Preliminary experience of transcatheter pulmonary valve replacement using domestic balloon-expandable valve

Abstract

Objectives: To evaluate the feasibility and preliminary clinical results of transcatheter pulmonary valve replacement (TPVR) with the domestically-produced balloon-expandable Prizvalve system. Methods: This is a prospective single-center observational study. Patients with postoperative right ventricular outflow tract (RVOT) dysfunction, who were admitted to West China Hospital of Sichuan University from September 2021 to March 2023 and deemed anatomically suitable for TPVR with balloon-expandable valve, were included. Clinical, imaging, procedural and follow-up data were analyzed. The immediate procedural results were evaluated by clinical implant success rate, which is defined as successful valve implantation with echocardiography-assessed pulmonary regurgitation<moderate and peak trans-pulmonary pressure gradient<40 mmHg (1 mmHg=0.133 kPa). Results: A total of 5 patients were included, with 4 males, aged 14 to 37 years. The initial diagnosis included Tetralogy of Fallot (2 cases), truncus arteriosus (1 case), pulmonary atresia (1 case) and subaortic stenosis (1 case, prior Ross procedure). Four patients underwent RVOT reconstruction with homograft or artificial conduit, and one patient was treated with trans-annular patch technique. The indications of TPVR included RVOT obstruction and regurgitation (3 cases), isolated obstruction (1 case), and isolated regurgitation (1 case). Of the 4 patients with varying severity of ROVT obstruction, the average preprocedural peak jet velocity of RVOT was 3.5 m/s, and the average peak pressure gradient was 50.0 mmHg. Except for one patient, who had previously been implanted with a covered Cheatham-Platinum (CP) stent due to severe stenosis of the main pulmonary artery, other patients underwent pre-stenting with a covered CP stent before TPVR. Clinical implant success was achieved in all of the 5 patients, and there was no serious periprocedural complications. The average trans-pulmonary peak jet velocity and peak pressure gradient derived from postprocedural echocardiography was 2.3 m/s and 21.2 mmHg, respectively. All patients experienced significant symptom relief after the procedure. All patients completed 3-month follow-up, and 4 completed 6-month follow-up. There was no case of infectious endocarditis during follow-up. All patients were graded as NYHA functional class one at the latest follow-up. Conclusions: TPVR using the domestically-produced balloon-expandable Prizvalve system is safe and feasible for the treatment of patients with post-surgical RVOT dysfunction and suitable landing-zone anatomy. The safety, effectiveness, and long-term valve durability of the Prizvalve system deserve further research.