Original paper
Percutaneous interventions in patients with hypoplastic left heart syndrome after stage first Norwood operation

Background: Hypoplastic left heart syndrome (HLHS) still remains a therapeutic challenge due to complex anatomical and haemodynamic abnormalities. The multistage treatment leads to consequences and complications limiting the efficacy of surgery and necessitating additional percutaneous interventions.

Aim: To evaluate the type of necessary percutaneous interventions in patients after stage first Norwood operation for HLHS with a focus on different techniques and equipment and to determine the efficacy of interventional treatment.

Material and methods: Between 2001 and 2010 we conducted 161 interventions in 88 patients with HLHS at all stages of palliation. We performed 47 interventions in 38 patients after stage first Norwood operation. The main reasons for percutaneous treatment in this group were as follows: stenosis of the aortic arch/isthmus (20 patients), stenosis of the Sano shunt (8), proximal pulmonary arteries stenosis (6) and secondary restriction of the atrial communication (4).

Results: In the group of 20 infants with stenosis of the aortic arch/isthmus balloon angioplasty allowed widening of the stenosis from 2.87 ±0.82 mm to 5.15 ±0.82 mm (p < 0.05) and a decrease of the systolic pressure gradient between the aortic arch and the descending aorta from 29.38 ±15.40 mmHg to 7.14 ±4.28 mmHg (p < 0.05). In 1 patient a stent was implanted due to rapid recurrence of the stenosis. In the group of 8 patients with critical stenosis of the right ventricle to pulmonary artery shunt successful interventions were done in 7 infants (87%). In 5 cases (62%) percutaneous balloon angioplasty turned out to be a sufficient treatment. Two patients (25%) required implantation of a stent to the Sano shunt. Oxygen saturation increased from 52 ±12% to 75 ±4% (p = 0.002) and the diameter of the stenosis increased from 2.28 ±0.48 mm to 4.14 ±0.69 mm (p = 0.0025). Six patients after stage first of the surgical palliation required balloon angioplasty of the tight proximal pulmonary artery stenosis. The diameter of the stenosis increased from 2.33 ±0.51 mm to 3.58 ±0.49 mm (p = 0.0099); however, the decrease of the pressure gradient from 3.33 ±1.63 mmHg to 2.5 ±1.05 mmHg was statistically insignificant. Secondary restriction of the atrial communication was successfully treated in all 4 patients. The diameter of the connection increased from 4.2 ±1.15 mm to 9.9 ±3.17 mm (p = 0.0079) and left atrial pressure decreased from 19.4 ±4.1 mmHg to 13.8 ±2.4 mmHg (p = 0.0075). In half of the patients it was sufficient to perform static atrioseptostomy whereas the second half required stent implantation.

Conclusions: Percutaneous interventions lead to haemodynamic stabilization prior to the next step of treatment, increase arterial oxygen saturation and decrease pulmonary arterial pressure, therefore lowering the number of required operations. Rescue interventions such as stenting of the interatrial septum or critically stenosed Sano shunt should be considered in deteriorating patients even despite the risk of complications.