Stenting of critical aortic coarctation in neonates between 600 and 1,350 g. Using a transfemoral artery approach. A single center experience

Background

Stenting of aortic coarctation (CoA) in newborns with a very low bodyweight remains rare and challenging. In this study we aim to highlight on two points: first the feasibility of CoA stenting in such babies and second the importance of using echocardiogram for guiding the intervention without the need for contrast agent.

Methods

Between 2020 and 2022 three preterm babies with very low (VLWB) and extremely low weight (ELWB) underwent CoA-stenting in our center. The weight of the patients at time of intervention was 1,350, 1,200, and 600 g, respectively. The femoral artery was chosen in all patients as vascular access. Transthoracic echocardiography, sonography of the femoral arteries and head ultrasound were applied for follow up.

Results

All three interventions were successfully done, with no complications. Coronary stents were implanted. In one Patient (1,350 g) the stent was inserted without sheath. In two patients with renal failure, the stenting was performed under echocardiography-guidance without contrast agent. The follow up showed a preserved function of the left ventricle in all patients. No relevant gradient was reported and no stent re-intervention was required. Sonographic follow up showed a patent femoral artery in all patients. Two patients were operated 73 and 110 days after stenting, and the stents were successfully removed. In the third patient the intervention was performed 130 days ago and he is waiting for the operation.

Conclusion

CoA-stenting in VLWB and ELWB is feasible and can bridge them to the next surgery without complications. Echocardiography-guided CoA-stenting in VLWB is a considerate option especially in patients with renal failure. Accessing the femoral artery by experienced doctors, using local anesthesia before the puncture and before removing the sheath might help to protect the vessel from stenosis or occlusion.

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.

Evaluating the severity of aortic coarctation in infants using anatomic features measured on CTA

OBJECTIVES

A machine learning model was developed to evaluate the severity of aortic coarctation (CoA) in infants based on anatomical features measured on CTA.

METHODS

In total, 239 infant patients undergoing both thorax CTA and echocardiography were retrospectively reviewed. The patients were assigned to either mild or severe CoA group based on their pressure gradient on echocardiography. They were further divided into patent ductus arteriosus (PDA) and non-PDA groups. The anatomical features were measured on double-oblique multiplanar reconstructed CTA images. Then, the optimal features were identified by using the Boruta algorithm. Subsequently, the coarctation severity was classified using linear discriminant analysis (LDA). We further investigated the relationship between the anatomical features and re-coarctation using Cox regression.

RESULTS

Four anatomical features showed significant differences between the mild and severe CoA groups, including the smallest aortic cross-sectional area indexed to body surface area (p < 0.001), the narrowest aortic diameter (CoA diameter) indexed to height (p < 0.001), the diameter of the descending aorta at the diaphragmatic level (p < 0.001) and weight (p = 0.005). With these features, accuracy of 88.6% and 90.2%, sensitivity of 65.0% and 72.1%, and specificity of 92.9% and 100% were obtained for classifying the CoA severity in the non-PDA and PDA groups, respectively. Moreover, CoA diameter indexed to weight was associated with the risk of re-coarctation.

CONCLUSIONS

CoA severity can be evaluated by using LDA with anatomical features. When quantifying the severity of CoA and risk of re-coarctation, both anatomical alternations at the CoA site and the growth of the patients need to be considered.

KEY POINTS

• CTA is routinely ordered for infants with coarctation of the aorta; however, whether anatomical variations observed with CTA could be used to assess the severity of CoA remains unknown. • Using the diameter and area of the coarctation site adjusted to body growth as features, the LDA model achieved an accuracy of 88.6% and 90.2% in differentiating between the mild and severe CoA patients in the non-PDA group and PDA group, respectively. • The narrowest aortic diameter (CoA diameter) indexed to weight has a hazard ratio of 10.29 for re-coarctation.