Cardiovascular Journal of Africa: Vol 24 No 1 (February 2013) - page 59

CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013 AFRICA 57
1527: OUTCOMES FOR SIMPLE TRANSPOSITION IN THE
CURRENT ERA
Karthik Ramakrishnan1 , Gabriela Abrahamson1 , Andrew Cole1,
Nadia Badawi2, Karen Walker2, Richard Chard 1,3, Ian Nicholson1,3,
Gary Sholler1,3, David Winlaw1,3
1Heart Centre for Children, The Children’s Hospital at Westmead,
Australia
2Grace Centre for Newborn Care, The Children’s Hospital at
Westmead, Australia
3Sydney Medical School, University of Sydney, Australia
Background: We report outcomes for simple transposition of the
great arteries (TGA) in a contemporary cohort.
Methods: Ninety-six patients were diagnosed between 2004 and
2011. Five did not undergo operations because of associated severe
congenital anomalies (n = 1, antenatal diagnosis), hypoxic encepha-
lopathy (n = 3, one antenatal diagnosis) or intracranial bleed (n =
1). Ninety-one neonates underwent surgery with preservation of the
neo-aortic sino-tubular junction where possible.
Results: Mean age at operation was 8.1 days. There was one opera-
tive mortality in a premature low-birth weight neonate in circulatory
shock prior to the operation. There were two late mortalities. One
child had complicated coronary anatomy (operation involved peri-
cardial patch augmentation of the left main coronary artery) and died
suddenly at home 52 days after surgery. The other had unexplained
severe pulmonary hypertension and died 169 days after operation.
Coronary artery pattern was Leiden 1LCx2R (63%) and two intra-
mural coronary arteries were encountered. The sino-tubular junction
was preserved in 57 (63%) patients. Follow up ranged from 6–96
months (median 39 months), 81% complete. Neo-aortic regurgitation
was mild to moderate (three), mild (10), and trivial (16). Two of the
children with mild to moderate neo-aortic regurgitation had a single
coronary origin implanted using a trapdoor. Otherwise, there was no
specific coronary pattern or transfer technique identified as a risk
factor for the development of neo-aortic regurgitation. Six required
re-intervention for relief of supra-valvar pulmonary stenosis or right
pulmonary artery narrowing at a median of 18 months. There were
no aortic root or coronary arterial re-interventions.
Conclusions: In this series 5% of patients with TGA did not reach
operation, highlighting the need for planning of delivery to optimise
outcomes. Mortality in the operated group at one year was 3%.
Re-operations for pulmonary artery stenosis are the most important
late re-intervention (7%). Clinically apparent coronary problems are
uncommon at mid-term follow-up.
1528: PRELIMINARY STUDY OF INTRA-OPERATIVE
CHANGES IN RESPIRATORY AND HAEMODYNAMIC
PARAMETERS IN THE MODIFIED BLALOCK-TAUSSIG
SURGERY
Eduardo G Chamlian 1, Glaucio Furlanetto1, Ana Maria Rocha Pinto e
Silva1, Valquiria P Campagnucci1, Wilson L Pereira 1, Alexey P Peroni1,
Sylvio MA Gandra1, Felipe M Silva1, Liane H Catani2, Luis A Rivetti1
1Santa Casa de Sao Paulo Heart Surgery Unit, Faculty of Medical
Sciences, Brazil
2Santa Casa de Sao Paulo Pediatric Cardiology Unit, Faculty of
Medical Sciences, Brazil
Objectives: The modified Blalock-Taussig surgery has a high
mortality rate, especially in neonates with low birth weight. The
objective of this study was to compare changes in haemodynamic
and respiratory parameters in patients with cyanotic congenital heart
defects undergoing modified Blalock-Taussig surgery.
Methods: Five consecutive patients submitted for modified Blalock-
Taussig surgery were sampled for three arterial blood gas analyses
(ABG): one at the beginning of the surgery as a control, followed by
two more ABG taken five minutes after clamping the right pulmo-
nary artery and five minutes after removal of the clamp to obtain
acid–base, ventilation and systemic perfusion parameters. We used
the Student’s t -test, Wilcoxon test or the Mann-Whitney U-test to
compare the same variable in two different times. A p-value < 0.05
was considered statistically significant.
Results: The mean age was 29.2 ± 35.8 days (range 2–86) and the
mean weight was 3.11 ± 0.58 kg (range 2.66–4.05). The mean arterial
blood gas parameters five minutes after pulmonary artery clamping
were: pH: 7.20 ± 0.12, pCO 2: 53.9 ± 20.0 mmHg, HCO3 : 16.5 ± 1.7
mEq/l, pO2: 30.3 ± 10.6 mmHg, and SaO2: 48.1 ± 23.1%. The haemo-
dynamic variables were: mean arterial pressure: 30.2 ± 7.4 mmHg
and arterial lactate: 3.2 ± 2.6 mmol/l. The mean pulmonary artery
clamping time was 8.4 ± 0.5 minutes.
Conclusions: In these patients submitted for modified Blalock-
Taussig surgery, we found the following statistically significant
changes in haemodynamic and ventilator parameters during the
clamping of the pulmonary artery: decreased blood concentration
of bicarbonate ions, decreased arterial oxygen partial pressure and
decreased mean arterial pressure.
1534: DO IT YOURSELF: DEFINING INSTITUTIONAL
PREDICTORS OF MAJOR ADVERSE EVENTS EARLY
AFTER PAEDIATRIC CARDIAC SURGERY
Christian Stocker1 , Andreas Schibler1, Kristen Gibbons 2, Sara
Mayfield1, Tom Karl 1
1Queensland Paediatric Cardiac Service, Mater Children’s Hospital,
Brisbane, Australia
2Mater Medical Research Institute, Brisbane, Australia
Background: Few reported predictors of major adverse events
(MAE: cardiac arrest, cardiopulmonary resuscitation, emergency
extracorporeal life support, or death) early after paediatric cardiac
surgery have stood the test of time and shown universal applicability.
Each institution needs to identify its own predictors and define local
thresholds for intervention.
Methods: Over a three-year period, a range of reported clinical
and laboratory predictors was assessed in patients following bypass
surgery on admission to our tertiary-care paediatric intensive care
unit (PICU). Peri-operative data were retrieved from our institu-
tional Aristotle database, and automated extraction of clinical and
laboratory data from our clinical information system was applied.
Generalised estimating equations (GEE) were used to determine vari-
ables and their thresholds predictive of MAE.
Results: We analysed 505 procedures in 483 patients, median age
was 40.8 (0–217) months, weight was 9.8 (2.2–110) kg. MAE
occurred in 21 (4.2%) patients within 48 hours of surgery. The odds
ratio (OR) for presence of pre-operative risk factors as defined by
the Aristotle Institute was 3.4 (p = 0.02) for MAE. For continuous
variables, GEE calculates the OR for any increase from the mean of
the population by a predefined scale, e.g. the mean ± SD heart rate
on admission to PICU was 133.7 ± 30/min, and for any increased
heart rate by 20/min the OR for MAE was 2.11 (p < 0.001). Further
identified predictors were: lactate, bypass time, vasoactive-inotropic
score, pO2–FiO2 ratio, end-tidal CO2–pCO2 difference, and systolic
arterial pressure.
Conclusions: Although not the most powerful outcome model, for
units with low paediatric cardiac surgical patient volume, GEE is a
validated and pragmatic tool for this purpose. However, while dealing
with missing data, GEE is unable to examine interactions and combi-
nations of predictors. In summary, we identified our institutional
predictors of MAE and defined clinically useful local thresholds for
early intervention. Remodelling is warranted at defined intervals,
allowing for changes in our practice over time.
1541: PREDICTIVE VALUE OF ARISTOTLE COMPLEXITY
SCORE FOR RISKS OF CONGENITAL HEART SURGERY
IN KOREA
Han Ki Park1, Eun Seong Lee1, Woosik Yu 1, Do Jung Kim1, Young-
Hwan Park1, Su-Jin Park2, Nam Kyun Kim2, Jae Young Choi2
1Gangnam Severance Cardiovascular Hospital, South Korea
2Yonsei University College of Medicine, South Korea