How should an interrupted aortic arch be managed in an adult?

Management of Interrupted Aortic Arch in Adults

Adults with interrupted aortic arch (IAA) should be managed at a specialized adult congenital heart disease (ACHD) center with experienced surgical and medical personnel, as IAA is classified as a "great complexity" lesion requiring expert multidisciplinary care. 1, 2

Classification and Risk Stratification

• IAA is categorized as a Class III (Great Complexity) congenital heart defect by both ACC/AHA and ESC guidelines, placing it in the highest risk category alongside conditions like single ventricle and Fontan circulation 1, 2
• This classification mandates lifelong specialized ACHD follow-up regardless of whether the patient has undergone repair 2

Initial Diagnostic Evaluation

Comprehensive cardiovascular imaging with CT angiography (CTA) or cardiovascular magnetic resonance (CMR) is essential to define:

• The precise anatomic interruption type (Type A: distal to left subclavian artery; Type B: between left carotid and left subclavian; Type C: between innominate and left carotid) 3, 4, 5
• Extent and pattern of collateral circulation, which is universally present in adults who survive to adulthood 6, 7, 5
• Associated cardiac anomalies, particularly bicuspid aortic valve, ventricular septal defect, and left ventricular outflow tract obstruction 3, 8
• Presence of post-interruption aneurysmal changes or dissection 3, 9

Blood pressure measurement in all four extremities is mandatory to assess the hemodynamic significance and degree of upper body hypertension 10

Treatment Decision Algorithm

Indications for Surgical Intervention

Surgery is recommended when:

• Symptomatic hypertension is present despite medical management 10, 7
• Progressive left ventricular dysfunction or dilatation develops 7
• Associated cardiac lesions require surgical correction 8
• Evidence of aortic complications (aneurysm, dissection risk) exists 3, 9

Surgical Approach

Extra-anatomic bypass is the preferred surgical technique in adults, specifically:

• Ventral aortic repair through midline sternotomy with upper midline laparotomy is the optimal approach, as it avoids extensive collateral networks on the chest wall and allows simultaneous treatment of associated cardiac lesions 7
• Bovine collagen-impregnated polyester grafts are typically used 7
• Surgery should be performed without cardiopulmonary bypass when feasible to reduce morbidity 7
• Surgeons with specific training and expertise in ACHD must perform these operations 11

Conservative Management Considerations

Medical management alone may be considered when:

• Extensive, well-developed collateral circulation provides adequate lower body perfusion 6, 5
• The patient is asymptomatic or minimally symptomatic with controlled blood pressure 6, 5
• Surgical risk is prohibitively high due to comorbidities 6

However, this approach carries significant risks:

• Spontaneous aortic dissection of the descending aorta can occur due to abnormal hemodynamic forces from collateral jet flows, even without traditional risk factors like atherosclerosis or aneurysm 12, 9
• Recurrent ischemic strokes from accelerated atherosclerotic arteriopathy secondary to upper body hypertension have been reported 12
• Progressive heart failure from chronic pressure overload may develop 6

Medical Management

Aggressive antihypertensive therapy is mandatory regardless of surgical status:

• Beta-blockers, ACE inhibitors, or angiotensin receptor blockers should be used as first-line agents 13, 11, 10
• Target blood pressure control in upper extremities to prevent end-organ damage 10
• Ambulatory blood pressure monitoring is useful for diagnosis and management optimization 10

Follow-Up Protocol

For unoperated or conservatively managed patients (Physiological Stage C or D):

• ACHD cardiologist visits every 3-6 months 10
• Electrocardiogram every 12 months 10
• Transthoracic echocardiography every 12 months 10
• CMR or CTA imaging every 12-24 months to monitor for aneurysm formation, dissection, or progression 10
• Exercise testing annually to assess functional capacity and exercise-induced hypertension 10

For post-surgical patients:

• Similar intensive follow-up is required lifelong 10
• Graft patency must be confirmed with serial CTA imaging 7
• Residual hypertension is common and requires ongoing medical management 7

Critical Pitfalls to Avoid

• Do not assume IAA in adults is simply severe coarctation—while related, IAA represents complete anatomic interruption and requires different surgical planning 4
• Do not delay referral to an ACHD center—these patients require specialized expertise that general cardiologists and cardiac surgeons may lack 11
• Do not underestimate dissection risk—even with good collateralization, abnormal hemodynamic forces can cause spontaneous dissection of the descending aorta 12, 9
• Do not perform staged repairs when possible—staged approaches are associated with significantly worse long-term mortality (aHR 2.50) compared to single-stage repair 8