Devices for mitral valve repair

Our Anaesthetic Experiences in Patients Undergoing Percutaneous Mitraclip Implantation

OBJECTIVE

Percutaneous mitraclip implantation system, is a new technique developed for patients with high surgical risks. It is generally performed in a catheterisation laboratory with the guidance of fluoroscopy and transesophageal echocardiography. In this study, we aimed to share our experiences on anaesthetic in patients undergoing mitraclip implantation under general anaesthesia.

METHODS

Eighty four patients with severe, symptomatic mitral insufficiency, who had undergone MitraClip implantation under general anaesthesia between July 2012 and March 2015 (54 male, 30 female; mean age: 68.5±10.2 years) were retrospectively investigated in terms of anaesthetic management.

RESULTS

Of the 84 patients undergoing percutaneous mitraclip implantation under general anaesthesia, 84.5% had sodium thiopental and 75% had midazolam for anaesthesia induction. For the maintenance of anaesthesia, 57% of the patients were reported to have sevoflurane, whereas the rest had desflurane. The mean duration of the procedure and anaesthesia was 140.9±48.2 mins and 165.7±50.6 min, respectively. Seventy seven patients were transported to the intensive care unit and intubated after the procedure. The median extubation time was 3 h. Length of stay in the intensive care unit was 2 days, whereas it was 4 days for hospital stay. One patient died during the procedure and six patients died after the procedure.

CONCLUSION

Percutaneous mitraclip implantation procedure is quite difficult for anaesthesiologists because of the procedure itself and the population on which the procedure is performed. The primary aim of anaesthesia management is to provide haemodynamic stability. The preoperative preparation and anaesthesia methods should be the same as for patients undergoing cardiac surgery. It is reported that as the experience regarding this subject increases, success of the procedure increases, with better protected haemodynamic stability, less inotropic and vasopressor requirement and shorter length of hospital stay.

In vitro and in silico approaches to quantify the effects of the Mitraclip® system on mitral valve function

Mitraclip^® implantation is widely used as a valid alternative to conventional open-chest surgery in high-risk patients with severe mitral valve (MV) regurgitation. Although effective in reducing mitral regurgitation (MR) in the majority of cases, the clip implantation produces a double-orifice area that can result in altered MV biomechanics, particularly in term of hemodynamics and mechanical stress distribution on the leaflets. In this scenario, we combined the consistency of in vitro experimental platforms with the versatility of numerical simulations to investigate clip impact on MV functioning. The fluid dynamic determinants of the procedure were experimentally investigated under different working conditions (from 40bpm to 100bpm of simulated heart rate) on six swine hearts; subsequently, fluid dynamic data served as realistic boundary conditions in a computational framework able to quantitatively assess the post-procedural MV biomechanics. The finite element model of a human mitral valve featuring an isolated posterior leaflet prolapse was reconstructed from cardiac magnetic resonance. A complete as well as a marginal, sub-optimal grasping of the leaflets were finally simulated. The clipping procedure resulted in a properly coapting valve from the geometrical perspective in all the simulated configurations. Symmetrical complete grasping resulted in symmetrical distribution of the mechanical stress, while uncomplete asymmetrical grasping resulted in higher stress distribution, particularly on the prolapsing leaflet. This work pinpointed that the mechanical stress distribution following the clipping procedure is dependent on the cardiac hemodynamics and has a correlation with the proper execution of the grasping procedure, requiring accurate evaluation prior to clip delivery.

Functional and Biomechanical Effects of the Edge-to-Edge Repair in the Setting of Mitral Regurgitation: Consolidated Knowledge and Novel Tools to Gain Insight into Its Percutaneous Implementation

Mitral regurgitation is the most prevalent heart valve disease in the western population. When severe, it requires surgical treatment, repair being the preferred option. The edge-to-edge repair technique treats mitral regurgitation by suturing the leaflets together and creating a double-orifice valve. Due to its relative simplicity and versatility, it has become progressively more widespread. Recently, its percutaneous version has become feasible, and has raised interest thanks to the positive results of the Mitraclip(®) device. Edge-to-edge features and evolution have stimulated debate and multidisciplinary research by both clinicians and engineers. After providing an overview of representative studies in the field, here we propose a novel computational approach to the most recent percutaneous evolution of the edge-to-edge technique. Image-based structural finite element models of three mitral valves affected by posterior prolapse were derived from cine-cardiac magnetic resonance imaging. The models accounted for the patient-specific 3D geometry of the valve, including leaflet compound curvature pattern, patient-specific motion of annulus and papillary muscles, and hyperelastic and anisotropic mechanical properties of tissues. The biomechanics of the three valves throughout the entire cardiac cycle was simulated before and after Mitraclip(®) implantation, assessing the biomechanical impact of the procedure. For all three simulated MVs, Mitraclip(®) implantation significantly improved systolic leaflets coaptation, without inducing major alterations in systolic peak stresses. Diastolic orifice area was decreased, by up to 58.9%, and leaflets diastolic stresses became comparable, although lower, to systolic ones. Despite established knowledge on the edge-to-edge surgical repair, latest technological advances make its percutanoues implementation a challenging field of research. The modeling approach herein proposed may be expanded to analyze clinical scenarios that are currently critical for Mitraclip(®) implantation, helping the search for possible solutions.

Is there a need for bacterial endocarditis prophylaxis in patients undergoing urological procedures?

Heart valve repair or replacement is a serious problem.The focused update on infective endocarditis of American College of Cardiology/American Heart Association 2008 (ACC/AHA guidelines) and Guidelines on the prevention, diagnosis, and treatment of infective endocarditis (new version 2009) of the European Society of Cardiology (ESC guidelines) describe prophylaxis against infective endocarditis as not recommended for urinary tract procedures in the absence of active infection. A statistical association has been recently shown between urological procedures and the development of infective endocarditis. New evidences concerning infective endocarditis due to Actinobaculum schaalii, Neisseria gonorrhoeae, Streptococcus agalactiae, Enterococcus faecalis, Pseudomonas aeruginosa, Aerococci and Staphylococcus aureus, and new findings indicate there is a need for bacterial endocarditis prophylaxis in patients undergoing urological procedures especially in elderly patients and in cancer and immunocompromised patients, to avoid serious consequences.

Is there a need for bacterial endocarditis prophylaxis in patients undergoing gastrointestinal endoscopy?

Heart valve repair or replacement is a serious problem. Patients can benefit from an open dialogue between both cardiologists and gastroenterologists for the optimal effective patients care. The focused update on infective endocarditis of the American College of Cardiology/American Heart Association 2008 (ACC/AHA guidelines) and guidelines on the prevention, diagnosis, and treatment of infective endocarditis (new version 2009) of the European Society of Cardiology (ESC guidelines) describe prophylaxis against infective endocarditis (IE) as not recommended for gastroscopy and colonoscopy in the absence of active infection but increasing evidence suggests that the role of IE antibiotic prophylaxis remains a dark side of the cardio-oncology prevention. New evidences concerning infective endocarditis due to Streptococcus bovis, Streptococcus agalactiae, Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, and new findings indicate that there is a need for bacterial endocarditis prophylaxis in patients undergoing gastrointestinal endoscopy especially in elderly patients and in cancer and immunocompromised patients, to avoid serious consequences.