Stent protrusion in palliative congenital heart disease interventions: does it cause any harm?

Protrusion of the patent ductus arteriosus (PDA) stent can occur into the lumen of the main pulmonary artery (MPA) branch, the aorta, or both. This protrusion can vary from trivial to major, causing potential obstruction to the vessel lumen, which may cause flow obstruction or risk of thromboses. As far as we know, no one has followed these patients with protruding stents to see whether they do pose a risk of obstruction or thromboses.

A retrospective, descriptive, cross-sectional study reviewing charts of all included patients who received stents in the MPA branches with residual protrusion into the pulmonary artery branch lumen (total, 87 patients; 34 patients with protruding stents) was performed to determine whether this protrusion caused any undesired effects on flow or coagulation. The patients were divided into two groups: the protruding stents group (group 1); and the non-protruding stent group that served as a control group (group 2). Each group was then categorized into 3 sections according to the stent position, the PDA, the MPA branches, and the Blalock-Taussig shunt.

The only risk factor that had statistical significance was the number of stents in the PDA site.

Protruding stents do not cause an increased risk of thrombosis in patients on aspirin. Mild protrusion is more likely in PDA stents and severe protrusion is more likely in the MPA branch stents. Severe protrusion is more likely when more stents are used in the PDA location. There is no statistical evidence that protrusion can cause lung perfusion defects from the small numbers we have.