Catheter interventional treatment of Sano shunt obstruction in patients following modified Norwood palliation for hypoplastic left heart syndrome

Shunts placed between the right ventricle and the pulmonary arteries, called Sano shunts, recently modified Norwood surgery for hypoplastic left heart syndrome. Patients with Sano shunts tend to be more stable thus reducing the interstage mortality of this still challenging complex cardiac anomaly. However, Sano shunt stenosis may develop and is a life threatening complication. We report on our experience in patients with Sano shunt obstruction. Patients Eight infants presenting with decreasing transcutaneous oxygen saturations (43-63%, median 58%) following modified Norwood procedures were shown to have relevant Sano shunt stenosis. None was suited for early stage two surgery (cavopulmonary Glenn anastomosis). Catheterization was performed at the age of 21 to 112 (median 85) days. Weight was 3.9 to 6.0 (median 4.8) kg. Technique Femoral 5F venous access. Long sheaths were not used. The shunt was entered with a 4F right Judkins catheter and a selective angiography was performed. The stenosis was localized proximal in 5, distal in 1 and proximal and distal in 2 patients. Ten coronary stents were implanted. Results There were no procedure related complications. Oxygen saturation increased immediately to 75-86% (median 80%) and remained above 70% during follow-up in all. Seven patients had successful stage two surgery 61-288 (median 134) days after stent implantation, one is awaiting this. Conclusion Sano shunt obstruction can be treated safely and effectively by stent implantation. Early in-stent restenosis does not seem to be a problem.