## 2 Case Presentation  
A 58-year-old woman was referred to the Cardiac Surgery Department (Cardiovascular Diseases Institute, Iasi, Romania) for fatigue, severe dyspnea with orthopnea and progressive refractory anasarca (10 cm bilateral pleural effusion at admission). The patient was previously diagnosed with New York Heart Association (NYHA) IV heart failure, decompensated cardiac cirrhosis, splenomegaly, umbilical hernia, permanent atrial fibrillation and moderate to severe pulmonary hypertension associated to the dysfunction of a tricuspid bioprosthesis. At age 39 she underwent surgical aortic valve replacement with a 23 mm Edwards MIRA Mechanical Bileaflet Valve (Edwards Lifesciences, Irvine, CA, USA), mitral valve replacement with a 29 mm Sorin Bicarbon Mechanical Bileaflet Valve (Sorin Biomedical Cardio, Saluggia, Italy) and tricuspid valve replacement with a 33 mm Sorin Pericarbon Bioprosthesis (Sorin Biomedica Cardio, Saluggia, Italy) for rheumatic heart valve disease. Because of atrial fibrillation and triple valve replacement, the patient was on oral anticoagulation with acenocoumarol (vitamin-K antagonist). The transoesophageal echocardiography (TEE) performed upon admission revealed normofunctional aortic and mitral valves, severe bi-atrial dilatation, a calcified tricuspid bioprosthesis with severe stenosis and regurgitation leading to a mild right ventricular dysfunction. The mean tricuspid transvalvular gradient was 13 mmHg; the peak transvalvular gradient 17 mmHg; peak velocity 2 m/s; PHT (pressure half time) 626 ms; and the tricuspid orifice area 0.4 cm\({}^{2}\) (Figure 1). The right atrium was severely dilated with spontaneous contrast inside; bilateral pleural effusion and ascites were also present. The patient presented multiple comorbidities and the Heart Team considered her at prohibitive surgical risk according to the Society of Thoracic Surgeons (STS) score (17.92% for mortality and 48% for morbidity), European System for Cardiac Operative Risk Evaluation (Euroscore) II (22.2%) and Charlson comorbidity index score [7]. In this context, the Heart Team opted for a transatrial TTVIV replacement with a 29 mm Edwards Lifesciences Sapien 3 valve (Edwards Lifesciences, Irvine, CA, USA). Figure 1: Transoesophageal echocardiography mid-oesophageal four-chamber incidence showing severe tricuspid stenosis with pressure half time (PHT) 626 ms and tricuspid valve area (TVA) 0.4 cm\({}^{2}\). TTVIV sizing was based on the cardiac computed tomography angiography (CCTA) evaluation of the pre-existing bioprosthesis and not on the reported size of the Sorin Pericarbon bioprosthesis (Sorin Biomedicalc Cardio, Saluggia, Italy) because, according to [PERSON] et al. [7], the true internal diameter of the pre-existing bioprosthesis (of interest for TTVIV) is generally 1 to 2 mm smaller than the one reported by the manufacturer (Figure 2). In our case, the 33 mm Sorin Pericarbon bioprosthesis (Sorin Biomedicalc Cardio, Saluggia, Italy) proved to have a 29 mm internal diameter. After informed consent was obtained, the patient received general anesthesia with endotracheal intubation, and the approach to the tricuspid valve was performed by right lateral thoracotomy in the fourth intercostal space. The cardiac surgery team and an extracorporeal membrane oxygenation were on standby in the event of an acute complication that would impose open heart surgery. The right lung was retracted to expose the pericardium and 2 Prolene 3.0 (Ethicon, Somerville, NJ, USA) purse-string sutures reinforced with pledges were placed in the lateral wall of the right atrium. A bolus of 5000 IU of heparin was administered intravenously prior to puncturing the right atrium in the middle of the purse-string sutures. The interventional cardiologist was guided by TEE during the whole procedure. The dysfunctional tricuspid valve was accessed with a soft J-guidewire inserted through the puncture and advanced to the right ventricle. Afterwards, a 7F sheath with a pigtail catheter was mounted with subsequent removal of the guidewire.