Double Outlet Right Ventricle (DORV) — #7 Clinical and Anatomical Classifications (Upgraded)

DORV is best approached as a family of ventriculo–arterial connection patterns in which the VSD becomes the LV’s obligate exit. A single label is rarely sufficient; instead, durable decision-making comes from using two complementary lenses:

1. Clinical (physiology-first) classification

What is the dominant physiology today—pulmonary overcirposed flow, cyanosis, “TGA-like” streaming, or a single-ventricle trajectory?

2. Anatomical (geometry-first) classification

Where is the VSD relative to the semilunar valves—i.e., what is the “routing geometry” that determines whether a safe biventricular repair exists?

Modern nomenclature systems explicitly embed this concept: DORV subtypes are defined by VSD–great artery relationship and key modifiers such as RVOTO (and/or great-artery relationships), because these features predict both physiology and repair options. [1,2]

1) Two complementary lenses

1A) Clinical classification (physiology-first)

Clinical groups on your slide (VSD-type, TOF-type, TGA-type, single-ventricle pathway) are best understood as dominant hemodynamic outcomes driven by:

• RVOTO / PS severity
• SVR vs PVR balance
• Streaming vs mixing across VSD/ASD/PDA
• Associated lesions (arch obstruction, AV valve regurgitation, pulmonary venous disease, ventricular hypoplasia)

This “physiology-first” lens is crucial for timing and stabilization, but it must ultimately “return” to anatomy for definitive strategy. [3]

1B) Anatomical classification (geometry-first)

Your lower panel (subaortic, doubly committed, subpulmonary, noncommitted/remote) is the surgical steering wheel, because it describes whether the LV can be routed to a systemic outflow without creating a new obstruction.

A widely used framework (STS–EACTS) formalizes this by classifying DORV according to VSD relationship plus presence/absence of RVOTO. [1]

Other echocardiography-driven systems add great-artery spatial relationships and further stratify the “committed/noncommitted” concept into more granular subtypes to better map anatomy to operative approach. [2]

2) Clinical classification — what each physiology means (and why it matters)

2.1 VSD-type physiology (pulmonary overcirculation)

Hemodynamic signature

• Minimal/no RVOTO → Qp ≫ Qs
• Heart failure phenotype: tachypnea, poor growth, recurrent respiratory symptoms

Common anatomic substrates

• Often subaortic or doubly committed VSD (large nonrestrictive VSD + unprotected pulmonary bed)

Strategy implications

• Early: control overcirculation (medical therapy; selected cases may need palliation)
• Definitive: biventricular repair is often feasible, but the repair must be planned around post-baffle LVOT geometry and conduction safety. [3]

2.2 TOF-type physiology (cyanosis-driven)

Hemodynamic signature

• Significant RVOTO/PS → right-to-left VSD shunt → cyanosis
• “Protected Qp,” but saturation limited by RVOTO severity

Common anatomic substrates

• Frequently subaortic VSD + RVOTO (Tetralogy-like physiology within DORV anatomy)

Strategy implications

• Short-term: ensure adequate pulmonary blood flow (ductal patency / palliation when needed)
• Definitive: relief of RVOTO + LV→Ao routing with careful avoidance of LVOTO and valve distortion. [3]

2.3 TGA-type physiology (streaming/parallel-circulation problem)

Hemodynamic signature

• Systemic and pulmonary flows behave more “in parallel,” and outcome depends on mixing sites and streaming
• Pulmonary overcirculation may coexist

Common anatomic substrates

• Classically linked to subpulmonary VSD (Taussig–Bing spectrum), where LV output preferentially streams to PA

Strategy implications

• Stabilize like TGA (ensure mixing; manage Qp if excessive)
• Definitive: switch-/routing-based strategies are chosen based on coronary pattern, arch anatomy, and feasibility of physiologic VA matching. [2,3]

2.4 Single-ventricle pathway (capacity-limited rather than route-limited)

Hemodynamic signature

• The limiting factor is not only “where blood streams,” but whether two-ventricle repair is anatomically and functionally safe

Common drivers

• Remote/noncommitted VSD requiring a long hazardous baffle
• Hypoplastic or unbalanced ventricles
• Prohibitive AV valve anatomy (straddling, severe regurgitation, complex chordal geography)

Evidence-based caution

Large outcome series show that “borderline” anatomy—particularly inadequate left-sided structures and/or nonsubaortic VSD geometry—strongly influences the likelihood of ending in a Fontan-type pathway and raises concern about pushing biventricular repair beyond safe candidates. [4,5]

3) Anatomical classification — why VSD commitment is the “surgical steering wheel”

3.1 Subaortic VSD

Geometry

• VSD aligned with the aortic valve → relatively direct LV→Ao route

Repair logic

• Often favorable for intraventricular baffle (LV→Ao)
• Main hazards:
• LVOTO from tunnel angle/size and conal septal relationships
• Conduction injury during VSD enlargement/closure
• Residual VSD or late subaortic stenosis in select morphologies [6,8]

3.2 Doubly committed (juxtaarterial) VSD

Geometry

• VSD lies beneath both semilunar valves → tight “valvar neighborhood”

Repair logic

• Routing can be flexible, but requires heightened attention to:
• Semilunar valve integrity
• Post-baffle outflow geometry (both LVOT and RVOT)

3.3 Subpulmonary VSD (Taussig–Bing spectrum)

Geometry

• VSD aligned with the pulmonary valve → LV preferentially streams to PA

Repair logic

• Often maps to “TGA-type” physiology
• Strategy selection is anatomy-dependent; switch-/routing-based repairs are common in contemporary series, with early risk influenced by the complexity of the chosen reconstruction. [7]

3.4 Noncommitted / remote VSD

Geometry

• VSD distant from both arterial valves → LV egress requires a long, angled, potentially obstructable route

Why it is a “decision lesion”

• Remote VSD anatomy is consistently overrepresented among higher-risk subgroups:
• Greater risk of reoperation and mortality after biventricular repair in multicenter data [7]
• More frequent need for VSD enlargement and complex baffling in surgical series [6]
• Therefore, it is a common pivot point toward staged single-ventricle strategy when ventricular balance/valvar anatomy is unfavorable. [3–5]

4) Integrating both lenses — an “OR-ready” workflow

A practical (and teachable) sequence is:

1. Name the physiology (clinical class)

VSD-type / TOF-type / TGA-type / single-ventricle trajectory

2. Define the routing geometry (anatomic class)

Subaortic / doubly committed / subpulmonary / remote

3. Interrogate the “make-or-break modifiers”
• Ventricular adequacy (LV size/function; balance) [5]
• Aortic arch anatomy (hypoplasia/coarctation) [4,5]
• Coronary anatomy (especially when switch-based repair is contemplated) [7]
• AV valve anatomy/regurgitation (cleft/straddling/competence) [4,7]
• Anticipated post-repair LVOT/RVOT geometry (risk of LVOTO/RVOTO) [6,8]
4. Choose a strategy that is anatomically honest
• Physiology guides timing + stabilization
• Anatomy dictates what is safe and durable

This “anatomy-honest” principle is consistent across eras—from early intraventricular tunnel concepts to contemporary multicenter outcome analyses. [7,9]

References (PubMed-verified)

[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] 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.

[3] Cetta F, Edwards WD, Hagler DJ. Double outlet right ventricle: opinions regarding management. Curr Treat Options Cardiovasc Med. 2005;7(5):385-390.

[4] Kleinert S, Sano T, Weintraub RG, Mee RB, Karl TR, Wilkinson JL. Anatomic features and surgical strategies in double-outlet right ventricle. Circulation. 1997;96(4):1233-1239.

[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] 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):545-550.

[7] Villemain O, Belli E, Ladouceur M, Houyel L, Jalal Z, Lambert V, Ly M, Vouhé P, Bonnet D. Impact of anatomic characteristics and initial biventricular surgical strategy on outcomes in various forms of double-outlet right ventricle. J Thorac Cardiovasc Surg. 2016;152(3):698-706.e3.

[8] Serraf A, Lacour-Gayet F, Houyel L, Bruniaux L, Touchot C, Planche C. Subaortic obstruction in double outlet right ventricle. Circulation. 1993;88(5 Pt 2):II177-II182.

[9] Kirklin JW, Blackstone EH, Kirklin JK, Pacifico AD, Bargeron LM Jr. Intraventricular tunnel repair of double-outlet right ventricle with transposition of the great arteries. J Card Surg. 1987;2(4):405-411.