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.

Evaluation of exercise-induced hypertension post endovascular stenting of coarctation of aorta.

BACKGROUND: Coarctation of the aorta (COA) is a defect that accounts for 5-8% of all congenital heart diseases. Balloon angioplasty as a treatment for COA is increasingly performed, with endovascular stents having been proposed as a means of improving the efficacy and safety of the procedure. The aim of this study was to evaluate the systolic blood pressure gradient at rest and during maximal exercise at follow-up in patients post endovascular stenting of COA. METHODS: Thirteen patients (4 native and 9 re-coarctation cases of COA after surgery or balloon angioplasty) with a mean age of 11.1 ± 4.7 years underwent endovascular stenting between November 2007 and December 2009 via standard techniques for native COA as an alternative to surgical repair. Doppler echocardiography was performed pre and post stenting. Resting and exercise assessment of blood pressure was performed at follow-up. RESULTS: Post stent implantation, no angiographic major complications were evident. Systolic blood pressure gradient decreased from 42 ± 8.8 mm Hg before stent placement to 7 ± 10 mm Hg at follow-up (p value < 0.001). Peak Doppler pressure gradient decreased from 30 ± 14 mm Hg to 14 ± 10 mm Hg at follow-up (p value < 0.007). One case of exercise-induced hypertension was seen in patients. CONCLUSION: Endovascular stenting for native COA in older children and post-surgical COA repair in patients with residual COA and re-coarctation is a reasonable alternative to surgical correction. During early follow-up, stenting effectively alleviates the aortic arch obstruction with normalization of the systemic blood pressure both at rest and during maximal exercise.