Coarctation of Aorta Dilated with a Stent
32 y/o female diagnosed with coarctation of the aorta having presented with a murmur and mild systolic hypertension. Blood pressure (in right arm) was 145/85, (in left leg, systolic was 105). ECG was normal. Echo showed a 33 mmHg gradient across the coarctation with mild diastolic continuation. MRI showed narrowing in the aorta 2.5 cm distal to the left subclavian artery with post-stenotic dilation. The patient subsequently had a Palmaz 308 stent placed, reducing the gradient from 20 mmHg to 0.
Stent placement is considered by some the treatment of choice to replace surgery in older children and adults with coarctation. Studies have shown excellent results in the short and intermediate term.
COARCTATION NOTES:
Stents for Coarctation
Coarctation is a discrete stenosis in the proximal thoracic aorta first described by Morgagni at autopsy in 1760. It has a wide spectrum of presentations from asymptomatic murmur and hypertension in adults (as in the above patient), to cardiogenic shock in neonates.
Transcatheter treatment by balloon dilation was first described in 1982. Balloon-expandable endovascular stents have been used successfully in coarctation. Stents create a 'controlled tear' in the aortic wall supported by the framework of the stent upon dilation. Stent placement is considered by some the treatment of choice to replace surgery in older children and adults with coarctation.
Studies have shown excellent results in the short and intermediate terms. In 33 patients with native or recurrent coarctation who underwent stent placement at our institution between 1993-1999, complete relief of the obstruction occurred in 32. Complications of stent placement are well tolerated and rarely serious. In our patient population we encountered such complications as:
arterial access problems 6%,
stent migration 6%,
and early failure 3%.
Other complications include early and late aneurysm formation in 6% and late restenosis. Although stents can be re-dilated up to 3 years after implantation to accommodate somatic growth in growing patients, their wide use is limited by the large sheaths required relative to the size of young patients and the lack of long-term follow-up studies.
References:
1- Hamdan MA et al., Endovascular stents for coarctation of the aorta: initial results and intermediate-term follow up. (Circulation supplement 10/2000)
2- Ovaert C et al., Transcatheter treatment of coarctation of the aorta: a review. Pediatric Cardiology 1998;19:27-44
3- De Lezo JS et al., Immediate and follow-up findings after stent treatment for severe coarctation of the aorta. Am J Cardiol 1999;83:400-406
Angio (PA view) prior to stent deployment.
Angio (PA view) post stent deployment.
Sagittal images 1 cm apart show the extent of the discrete narrowing (arrow) and the resulting disturbed flow effects.
Continuous wave doppler signals from supra-sternal notch pre- and post-procedure show a reduction in velocity (and therefore pressure gradient) after the stent is deployed.
