Transposition of the Great Arteries Preoperative Diagnostic Considerations. John Simpson Evelina Children s Hospital London, UK

Transcription

1 Transposition of the Great Arteries Preoperative Diagnostic Considerations John Simpson Evelina Children s Hospital London, UK

2 Areas to be covered Definitions Scope of occurrence of transposition of the great arteries Echocardiographic findings Important considerations

3 Transposition of the great arteries The aorta arises predominantly / exclusively from the morphologic right ventricle The pulmonary artery arises predominantly / exclusively from the morphologic left ventricle The relationship of the great arteries to each other does not define the condition e.g. aorta anterior

4 Morphologies Transposition of the great arteries may occur in association with a wide range of morphologies As an example, Pascal et al (2007) 120 consecutive cases of prenatal transposed Gas 56 cases had concordant atrioventricular connection 64 cases had other subarterial morphologies

5 Morphologies Pascal 2007

6 Simple transposition of the great arteries Differential sats : UL < LL Image :

7 Prenatal diagnosis

8 Paris Data Bonnet et al, Circulation, 1999

9 Simple transposition of the great arteries Inadequate mixing Restrictive PFO Restrictive duct Has a significant impact on outcome Image :

10 Cardiac Situs

11 Interatrial Communication Restrictive Unrestrictive

12 Balloon Atrial Septostomy

13 Four Chamber View

14 Subcostal Views of Great Arteries LV to PA Ao from RV

15 Transposition of the Great Arteries

16 Parasternal Long Axis

17 Parasternal short axis Ant Ao Ao R L PA PA Post Both of these examples taken from infants with TGA The spatial relationship of the great arteries does not define the lesion

18 Suprasternal Views

19 Late presentation Once PVR falls postnatally, the LV faces pulmonary vascular resistance LV involutes Primary arterial switch impossible Careful evaluation if presentation beyond 4-6 weeks of age with simple TGA

20 Late presentation of TGA Note septal appearance Hyperdynamic LV

21 The Coronary Arteries Coronaries almost invariably from facing sinuses Key point: Draw a labelled diagram of the coronaries

22 Coronary arteries RCA LAD Anterior Ao PA R L Posterior Do not be fooled by pericardial folds

23 Coronary Arteries Coronary artery abnormalities are important prognostically e.g Can an arterial switch operation be performed? Identification of : Intramural Single coronary artery particularly important

24 Associated Lesions Ventricular septal defect AV valve abnormalities Pulmonary / Subpulmonary Stenosis Aortic obstruction Coronary artery abnormalities

25 Ventricular Septal Defect

26 Ventricular Septal Defect

27 Watch for multiple VSDs

28 Mitral Valve Abnormalities RA LA RV LV MV Attachments

29 Cleft Mitral Valve

30 Cleft Mitral Valve

31 Subpulmonary Obstruction

32 Subpulmonary Obstruction

33 Doppler Assessment Day 1 : Vmax 1.5m/s Day 10 : Vmax 3.2m/s

34 Arch Views in TGA Aortic arch above ductal arch Aortic and ductal arches similar plane Ductal patency may obscure coarctation of the aorta

35 Relative size and relationship of GAs Ao Ao PA PA Ao PA Long Axis Short Axis

36 Careful Assessment of Aortic Arch

37 Tips and tricks : Transposition Initial assessment 1. Know the upper and lower limb saturations The upper limbs are most important brain sats 2. Baby should be on PGE to maintain ductal patency 3. If sats v. low, get senior help early 4. Know the baby s age! Rapidly assess main diagnostic points VA discordance Mixing status Atrial mixing Duct Ventricular septal defects

38 Further assessment Ventricular septum VSDs often slit like, take multiple views / 3D Watch out for multiple VSDs, check the apex! AV Valves Do not assume normal AV valve morphology e.g. MV cleft Careful exclusion of outflow tract obstruction CF: reassess when PVR falls Identify potential obstruction Check the aortic arch particularly carefully Exclusion of coarctation difficult in TGA Occasionally septostomy + leave off PGE