Marc Gewillig

Transverse arch hypoplasia predisposes to aneurysm formation at the repair site after patch angioplasty for coarctation of the aorta

OBJECTIVESnThis study used magnetic resonance imaging (MRI) to evaluate the morphology and pathophysiology of aneurysm formation after patch angioplasty for coarctation of the aorta.nnnBACKGROUNDnLate aneurysm formation at the repair site is a well known and frequent complication after patch angioplasty. However, because the underlying mechanisms remain unresolved, postoperative outcome is unpredictable and adequate follow-up difficult.nnnMETHODSnSeventy-three of 85 patients with patch angioplasty for coarctation of the aorta were screened for aneurysm formation. Magnetic resonance imaging was performed in all 33 patients with an aneurysm, and results were compared with those for 13 control patients and 10 normal subjects. Mean (+/- SD) time between operation and MRI was 12.0 +/- 2.0 years. Aneurysm was defined as the ratio of the diameter of the aorta at the repair site to the diaphragmatic aorta > or = 1.5. Hypoplasia of the transverse arch and recoarctation at the repair site were defined as a ratio < 0.9. Transverse arch ratios on MRI were compared with those on preoperative cineangiography and the pressure gradient between the patients right and left arm.nnnRESULTSnAll 33 patients with an aneurysm had a hypoplastic transverse arch. The 13 patients with a normal ratio at the repair site had a normal transverse arch ratio (chi square, p < 0.0001). Logarithmic regression showed a significant negative correlation (r = 0.62) between the repair site and transverse arch ratios. A significant pressure difference between the patients right and left arm was found in patients with versus those without aneurysm (p = 0.0009). No significant difference was found between transverse arch ratios on preoperative cineangiography and postoperative MRI (mean 0.014 +/- 0.1, p = 0.4).nnnCONCLUSIONSnAneurysm formation at the repair site is highly related to hypoplasia of the transverse arch. Sufficient catch-up growth of a hypoplastic transverse arch is rare after late patch angioplasty. Dynamic phenomena, such as flow acceleration and turbulence, originating in a narrow transverse arch, may contribute to aneurysm formation at the repair site after patch angioplasty.

A complex submicroscopic chromosomal imbalance in 19p13.11 with one microduplication and two microtriplications

Complex chromosomal rearrangements [CCRs] are considered very rare, but are being detected with an increasing frequency because of the enhanced resolution of novel molecular karyotyping techniques like array-CGH. This report describes a patient carrying a unique CCR involving one duplication and two triplications in a 3.2 Mb region on 19p13.11. The patient presented with microcephaly, velopharyngeal insufficiency, dysmorphism, mental retardation and a muscular ventricular septal defect. We show that CCRs are likely to be more frequent than hitherto appreciated. This has important consequences for genotype-phenotype correlations and warrants caution before labelling imbalances as simple.

Manipulating parallel circuits: the perioperative management of patients with complex congenital cardiac disease

In all patients undergoing cardiac surgery, the effective delivery of oxygen to the tissues is of paramount importance. In the patient with relatively normal cardiac structures, the pulmonary and systemic circulations are relatively independent of each other. In the patient with a functional single ventricle, the pulmonary and systemic circulations are dependent on the same pump. As a consequence of this interdependency, the haemodynamic changes following complex palliative procedures, such as the Norwood operation, can be difficult to understand. Comparison of the newly created surgical connections to a simple set of direct current electrical circuits may help the practitioner to successfully care for the patient. In patients undergoing complex palliations, the pulmonary and systemic circulations can be compared to two circuits in parallel. Manipulations of variables, such as resistance or flow, in one circuit, can profoundly affect the performance of the other circuit. A large pulmonary flow might result in a large increase in the saturation of haemoglobin with oxygen returning to the heart via the pulmonary veins at the expense of a decreased systemic flow. Accurate balancing of these parallel circulations requires an appreciation of all interventions that can affect individual components of both circulations.

Pericardial effusion in the first trimester of pregnancy

Ingrid Witters1,2,6*, Derize Boshoff3, Luc De Catte4, Tinne Mesens2, Wilfried Gyselaers2, Claire Theyskens2, Els Bruneel2, Marc Gewillig5 and Jean-Pierre Fryns1 1Center for Human Genetics, Catholic University of Leuven, Leuven, Belgium 2Department of Obstetrics and Gynecology, St-Jans Hospital, Genk, Belgium 3Department of Pediatric Cardiology, St-Jans Hospital, Genk, Belgium 4Department of Obstetrics and Gynecology, Catholic University of Leuven, Leuven, Belgium 5Department of Pediatrics, Catholic University of Leuven, Leuven, Belgium 6GROW School of Oncology and Developmental Biology, Maastricht University Medical Centre, Leuven, Belgium

Exercise Tolerance in Children with Simple Congenitally Corrected Transposition of the Great Arteries: A Comparative Study

Background: The aim of our study was to investigate the exercise capacity of children with congenitally corrected transposition of the great arteries without signifi cant associated heart defects (l-TGA) in comparison with children with the classical type of TGA (d-TGA) and a healthy control group.

6 Cardiale revalidatie bij kinderen met congenitale hartafwijkingen: klinische richtlijnen

Omdat de meeste patienten met congenitale hartafwijkingen tot de pediatrische leeftijdsgroep behoren, moeten procedures voor inspanningstests en revalidatieprogramma’s aangepast worden voor kinderen. Een onderscheid wordt gemaakt tussen cyanogene hartafwijkingen (bijv. tetralogie van Fallot) en acyanogene hartafwijkingen (bijv. ventrikelseptumdefect). De functionele capaciteit kan beoordeeld worden door metingen van de gastuitwisseling tijdens inspanning. Nieuwe concepten hierbij zijn breath by breath-analyse van de respiratoire gasuitwisseling tijdens inspanning. De inspanningsintensiteit tijdens revalidatieprogramma’s wordt bepaald aan de hand van de talktest, wat betekent dat de kinderen nog in staat moeten zijn om te kunnen spreken tijdens inspanning.

Hybrid Procedure in Neonatal Critical Aortic Stenosis and Borderline Left Heart: Buying Time for Left Heart Growth

Infants with “borderline” left ventricles due to congenital aortic valve stenosis may be critically ill soon after birth since the left ventricle may be unable to sustain the complete systemic circulation. In these hearts, the stroke volume of the left ventricle is markedly decreased because of diminutive left ventricular internal dimensions. As the arterial duct closes in the first hours after birth, the left ventricle becomes responsible for generating the full systemic output. If the left heart is of borderline dimensions, this may lead to shock and even death. However, postnatal loading and growth conditions of the left ventricle differ significantly from foetal life and in so doing influence the postnatal course. Left ventricular growth potential remains and is likely to be stimulated by these physiological changes. Some may occur rapidly following birth whilst others may take weeks to months. Infants with borderline left ventricles present the physician with a unique dilemma: is this child able to tolerate a biventricular circulation or should one rather embark on a univentricular strategy? In recent years, experience with the hybrid procedure for hypoplastic left heart syndrome showed that indications may be extended to patients with critical aortic stenosis and borderline left heart. A hybrid procedure typically consists of surgical bilateral banding of the branch pulmonary arteries in combination with placement of a stent in the ductus arteriosus after balloon angioplasty of the stenosed aortic valve (Fig 1). As a result, a parallel circulation is created and the right heart can support the left heart to maintain adequate systemic output. This “buys time” to observe the growth potential of the left heart and allows the physician more room to make an informed decision regarding univentricular or biventricular long-term strategy. In this chapter we describe the background, possibilities, technical aspects and results of this strategy in neonates with critical aortic stenosis and borderline left heart.