Case 1

A 12-year-old male affected by Williams syndrome underwent surgical resection with end-to-end anastomosis for aortic arch hypoplasia and native aortic coarctation at 2 months of age. Because of severe recoarctation, the patient underwent a redo surgery at the age of 1 year. When 6 years old, a cardiac catheterisation showed that a recoarctation and a sequential balloon angioplasty (NuMED Tyshak balloon 8 × 20 mm and 10 × 30 mm) were performed lowering the pressure gradient across the aortic arch. During follow-up, the patient remained asymptomatic, but echocardiographic follow-up showed a steady increase of the pressure gradient. At the age of 12 years, a cardiac catheterisation demonstrated a severe recoarctation of the aortic isthmus (minimum diameter 5 mm) involving the origin of the left subclavian artery (Fig 1a) with a pressure gradient of 35 mmHg. As he was deemed a high-risk surgical candidate, a percutaneous catheter intervention was indicated and informed consent was obtained. After induction of general anaesthesia, a 4-Fr arterial catheter was advanced percutaneously in the left radial artery for invasive haemodynamic monitoring. The right femoral artery was accessed after surgical exposure, whereas the right femoral vein was accessed percutaneously and a 6-Fr central venous catheter was advanced. A 34-mm-long NuMED-covered Cheatham-platinum stent was chosen after accurate measurements (Fig 1b) and modified before the implantation to avoid the left subclavian artery occlusion. A tiny fenestration was created at 8 mm of its caudal extremity by a needle 18G (BD Microlance 3; Becton Dickynson, Franklin Lakes, NJ, USA) used to puncture the expanded polytetrafluoroethylene of the stent (Fig 1c-d). Afterwards, the stent was hand crimped on a 12 × 40-mm-long Balloon-in-Balloon delivery catheter (NuMed, Hopkinton, NY, United States of America). A 14-Fr-long sheat Mullins (Medical Cook, Bloomington, IN, United States of America) from the right femoral artery was adopted for the stent delivery using a two-guidewire technique. The stent was advanced over a 0.035-inch Stiff 260-cm Amplatzer J tip exchange guidewire (Boston Scientific, Marlborough, MA, United States of America) in the ascending aorta through the balloon lumen and a 0.035-inch J-Tip Glidewire (Terumo, Tokyo, Japan) placed in the left subclavian artery through the puncture site of the stent (Fig 2a). Multiple angiograms were performed to show a reliable position of the stent and then it was deployed. A following angiogram showed a good flow into the descending aorta and left subclavian artery without findings of dissection (Fig 2b). A balloon Armada 6 × 40 mm (Abbott Vascular, Chicago, IL, United States of America) was advanced over the guidewire in the left subclavian artery, and a further enlargement of the stent fenestration was performed to improve the flow (Fig 2c) according to the artery size. A final angiogram (Fig 2d) showed a correct position of the stent and an adequate perfusion of the descending aorta and subclavian artery. After stent implantation, the gradient across the aortic arch decreased to 3 mmHg.

Figure 1. Left anterior oblique view showing aortic recoarctation: the left subclavian artery was within the area of the coarctation and had a stenosis at its origin ( a ); measurements of the different areas ( b ). Stent fenestration procedure: a needle perforated the covering and passed through the cell of a 34 mm, 8 Zig, Cheatham-Platinum (CP) stent ( c ); a tiny perforation was created ( d ).

Figure 2. Bench simulation of the stent-balloon-guidewires assembly: the balloon lumen was passed over the stiff guidewire and the covered CP stent was crimped on a balloon; an exchange glidewire was passing between the balloon and the stent, then it exited from the pinhole fenestration and was placed in the left subclavian artery ( a ). Left anterior oblique view showing stent implantation within the aortic recoarctation: the stiff guidewire was in the ascending aorta, while the glidewire was passing through the fenestration in the left subclavian artery ( b ); an Armada balloon was advanced over the wire and it was inflated across the fenestration in an anteroposterior view ( c ); improved flow across the left subclavian artery and proper position of the covered CP stent ( d ).

The patient was haemodynamically stable during the procedure and post-procedural course was uneventful. He was continued on beta-blockade, as well as an anti-platelet dose of aspirin. At follow-up 24 months later, the patient was in New York Heart Association (NYHA) class I and assessment of blood pressure revealed increased arterial pressure difference between arms with normal values in the lower extremities. A redo procedure was performed to dilate the stent and it was necessary to accommodate for somatic growth. The flow in the left subclavian artery was normal. Further 6-month follow-up showed no significant problems.

Case 2

A 28-year-old female affected by aortic coarctation underwent surgical resection with end-to-end anastomosis at 4 months of age. Echocardiographic follow-up showed a steady increase of the pressure gradient. When 27 years old, a cardiac catheterisation confirmed a severe recoarctation (minimum diameter 6 mm) involving the origin of the left subclavian artery with a pressure gradient of 45 mmHg. A percutaneous catheter intervention was indicated and informed consent was obtained. The procedural steps were similar to Case 1. A 45-mm-long NuMED-covered Cheatham-platinum stent was chosen and a tiny fenestration was created at 10 mm of its caudal extremity. Afterwards, the stent was hand crimped on a 16 × 40-mm-long Balloon-in-Balloon delivery catheter (NuMed). The stent was implanted as previously described in Case 1. A balloon Armada 8 × 40 mm (Abbott Vascular) was advanced over the guidewire in the left subclavian artery and a further enlargement of the fenestration was performed. Final angiogram showed a correct position of the stent and an adequate perfusion of the descending aorta and subclavian artery. After stent implantation, the gradient across the aortic arch decreased to 2 mmHg. The procedure was uneventful and she was discharged home 2 days later under aspirin. At follow-up 36 months later, the patient was in NYHA class I and assessment revealed no pressure gradient across the aortic arch and good flow in the left subclavian artery.