A 59-year-old woman with a medical history of atrial fibrillation and prior cardiac surgery presented to our hospital with severe heart failure. Upon admission, she suffered from New York Heart Association functional class IV heart failure symptoms, and a grade 4/6 systolic murmur over the apex was noted. The patient had been diagnosed with a congenital atrial septal defect (ASD) 45 years ago and underwent surgical repair. Thirteen years prior to admission, she received mitral valve replacement using a Perimount Magna Mitral 29 mm valve (Edwards Lifescience, Irvine, CA, USA), tricuspid valve repair, and permanent pacemaker implantation due to severe mitral regurgitation, tricuspid regurgitation, and tachy-brady syndrome. Transthoracic and transoesophageal echocardiography revealed that the patient had preserved biventricular function and a well-functioning repaired tricuspid valve. However, the mitral bioprosthesis had degenerated, resulting in severe regurgitation ( and ). After a thorough discussion with the patient and her family, they declined the option of trido surgery. Consequently, our multidisciplinary Heart-Team decided to perform a transcatheter mitral valve-in-valve implantation to replace the failed bioprosthesis. Before the procedure, a computed tomography (CT) scan revealed a thickened atrial septum, possibly owing to the patient’s previous ASD repair. Based on the CT scan finding, a transapical approach was chosen. The CT sizing provided important parameters, including as follows: aorto-mitral angle of 128°; neo-left ventricular outflow tract (LVOT) area of 203 mm2; and inner diameter of the mitral bioprosthesis of 27 mm ( and ), therefore, a 29 mm Sapien 3 valve was selected for the procedure. A temporary endocardial pacing lead was inserted into the right ventricle through right femoral vein. The optimal apex position for transapical approach was determined by echocardiographic and CT guidance, and then a left anterolateral thoracotomy was performed to access the pericardium. After a transapical puncture, a 21F Edwards Certitude introducer sheath was inserted and a 0.035 guide wire was introduced through the ventricle towards the mitral prosthesis, eventually reaching the right upper pulmonary vein. Subsequently, the wire was replaced with a Safari wire. Under the guidance of fluoroscopy and transoesophageal echocardiography, the Sapien 3 valve was successfully crossed and positioned in the surgical bioprosthesis. Valve deployment was performed under rapid ventricular pacing, although we noticed that the central marker of the balloon had shifted to the distal part of the Sapien 3 valve (). Unfortunately, the partially inflated distal part of the balloon caused the valve to embolize into the left ventricle ( and ). To reposition the embolized valve back to the mitral position, we attempted to recapture it using the Lasso method, snaring the valve frame of the embolized valve with a 6 F EN Snare® (Merit Medical System, South Jordan, UT, USA) via parallel access, but unfortunately, this approach was unsuccessful (). Instead, by positioning the snare at the nosecone of the delivery system, the Sapien 3 valve was able to be re-directed and crossed the bioprosthetic annulus ( and ). However, during the second valve deployment, only the proximal portion of the balloon was inflated (), which pushed the valve upwards and caused it to embolize into the left atrium (). As the patient was haemodynamically stable, we utilized the Safari wire to secure the embolized valve against the atrial wall to prevent its rotation. Next, we advanced the deflated deployment balloon into the partially opened frame of the embolized valve and inflated the balloon at a low volume, which fortunately anchored the valve in place. We then retracted the entire system into the bioprosthetic mitral valve (), and the Sapien 3 valve was able to cross the bioprosthetic annulus again and reposition correctly (). Finally, the valve was successfully deployed ( and ). The final result was satisfactory, the new valve functioned well with no paravalvular leakage. The patient was discharged after an uneventful hospital course, and her heart failure symptoms improved to function class I status.