Arterial Switch Operation — Overview and Core Principles

Purpose and Indications

The arterial switch operation (ASO) anatomically restores ventriculo-arterial concordance by transposing the great arteries and reimplanting the coronary arteries onto the neoaortic root. It is the standard definitive repair for d-transposition of the great arteries (d-TGA) and selected related variants (e.g., Taussig–Bing anomaly with subpulmonary VSD) when coronary anatomy and ventricular function are suitable. Contemporary series and meta-analyses demonstrate excellent survival from the neonatal period into adulthood, supporting early primary repair to avoid LV deconditioning and hypoxemia-related morbidity [1–3].

Common indications

• d-TGA with/without VSD (± LVOT considerations) [1–3]
• Double-outlet RV with subpulmonary VSD (Taussig–Bing) when LVOT can be made adequate [2,3]
• Selected cases with arch hypoplasia/coarctation (single-stage ASO + arch repair) [4,8]

Contraindications/relative cautions

• Marked LV regression in late presenters when retraining is not feasible
• Coronary variants in which safe transfer is not achievable (rare but important) [4]
• Comorbidities precluding CPB

Preoperative Evaluation and Optimization

• Segmental anatomy: high-quality echocardiography to confirm VA discordance; define VSD size/location and LVOT/RVOT geometry.
• Coronary mapping: identify ostial number and sinusal origin; delineate intramural segments, single ostium, high/remote take-off, and looping patterns—the feasibility and safety of transfer dictate the operative plan [4].
• Pulmonary arteries and arch: evaluate branch PA caliber/alignment, ductal tissue, and aortic arch hypoplasia/coarctation; plan concomitant arch work if needed [8].
• Physiology/LCOS risk: optimize oxygen delivery and mixing (PGE, targeted ventilation); perform balloon atrial septostomy when restrictive atrial communication compromises systemic oxygenation.

Operative Strategy — Stepwise Outline

1. Exposure and CPB

Median sternotomy with bicaval drainage. Arterial cannulation in the distal ascending aorta or innominate artery per anatomy. Cold blood cardioplegia and institutional cooling strategy.

2. Great-Artery Transection

Divide the aorta above the sinotubular junction and the pulmonary trunk proximal to the bifurcation, preserving generous cuffs. Mark sinuses and coronary button orientation before mobilization.

3. Coronary Harvest and Transfer

Create generous coronary buttons and mobilize proximal epicardial segments to avoid tension, kinking, and rotation. Reimplant into the neoaortic root (former pulmonary root) using trapdoor or pedicled techniques to maintain a non-stenotic, non-angulated course.

Special scenarios:

1. Single ostium: construct an ample, oval neo-ostium; orient obliquely to prevent compression [4].
2. Intramural coronary: completely unroof the intramural segment; consider open trapdoor or hood augmentation if needed [4].
3. High/remote take-off: add a pericardial hood to relieve tension.
4. Lecompte Maneuver

Bring the branch PAs anterior to the neoaorta to reduce posterior compression and create a straight, non-torsed neopulmonary pathway.

5. Great-Artery Reconstruction
• Neoaorta: end-to-end anastomosis to the distal ascending aorta; tailor the sinotubular junction to preserve leaflet coaptation and minimize neo-AR risk.
• Neopulmonary artery: reconstruct the anterior wall (commonly with autologous pericardium) and complete an end-to-end anastomosis to the proximal PA bifurcation, ensuring symmetric branch alignment.
6. Associated Procedures (as indicated)

VSD closure (directing LV outflow to the neoaorta), arch repair (extended end-to-end or patch), and atrial septectomy when restrictive mixing persists.

7. Weaning and Assessment

Meticulous deairing and rewarming. Before leaving CPB, confirm by echo: competent neoaortic valve with laminar LVOT, unobstructed neopulmonary pathway/branch PAs, and satisfactory coronary perfusion (ECG/echo/lactate). Maintain adequate diastolic pressure and sinus rhythm to protect coronary flow.

Technical Priorities and Pitfalls

Coronary transfer is the operation. Outcomes are driven by tension-free, non-kinked, non-twisted coronary reimplantation with secure hemostasis [4].

• Buttons: harvest generous sinus tissue; avoid purse-string narrowing at the neo-ostium.
• Orientation: pre-mark epicardial courses; avoid over-rotation of the neoaortic root.
• Intramural segments: unroof completely; partial unroofing risks dynamic compression and ischemia [4].
• Lecompte details: check for PA torsion or posterior compression by the neoaorta.
• Neopulmonary reconstruction: make the anterior patch wide and smoothly contoured; remove/avoid ductal tissue that predisposes to bifurcation stenosis [2,7–9].

Postoperative Management — Early Phase

• Coronary perfusion vigilance: continuous ECG, regional wall-motion surveillance, and serial lactate/enzymes; promptly address low diastolic pressure, spasm, or arrhythmias.
• Ventilation/PVR: maintain low-normal PVR (adequate oxygenation, normocapnia, gentle lung strategies) to protect RV after the switch.
• Afterload and valve care: avoid excessive hypertension (neo-AR risk) while preserving diastolic pressure for coronary flow.
• Branch PA patency: investigate differential saturations or RV strain early.
• Rhythm: maintain sinus rhythm; treat junctional rhythms or AV block promptly.

Outcomes and Late Surveillance

Evidence synthesized across 151 studies (30,186 patients) shows short-term survival ~92% and medium-term ~90%; most patients reach adulthood with near-normal LV function when coronaries are intact and outflows unobstructed [1–3,6]. Long-term cohorts report ~95–97% survival at 20–25 years, with ongoing but manageable reintervention needs (most commonly for RVOT/branch PA obstruction) [2,6,7].

Predictable late issues and risk markers

• Neoaortic root/valve: progressive neo-aortic root dilation is common and correlates with later neo-AR; risk is higher with Taussig–Bing anatomy, prior PA banding, larger great-artery discrepancy, and longer follow-up [2,5,9,10].
• Pulmonary pathway: supravalvar and branch PA stenosis remain the leading cause of reintervention; concomitant arch obstruction at index surgery increases late reintervention risk [2,7,8].
• Coronary events: uncommon but potentially catastrophic; variant patterns (single ostium, intramural course) increase early/late risk and justify lifelong surveillance [2,3,4,6].

Follow-up program (typical)

Structured echocardiography in infancy/early childhood; periodic CMR/CT for coronaries, neoaortic root, and branch PAs; and exercise testing in later childhood/adolescence—lifelong congenital cardiology follow-up is recommended [2,3,6].

Special Anatomical Considerations

• d-TGA + VSD ± LVOT obstruction: ASO with VSD closure and tailored LVOT work; if an adequate LVOT cannot be achieved, alternatives (e.g., Rastelli/REV) may be considered in selected anatomies [2,3].
• Taussig–Bing anomaly: ASO with VSD baffling of LV to neoaorta; anticipate higher rates of RVOT/branch PA interventions and vigilant coronary assessment [2,7].
• Arch hypoplasia/coarctation: single-stage ASO + arch reconstruction is feasible with excellent outcomes when cerebral/visceral protection and anastomotic geometry are optimized; arch obstruction at index repair predicts later interventions [2,7,8].

One-Paragraph Synopsis

The arterial switch operation anatomically corrects d-TGA by transposing the great arteries, transferring coronary arteries to the neoaortic root, and performing the Lecompte maneuver to establish an anterior neopulmonary pathway. Success hinges on tension-free coronary reimplantation, unobstructed neoaortic/neopulmonary reconstruction, and vigilant early protection of coronary perfusion. Contemporary data show excellent survival from the neonatal period to 25 years, with reinterventions driven primarily by branch PA/RVOT obstruction and a smaller but important burden of neo-aortic root dilatation/valve regurgitation; coronary events are uncommon but mandate lifelong surveillance [1–3,5–7,9].

References

[1] Morfaw F, Leenus A, Mbuagbaw L, Anderson LN, Dillenburg R, Thabane L. Outcomes after corrective surgery for congenital dextro-transposition of the arteries using the arterial switch technique: a scoping systematic review. Syst Rev. 2020;9(1):231.

[2] Lim HG, Kim W-H, Lee JR, Kim YJ. Long-term results of the arterial switch operation for ventriculo-arterial discordance. Eur J Cardiothorac Surg. 2013;43(2):325-334.

[3] Villafañe J, Lantin-Hermann K, Hollander SA, et al. D-transposition of the great arteries: the current era of the arterial switch operation. Circulation. 2014;130(14):1159-1169.

[4] Pasquali SK, Hasselblad V, Li JS, Kong DF, Sanders SP. Coronary artery pattern and outcome of arterial switch operation for transposition of the great arteries: a meta-analysis. Circulation. 2002;106(20):2575-2580.

[5] Co-Vu JG, Ginde S, Bartz PJ, Frommelt PC, Tweddell JS, Earing MG. Long-term outcomes of the neoaorta after arterial switch operation. Ann Thorac Surg. 2013;95(5):1654-1659.

[6] Fricke TA, d’Udekem Y, Richardson M, et al. Long-term outcomes of the arterial switch operation. J Thorac Cardiovasc Surg. 2022;164(4):1197-1206.e6.

[7] Baruteau A-E, Vergnat M, Kalfa D, et al. Long-term outcomes of the arterial switch operation for complex transposition of the great arteries. Interact Cardiovasc Thorac Surg. 2016;23(2):240-246.

[8] Jonas K, Waldmann V, Cvitkovic T, et al. Early and late outcomes after arterial switch operation: a 23-year single-center experience. Medicina (Kaunas). 2021;57(9):905.

[9] van der Palen RLF, Nijveld A, Hazekamp MG, et al. Progression of aortic root dilatation and aortic valve regurgitation after the arterial switch operation. Heart. 2019;105(22):1732-1739.

[10] Zhu MZL, Lau KC, Brizard CP, et al. Outcomes of neo-aortic valve and root surgery late after the arterial switch operation. J Thorac Cardiovasc Surg. 2024;168(3):e81-e91.