Percutaneous Implantation of Adult Sized Stents for Coarctation of the Aorta in Children ≤20 kg: A 12-Year Experience

Brian A Boe ¹, Aimee K Armstrong ¹, Sarah A Janse ², Eméfah C Loccoh ³, Katie Stockmaster ¹, Ralf J Holzer ⁴, Sharon L Cheatham ¹, John P Cheatham ¹, Darren P Berman ¹

Circ Cardiovasc Interv. 2021 Feb;14(2):e009399.

 doi: 10.1161/CIRCINTERVENTIONS.120.009399. Epub 2021 Feb 5.

PMID: 33544625

DOI: 10.1161/CIRCINTERVENTIONS.120.009399

 

Take Home Points:

• Stent [which can be dilated to adult size; 18mm] implantation can be performed for coarctation of aorta in children ≤20 kg.
• Vascular injury is the main concern due to small femoral arterial size and relatively large size of the sheath required for stent implantation.
• Reintervention is common and needed for either balloon angioplasty of the stent or intervention due to stent fracture.
• Development of lower profile stents in the future can help improve outcomes.

 

Commentary from Dr. Varun Aggarwal (Minneapolis, MN, USA), section editor of Congenital

Heart Disease Interventions Journal Watch: Most institutions perform primary surgical repair for native coarctation in infants. However, balloon angioplasty or stent implantation is offered to patients with recurrent coarctation of aorta. Stent implantation as the primary intervention for native coarctation is performed in older children and adults when the femoral artery can accommodate the large arterial sheath needed for stent placement. Compared to balloon angioplasty, stent implantation provides better relief of obstruction but results in a fixed diameter (of the stent) which does not grow as the child grows. This is specifically important in young children who will need re-dilation of the stent. The stent which can be placed in small children and subsequently dilated to adult sizes ( 18mm) are limited by the large sheath size.

 

This study is a retrospective review of the outcomes at Nationwide Children’s hospital of children <20 kg who underwent stent implantation (which can be dilated to adult size in the future) for coarctation of aorta from 2004-2015. The study flow sheet is shown in the Figure 1. 39 patients with a median age and weight of 1.1 (range, 0.3–7.9) years and 9.9 (5.5–20.4) kg, respectively met the inclusion criteria. This cohort comprised of 20 patients with weight 10kg. Acute procedural success was achieved in all patients except one (38/39, 97%) who developed an aneurysm of the aorta requiring placement of a covered CP Stent. The mean gradient across the coarctation was 0mmHg post stent deployment. Adverse events were seen in 7 patients (18%). These consisted of femoral arterial complications at the site of vascular access (n= 3), vascular injury at the site of CoA (n=2), intraprocedural hypotension with bradycardia (n=1), and stent embolization (n=1). Two of the three patients with femoral arterial complication had normal femoral artery on follow up ultrasound. There was no mortality or limb loss due to femoral arterial injury. 28 patients had follow up evaluation of the femoral artery and 4 had persistent vascular injury documented (3 femoral arterial occlusions and one with femoral artery stenosis).

 

72% (n=28) patients needed reintervention at the median follow up of 67.2 (IQR, 33.8- 116.1) months, Figure 2. The median time to reintervention was significantly shorter in patients who were 10kg at the time of stent implantation (26.5 vs 62.3 months, p=0.01). The most common reintervention was balloon angioplasty of the previously placed stent, however 8 patients had stent fractures (all in Palmaz Genesis XD stents).

 

This retrospective review by Boe B et al (1) exquisitely describes the technical feasibility of implantation of a stent (which can potentially be dilated to adult size) in children 20kg for coarctation of aorta. Acute success of stent implantation is higher as compared to balloon angioplasty alone. Procedural complications were seen in 18% patients. Vascular access complication (femoral arterial injury) remains a concern in small patients and careful preprocedural assessment of femoral arterial size using ultrasound, avoiding multiple sheath exchanges, use of smaller profile stents and institutional protocol for pulse loss post cardiac catheterization can be a key to a safe and successful outcome. Development of low profile stents can help improve the outcomes in the future.

 

FIGURE 1: Study Flow sheet (1)

[Figure reproduced from Circ Cardiovasc Interv. 2021 Feb;14(2):e009399. (1)]

 

 

Figure 2: Kaplan-Meier curve showing time to first reintervention for the entire cohort (solid line) and separated by weight (≤10 kg, dashed line; >10 kg, dotted line).

[Figure reproduced from Circ Cardiovasc Interv. 2021 Feb;14(2):e009399. (1)]

 

 

1. Boe BA, Armstrong AK, Janse SA, Loccoh EC, Stockmaster K, Holzer RJ, et al. Percutaneous Implantation of Adult Sized Stents for Coarctation of the Aorta in Children </=20 kg: A 12-Year Experience. Circ Cardiovasc Interv. 2021;14(2):e009399.