Validation and Diagnostic Performance of a CFD-Based Non-invasive Method for the Diagnosis of Aortic Coarctation

Purpose: The clinical diagnosis of aorta coarctation (CoA) constitutes a challenge, which is usually tackled by applying the peak systolic pressure gradient (PSPG) method. Recent advances in computational fluid dynamics (CFD) have suggested that multi-detector computed tomography angiography (MDCTA)-based CFD can serve as a non-invasive PSPG measurement. The aim of this study was to validate a new CFD method that does not require any medical examination data other than MDCTA images for the diagnosis of CoA.Materials and methods: Our study included 65 pediatric patients (38 with CoA, and 27 without CoA). All patients underwent cardiac catheterization to confirm if they were suffering from CoA or any other congenital heart disease (CHD). A series of boundary conditions were specified and the simulated results were combined to obtain a stenosis pressure-flow curve. Subsequently, we built a prediction model and evaluated its predictive performance by considering the AUC of the ROC by 5-fold cross-validation.Results: The proposed MDCTA-based CFD method exhibited a good predictive performance in both the training and test sets (average AUC: 0.948 vs. 0.958; average accuracies: 0.881 vs. 0.877). It also had a higher predictive accuracy compared with the non-invasive criteria presented in the European Society of Cardiology (ESC) guidelines (average accuracies: 0.877 vs. 0.539).Conclusion: The new non-invasive CFD-based method presented in this work is a promising approach for the accurate diagnosis of CoA, and will likely benefit clinical decision-making.

Balloon Angioplasty for Native Aortic Coarctation in 3- to 12-Month-Old Infants

Background: Balloon angioplasty for native coarctation of the aorta (CoA) is successful in children and adults but in neonates results in frequent restenosis. The efficacy of balloon angioplasty for native CoA during infancy beyond the neonatal period was examined in infants aged 3 to 12 months of age. Methods: A retrospective review of 68 infants who underwent balloon angioplasty for native CoA. 95% CI are in parentheses. Results: Procedural age was (mean±SD) 6±3.4 months and weight was 7±1.8 kg. Balloon angioplasty produced a large decrease in both the noninvasive arm-to-leg blood pressure gradient (41.2±18.7 to 5.6±9.6 mm Hg) and the invasive peak systolic pressure gradient (34±12 to 11±9 mm Hg). Balloon angioplasty increased the CoA diameter from 2.7±1 mm to 4.6±1.2 mm. One patient was lost to follow-up. A catheter reintervention was required in 11.8% and surgery in 10.3%. The hazard of reintervention was highest early. Median freedom from reintervention was 89% (95% CI, 80%–96%) at 1 year, 83% (95% CI, 73%–92%) at 5 years, and 81% (95% CI, 69%–90%) at 10 years. Femoral artery thrombosis was documented in 6 (9%) infants without any long-term consequence. One patient developed a small aortic aneurysm late and has not required treatment. A robust estimate of the frequency of aortic aneurysms remains to be determined as the majority of subjects have not had cross-sectional imaging. Conclusions: Balloon angioplasty of native CoA is effective and safe in infants aged 3 to 12 months with outcomes comparable to those in older children and adults. Catheter reinterventions can avoid the need for surgery in most patients.

Original method of posterior aortoplasty for aortic valve replacement in cases with narrow aortic ostium

132 patients with isolated aortic valve disease with narrow aortic ostium who underwent surgery in the Institute from 1 May 2009 to 01 Jan 2019 are included in the study group. Among 132 patients, 6 died at the hospital stage (hospital mortality – 4.5%). There were no negative remarks to the surgical technique in any case. Changes in echo data during the hospital stay: systolic pressure gradient across the left ventricular outflow tract (LVOT) before operation was 105.1±11.5 mmHg, with 25.9±4.1 mmHg on the aortic prosthesis upon discharge. Reconstruction of the root and ascending aorta according to the proposed method in cases of aortic hypoplasia and aortic valve replacement (AVR) is highly effective intervention. The purpose of this research is to study possibilities of a new approach to the reconstruction of the root and ascending aorta in AVR.

Balloon Pulmonary Valvuloplasty in patients with Congenital Valvular Pulmonary Stenosis

Background Congenital valvular pulmonary stenosis (PS) accounts for most of the etiology of PS, and constitutes about 5 to 10% of all congenital heart disease. Balloon Pulmonary Valvuloplasty has become the choice of treatment for valvular PS since the first series reported by Kan et al in 19824 and has almost replaced surgical valvotomy in pediatric patients. The purpose of this study was to investigate the immediate results of balloon valvuloplasty in patients with congenital valvular pulmonary stenosis. Method We analyzed hemodynamic data of 122 patients who underwent balloon pulmonary valvuloplasty (ages14days- 50 years mean 25 years). Single-balloon technique was used. Right ventricle systolic pressure and pulmonary valve Peak-to-peak systolic pressure gradient were recorded before and after balloon dilatation of pulmonary valve. Result Right ventricle systolic pressure decreased from 128±44.9 to 60±24.9 mmHg (p <0.001) and pulmonary valve peak-to-peak systolic pressure gradient decreased from 89±38.6 to 45 ± 22.4 mmHg (p <0.001). No major complication or mortality was noted. Conclusion Balloon pulmonary valvuloplasty is a safe and effective treatment for patients with congenital valvular PS. DOI: http://dx.doi.org/10.3126/njh.v9i1.8340 Nepalese Heart Journal Vol.9(1) 2012 pp.7-9ca

Extra-Anatomical Bypass: A Surgical Option for Recurrent Aortic Coarctation

Background. Balloon aortoplasty with or without stenting is a less invasive alternative to open surgery for the management of recurrent isthmic coarctation. However, in patients with previous small size tube graft, an open surgical correction is mandatory and, in most cases, an anatomical aortic reconstruction is carried out.Methods. We present the case of a 48-year-old woman with recurrent aortic coarctation and systemic hypertension with systolic value around 190–200 mmHg and preoperative systolic pressure gradient 70 mmHg, submitted to an extra-anatomical bypass. Through a median sternotomy, an extra-anatomical bypass from ascending to descending aorta was performed.Results. No intra- or postoperative complications were observed. The postoperative pressure gradient was 10 mmHg and the systolic pressure ranged from 130 to 140 mmHg.Conclusion. The extra-anatomical bypass can be considered an effective and safe alternative to the anatomical aortic reconstruction in the cases with recurrent aortic coarctation unfit for endovascular treatment.

Results of balloon dilatation of stenotic homografts in pulmonary position in children and young adults

ObjectivesTo evaluate the results of balloon dilatation of stenotic homografts in children, adolescents, and young adults and to identify factors that might influence or predict the effect of the dilatation.BackgroundHomografts are widely used in congenital cardiac surgery; however, the longevity remains a problem mostly because of stenosis in the homograft. The effect of treatment by balloon dilatation is unclear.MethodsIn a retrospective study, the effect of balloon dilatation was determined by the percentage of reduction of the peak systolic pressure gradient over the homograft during catheterisation and the postponement of re-intervention or replacement of the homograft in months. Successful dilatations – defined in this study as a reduction of more than 33% and postponement of more than 18 months – were compared with unsuccessful dilatations in search of factors influencing or predicting the results.ResultsThe mean reduction of the peak systolic pressure gradient was 30% in 40 procedures. Re-intervention or replacement of the homograft was postponed by a mean of 19 months. In all, 14 balloon dilatations (35%) were successful; the mean reduction was 49% and the mean postponement was 34 months. The time since homograft implantation, the presence of calcification, the homograft/balloon ratio, and the pressure applied during dilatation all tended to correlate with outcome, but were not statistically significant.ConclusionsBalloon dilatation is able to reduce the peak systolic pressure gradient over homografts in a subgroup of patients and can be of clinical significance to postpone re-intervention or pulmonary valve replacement.

Stenosis of a Reconstructed Aorta Caused a Paradoxical Diastolic Pressure Gradient after Norwood Operation

An infant with hypoplastic left heart syndrome showed paroxysmal episodes of bradycardia, hypotension, and hypoxemia upon crying after modified Norwood operation. Echocardiography showed decreased right ventricular ejection with grade III tricuspid regurgitation, a markedly enlarged aortic arch, and accelerated blood flow distal to the enlarged aorta. Aortography demonstrated an aneurysmal neo-aorta with an apple-shaped appearance. The pressure measurements revealed intriguing aortic hemodynamics: the diastolic pressure of the ascending aorta was lower than that of the descending aorta (42 mmHg vs. 52 mmHg) despite no systolic pressure gradient. Markedly reduced compliance in the ascending aorta relative to that in the descending aorta, which was suggested by the difference in time constant of aortic pressure decay, may explain this hemodynamics. Impaired coronary circulation caused by lowered diastolic pressure in ascending aorta was indicated by reduced subendocardial viability ratio, and may account for her symptom and lowered ventricular ejection. The patient's condition was indeed significantly improved by surgical correction of the aortic shape. This case highlights the importance of aortic shape and properties after Norwood operation.