Magnetic resonance imaging (MRI) or computed tomography (CT) with three-dimensional reconstruction: According to the current guidelines, all adults with aortic isthmus stenosis should undergo an initial examination with demonstration of the entire aorta and intracranial vessels (Warnes et al. 2008). MRI produces high-quality, high-resolution images that show the anatomy very well and it can also be used to quantify the flow in collateral vessels (Fig. 2.1-29) (Warnes et al. 2008). It provides all the information required for surgical correction, and it is also used for follow-up imaging examinations in patients who have undergone surgery for aortic isthmus stenosis. Several studies have confirmed that MRI can also be used in infants and neonates.
Fig. 2.1–29 Aortic isthmus stenosis on magnetic resonance imaging, with marked collateral formation and development of an aneurysm in the ascending aorta. Sagittal image with gadolinium contrast.
Fig. 2.1–30a, b Angiographic imaging of an aortic isthmus stenosis before (a) and after balloon angioplasty with successful stent placement (b, arrows).
Intracardiac catheter examination: Invasive diagnosis is by today’s standards only indicated in the context of interventional therapy for the aortic isthmus stenosis or to clarify complex cardiac defects, or in adults for preoperative exclusion of coronary heart disease (Fig. 2.1-30) (Warnes et al. 2008; Marek et al. 1995).
2.1.10.5 Treatment
Conservative treatment and general principles
Official recommendations are only available for control of arterial hypertension with medications. β-Blockers, angiotensin-converting enzyme (ACE) inhibitors and sartanes are the agents of choice (Warnes et al. 2008). In patients with aneurysm formation, β-blockers and vasodilators are particularly recommended (Warnes et al. 2008). The effect of statins is currently being tested for reducing atherosclerotic complications in adult patients with congenital heart defects (Krieger and Stout 2010). In accordance with the recommendations of the 36th Bethesda Conference, patients with significant re-stenosis or untreated isthmus stenosis, associated bicuspid aortic valve with aortic stenosis and those with dilation of the aortic root are advised not to take part in contact sports, isometric exercise, weightlifting, or sports involving abrupt starting and stopping (Graham et al. 2005). There has often been critical discussion of pregnancy in women with aortic isthmus stenosis. However, the published data suggest that relatively few complications occur and in particular that the risk of aortic dissection only appears to be slightly increased (Warnes et al. 2008; Pourmoghadam et al. 2002). According to the current guidelines, endocarditis prophylaxis is only indicated if surgical correction or stent placement has taken place during the previous 6 months, while uncomplicated and untreated aortic isthmus stenoses and uncomplicated re-stenoses do not require endocarditis prophylaxis (Warnes et al. 2008).
Correction of aortic isthmus stenosis
An indication for correction is basically established at the first diagnosis of aortic isthmus stenosis. In adults with previously undiagnosed aortic isthmus stenosis, an intervention is indicated according to the current guidelines if the peak-to-peak gradient over the isthmus stenosis on invasive measurement is ≥ 20 mmHg, or with smaller gradients if there is evidence on noninvasive imaging of severe isthmus stenosis with clear collateral formation (Warnes et al. 2008). If the noninvasively measured gradient already shows clear evidence of high-grade aortic isthmus stenosis, invasive measurement is not absolutely necessary.
Choice of technique
Surgical and percutaneous interventional procedures are available as alternatives for treating aortic isthmus stenosis. There are two indications for which one of these two options is clearly preferable. Firstly, surgical treatment for primary correction of aortic isthmus stenosis is currently recommended in neonates, since balloon angioplasty leads to re-stenosis or aneurysm formation in 10–70% of cases in this age group (Pourmoghadam et al. 2002). On the other hand, primary balloon angioplasty is also a good treatment option in this age group as well if the patient is at high surgical risk due to severe systemic diseases. Secondly, balloon angioplasty is regarded as the procedure of choice for the treatment of re-stenoses after corrected aortic isthmus stenosis in older children and young adults. In all other patients, there are currently no recommendations regarding the preference for a surgical or interventional correction procedure. However, in many centers surgical correction for aortic isthmus stenosis in adults is now only carried out when percutaneous interventional procedures do not appear appropriate (Warnes et al. 2008). It is recommended that the decision regarding which procedure to use should be made in a center for adults with congenital heart defects in collaboration between cardiologists, interventionalists and surgeons (Warnes et al. 2008). The choice of surgical technique is mainly based on the patient’s age (Table 2.1-11). In women who wish to have children, the advice tends to be to carry out primary treatment for aortic isthmus stenosis using a direct surgical approach with complete resection of the paraisthmic tissue (Warnes et al. 2008).
Table 2.1–11 Typical criteria for choice of the correction technique in patients with aortic isthmus stenosis.
| Technique | Typical indication |
| End-to-end anastomosis/extended end-to-end anastomosis; Waldhausen subclavian flap plasty* | Age 0–2 years |
| Patch enlargement plasty* | Age 2–16 years |
| Tube prosthesis interposition | Age > 16 yearsLong or atypically locatedstenosesRe-stenosisLocal aneurysm formation |
| Balloon angioplasty/stent placement |
Method of choice
|