Use of Noninvasive Imaging in the Evaluation of Coarctation of Aorta:

Pre-operative Imaging of Critical Coarctation of the Aorta: Impact on Surgical Approach and Outcomes

Computed tomographic angiography (CTA) has been increasingly used for the evaluation of infants with aortic arch hypoplasia and coarctation of the aorta. The goals of this study were to compare echocardiographic and CTA findings in critical coarctation of the aorta, to evaluate each modality's influence on surgical approach for repair and determine if pre-operative measurements or surgical approach are associated with residual lesions/re-interventions. This was a single-center retrospective cohort study that included 85 neonates and infants who underwent repair of coarctation/arch hypoplasia by three months of age. Two groups were compared: patients with pre-operative echocardiograms only and patients with both echocardiogram and CTA evaluations. 44 (52%) patients received an echocardiogram and CTA, and 41 (48%) patients received an echocardiogram only. Patients in the CTA + echo group had smaller mitral valve and ascending aorta measurements (p = 0.01). When comparing CTA to echocardiogram measurements, the aortic valve annulus, ascending aorta, proximal and distal transverse arch, and isthmus were smaller on echo (p < 0.01). A smaller aortic valve annulus and aortic root as well as thoracotomy approach were associated with residual gradients/re-intervention (p < 0.01). Our study found that patients who underwent CTA preoperatively had smaller left-sided structures. Aortic measurements were smaller on echocardiogram when compared to CTA. Smaller left-sided structures proximal to the aortic arch and thoracotomy predicted the development of residual lesions/re-intervention. CTA is useful in the surgical planning for neonates with arch hypoplasia/coarctation and may help risk stratify for residual lesions/re-intervention.

Non-Invasive Imaging Assessment in Patients with Aortic Coarctation: A Contemporary Review

Coarctation of the aorta (CoA) is a congenital abnormality characterized by a narrowing of the aortic lumen, which can lead to significant morbidity and mortality if left untreated. Even after repair and despite significant advances in therapeutic management, these patients have overall reduced long-term survival due to the consequences of chronic afterload increase. Cardiovascular imaging is key from the first diagnosis to serial follow-up. In recent years, novel imaging techniques have emerged, increasing accessibility to advanced imaging modalities and enabling early and non-invasive identification of complications after repair. The aim of this paper is to provide a comprehensive review of the role of different imaging techniques in the evaluation and management of patients with native or repaired CoA, highlighting their unique strengths and limitations.

Diagnosis of covert coarctation of the aorta in adolescents

Objectives

By reviewing the diagnostic process for adolescents with coarctation of the aorta (CoA) in our institution, we analyzed the reasons for delayed diagnosis of CoA. We also proposed a diagnostic protocol to improve the detection rate of CoA.

Methods

In this retrospective study, we included 48 patients aged 12-18 years who were diagnosed with CoA in our hospital from January 2000 to November 2022. Clinical data from involved cases in local hospitals and our institution were collected.

Results

All patients had blood pressure (BP) measurements in upper and lower extremities in our institution. They all had hypertension, 29 (60.4%) of whom had known histories of the same. BP in the upper limbs of 47 (97.9%) patients was ≥20 mmHg higher than that in the lower limbs, and BP in the upper limb of 1 (2.1%) patient was greater than 0 and less than 20 mmHg than that in the lower limb. Echocardiography (ECHO) was performed in all patients, computed tomography (CT) or magnetic resonance imaging (MRI) was performed in 44 patients (91.7%). There were 38 (79.2%) patients who visited local hospitals. Among them, a total of 20 (52.6%) patients had their right upper extremity BP measured, 18 (47.4%) only had their left upper extremity BP measured, and 16 (42.1%) had their lower extremity BP measured. ECHO was performed in 27 (56.2%) patients and CT/MRI was performed in 18 (37.5%) patients. The detection rate for CT/MRI was 100%, and those of ECHO were 72.9% and 18.5% at our institution and a local hospital, respectively. Forty-eight (100%) and 23 (60.5%) patients were detected in our institution and local hospitals (P < 0.0001).

Conclusion

We recommend measuring BP in the bilateral upper extremities. Measurement of BP in the lower extremities is recommended if hypertension is diagnosed. MRI/CT is recommended when BP in the upper extremity is greater than that in the lower extremity.

Intravascular Ultrasound for Assessment of Residual Coarctation of the Aorta after Balloon Angioplasty in Infants

Intravascular ultrasound (IVUS) has been introduced as an accurate and minimally invasive diagnostic technique for the assessment of vascular anatomy and its abnormalities. We believe that IVUS can be used for clarifying the reasons for failure of balloon angiography in infantile coarctation of the aorta (CoA), because post-balloon angioplasty tearing, intimal flap, thrombosis and pseudoaneurysm of the aorta can be evaluated by IVUS with greater sensitivity and specificity. We aimed to assess the outcome of balloon angioplasty of CoA using angiography as the gold standard and IVUS as a new method in infants, comparing the two techniques for the evaluation of the diameter and area of CoA segment pre- and post-procedure. This cross-sectional study was performed on 18 infants hospitalized with a final diagnosis of CoA. All the infants underwent angiography and were also assessed by IVUS to measure the preoperative and postoperative diameter of the narrow segment in the two anterior-posterior and lateral views. In assessment by IVUS, the mean diameter of the coarctation site increased from 2.10 ± 0.30 mm to 4.50 ± 0.94 mm (P < 0.001). Similarly, the average minimum area of the coarctation level increased from 5.26 ± 1.50 mm² to 13.77 ± 3.48 mm² after angioplasty (P < 0.001). Comparing these findings, angiography and IVUS showed a high level of agreement. In the assessment of a dissection flap, there was a high level of agreement between angioplasty and IVUS before the procedure, but IVUS had higher accuracy after the procedure. Our study showed that IVUS was more reliable than angiography in the assessment of residual coarctation. IVUS yielded high sensitivity (58.3%) and specificity (100%) for discriminating the presence and absence of residual coarctation as well as the need for repeating the procedure. The assessment of coarctation before and after angioplasty procedures in children is possible using the IVUS method, with high accuracy. IVUS can offer greater accuracy than angiography in the evaluation of the coarctation area, detecting tears, dissection and flaps, and assessment of residual coarctation.

Preoperative Physiology, Imaging, and Management of Coarctation of Aorta in Children

Coarctation of the aorta (CoA) is a narrowing of the proximal thoracic aorta typically located at the junction of the aorta with the ductus arteriosus. While it is a simple lesion to understand, considerable variation exists in the anatomy and pathophysiology, leading to varied clinical presentation, management options, and prognosis. On the one hand critical CoA manifests in the neonatal period as a duct-dependent lesion, while less severe forms of obstruction present later in childhood or adulthood as hypertension or incidentally noted precordial murmurs. While transthoracic echocardiography is usually adequate, older children and adults may need more advanced imaging modalities like computed tomography and magnetic resonance imaging prior to intervention. Depending on the type of lesion, management options currently available include surgery and percutaneous balloon angioplasty and stenting. Even after successful interventions, these patients need life-long surveillance for residual aortic obstruction and systemic hypertension with variable long-term clinical outcomes.

Diagnosis of Congenital Coarctation of the Aorta and Accompany Malformations in Infants by Multi-Detector Computed Tomography Angiography and Transthoracic Echocardiography: A Chinese Clinical Study

Background

The purpose of this study was to evaluate the utility of multi-detector computed tomography (MDCT) angiography and transthoracic echocardiography (TTE) in the diagnosis of congenital coarctation of the aorta (CoA) and accompanying malformations in infants.

Material/Methods

From January 2012 and December 2015, we enrolled 68 infants with clinically suspected CoA who underwent MDCT angiography and TTE in our hospital. Surgical correction was conducted to confirm the diagnostic accuracy of both examinations in all patients.

Results

In this study, the diagnosis of CoA was confirmed infants by surgical results in 55 of 68 infants. The diagnostic accuracy, sensitivity, and specificity of MDCT angiography were 95.6%, 96.4%, and 92.3%, respectively. The diagnostic accuracy, sensitivity, and specificity of TTE were 88.2%, 90.9%, and 76.9%, respectively. There was no significant difference in diagnostic accuracy, sensitivity, and specificity between MDCT angiography and TTE (χ²=2.473, p>0.05, χ²=1.373, p>0.05 and χ²=1.182, p>0.05, respectively). In the diagnosis of concomitant cardiac abnormalities with CoA, the 2 methods also play different roles.

Conclusions

MDCT angiography and TTE play different roles in the diagnosis of CoA and accompany malformations. MDCT angiography in the diagnosis of the extra-cardiac vascular malformations is better than TTE, and TTE is superior to MDCT angiography in diagnosing intracardiac malformation. Combined MDCT angiography and TTE is a relatively valuable, reliable, and noninvasive method in the diagnosis of CoA and accompany malformations in infants.

Comparison of invasive and non-invasive pressure gradients in aortic arch obstruction

BACKGROUND

Aortic arch obstruction can be evaluated by catheter peak-to-peak gradient or by Doppler peak instantaneous pressure gradient. Previous studies have shown moderate correlation in discrete coarctation, but few have assessed correlation in patients with more complex aortic reconstruction.

METHODS

We carried out retrospective comparison of cardiac catheterisations and pre- and post-catheterisation echocardiograms in 60 patients with native/recurrent coarctation or aortic reconstruction. Aortic arch obstruction was defined as peak-to-peak gradient ⩾25 mmHg in patients with native/recurrent coarctation and ⩾10 mmHg in aortic reconstruction.

RESULTS

Diastolic continuation of flow was not associated with aortic arch obstruction in either group. Doppler peak instantaneous pressure gradient, with and without the expanded Bernoulli equation, weakly correlated with peak-to-peak gradient even in patients with a normal cardiac index (r=0.36, p=0.016, and r=0.49, p=0.001, respectively). Receiver operating characteristic curve analysis identified an area under the curve of 0.61 for patients with all types of obstruction, with a cut-off point of 45 mmHg correctly classifying 64% of patients with arch obstruction (sensitivity 39%, specificity 89%). In patients with aortic arch reconstruction who had a cardiac index ⩾3 L/min/m², a cut-off point of 23 mmHg correctly classified 69% of patients (71% sensitivity, 50% specificity) with an area under the curve of 0.82.

CONCLUSION

The non-invasive assessment of aortic obstruction remains challenging. The greatest correlation of Doppler indices was noted in patients with aortic reconstruction and a normal cardiac index.

CT and MRI of aortic coarctation: pre- and postsurgical findings

OBJECTIVE. The purpose of this article is to summarize the roles of CT and MRI in the diagnosis and follow-up of patients with aortic coarctation. CONCLUSION. Aortic coarctation is a common congenital heart disease accounting for approximately 6-8% of congenital heart defects. Despite its deceptively simple anatomic presentation, it is a complex medical problem with several associated anatomic and physiologic abnormalities. CT and MRI may provide very accurate information of the coarctation anatomy and other associated cardiac abnormalities.