Project description:BackgroundAortic stenosis (AS) is one of the most common valvular disorders worldwide. An increasing number of transcatheter aortic valve implantation (TAVI) procedures are being performed yearly for managing AS. This, along with the occurrence of common complications, makes timely diagnosis essential to manage rare complications and improve patient outcomes.Case summaryWe present a case of a 77-year-old Caucasian male with severe AS with a dysfunctional bioprosthetic valve following previous surgical valve replacement. During valve-in-valve TAVI, we noted bioprosthetic valve leaflet avulsion and embolization causing a major vascular occlusion that resulted in vascular insufficiency of the left lower extremity. This condition was managed successfully via immediate diagnosis using transoesophageal echocardiogram, angiogram, and vascular surgical intervention for retrieving the embolized valve to re-establish circulation.DiscussionTo our knowledge, this is the first case of aortic valve leaflet embolization during TAVI resulting in significant vascular insufficiency. Vascular complications are common during TAVI. However, not all vascular complications are the same. Our case highlights an embolic vascular complication from an avulsed prosthetic material during a challenging valve-in-valve TAVI procedure.
Project description:BackgroundValve-in-valve transcatheter aortic valve implantation (ViV-TAVI) in degenerated surgical aortic valve replacement (SAVR) is an alternative to redo-SAVR. However, reports on leaflet thrombosis following ViV-TAVI are emerging and subclinical thrombosis has gained recent attention. Although the incidence of transcatheter heart valve (THV) thrombosis after TAVI for native aortic valve disease is low, current imaging studies suggest the incidence of subclinical THV thrombosis may be significantly higher. While anticoagulation strategies for THV patients for native aortic stenosis presenting with symptomatic obstructive thrombosis has been described, the optimal management and anticoagulation therapy of patients with THV thrombosis following ViV-TAVI are less evident.Case summaryWe report a case series of three patients presenting with early and late THV thrombosis after ViV-TAVI. Two patients presented clinically on single antiplatelet therapy and one patient presented with subclinical valve thrombosis whilst taking a non-vitamin K oral anticoagulation agent.DiscussionLeaflet thrombosis after ViV-TAVI is an important cause of THV degeneration and may present subclinically. Imaging modalities such as serial transthoracic echocardiograms and multidetector computerized tomography aid diagnosis and guide management. Patient-individualized risk- vs. -benefit prophylactic post-procedural oral anticoagulation may be indicated.
Project description:Transcatheter closure of mitral valve leaflet perforation is a very rarely performed and a difficult procedure for repairing the defect. Herein, we are the first to report on both the safety and feasibility of percutaneous retrograde transcatheter closure of anterior mitral valve leaflet perforation with an AMPLATZER™ Duct Occluder II (6 mm × 6 mm, ADO II; Abbott Vascular, IL, USA) device in a 19-year-old patient with a severe mitral valve regurgitation following cardiac surgery.
Project description:Leaflet thrombosis has been suggested as the reason for the reduced leaflet motion in cases of hypoattenuated leaflet thickening of bioprosthetic aortic valves. This work aimed to estimate the risk of leaflet thrombosis in two post-valve-in-valve (ViV) configurations, using five different numerical approaches. Realistic ViV configurations were calculated by modelling the deployments of the latest version of transcatheter aortic valve devices (Medtronic Evolut PRO, Edwards SAPIEN 3) in the surgical Sorin Mitroflow. Computational fluid dynamics simulations of blood flow followed the dry models. Lagrangian and Eulerian measures of near-wall stagnation were implemented by particle and concentration tracking, respectively, to estimate the thrombogenicity and to predict the risk locations. Most of the numerical approaches indicate a higher leaflet thrombosis risk in the Edwards SAPIEN 3 device because of its intra-annular implantation. The Eulerian approaches estimated high-risk locations in agreement with the wall sheer stress (WSS) separation points. On the other hand, the Lagrangian approaches predicted high-risk locations at the proximal regions of the leaflets matching the low WSS magnitude regions of both transcatheter aortic valve implantation models and reported clinical and experimental data. The proposed methods can help optimizing future designs of transcatheter aortic valves with minimal thrombotic risks.
Project description:BackgroundFatal thrombo-embolic events like cerebral stroke or myocardial infarction are rare complications of prosthetic heart valve leaflet thrombosis. Nevertheless, prevention and management of leaflet thrombosis is gaining increased attention, particularly with the widespread adoption of transcatheter heart valves.Case summaryWe herein present the case of a 79-year-old man who had undergone a transcatheter aortic valve implantation procedure. Seven months later, he presented with a non-ST-segment elevation myocardial infarction. Coronary angiography did not reveal obstructive lesions. A dedicated cardiac computed tomography scan showed thrombosis of both right- and non-coronary leaflets of the prosthetic aortic valve, while prosthetic valve function was normal on echocardiography. Transmural myocardial infarction lesions in the midventricular and apical inferior wall were detected by cardiac magnetic resonance imaging.DiscussionSubclinical leaflet thrombosis of prosthetic aortic valves is a common finding. In this case report, we show that myocardial infarction presumably due to leaflet thrombosis was the first symptom in an otherwise asymptomatic patient. This finding raises the question of the validity in distinguishing between subclinical and clinical leaflet thrombosis based on prosthetic valve function.
Project description:Background: The outcome of redo transcatheter aortic valve (TAV) implantation (TAVI) is unknown for TAV structural valve degeneration (SVD). This paper reports the initial results of redo TAVI for TAV-SVD in Japanese patients. Methods and Results: Of 630 consecutive patients, 6 (1.0%) underwent redo TAVI for TAV-SVD (689-1,932 days after the first TAVI). The first TAV were 23-mm balloon-expandable valves (BEV, n=5) and a 26-mm self-expandable valve (SEV, n=1). All patients underwent multidetector computed tomography (MDCT) before redo TAVI, which showed first-TAV under-expansion (range, 19.1-21.0 mm) compared with the label size. Two BEV and 4 SEV were successfully implanted as second TAV, without moderate/severe regurgitation or 30-day mortality. One of 2 patients with a BEV-inside-BEV implantation had a high transvalvular mean pressure gradient post-procedurally (34 mmHg) and required surgical valve replacement 248 days after the redo TAVI. This, however, was unnoted in patients with SEV implantation during redo TAVI. Planned coronary artery bypass grafting was concomitantly performed in 1 patient with a small sino-tubular junction and SEV-inside-SEV implantation because of the risk of coronary malperfusion caused by the first TAV leaflets. Five of the 6 patients survived during the follow-up period (range, 285-1,503 days). Conclusions: Redo TAVI for TAV-SVD appears safe and feasible, while specific strategies based on MDCT and device selection seem important for better outcomes.
Project description:Transcatheter aortic valve implantation (TAVI) has emerged as the gold standard technique for all patients with symptomatic severe aortic stenosis at elevated surgical risk. Much progress has been made to reduce procedural complications and improve patient outcomes. The impressive results of contemporary TAVI can be attributed to a variety of factors, including improving operator experience, pre-operative patient screening, and developments in transcatheter heart valve and delivery system technology. Despite these advances, serious procedural complications continue to occur and there remain some anatomical subsets and patient groups to whom TAVI technology has not been expanded. Herein we discuss these unmet needs in TAVI.
Project description:ObjectiveTranscatheter aortic valve implantation (TAVI) procedures are increasing rapidly, but the durability of tissue valve and periprocedural complications are not satisfactory. Immune reaction to the galactose-α-1,3 galactose β-1,4-N-acetylglucosamine (α-Gal) and conventional processing protocols of cardiac xenografts lead to calcification. Next-generation TAVI needs to be made with α-Gal-free xenografts by multiple anticalcification therapies to avoid immune rejection and enhance durability, and three-dimensional (3D) printing technology to improve the procedural safety.MethodsPorcine pericardia were decellularized and immunologically modified with α-galactosidase. The pericardia were treated by space filler, crosslinked with glutaraldehyde in organic solvent, and detoxified. The sheep-specific nitinol (nickel-titanium memory alloy) wire backbone was made from a 3D-printed model for ovine aortic root. After it passed the fitting test, we manufactured a self-expandable stented valve with the porcine pericardia mounted on the customized nitinol wire-based stent. After in vitro circulation using customized silicone aortic root, we performed TAVI in 9 sheep and obtained hemodynamic, radiological, immunohistopathological, and biochemical results.ResultsThe valve functioned well, with excellent stent fitting and good coronary flow under in vitro circulation. Sheep were sequentially scheduled to be humanely killed until 238 days after TAVI. Echocardiography and cardiac catheterization demonstrated good hemodynamic status and function of the aortic valve. The xenografts were well preserved without α-Gal immune reaction or calcification based on the immunological, radiographic, microscopic, and biochemical examinations.ConclusionsWe proved preclinical safety and efficacy for next-generation α-Gal-free TAVI with multiple anticalcification therapies and 3D-printing technology. A future clinical study is warranted based on these promising preclinical results.
Project description:The use of transcatheter aortic valve implantation (TAVI) to treat severe symptomatic aortic valve stenosis has increased exponentially in the last decade. This rapid expansion was seen predominantly in Western developed nations and has been fuelled by favorable results reported from a plethora of well-publicized randomized controlled trials, large retrospective series and national registries. Now, TAVI has become the standard of care for inoperable patients and an alternative to open surgery in patients who are at intermediate to high risk for open surgery. Notwithstanding these positive results, Asia has been relatively slow to adopt this technology despite a potentially large patient pool. Unique features of Asian medical environments and differences in Asian anatomy affecting TAVI uptake in Asia will be discussed. This article serves to outline the various challenging aspects of disseminating TAVI in Asian countries.