ALCAPA #4 — Operative Technique: Two-Patch Flap

1) Concept and Surgical Rationale

The two-patch flap technique is a geometry-driven coronary extension strategy for ALCAPA: instead of relocating the anomalous origin, it constructs a short, tension-free tubular channel that delivers systemic (aortic) pressure and oxygen content to the left coronary artery (LCA). The physiologic objective is identical to all definitive ALCAPA repairs—restore a durable two-coronary system and eliminate the “wrong-source” coronary circulation that perpetuates LV ischemia and papillary muscle dysfunction. [1,3,4]

Why this matters clinically

• Most series show substantial LV functional recovery after establishing a two-coronary system, often accompanied by mitral regurgitation (MR) improvement over time. [5,6]
• When comparing strategies, coronary transfer/reimplantation tends to provide excellent durability, whereas Takeuchi can carry a higher burden of late pulmonary artery (PA)–related complications, especially pulmonary regurgitation and/or baffle/PA issues. [1,7]

2) When This Technique Is Considered (Selection Logic)

In contemporary practice, direct coronary transfer (LCA button reimplantation) is preferred whenever feasible because it most closely restores normal anatomy and has strong long-term performance. [1,9]

The two-patch flap / tubular channel approach becomes attractive when direct transfer is not feasible or would be high risk, such as:

1. Limited coronary mobility
• Short main trunk, tethering, or a course that predicts tension, torsion, or kinking after transfer.
2. Unfavorable spatial relationship (distance/angle)
• LCA ostium location and the aortic target site are mismatched such that a conduit provides a straighter, safer inflow line.
3. Need for a wider, less angulated pathway
• Particularly when a small coronary button alone may create a pinch point at the aortic anastomosis.
4. “Takeuchi not ideal, transfer not safe” niche
• If intrapulmonary tunnel repair is undesirable due to its known late PA/baffle morbidity profile, an extra-pulmonary coronary extension can be a more target-specific solution for selected anatomies. [1,7]

Key principle: this is fundamentally a flow-path engineering decision—choose the construct that most reliably yields a short, non-compressive, non-stenotic systemic inflow to the LCA. [3,4]

3) Core Construct (What You Are Building)

This repair forms a tube (a short conduit) from the aorta → LCA using two complementary “walls”:

• Posterior wall: an aortic flap (posterior aortic-wall incision with a flap)
• Anterior wall: a PA wall flap harvested with the coronary button (anterior PA-wall component)

These are anastomosed to each other to create a tubular channel directing aortic flow → LCA, while the PA is reconstructed to maintain unobstructed RV outflow. [3,4]

4) Stepwise Operative Description (Textbook Style)

Step 1. Harvest the LCA button with a generous PA wall flap

• Excise the LCA from the MPA with a generous cuff/flap of PA wall to preserve:
• Ostial geometry
• Proximal coronary integrity
• A non-kinked proximal course after mobilization toward the aorta
• Mobilize enough length to eliminate traction on the proximal LCA once the heart is filled. [3,4]

Step 2. Create the aortic incision and posterior aortic flap (the inflow “landing zone”)

• Make an aortic incision positioned to align with the intended coronary flow vector.
• Fashion a posterior aortic-wall flap that will provide:
• Broad inflow (avoid a slit-like inlet)
• Minimal angulation
• No torsion across the coronary takeoff once the great vessels return to their native geometry. [3,4]

Step 3. Anastomose the two flaps to form a tubular channel

• Suture the posterior aortic flap to the anterior PA-wall flap to create a short, smooth conduit from the aorta to the LCA.
• The target is a round/oval lumen (a “tube”), not a flattened tunnel—this reduces turbulence and avoids late functional stenosis. [3,4]

Step 4. Reconstruct the PA (do not “borrow” PA wall without paying it back)

• Re-establish PA continuity to prevent:
• Supravalvar/MPA narrowing
• Distortion of branch PA geometry
• A residual lesion that can dominate late outcomes even when coronary perfusion is excellent. [1,7]

5) Technical Pearls (Determinants of Success)

A. Geometry is everything

• Keep the channel short, straight, and non-compressive.
• Avoid:
• Stretch with cardiac motion/growth
• External compression between great vessels
• Angulation at aortic inflow or coronary outflow. [3,4]

B. Flap generosity is a durability strategy

• A narrow construct may look acceptable in a small infant but becomes limiting as coronary flow demand rises.
• Series describing coronary extension approaches report low coronary reintervention rates when the pathway is constructed in a generous, non-stenotic fashion. [3,4]

C. Protect the “no-kink zone” of the proximal LCA

• Confirm lie and orientation after reperfusion and filling, when the heart and great vessels assume their physiologic positions. [3,4]

6) Pitfalls and Failure Modes (and How to Avoid Them)

1. Aortic inflow stenosis
• Mechanism: small aortic flap or poor alignment
• Prevention: build a broad, well-oriented inflow and avoid acute entry angles.
2. Coronary outflow compromise
• Mechanism: torsion or tension at the proximal LCA
• Prevention: adequate mobilization; confirm a relaxed lie with the heart filled.
3. Conduit flattening / functional narrowing
• Mechanism: insufficient flap width or external compression
• Prevention: aim for a true tube, not a long thin tunnel; avoid constructs vulnerable to squeeze.
4. PA distortion or regurgitation/obstruction phenotype
• Mechanism: inadequate PA reconstruction after using PA wall
• Prevention: meticulous PA restoration; remember that late PA lesions are a known vulnerability of intrapulmonary tunnel strategies and must be proactively avoided in any repair that manipulates PA tissue. [1,7]

7) Intraoperative and Postoperative Assessment (What You Must Prove)

A. Coronary adequacy (physiology first)

• Stable ECG, improving LV performance trend, no ischemic instability.
• Early LV functional recovery after establishing a two-coronary system is well described across cohorts. [1,6,8]

B. Mitral regurgitation trajectory

• MR often improves with restored perfusion; long-term series show marked reductions in significant MR in many patients, though severe MR may persist in a subset and requires structured follow-up. [5,9]

C. Patency of the channel

• Ensure there is no evidence of inflow/outflow limitation; extension techniques have demonstrated low coronary stenosis–related reoperation rates when geometry is favorable. [3,4]

D. PA patency

• Exclude RVOT/MPA obstruction and confirm PA geometry, since PA-related morbidity is a dominant late issue in some ALCAPA repair strategies. [1,7]

References

[1] Neumann A, Sarikouch S, Bobylev D, Meschenmoser L, Breymann T, Westhoff-Bleck M, et al. Long-term results after repair of anomalous origin of left coronary artery from the pulmonary artery: Takeuchi repair versus coronary transfer. Eur J Cardiothorac Surg. 2017;51(2):308-315.

[2] Yuan X, Li B, Sun H, Yang Y, Meng H, Xu L, et al. Surgical Outcome in Adolescents and Adults With Anomalous Left Coronary Artery From Pulmonary Artery. Ann Thorac Surg. 2018;106(6):1860-1867.

[3] Kazmierczak PA, Ostrowska K, Dryzek P, Moll JA, Moll JJ. Repair of anomalous origin of the left coronary artery from the pulmonary artery in infants. Interact Cardiovasc Thorac Surg. 2013;16(6):797-801.

[4] Alsoufi B, Sallehuddin A, Bulbul Z, Joufan M, Khouqeer F, Canver CC, et al. Surgical strategy to establish a dual-coronary system for the management of anomalous left coronary artery origin from the pulmonary artery. Ann Thorac Surg. 2008;86(1):170-176.

[5] Kudumula V, Mehta C, Stumper O, Desai T, Chikermane A, Miller P, et al. Twenty-year outcome of anomalous origin of left coronary artery from pulmonary artery: management of mitral regurgitation. Ann Thorac Surg. 2014;97(3):938-944.

[6] Zhang C, Zhang H, Yan J, Hua Z, Song Y, Sun H, et al. Mid-Term Outcome for Anomalous Origin of the Left Coronary Artery From the Pulmonary Artery. Heart Lung Circ. 2020;29(5):766-771.

[7] Hoashi T, Kagisaki K, Okuda N, Shiraishi I, Yagihara T, Ichikawa H. Indication of Takeuchi technique for patients with anomalous origin of the left coronary artery from the pulmonary artery. Circ J. 2013;77(5):1202-1207.

[8] Hu R, Zhang W, Yu X, Zhu H, Zhang H, Liu J. Midterm Surgical Outcomes for ALCAPA Repair in Infants and Children. Thorac Cardiovasc Surg. 2022;70(1):2-9.

[9] Naimo PS, Fricke TA, d'Udekem Y, Cochrane AD, Bullock A, Robertson T, et al. Surgical Intervention for Anomalous Origin of Left Coronary Artery From the Pulmonary Artery in Children: A Long-Term Follow-Up. Ann Thorac Surg. 2016;101(5):1842-1848.

[10] Ling Y, Bhushan S, Fan Q, Tang M. Midterm outcome after surgical correction of anomalous left coronary artery from the pulmonary artery. J Cardiothorac Surg. 2016;11(1):137.