Multicenter Pivotal Trial of the Minima Stent for Vascular Stenosis in Infants and Young Children.

Background: The Minima Stent System is the first stent designed, tested, and Food and Drug Administration-approved for use in neonates, infants, and children. Our objective was to evaluate the safety and efficacy of Minima implantation for pulmonary artery stenosis (PAS) and coarctation of the aorta (CoA).

Methods: Multicenter, single-arm, prospective, nonrandomized trial. Primary end points included stenosis relief, freedom from device-related serious adverse events or surgical intervention through 6 months, and maintenance of vessel lumen diameter on computed tomography or catheter angiography at 6 months.

Results: Forty-two patients (21 PAS, 15 recurrent CoA, and 6 native CoA) underwent Minima implantation at a median age and weight of 9 (range, 0.4-112) months and 7.8 (3.4-28.3) kg. Implantation was successful in 41 (97.6%) and resulted in a median increase in minimal vessel diameter of 131% (46%-483%) and reduction in median pressure gradients from 25 (0-63) to 0 (0-6; P<0.001) mm Hg in patients with CoA. Two acute PAS stent embolizations occurred; both stents were secured in the contralateral PA, and one was treated with an additional Minima stent. Seven patients with CoA, all under 6 kg, experienced transient femoral artery thrombosis. At 6 months, there were no explants or device-related serious adverse events. Luminal diameter was maintained at 89% (59%-137%) of the implant diameter. During a median follow-up of 596 (412-979) days, 13 (31%; 7 CoA and 6 PAS) patients underwent planned stent expansion without complications.

Conclusions: The Minima system is safe and effective for treating PAS and CoA in infants and small pediatric patients. Luminal patency was preserved, and planned reinterventions for somatic growth seem well-tolerated in early follow-up.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05086016.