Typical long-term complications after correction of an aortic isthmus stenosis are listed in Table 2.1-12. Arterial hypertension and atherosclerotic complications are the main factors involved in an unfavorable long-term prognosis. When aortic isthmus stenosis is corrected later than the neonatal period, there is an increased risk for the development of chronic hypertension. This “paradoxical” or “rebound” hypertension may first occur immediately postoperatively, typically after an interval of 24–36 hours, with an increase in mean arterial pressure. This early hypertension is caused by activation of sympathicotonia and is best treated with β-blockers (Warnes et al. 2008). Secondly, the hypertension may occur at a late postoperative stage, with an increase in diastolic blood pressure in particular, even years after successful correction of the aortic isthmus stenosis. This type of hypertension is caused by activation of the renin–angiotensin–aldosterone system and occurs independently of re-stenosis of the aortic isthmus (Hager et al. 2007). Disturbed tissue elasticity in the aortic wall is also an important factor in the pathogenesis here.
Table 2.1–12 Typical long-term complications after correction of an aortic isthmus stenosis.
| Complications | Frequency (after Krieger and Stout 2010)(%) |
| Persistent arterial hypertension or arterial hypertension developing during subsequent course | Correction during childhood: < 5%Correction in adults: > 25% |
| Re-stenosis of the aortic isthmus | Correction in neonates: 2.4–5.5%Correction at a later age: < 1% |
| Aortic aneurysm/aortic dissection | 5–16% |
Re-stenosis is defined as the recurrence of a peak-to-peak gradient ≥ 20 mmHg, and is often associated with symptoms of uncontrolled arterial hypertension. Re-stenosis may remain asymptomatic for a long period and then can only be diagnosed using a targeted examination. The main risk factor for re-stenosis developing is correction of the aortic isthmus stenosis in neonates and children aged under 1 year. Re-stenosis is an important risk factor for recurrent arterial hypertension. A second procedure is indicated when the peak-to-peak gradient is ≥ 20 mmHg, or with smaller gradients if hypertension cannot be controlled with drugs or collateral circulation circuits have developed (Krieger and Stout 2010; Warnes et al. 2008). The treatment primarily involves the use of interventional procedures (Warnes et al. 2008). Successful elimination of the re-stenosis usually also leads to a reduction in blood pressure (Krieger and Stout 2010).
Fig. 2.1–32 Bicuspid aortic valve is an independent risk factor for the development of aneurysms, particularly in the area of the ascending aorta (Aydin et al. 2011). Patients who have undergone successful correction of an aortic isthmus stenosis, particularly with a bicuspid aortic valve, always require lifelong follow-up with imaging including the ascending aorta (von Kodolitsch et al. 2002; 2010).
Fig. 2.1–33 Anatomic types of aneurysm development in the aorta after primary correction of an aortic isthmus stenosis.
Table 2.1–13 Aneurysm development after surgical correction of aortic isthmus stenosis (von Kodolitsch et al. 2002).
– = information not available.
Aneurysm formation is another complication and is associated with a high mortality rate (Table 2.1-13) (von Kodolitsch et al. 2002, 2010; Oliver et al. 2004; Aydin et al. 2002). Aneurysms may develop independently of the technique used, the patient’s age and the success of the aortic isthmus stenosis correction. Local aneurysms have even been observed in 8% of cases after balloon angioplasty (Fawzy et al. 2004). The development of local aneurysms is noted postoperatively particularly after patch enlargement plasty (Karck et al. 2003), while aneurysms in the ascending aorta appear particularly in patients with a bicuspid aortic valve (Aydin et al. 2002; von Kodolitsch et al. 2002). Depending on the pathological mechanism and location, true, false, and dissecting aneurysms may occur (Figs. 2.1-32 and 2.1-33). Treatment for local aneurysms is generally surgical, although it can also be carried out using stent grafts in individual cases (Warnes et al. 2008).
Follow-up
Due to the high complication rates and even higher mortality after correction of aortic isthmus stenosis, the affected patients need lifelong follow-up with cardiologists with expertise in caring for adult patients with congenital heart disease (Schmaltz et al. 2008; Krieger and Stout 2010; Warnes et al. 2008). Follow-up examinations should be carried out at least at annual intervals. At each follow-up examination, a physical examination should be carried out with measurement of blood pressure and an ECG recording (Krieger and Stouth 2010). Measurement of blood pressure in both arms with the patient supine, simultaneous palpation of the radial and femoral pulse, and auscultation at precordium and left paravertebral position to detect any re-stenosis are obligatory elements in the physical examination (Krieger and Stout 2010). Ophthalmoscopy of the fundus of the eyeball to note any chronic hypertension, are also recommended at each follow-up consultation.
Measurement of blood pressure over 24 hours and ergometry testing to identify exercise hypertension are recommended by many authors, but these are not obligatory. Imaging of the entire aorta every 2–5 years is recommended (Krieger and Stout 2010).
References
Abbott ME. Coarctation of the aorta of the adult type. Am Heart J 1928; 381: 574.
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