Intravascular stents for management of pulmonary artery and right ventricular outflow obstruction

Abstract

This study was performed to determine the efficacy of balloon-expandable stents in the treatment of branch pulmonary artery-stenoses and conduit stenosis in children. A total of eight stainless steel stents were implanted in seven patients. Three patients had tetralogy of Fallot with pulmonary artery stenosis following total correction, one patient had conduit stenosis following correction of transposition of the great arteries, one patient had intra-cardiac conduit stenosis after septation for single left ventricle, and two patients had pulmonary artery stenosis after Fontan operation. Six stents were placed in the branch pulmonary arteries, one in the extracardiac conduit, and one in the intracardiac conduit. The mean age at implantation was 13 +/- 3 years and the mean weight 37 +/- 12 kg. Follow-up time ranged from 0.3-2 years. The diameter of pulmonary arteries with stenoses increased from 5.6 +/- 2.2 mm to 10.6 +/- 1.8 mm (n = 7). The systolic pressure gradient decreased from 56 +/- 26 mmHg to 22 +/- 16 mmHg (n = 5). No embolization or thrombotic event has been noted. One stent placed in the intracardiac conduit was compressed and fractured. These data indicate that balloon-expandable stents are useful in the treatment of pulmonary artery branch stenoses and extracardiac conduit stenosis in children. The use of stents for intracardiac stenosis may result in stent fracture.

Transcatheter Stent Therapy in Children: An Update

“…They found that the peak pressure gradients decreased (51 +/-24 vs. 16 +/-13 mmHg; p<0.01) and the vessel diameter increased (5 +/-3 vs. 11 +/-4 mm; p<0.01). Subsequent studies [16,17,[48][49][50][52][53][54][55][56][57], including our own [25,50] documented similar results. The results are similar in both post-operative and native BPAS lesions [17].…”

“…Balloon dilation of these valves has produced some improvement with nominal extension of the life span of the conduit, as reviewed elsewhere [142]. Therefore, use of stents to relieve the obstruction has been advocated [13,52,[143][144][145][146][147][148][149].…”

“…An example from our experience is shown in figure 7. Most reports cited [13,52,[143][144][145][146][147][148][149] demonstrate decrease of peak systolic gradient, improvement in conduit stenosis diameter and prolongation of life span of the conduit for varying time periods. However, fractures of the stent have been seen at follow-up.…”

Native right ventricular outflow stent implantation in patients with unsalvageable extracardiac conduits

“…The inherent morbidity and mortality risk of repeat sternotomy have encouraged alternative management strategies, which defer operative intervention. Endovascular stent implantation to the failing conduit has been established by our laboratory and others [3][4][5][6] as effective and safe palliation. Occasionally, the failing conduit may not be suitable for endovascular stent implantation [1,5].…”

Rupture and Migration of an Endovascular Stent in the Brachiocephalic Trunk Causing a Vertebral Steal Syndrome

“…Mechanical stress seems to be a risk factor for fracture [7]. Stents positioned in arteries frequently bent (i.e., femoropopliteal artery) or placed near a pulsatile structure (like the heart or great vessels) also have a higher risk of fracture [13]. Localized stiffness of the arterial wall may play a role in the breakage of the device, as observed with overlapping stents or stents used for intrastent restenosis [8].…”