China
Africa
Explore chapters and articles related to this topic
Biomaterials in Tissue Engineering
Published in Rajesh K. Kesharwani, Raj K. Keservani, Anil K. Sharma, Tissue Engineering, 2022
Blessing Atim Aderibigbe, Shesan John Owonubi
Polyamides are used for the development of catheters and hemodialysis membranes. Polytetrafluorethylene is a monofilament plastic polymer, which is durable with good flexibility, biostability, and breaking strength with negative charge-like native endothelium (El Khoury and Vohra, 2012). It exhibits good hemodynamic properties but its use in the development of prosthetic heart valves and vascular grafts is limited by calcification, thrombosis, and stiffening of leaflets (Hayabuchi et al., 2007; Saha et al., 2011; Mehta et al., 2011). Polyethylene terephthalate has been used for the sewing cuffs of prosthetic heart valves in vitro. The pretreatment of prosthetic heart valves with antibiotics reduced the risk of bacterial adhesion and infections. The soaking of prosthetic heart valves in antibiotic solutions before implantation and combination with fibrin glue can prevent the development of early prosthetic valve endocarditis (Mashaqi et al., 2011).
Microbial Biofilm in Clinical Bioremediation Practices in Human Health
Published in Bakrudeen Ali Ahmed Abdul, Microbial Biofilms, 2020
Rengasamy Sathya, Thangaprakasam Ushadevi, S. Ambiga, Bakrudeen Ali Ahmed Abdul
The attachment of biofilm on mechanical heart valves and surrounding tissues causes endocarditis. The group of bacteria Enterococcus, S. epidermidis, and S. aureus gets accumulated and causes an unpleasant condition. At the time of surgical implantation of prosthetic heart valves, tissue damage may appear as a result of aggregation of platelets and fibrin at the point of location, and microbes have good ability to colonize the particular part. In the popular open catheter method, contaminations highly flowed causing the urinary tract infections to spread very quickly. In the closed method urine gathers in a plastic bag, and during this condition E. coli, Enterococcus faecalis, K. pneumonia, and other bacteria pollute the device (Stickler 1996).
Mitral valve surgery: current status and future prospects of the minimally invasive approach
Published in Expert Review of Medical Devices, 2021
Karel M. Van Praet, Jörg Kempfert, Stephan Jacobs, Christof Stamm, Serdar Akansel, Markus Kofler, Simon H. Sündermann, Timo Z. Nazari Shafti, Katharina Jakobs, Stefan Holzendorf, Axel Unbehaun, Volkmar Falk
Current guidelines recommend, surgical treatment of chronic MR in symptomatic patients with severe primary MR [4,8], as depicted in Figure 1. Signs of ongoing left ventricular (LV) remodeling (LV end-systolic diameter (LVESD) ≥ 45 mm or LV ejection fraction (LVEF) ≤ 60%), right ventricular (RV) impairment and pulmonary hypertension (systolic pulmonary pressure ≥50 mmHg), and left atrial (LA) remodeling (atrial fibrillation (AF) predict worse postoperative outcomes, independent of the symptomatic status, and hence have become triggers for early surgery in asymptomatic patients [4]. Regarding asymptomatic patients, there is ongoing debate about the ideal timing for intervention [2,9]. Some groups prefer a watchful waiting strategy with very strict follow-up and echo assessment; others promote early intervention as is recommended in the 2017 European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines for the management of VHD [2,8]. Urgent surgery in primary MR is only required for patients with acute severe MR resulting from an acute papillary muscle or chordal rupture or in infective endocarditis (IE) of the MV [4,10].
Prevention and management of endocarditis after transcatheter pulmonary valve replacement: current status and future prospects
Published in Expert Review of Medical Devices, 2021
TPVR with the Melody valve (Medtronic Inc., Minneapolis, MN) was initially described by Bonhoeffer et al. in 2000 [9], and the first case of post-TPVR endocarditis was reported 5 years later in an article summarizing their 59-patient experience [10]. When the Sapien XT transcatheter heart valve (Edwards Lifesciences, Irvine, CA) was approved for TPVR in 2012, the instructions for use reported 5 cases of endocarditis among 69 valve implants performed during the investigational trial [11]. In the years since those seminal reports, a large and growing literature on this topic has emerged [12–31], and it has become clear that the risk of endocarditis is perceived as one of the most important drawbacks of TPVR. In this review, we will discuss the current state of knowledge about endocarditis after TPVR, with a focus on risk factors and measures to mitigate the incidence and impact of this complication.
Catheter-based closure of aortic and mitral paravalvular leaks: existing techniques and new frontiers
Published in Expert Review of Medical Devices, 2018
Timothy A. Joseph, Colleen E. Lane, Erin A. Fender, Chad J. Zack, Charanjit S. Rihal
TEE may be less prone to acoustic shadowing and can achieve better Doppler alignment with the regurgitant jet resulting in better visualization [34,35]. Transesophageal echocardiography is better suited than TTE for assessing the mechanism of PVL particularly when endocarditis is suspected, as well as localizing the defect in the annulus [35]. ECG-gated cardiac computed tomography angiography also aides in procedural planning as it can help in localizing the defect, provide better anatomic assessment of the size and shape of the leak, and identify the optimal fluoroscopic angles to use when crossing the leak. Finally for aortic PVL CT can be used to measure the height between the valve and coronary ostium to ensure the closure device does not compromise coronary flow [27,36]. However, all imaging modalities have pitfalls due to shadowing and artifact and as a result, if there is a discrepancy between imaging and symptoms a hemodynamic catheterization with aortic root injection or left ventriculography may be indicated to better quantify the regurgitation [29,31].