Transcatheter pulmonary valve implantation following prosthesis modification: lessons from a small bioIntegral prosthetic valve

The clinical case describes a 13-year-old boy with a history of transposition of the great arteries, ventricular septal defect, and pulmonary stenosis who underwent surgical correction at age 1 with the REV procedure and the Lecompte maneuver. At age 2, severe subaortic obstruction required reoperation for subaortic tunnel reconstruction, myectomy, and reimplantation. Due to severe right ventricular outflow tract dysfunction, a 19 mm No-React Injectable BioPulmonic prosthesis was implanted. At 12 years, the patient presented with reduced exercise tolerance. Echocardiography and cardiac catheterisation demonstrated severe stenosis and regurgitation of the pulmonary bioprosthesis, right ventricular dilatation and hypertrophy, and an increased right ventricular-pulmonary artery gradient with normal pulmonary artery pressures. The manuscript presents an in vitro test demonstrating that the No-React Injectable BioPulmonic prosthesis frame can be modified using high-pressure balloons to increase its true inner diameter. The patient subsequently underwent transcatheter valve-in-valve implantation of a 23 mm Sapien 3 following pre-dilation and frame modification of the 19 mm No-React Injectable BioPulmonic prosthesis with a 22 × 20 mm Atlas Gold balloon, achieving an favourable haemodynamic outcome. Post-implant pulmonary arteriography excluded any intra-perivalvular regurgitation. Post-procedure haemodynamic assessment showed a residual peak-to-peak gradient of 10 mmHg, with systolic right ventricular pressures below half of systemic pressure. At the 6-month follow-up after the procedure, the post-procedural peak echocardiographic gradient across the pulmonary prosthesis was measured at 28 mmHg, with no evidence of regurgitation. Short-term results have been optimal, which encourages the use of this strategy for the treatment of similar cases.