Double Outlet Right Ventricle (DORV) — #2 Anatomic Classifications

“In DORV, the VSD–outflow relationship is the anatomic steering wheel—because the LV’s exit is VSD-dependent.”\

Double outlet right ventricle (DORV) is best understood as a spectrum of ventriculo–arterial connections in which both great arteries arise entirely or predominantly from the right ventricle. The shared physiologic consequence is that left-ventricular egress is VSD-dependent, making the VSD–semilunar valve relationship the most practical “first classifier” for operative planning and outcome prediction. [1, 2]

1) Why the “VSD commitment” classification matters

This taxonomy is not merely descriptive—it is a surgeon-facing decision framework:

• Streaming physiology
• VSD alignment determines whether LV output preferentially reaches the aorta, the pulmonary artery, or both—thereby shaping mixing, oxygenation, and pulmonary blood flow. [1, 6]
• Repair feasibility
• It predicts whether a short, non-obstructive intraventricular tunnel (baffle) to a semilunar valve can be constructed—or whether alternative strategies are needed (e.g., arterial switch–based approaches, outflow reconstruction, staged pathways). [2, 4, 6]
• Risk forecasting
• It correlates with the likelihood of LVOT/RVOT obstruction, need for conal/outlet septum resection, and “patch geometry” issues (tunnel length, angulation, residual gradients). [5, 7]

Epidemiologic context (from large surgical series): subaortic VSD is most common (≈half), subpulmonary VSD accounts for ≈one-quarter, doubly committed VSD is uncommon, and noncommitted/remote VSD comprises roughly one-quarter—though proportions vary by referral patterns and inclusion criteria. [1, 2] In a large cohort study, biventricular repair was feasible in a majority of patients, but reintervention and mortality were driven by anatomic complexity and strategy selection. [2]

2) The four canonical anatomic subtypes (VSD–outflow commitment)

2.1 Subaortic VSD (aortic-committed)

Core definition: the VSD lies beneath and primarily relates to the aortic valve, offering the most direct potential LV→Ao route. [6, 9]

• Anatomic signature
• VSD margin closest to the aortic valve hinge (“aortic commitment”).
• LV→Ao pathway can often be achieved with a relatively straight baffle.
• Physiology (typical patterns)
• Often TOF-like when RVOTO/PS is present (a common association).
• Without RVOTO, physiology may resemble large VSD physiology with variable mixing.
• Surgical implication (conceptual)
• Frequently amenable to biventricular repair via intraventricular routing of LV→Ao, with RVOT management tailored to the obstruction substrate. [2, 10]

2.2 Subpulmonary VSD (Taussig–Bing type)

Core definition: the VSD primarily relates to the pulmonary valve, and the aorta is often anterior and rightward or side-by-side relative to the PA. [2, 6]

• Anatomic signature
• LV streaming preferentially enters the pulmonary outflow (subpulmonary commitment).
• Great-artery geometry often resembles TGA-like malposition, though the spectrum is broad.
• Physiology (typical patterns)
• Frequently behaves like TGA with VSD: systemic desaturation and pulmonary overcirculation depend on mixing and relative resistances.
• Surgical implication (conceptual)
• Strategies often aim to restore physiologic ventriculo–arterial matching (commonly switch- and/or rerouting-based), while ensuring unobstructed LVOT and coronary-safe reconstruction. [2, 6]

2.3 Doubly committed VSD

Core definition: the outlet (infundibular) septum is absent/deficient, placing both semilunar valves at the same level, and the VSD relates to both outflows. [6, 9]

• Anatomic signature
• “Juxtaarterial” configuration: the defect sits immediately beneath both arterial valves.
• Valve-level relationships (commissures, hinge lines) become critical operative landmarks.
• Physiology (typical patterns)
• Often prominent mixing; hemodynamics are heavily influenced by associated RVOTO/LVOTO and vascular resistances.
• Surgical implication (conceptual)
• Patch design must protect both semilunar valves and avoid creating subaortic or subpulmonary narrowing at the cardiac base. [6, 7]

2.4 Noncommitted (remote) VSD

Core definition: the VSD is distant from both great arteries, without direct alignment to either outlet. [3, 4]

• Anatomic signature
• Achieving LV→outlet continuity requires a longer, more angulated tunnel, often crossing complex RV geometry.
• Frequently accompanied by additional complexity (trabeculations, inlet extension, AV-valve malalignment, ventricular imbalance).
• Physiology (typical patterns)
• Marked mixing is common; obstruction risk may arise from tunnel geometry and “crowding” rather than valve-level commitment alone.
• Surgical implication (strategy-sensitive)
• This subtype most clearly demonstrates that “classification becomes strategy”: feasibility depends on whether a non-obstructive baffle can be constructed without compromising TV function, RV volume, or outflow tracts; remote VSD anatomy has been linked to higher reoperation risk in operative series. [3, 5]

3) “Beyond the label”: essential modifiers that complete the anatomic diagnosis

VSD commitment is the first axis, but a complete DORV description should include:

1. Great-artery relationship
• Anteroposterior vs side-by-side; degree of malposition; conal rotation pattern. [6]
2. Outflow tract status
• Presence/level of RVOTO, and potential LVOTO—including the predicted risk after intraventricular routing. [5, 7]
3. VSD size and rims
• Adequacy for baffle construction; proximity to valve hinges; muscular vs fibrous margins; need for VSD enlargement. [3, 4]
4. AV valve anatomy
• Straddling/overriding and chordal attachments that may prohibit a tunnel plane; AVSD association. [4, 6]
5. Associated lesions
• Arch obstruction/coarctation, coronary pattern (when switch-based strategies are considered), pulmonary valve/branch PA anatomy. [2, 6]

4) Imaging checklist aligned to surgical planning (echo/CT/MRI language)

A “surgeon-ready” imaging report should explicitly document:

• VSD–arterial valve commitment (subaortic / subpulmonary / doubly committed / remote). [1]
• Distance + angle from VSD to each semilunar valve (anticipates tunnel length and gradient risk). [5]
• Outlet (conal/infundibular) septum anatomy (present vs absent; feasibility of resection; valve-level crowding). [6, 7]
• Outflow dimensions + dynamic obstruction (baseline and predicted after planned routing/repair). [5, 7]
• AV valve chordal map (any attachments crossing the intended baffle plane). [4, 6]

5) Outcomes perspective (what large series consistently show)

• Biventricular repair is achievable in many patients, but the “end-state” (two-ventricle vs staged/single-ventricle) is strongly influenced by anatomic substrate and institutional strategy. [2, 6]
• Early mortality in modern surgical series is typically single digits, while reintervention risk is non-trivial and increases with anatomic complexity—particularly in remote VSD and LVOT/RVOT vulnerability phenotypes. [2, 5, 8]
• Long-term, multicenter data emphasize that late outcomes and reintervention remain important, reinforcing the need for anatomy-precise planning and durable outflow tract geometry. [8]

References (PubMed-verified)

[1] Pang KJ, Meng H, Hu SS, Wang H, Hsi D, Hua Z, Pan X, Li S. 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.

[2] Bradley TJ, Karamlou T, Kulik A, Mitrovic B, Vigneswaran TV, Jaffer S, Glasgow P, 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.

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

[4] 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.

[5] Villemain O, Belli E, Ladouceur M, Houyel L, Capderou A, Raisky O, 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.e1.

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

[7] Serraf A, Lacour-Gayet F, Houyel L, Bruniaux J, Uva MS, Roux D, Piot D, Planché C. Subaortic obstruction in double outlet right ventricles. Surgical considerations for anatomic repair. Circulation. 1993;88(5 Pt 2):II177-II182.

[8] Lacour-Gayet F, Zoghbi J, Gouton M, Roussin R, Bical OM, Lucet V, Saint-Pick M, Leca F. Multicentre study on late outcomes of biventricular repair of double outlet right ventricle. Eur J Cardiothorac Surg. 2024;65(1):ezad423.

[9] Stewart RW, Kirklin JW, Pacifico AD, Bargeron LM Jr. Repair of double-outlet right ventricle. An analysis of 62 cases. J Thorac Cardiovasc Surg. 1979;78(4):502-514.

[10] Aoki M, Forbess JM, Jonas RA, Mayer JE Jr, Castaneda AR. Result of biventricular repair for double-outlet right ventricle. J Thorac Cardiovasc Surg. 1994;107(2):338-349.