Double outlet right ventricle (DORV) is defined as a ventriculoarterial connection anomaly, with the PA and aorta connected to the RV either directly or because the aorta overrides a VSD and shifts to the right (Video).
Video: 4-chamber view of a case of DORV; the RV is severely hypertrophied and connected to both PA and aorta through a VSD; the RV is on the right of the screen, because the case is a situs inversus.
The PA is stenotic in half of all cases [3]. The embryological cause of DORV is a rotation failure of the distal conus (see Figure 14.1) and a leftward shift of the conoventricular septum. The VSD is generally of a membranous type. The aorta and PA are often side-by-side, although not transposed [2]. This pathology is often associated with other malformations. Clinically, children generally present with cyanosis and congestive heart failure. When symptoms occur from birth, PA banding is performed if pulmonary flow is excessive or a Blalock shunt is created if pulmonary flow is insufficient. Correction is carried out at the age of 2-6 months and varies depending on each patient's specific anatomy. The haemodynamics of DORV are dependent on the extent and direction of shunting, which are dependent on several factors [2].
Video: 4-chamber view of a case of DORV; the RV is severely hypertrophied and connected to both PA and aorta through a VSD; the RV is on the right of the screen, because the case is a situs inversus.
The PA is stenotic in half of all cases [3]. The embryological cause of DORV is a rotation failure of the distal conus (see Figure 14.1) and a leftward shift of the conoventricular septum. The VSD is generally of a membranous type. The aorta and PA are often side-by-side, although not transposed [2]. This pathology is often associated with other malformations. Clinically, children generally present with cyanosis and congestive heart failure. When symptoms occur from birth, PA banding is performed if pulmonary flow is excessive or a Blalock shunt is created if pulmonary flow is insufficient. Correction is carried out at the age of 2-6 months and varies depending on each patient's specific anatomy. The haemodynamics of DORV are dependent on the extent and direction of shunting, which are dependent on several factors [2].
- Shunt size;
- Relation between the VSD and the great arteries;
- Obstruction present in the RVOT or LVOT;
- Pulmonary arterial resistance;
- In all combinations, the RV is connected to systemic pressure.
Surgical correction is generally performed in the first year of life. If the anatomical distance between the tricuspid and pulmonary valve is sufficient, an intraventricular correction is carried out.
- Normal pulmonary artery root: patch on the VSD, which redirects blood to the aorta.
- Stenosed pulmonary artery root: RV-PA widened by patch or conduit and tetralogy of Fallot-type correction.
If tricuspid-pulmonary distance is insufficient (< aorta diameter), reconstruction is more complex.
- Normal pulmonary artery root: LV-PA tunnelling and arterial switch;
- Stenosed pulmonary artery root: LV-aorta tunnelling and pulmonary artery root translocation to the anterior wall of the RV (Lecompte manoeuvre) or homograft between the RV and PA (Rastelli procedure, Figure 14.67); LV-PA tunnelling + aorta and Damus-Kaye-Stansel procedure (Figure 14.68).
The malformation exhibits five types of haemodynamic behaviour depending on the exact anatomy of the lesion [1,2].
- VSD-type in the absence of pulmonary stenosis but in the presence of a wide subaortic VSD (55% of cases);
- Tetralogy of Fallot (TOF)-type if pulmonary stenosis is significant;
- Transposition of the great arteries (TGA)-type if pulmonary stenosis is absent but a wide subpulmonary VSD is present. Venous and arterialised blood is only partially mixed in the RV as flows are more or less parallel.
- Single ventricle-type in cases of hypoplastic LV.
- Complete AV canal defect-type if there is significant distance between the VSD and ventriculoarterial valves.
Management entails adjusting SVR and PVR based on lesion type to balance Qp and Qs, maximise cardiac output, prevent systemic acidosis, and optimise O2 delivery. Please refer to the appropriate chapters for details of anaesthetic techniques: VSD, TOF, TGA, hypoplastic LV or AV canal defects.
| Double outlet right ventricle (DORV) |
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Characteristics: The PA and aorta are connected to the RV either directly or because the aortaoverrides a VSD and shifts to the right. Five haemodynamic variants:
- VSD-type (no pulmonary stenosis) - TOF-type if dominant pulmonary stenosis - TGA-type if wide subpulmonary VSD (mixture of arterial and venous blood) - Single ventricle-type if pulmonary hypoplasia - AV canal defect-type if significant distance between the VSD and ventriculoarterial valves Haemodynamic management is dependent on the type of pathology involved. |
© BETTEX D, BOEGLI Y, CHASSOT PG, June 2008, last update May 2018
References
- BENT ST. Anesthesia for left-to-right shunt lesions. In : ANDROPOULOS DA, et al, eds. Anesthesia for congenital heart disease. Oxford: Blackwell-Futura, 2005, 297-327
- NASR VG, DINARDO JA. The pediatric cardiac anesthesia handbook. Oxford: Wiley-Blackwell, 2017; 97-101
- SRIDAROMONT S, FELDT RH, RITTER DG, et al. Double outlet right ventricle: hemodynamic and anatomic correlations. Am J Cardiol. 1976; 38:85-94.