Background: Severe pulmonary regurgitation (PR) often occurs following a transannular patch repair of tetralogy of Fallot, resulting in an enlarged native right ventricular outflow tract (nRVOT) with varying shapes. Methods: We conducted a single-center study with eight patients having severe PR and enlarged nRVOT (diameters ≥ 29 mm). Transcatheter pulmonary valve replacement (TPVR) was performed using the self-expanding PT-Valve. Preoperative evaluation included echocardiography, computed tomography, and magnetic resonance imaging. A 3D-printed model of the nRVOT was used for preoperative assessment. Follow-up data were collected in 1-year follow-up. Results: PT-Valve was successfully implanted in all patients, resulting in immediate improvement of severe PR. Pulmonary artery diastolic pressure increased significantly (p < 0.001). No deaths or coronary compression occurred during the procedure. Over a 1-year follow-up, no stent displacement or fracture occurred. Only two patients had trace paravalvular leaks. Magnetic resonance imaging revealed a reversal of right ventricular remodeling, with a significant reduction in right ventricular end-diastolic volume index (p < 0.001) and improved right ventricular ejection fraction (p < 0.001). All patients achieved primary endpoints. Conclusion: 3D printing-guided PT-Valve implantation in enlarged nRVOT for severe PR is safe and effective, expanding TPVR indications and offering potential treatment for a broader patient population.

Background: Severe pulmonary regurgitation (PR) often occurs after treatment of tetralogy of Fallot with a valve ring patch, leading to enlargement and diverse morphological characteristics of the native right ventricular outflow tract (nRVOT), which increases the difficulty of transcatheter pulmonary valve replacement (TPVR). The purpose of this study was to use the TPVR simulator to help doctors improve their surgical skills by simulating the surgical process in vitro. Methods: The TPVR simulator was developed using three-dimensional (3D) printing technology under computer-aided design. In this study, the TPVR simulator was used for preoperative simulation training and teaching. First, 10 specialists were equally divided into a 3D-printed group and a non-3D-printed group, each performing one TPVR; then, another six specialists and six young surgeons were selected to complete three TPVR simulations. Results: For the 3D-printed simulation group, the over-flap time (5.22 min (range: 4.85–5.87 min) vs. 6.72 min (range: 6.12–7.70 min), p = 0.016), fluoroscopy time (15.00 min (range: 13.50–16.50 min) vs. 19.00 min (range: 17.50–21.50 min), p = 0.012), and total operative time for the five surgeons (57.00 min (range: 54.00–62.50 min) vs. 67.00 min (range: 62.00–69.50 min), p = 0.036) were shorter. In addition, the results showed significant reductions in the median over-flap time and total time required in both the expert panel and young surgeon groups (all p < 0.05). Conclusions: The reliability and validity of the TPVR simulator was initially demonstrated and has the potential to be a teaching and training tool for surgeons.

Background: Transcatheter mitral valve-in-ring replacement (TMViR) is an emerging alternative for patients with recurrent mitral regurgitation (MR) after a prior failed annuloplasty ring. However, intraoperative common issues and complications remain to be addressed. Case summary: We describe the case of a 67-year-old male patient who underwent surgical mitral concomitant tricuspid annuloplasty repair 7 years ago who developed recurrent severe MR (New York Heart Association functional class IV). To avoid a high-risk surgical reoperation, we chose to perform a TMViR using an innovative dedicated device—the Mi-thos system—via a transapical approach. A patient-specific, 3-dimensional printed model was used to guide the procedure to avoid potential challenges. The procedure was performed successfully, and the patient exhibited symptomatic improvement. Conclusions: This case report highlights the first use of the innovative Mi-thos system in a TMViR procedure. The findings demonstrate the feasibility and safety of utilizing the Mi-thos system, guided by 3-dimensional printing technology, for patients who have experienced recurrent mitral regurgitation MR following a failed annuloplasty ring.

Background: Transcatheter aortic valve replacement (TAVR) using the J-Valve system provides a solution for patients with aortic regurgitation (AR). However, it remains unclear whether its coaxiality performance is related to procedural complications. Aim: Our goal was to improve the efficacy and accuracy of TAVR in patients with AR by adjusting J-Valve coaxiality using three-dimensional printing (3DP). Methods: This multicenter, prospective study included 612 patients with AR who underwent transapical TAVR. Of these, 228 patients were assigned to the 3DP group, in which the insertion angle and implantation depth were pre-determined. The coaxiality index was calculated using the distances from the bottom of the bioprosthesis to the base of the three cusps. Results: Compared to the non-3DP group, the 3DP group demonstrated better coaxiality performance (coaxiality index: 3.4 ± 1.7 vs. 4.0 ± 2.1; coaxiality angle: 10.5 ± 3.7° vs. 12 ± 4.2°; both p<0.001). Post-operative coaxiality index showed a strong correlation with the coaxiality angle (correlation coefficients: 0.85 in the 3DP group and 0.88 in the non-3DP group). The procedural success rate was higher in the 3DP group (100% vs. 96.4%; p=0.008). Paravalvular leakage (PVL) occurred less frequently in the 3DP group (mild PVL: 3.51% vs. 18.2%; p<0.001; moderate PVL: 0% vs. 1.04%; p<0.001). Multivariable analysis identified the coaxiality index, coaxiality angle, and horizocardia as independent predictors of PVL. Conclusion: PVL incidence after TAVR can be reduced through pre-operative simulations that adjust coaxiality using 3DP. Relevance for patients: The high incidence of PVL in transapical TAVR with the J-Valve is associated with coaxiality after bioprosthesis implantation. This study suggests that adjusting coaxiality using pre-procedural 3DP simulations may effectively reduce PVL incidence and other procedural complications during transapical TAVR. In the future, randomized clinical trials will be needed to evaluate the efficacy and accuracy of pre-procedural 3DP simulations and the coaxiality index in treating patients with pure AR undergoing transapical TAVR.