DORV #2 — Clinical Classification

DORV is best approached as a ventriculo–arterial connection problem in which both great arteries arise predominantly from the morphologic RV, and the VSD becomes the functional outlet of the LV. A clinically useful classification is therefore the one that predicts (i) current physiology and (ii) the safest durable end-state (biventricular vs single-ventricle), rather than labeling anatomy alone. This concept is embedded in contemporary nomenclature frameworks and outcome-based analyses. [1–3]

The major determinants (the “decision drivers”)

Bedside decisions and operative feasibility are primarily determined by:

1. VSD location/commitment: subaortic, subpulmonary (Taussig–Bing), doubly committed, or remote/noncommitted [1–4]
2. Pulmonary stenosis / subpulmonary obstruction (PS/RVOTO) and its level(s) [3,4]
3. Great-artery relationship and the spatial feasibility of VSD routing (tunnel length/angulation) [3,4]
4. Adequacy of LV size, LVOT, and AV valve anatomy/function (including straddling/override/chordal constraints) [3–5]
5. Associated lesions (e.g., arch obstruction, branch PA distortion, coronary pattern—especially when an ASO-based strategy is considered) [3,5,6]

1) VSD-type DORV (Large VSD physiology; typically no/mild PS)

Definition (clinical)

DORV with a subaortic VSD or doubly committed VSD and no or mild PS behaves physiologically like a large VSD: LV → VSD → RV/PA streaming drives pulmonary overcirculation. [3,4,6]

Dominant physiology

• Pulmonary overcirculation (↑Qp) with heart failure symptoms [3,4]
• Systemic saturation often acceptable unless streaming/mixing is unfavorable [3,4]
• LV volume overload is typically prominent via increased pulmonary venous return [4,6]

Initial management (infancy)

• Treat as “large VSD physiology”: diuretics, afterload optimization, nutrition/feeding strategy [4,6]
• PA banding can be used as a physiology-control bridge when overcirculation is difficult to manage or when anatomy is not yet ideal for definitive routing. [4,6]

Definitive repair concept

• Elective LV-to-Ao intraventricular baffle (VSD routing) once symptoms are controlled and anatomy is favorable. [4,6]

Key determinants of success (high-yield)

• Baffle geometry: short/straight preferred; long/angulated tunnels increase LVOTO risk [4,6]
• LVOT adequacy after baffle (avoid iatrogenic LVOTO) [4,6]
• AV valve function/anatomy, especially chordal relationships that constrain tunnel design [4–6]

2) TOF-type DORV (Cyanotic physiology driven by PS/RVOTO)

Definition (clinical)

DORV with subaortic or doubly committed VSD plus significant PS/subpulmonary obstruction behaves like Tetralogy physiology. [3,4,6]

Dominant physiology

• Right-to-left shunt across the VSD due to RVOTO/PS [3,4]
• Cyanosis predominates (rather than overcirculation) [3,4]

Management pathway

1. Stable + anatomy suitable for early complete repair → proceed with definitive repair when feasible [4,6]
2. Symptomatic early infancy or anatomy unfavorable for immediate repair → consider palliation (e.g., mBTS, ductal stent in select programs, or RVOT-based palliation depending on strategy) [6]

Definitive repair concept

• Transatrial/transpulmonary approach with integrated planning for:
• RVOT relief (valve-sparing when feasible; patch strategy tailored to annulus/leaflets)
• VSD routing (LV→Ao baffle) when appropriate [4,6]

Surgical traps (explicit screening)

• RVOTO is often multilevel (infundibular + valvar ± supravalvar/branch PA) [6]
• RVOT relief can change geometry; tunnel design and RVOT strategy must be planned as one construct, not sequentially. [4,6]

3) TGA-type DORV (Taussig–Bing physiology; subpulmonary VSD)

Definition (clinical)

DORV with a subpulmonary VSD produces preferential LV→PA streaming, yielding TGA-like physiology (Taussig–Bing spectrum). [4,6]

Dominant physiology

• Systemic output tends to be RV→Ao, while LV ejects preferentially to the PA [4,6]
• Early stability depends on:
• Adequate mixing (atrial level, VSD, ductus)
• Arch patency (arch obstruction can coexist and materially changes neonatal management) [5,6]

Early stabilization priorities

• Ensure systemic oxygen delivery and perfusion:
• PGE when ductal patency is needed
• BAS if atrial level is restrictive and mixing is inadequate
• Evaluate and address coarctation/arch hypoplasia when present [5,6]

Definitive repair: match the operation to RVOT/PS status

• Minimal/no PS + favorable anatomy: ASO + intraventricular baffle (to align LV output with systemic circulation) [6]
• Significant PS/RVOTO or unfavorable ASO+baffle geometry: consider alternatives (e.g., Rastelli/REV/Nikaidoh-type pathways), recognizing that conduit-dependent strategies carry predictable late reintervention burden. [5,6]

Outcomes-informed nuance

In a large single-institution cohort analysis, Rastelli-type repair was associated with higher early reintervention risk and higher late post-repair mortality, while ASO-based strategies showed a different early/late risk tradeoff—reinforcing the need to match operation selection to anatomy rather than applying a “one-size-fits-all” approach. [5]

4) Remote (Noncommitted) VSD DORV: the “routing feasibility” problem

Definition (clinical)

A remote/noncommitted VSD is not committed to either semilunar valve; the LV outlet is geometrically distant from both great arteries. The central decision becomes:

Complex biventricular repair (long intraventricular tunnel ± additional reconstruction) vs single-ventricle palliation. [4–6]

Dominant physiology (typical)

• Frequently overcirculation if the VSD is large and pulmonary outflow is unrestrictive [6]
• Mixed physiology can occur depending on streaming and associated obstructions [6]

Bridge strategy (practical standard)

• PA banding to control Qp and protect pulmonary vasculature while buying time for growth, imaging definition, and team decision-making. [6]

Decision hinges (high-yield feasibility criteria)

1. Distance/alignment: can a tunnel be constructed that is short enough and non-obstructive (LVOT)? [4–6]
2. AV valve anatomy/function: straddling/override/abnormal chordal attachments can make BiV routing unsafe [5,6]
3. Ventricular adequacy (balanced vs hypoplastic/complex inlet anatomy) [5,6]
4. Great-artery relationship: long/angulated pathways increase LVOTO and reintervention risk [4–6]

Outcome anchor for counseling

In a dedicated series of noncommitted VSD DORV undergoing biventricular repair, hospital mortality was reported at 9%, and reoperations occurred in 35%, most commonly for subaortic stenosis—highlighting that the “price” of complex routing is often paid later as LVOT morbidity. [7]

5) A compact, physiology-first algorithm (bedside → OR planning)

Step 1: Identify the dominant physiology

• Overcirculation → VSD-type or remote VSD without significant PS [3,4,6]
• Cyanosis with PS/RVOTO → TOF-type [3,4,6]
• TGA-like mixing problem (subpulmonary VSD) → TGA/Taussig–Bing spectrum [4–6]

Step 2: Define the VSD in operative terms

• Subaortic / subpulmonary / doubly committed / remote
• Ask a single high-yield question:

“Can the LV be routed to the intended systemic outlet without creating LVOTO or injuring the AV valve apparatus?” [4–6]

Step 3: Choose the end-state

• Routable VSD + adequate LV/LVOT/AV valves → BiV repair (baffle-based ± outflow reconstruction) [4–6]
• Not safely routable, or borderline left-sided structures/AV valve constraints → SV palliation [5,6]

Step 4: Use staged palliation when physiology demands time

• Overcirculation → PA band [6]
• Inadequate mixing/systemic oxygen delivery → PGE ± BAS [6]
• Symptomatic cyanosis in early infancy → palliation (e.g., mBTS) or institutional alternative [6]

Step 5: Build “staged BiV” into the mental model for complex candidates

For anatomically complex DORV that may still be septatable, the modern bias is not simply “BiV vs SV,” but “primary BiV vs staged BiV vs SV”, acknowledging that a staged approach can convert marginal geometry into a safer definitive repair in selected patients. [8,9]

References

[1] Walters HL 3rd, Mavroudis C, Tchervenkov CI, Jacobs JP, Lacour-Gayet F, Jacobs ML. Congenital Heart Surgery Nomenclature and Database Project: double outlet right ventricle. Ann Thorac Surg. 2000;69(4 Suppl):S249-63.

[2] Artrip JH, Sauer H, Campbell DN, Mitchell MB, Haun C, Almodovar MC, Hraska V, Lacour-Gayet F. Biventricular repair in double outlet right ventricle: surgical results based on the STS-EACTS International Nomenclature classification. Eur J Cardiothorac Surg. 2006;29(4):545-50.

[3] Lacour-Gayet F. Intracardiac repair of double outlet right ventricle. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2008;11:39-43.

[4] Pang KJ, Meng H, Hu SS, Wang H, Hsi D, Hua ZD, Pan XB, Li SJ. Echocardiographic Classification and Surgical Approaches to Double-Outlet Right Ventricle for Great Arteries Arising Almost Exclusively from the Right Ventricle. Tex Heart Inst J. 2017;44(4):245-251.

[5] Bradley TJ, Karamlou T, Kulik A, Mitrovic B, Vigneswaran T, Jaffer S, Glasgow PD, Williams WG, Van Arsdell GS, McCrindle BW. Determinants of repair type, reintervention, and mortality in 393 children with double-outlet right ventricle. J Thorac Cardiovasc Surg. 2007;134(4):967-973.e6.

[6] Cetta F, Boston US, Dearani JA, Hagler DJ. Double outlet right ventricle: opinions regarding management. Curr Treat Options Cardiovasc Med. 2005;7(5):385-390.

[7] Belli E, Serraf A, Lacour-Gayet F, Hubler M, Zoghby J, Houyel L, Planche C. Double-outlet right ventricle with non-committed ventricular septal defect. Eur J Cardiothorac Surg. 1999;15(6):747-752.

[8] Backer CL. Double Outlet Right Ventricle: Where are we Now? Semin Thorac Cardiovasc Surg. 2016;28(1):79-80.

[9] Backer CL. Commentary: Double-outlet right ventricle revisited. J Thorac Cardiovasc Surg. 2020;159(1):265.

[10] Burkhart HM, Thompson JL, Mir A. Commentary: Double-outlet right ventricle: Complex solutions for a complex anomaly. J Thorac Cardiovasc Surg. 2020;159(1):266-267.