Precoronary stenosis after stage I palliation for hypoplastic left heart syndrome

Hypoplastic left heart syndrome: From bedside to bench and back

Hypoplastic Left Heart Syndrome (HLHS) is a complex Congenital Heart Disease (CHD) that was almost universally fatal until the advent of the Norwood operation in 1981. Children with HLHS who largely succumbed to the disease within the first year of life, are now surviving to adulthood. However, this survival is associated with multiple comorbidities and HLHS infants have a higher mortality rate as compared to other non-HLHS single ventricle patients. In this review we (a) discuss current clinical challenges associated in the care of HLHS patients, (b) explore the use of systems biology in understanding the molecular framework of this disease, (c) evaluate induced pluripotent stem cells as a translational model to understand molecular mechanisms and manipulate them to improve outcomes, and (d) investigate cell therapy, gene therapy, and tissue engineering as a potential tool to regenerate hypoplastic cardiac structures and improve outcomes.

Aortic root thrombosis with coronary embolization following neo-aortic reconstruction in a child with hypoplastic left heart syndrome

In the recent era, the diagnosis, treatment options, postoperative management and outcomes of infants born with hypoplastic left heart syndrome (HLHS) have undergone dramatic changes. As is the case with many other novel treatment modalities used for congenital heart diseases, data concerning the long-term outcomes and complications of the various strategies become gradually more available as the numbers of survivors grow. In general, complications of the three-stage surgical palliation used for HLHS tend to occur most commonly following the first-stage surgery. Post-stage 2 complications are substantially less common, and centre on the procedure itself and the unique physiology of the cavopulmonary connection. In the following case report, we describe a relatively rare adverse outcome that occurred following a stage 2 surgery in the form of native aortic root thrombosis extending to the coronary arteries. The selected methods of treatment used in the catheterization laboratory and later in the operating theatre, as well as its outcomes are described.

Left mammary artery bypass grafting rescued a patient with hypoplastic left heart syndrome with ascending aorta obstruction after norwood stage I procedure

A three-month-old boy with hypoplastic left heart syndrome (mitral atresia, aortic atresia) and moderate tricuspid regurgitation developed ascending aorta obstruction two months after a Norwood stage I procedure. An emergent left mammary artery bypass grafting to the ascending aorta and extracorporeal membrane oxygenator support resulted in successful salvage. The patient subsequently underwent a bidirectional Glenn procedure and tricuspid valve repair at the age of five months. Follow-up at an outpatient clinic reveals no electrocardiographic evidence of ischemia, and echocardiography shows recovery of ventricular function.

Risk factors for interstage death after stage 1 reconstruction of hypoplastic left heart syndrome and variants

OBJECTIVE

The risk of death during the interstage period remains high after stage 1 reconstruction for single ventricle lesions, despite improved surgical results. The purpose of this study is to identify risk factors for interstage death and to describe the events leading to interstage death.

METHODS

A nested case-control study was conducted of 368 patients who underwent stage 1 reconstruction at a single center between January 1998 and April 2005.

RESULTS

Among the 313 (85%) hospital survivors, there were 33 (10.5%) interstage deaths. Cases more frequently presented with intact or restrictive atrial septum (9 [27%] vs 4 [4%]; P < .001), were older at the time of surgery (5 [2-40] vs 3 [1-42] days; P = .005), had more postoperative arrhythmias (12 [36%] vs 15 [15%]; P = .01), and a higher incidence of airway or respiratory complications (12 [36%] vs 19 [19%]; P = .04). By multivariate analysis, only intact atrial septum (odds ratio 7.6; 95% confidence intervals 1.9-29.6; P = .003) and age at operation greater than 7 days (odds ratio 3.8; 95% confidence intervals 1.3-11.2; P = .017) were predictors of interstage death.

CONCLUSIONS

The presence of intact atrial septum and older age at the time of surgery are associated with a higher risk of interstage death. In addition, postoperative arrhythmia and airway complications are associated with a higher risk of interstage death in univariate analysis. The results of this study provide a focus for interstage monitoring and risk stratification of these high-risk infants, which may improve overall survival.

Thrombus formation in the native aortic root in patients with hypoplastic left heart syndrome

Thrombus formation in the native aortic root is a rare but potentially life-threatening complication in patients with hypoplastic left heart syndrome. The native aortic root in these patients serves as a conduit for the retrograde filling of the coronary arteries. Thrombus in this location could result in myocardial ischemia. We present three cases of native aortic root thrombosis at our institution with clinical presentations ranging from asymptomatic to sudden cardiac arrest. Our experience with these patients argues for careful and consistent evaluation of the native aortic root regardless of clinical symptoms.