dissection associated with coarctation of the aorta is a rare problem and difficult to manage surgically. Establishing a cardiopulmonary bypass (CPB) with adequate flows is the main objective of the procedure; optimal cannulation ensures the protection of cerebral and visceral organs. We successfully performed aortic valve re-implantation surgery (T. David Surgery), replacement of the ascending aorta and aortic arch, as well as debranching of the supra-aortic trunks. The cannulation technique was axillary and femoral to guarantee flows through the coarctation area.

Use of VA ECMO and percutaneous palliation of ductal dependent coarctation in a neonate with trisomy 21 and COVID-19 pneumonia

We present a case of a neonate with trisomy 21, ductal-dependent aortic coarctation, and severe respiratory failure secondary to coronavirus disease 2019 (COVID-19) pneumonia. The neonate was managed with venoarterial extracorporeal membrane oxygenation (VA ECMO), palliative stenting of the coarctation, and a vascular plug occlusion of a large patent ductus arteriosus. The patient was successfully weaned off extracorporeal membrane oxygenation (ECMO). The patient is currently awaiting a definitive surgical repair in the near future.

Comparison of stenosis models for usage in the estimation of pressure gradient across aortic coarctation

Non-invasive estimation of the pressure gradient in cardiovascular stenosis has much clinical importance in assisting the diagnosis and treatment of stenotic diseases. In this research, a systematic comparison is conducted to investigate the accuracy of a group of stenosis models against the MRI- and catheter-measured patient data under the aortic coarctation condition. Eight analytical stenosis models, including six from the literature and two proposed in this study, are investigated to examine their prediction accuracy against the clinical data. The two improved models proposed in this study consider comprehensively the Poiseuille loss, the Bernoulli loss in its exact form, and the entrance effect, of the blood flow. Comparison of the results shows that one of the proposed models demonstrates a cycle-averaged mean prediction error of -0.15 ± 3.03 mmHg, a peak-to-peak prediction error of -1.8 ± 6.89 mmHg, which is the best among the models studied.