Feasibility of Three-dimensional Printing in Transcatheter Tricuspid Valve Replacement after Surgical Mitral Valve Replacement
Authors: Mao Yu , Ma Xiaohui , Liu Yang , Li Lanlan , Ma Yanyan , Zhai Mengen , Xu Chennian , Jin Ping , Yang Jian 
Published: August 2022

Objectives
Our goal was to investigate the feasibility of applying 3-dimensional printing when treating 10 patients with severe tricuspid regurgitation (TR) secondary to surgical mitral valve replacement (SMVR) who received transcatheter tricuspid valve replacement (TTVR).
Background
Previous studies have shown that many patients develop TR secondary to SMVR and that functional TR is associated with more in-hospital deaths and poor clinical outcomes. Many transcatheter devices are currently in early-stage clinical trials, and little is known about the feasibility, safety, and outcomes of the reduction of TR resulting from TTVR for most of these devices.
Methods
From September 2020 to December 2021, a total of 10 patients [6 women (60.0%)] with severe or extremely severe TR secondary to SMVR in Xijing Hospital were enrolled. The preoperative tricuspid valve (TV) models of the 10 patients were reconstructed, printed, and simulated for the bench test. All patients underwent TTVR with the LuX-Valve. The patients were treated via the right atrial surgical approach. The valve was implanted under the guidance of X-ray fluoroscopy and intraoperative transesophageal echocardiography (TEE). Echocardiography data and clinical outcomes were collected at baseline, before discharge, and at follow-up examinations at 30 days and 6 months.
Results
The patients’ baseline characteristics showed a large comorbidity burden [severe TR, reduced right ventricular (RV) function at baseline]. The bioprostheses were successfully implanted in all 10 patients without device-related adverse events. The durations of the procedures were 140.0 (IQR: 120.0, 172.5) minutes, and the time in the intensive care unit was 3.0 (IQR: 2.0, 3.5) days. None of the patients died or experienced valvular events at 6 months of follow-up after the implant; they showed evidence of RV remodeling and increased cardiac output. TR continued to decrease in 10 patients from baseline to 6 month follows-up, with 10 (100.0%) patients experiencing a ≥ 2 grade reduction. All patients (100.0%) reached primary end points. Six patients were in New York Heart Association (NYHA) functional class I, four patients were in NYHA functional class II, and no device-related complications occurred. In addition, the 6-minute walking test showed significant improvement in motion performance [378.0 (IQR: 351.5, 406.5) m vs. 330 (IQR: 265.0, 351.5) m, p = 2.13×10− 5]. Kansas City cardiomyopathy questionnaire scores also improved significantly at the 6-month follow-up [63.33 (IQR: 54.59, 71.50) vs. 36.17 (IQR: 31.17, 40.42), p = 3.63×10− 5].
Conclusions
It is feasible to use 3-dimensional printing to guide placement of the LuX-Valve in the treatment of patients with severe TR, thereby effectively improving the success rate of the operation and reducing the incidence of complications. The majority of patients with TTVR exhibited RV remodeling, increased cardiac output, and improvement in NYHA functional class. The technology has the potential to be rapidly integrated into clinical practice to assist in decision making, procedural planning, and training. In the meantime, further research is needed to determine the long-term outcomes of TTVR.