Stenting of Significant Aortic Coarctation Near Artery of Adamkiewicz in a Toddler

Abstract

Background

Abdominal coarctation of the aorta is rare, and it poses unique procedural challenges when located near the artery of Adamkiewicz.

Case Summary

We describe a 4-year-old female patient who was found to have an abdominal coarctation of the aorta at the level of the diaphragm. Despite normal growth and minimal symptoms, the patient had significant upper-to-lower extremity blood pressure gradients and developed hypertension. The child underwent successful stent placement, achieving marked improvement in aortic diameter and pressure gradient without complications.

Discussion

Few pediatric cases of distal aortic coarctation have been reported, and many involve congenital disorders such as Williams syndrome. Significant controversy remains regarding open surgical vs percutaneous stent approaches, especially in children with anatomical complexities.

Take-Home Messages

Abdominal coarctation near the artery of Adamkiewicz is extremely uncommon. Careful preprocedural imaging and multidisciplinary planning can enable safe stent implantation, though follow-up is necessary to monitor for restenosis and vessel growth.

Graphical Abstract

History of Presentation

A 4-year-old female child born at term was noted to have a soft systolic murmur shortly after birth, which spontaneously resolved. However, a new murmur at age 3 prompted further evaluation, revealing focal stenosis of the aorta near the level of the diaphragm. Upon presentation, the patient was asymptomatic, with no exercise intolerance or chest/leg pain. Physical examination revealed normal upper extremity pulses (+2) but diminished femoral pulses (+1) and a 2/6 systolic murmur heard between the scapulae. Blood pressure readings demonstrated evidence of an obstruction between the right arm (118/72 mm Hg) and the right leg (85/61 mm Hg).

Take-Home Messages

• •Preprocedural imaging is vital to identify critical structures such as the artery of Adamkiewicz to avoid catastrophic complications in abdominal coarctation cases.
• •Stent placement can be a viable option even in pediatric patients, though long-term monitoring is essential given the risk of restenosis, vessel growth mismatch, or stent-related complications.

Past Medical History

The child had no hospital admissions apart from routine newborn care. Growth and development were normal, and no family history of congenital heart disease was disclosed. An older brother has Hirschsprung disease, but there was no other relevant family history.

Differential Diagnosis

Initially, the differential diagnosis for a child with a systolic murmur and discrepant upper vs lower extremity blood pressures included the following points:

• 1.Classic coarctation of the aorta (typically just distal to the left subclavian artery).
• 2.Middle aortic syndrome (narrowing of the distal thoracic or abdominal aorta and typically seen in older children or adults).
• 3.Genetic predisposition of long-segment arterial narrowing such as Williams syndrome.

Given the localization at the level of the diaphragm, a distal (abdominal) coarctation was ultimately confirmed.

Investigations

Initial echocardiogram showed turbulent, continuous flow in the abdominal aorta with a peak gradient of 41 mm Hg. The aortic arch and proximal descending aorta were normal, and no intracardiac anomalies were noted. Subsequent computed tomography angiogram delineated a 4 × 3 mm segment of concentric narrowing, approximately 1.7 cm in length at the diaphragmatic hiatus (Figure 1). Additional renal artery and lower extremity duplex studies revealed tardus-parvus waveforms consistent with proximal aortic obstruction, though the renal arteries themselves were patent. Six months after the initial echocardiogram, echocardiographic gradient estimates rose to 59 mm Hg (angle-corrected to 97 mm Hg) with the development of upper extremity hypertension. Genetic testing was negative for Williams syndrome, Turner syndrome, and aortopathy. Congenital heart disease panels were negative.

Figure 1.

Diagnostic Abdominal Computed Tomography Angiogram

(A) Coronal and (B) sagittal multiplanar reconstructions showing a focal stenosis (arrows) in the distal descending thoracic aorta.

Management

Owing to progressive gradients and the development of upper extremity hypertension, the patient was initiated on atenolol with dose adjustments over time to control blood pressure. Surgical repair vs a catheter-based approach was debated extensively. Although open surgical repair is sometimes favored in complex pediatric aortic lesions, the interventional team believed a stent could be placed if the artery of Adamkiewicz, identified arising from the left ninth intercostal artery, was sufficiently proximal to avoid compromise.

Under general anesthesia and heparin anticoagulation, the patient underwent right and left heart catheterization via a femoral approach. Using percutaneous entry and a sheath, a 6-F wedge catheter was inserted into the right femoral vein and advanced from the inferior vena cava to the right atrium, superior vena cava, right ventricle, and pulmonary arteries. Similarly, a 4-F pigtail catheter was inserted percutaneously into the right femoral artery and passed retrograde into the descending aorta, ascending aorta, and left ventricle. Angiographic assessment confirmed the distal aortic coarctation and location of the artery of Adamkiewicz (Figure 2). The vascular surgery team confirmed availability to intervene should injury to this vessel occur.

Figure 2.

Operative Digital Subtraction Angiogram

(A) Anterior-posterior DSA showing focal concentric stenosis of the abdominal aorta distal to the ninth intercostal arteries; there is extensive collateralization between the intercostal arteries. (B) DSA in the lateral projection showing the spinal artery arising from the ninth intercostal artery (arrow). (C) Later image from the same DSA showing the characteristic hairpin turn (straight arrow) and straight descending course (curved arrow) of the spinal artery in the anterior spinal canal.

The pigtail catheter was then exchanged for a 5-F Glidecath catheter (Terumo) that was advanced using a 0.035-inch Amplatz extra stiff wire to provide a secure rail. The indwelling femoral arterial sheath and the Glidecath catheter were exchanged for a 9-F 65-cm Arrow Metal sheath (Teleflex) that was advanced into the distal thoracic aorta, and the dilator was exchanged for a 7 mm × 4 cm Advance 35LP low-profile balloon dilation catheter (Cook Medical) that had been premounted with a 26-mm IntraStent Mega LD S17-26 large-diameter stent (Medtronic). With the balloon positioned angiographically across the coarctation, the balloon was inflated to 12 atm with ideal positioning of the stent, leaving mild residual narrowing in the cephalad portion of the now-stented long coarctation. The Advance 35LP catheter was subsequently exchanged for a 6 × 40 mm Dorado balloon dilation catheter (Becton Dickinson) and was inflated to 24 atm with some additional improvement in caliber of the stent and surrounding coarctation. The Dorado was then exchanged for a 7 × 40 mm Dorado that was positioned across the Mega stent and inflated to 14 atm with the stent expanding and becoming much more homogeneous. On final measurement, the aortic diameter increased from 3 mm to 7 mm, and the trans-stent gradient reduced from ∼39 mm Hg to ∼9 mm Hg (Figure 3). The postdeployment angiogram demonstrated preservation of the left ninth intercostal artery and spinal artery (Figure 4). Hemostasis was achieved via manual compression and without any closure devices.

Figure 3.

Before and After Stent Placement Pressure Tracings

Prestent (A) ascending aorta (ASAO) pressure tracing and (B) descending aorta (DSAO) pressure tracing. (C) Poststent ASAO/DSAO pressure tracings superimposed. ABAO on pressure tracing signifies abdominal aorta.

Figure 4.

Poststent Placement Digital Subtraction Angiogram

The image shows improved lumen diameter, no evidence of rupture or dissection, and early filling of the ninth intercostal artery (arrow).

Outcome and Follow-Up

After the procedure, the patient recovered in the postanesthesia care unit, briefly requiring dexmedetomidine sedation before resuming oral intake the same day. She was then observed overnight with continuous telemetry and was successfully discharged the next day. Follow-up evaluations at postoperative 2 and 4 weeks were unremarkable. Blood pressure was 99/60 mm Hg in the right arm and 88/53 mm Hg in the right leg at week 7, and atenolol was subsequently discontinued. Interestingly, mild abdominal symptoms and constipation resolved, which was not organically thought to be a clinical factor in the presentation. Looking forward, the patient is expected for follow-up at 6 months and at longer intervals thereafter. The stent can be dilated to a maximum of 26 mm; thus, the team remains optimistic about the stent's ability to accommodate significant somatic growth to adult size.

Visual Summary.

Timeline of the Case

Patient Age	Description
1 mo	Term birth
3 y 5 mo	Diagnosis of abdominal coarctation after new murmur noted
3 y 6-8 mo	Computed tomography angiography performed for anatomical clarification
3 y 7 mo	Atenolol initiated
4 y 1 mo	Genetic testing negative for Williams syndrome and other syndromes
4 y 5 mo	Gradient increased to 59 mm Hg on echocardiogram
4 y 6 mo	Cardiac catheterization and stent placement
4 y 8 mo	Atenolol discontinued

Discussion

Distal coarctation of the aorta is a rare entity, representing fewer than 2% of all aortic stenoses, and its location near the artery of Adamkiewicz further complicates intervention.^1,2 Stenting in young children is controversial because of potential intimal proliferation, stent fracture, or the need for redilation with somatic growth. Stents are contraindicated in patients with Williams syndrome, where in-stent proliferation is common.³ In our patient, thorough genetic workup was negative, highlighting the possibility of isolated abdominal coarctation. The current 2022 American Heart Association/American College of Cardiology guidelines for congenital heart disease recommend individualized management for coarctation, with endovascular therapy (balloon angioplasty ± stenting) favored in older children and adults when anatomically feasible. However, surgical repair remains a mainstay for complex anatomy or in young patients.⁴ Our patient's anatomy was deemed amenable to stent placement after detailed imaging, and the risk of compromising the artery of Adamkiewicz was carefully weighed against the morbidity of open surgical repair. This approach aligns with an evolving trend toward less invasive management, even in complex pediatric aortic lesions.

Careful planning is important to decrease the risk of intraprocedural complications such as aortic rupture, dissection, arterial thrombosis, or spinal cord ischemia. Postprocedure surveillance is required, as there is potential for functional narrowing secondary to somatic growth or, less likely, intimal proliferation. Given the minimal literature on stenting abdominal coarctation in children without syndromic associations, this case underscores the importance of multidisciplinary collaboration and meticulous follow-up.

Conclusions

This case highlights a rare presentation in a toddler of abdominal coarctation of the aorta located near the artery of Adamkiewicz. With deliberate imaging, planning, and a collaborative approach to intervention, stent placement was successfully achieved, alleviating the gradient and improving distal perfusion. The decision between open vs percutaneous treatment remains controversial in such complex scenarios, and long-term outcomes will guide best practices.

Funding Support and Author Disclosures

The authors have reported that they have no relationships relevant to the contents of this paper to disclose.