Although well-known for their thromboresistance, bileaflet mechanical heart valves (BMHV) require lifelong anti-thrombotic therapy. This must be associated with a certain level of thrombogenicity. ...Since both thromboresistance and thrombogenicity are explained by the blood-artificial surface or liquid-solid interactions, the aim of the present study was to explore BMHV thromboresistance from new perspectives. The wettability of BMHV pyrolytic carbon (PyC) occluders was investigated in under-liquid conditions. The submerged BMHV wettability clarifies the mechanisms involved in the thromboresistance.
The PyC occluders of a SJM Regent™ BMHV were previously laser irradiated, to create a surface hierarchical nano-texture, featuring three nano-configurations. Additionally, four PyC occluders of standard BMHV (Carbomedics, SJM Regent
, Bicarbon
, On-X
), were investigated. All occluders were evaluated in under-liquid configuration, with silicon oil used as the working droplet, while water, simulating blood, was used as the surrounding liquid. The under-liquid droplet-substrate wetting interactions were analyzed using contact angle goniometry.
All the standard occluders showed very low contact angle, reflecting a pronounced affinity for non-polar molecules. No receding of the contact line could be observed for the untreated occluders. The smallest static contact angle of around 61° could be observed for On-X
valve (the only valve made of full PyC). The laser-treated occluders strongly repelled oil in underwater conditions. A drastic change in their wetting behaviour was observed depending on the surrounding fluid, displaying a hydrophobic behaviour in the presence of air (as the surrounding medium), and showing instead a hydrophilic nature, when surrounded by water.
BMHV "fear" water and blood. The intrinsic affinity of BMHV for nonpolar fluids can be translated into a tendency to repel polar fluids, such as water and blood. The blood-artificial surface interaction in BMHV is minimized. The contact between blood and BMHV surface is drastically reduced by polar-nonpolar Van der Waals forces. The "hydro/bloodphobia" of BMHV is intrinsically related to their chemical composition and their surface energy, thus their material: PyC indeed. Pertaining to thromboresistance, the surface roughness does not play a significant role. Instead, the thromboresistance of BMHV lies in molecular interactions. BMHV wettability can be tuned by altering the surface interface, by means of nanotechnology.
Contained rupture of the ascending aorta is a rare condition, but the severity of this complication enforces strict guidelines for its prevention and a prompt diagnosis, once already occurred.
A ...66-year-old man with a history of type 2 diabetes, longstanding aortic valve stenosis and aortic root aneurysm of 47 mm was hospital admitted for elective surgery. A Bentall-De Bono procedure was performed in order to replace the stenotic bicuspid aortic valve and exclude the dilated portion of the aortic wall. Intraoperatively, a discontinuity of the aortic wall, just above the aortic annulus, at the non-coronary sinus of Valsalva was incidentally observed. The aortic wall discontinuity was none other than a contained aortic rupture. The preoperative CT-scan images were afterwards analyzed by the radiologist, in order to identify the contained aortic rupture. Indeed a false aneurysm of the non-coronary sinus of Valsalva of a maximum diameter of 15 mm was detected, thanks to a 3D reconstruction.
The diagnosis of contained aortic rupture is certainly demanding, particularly in absence of signs or symptoms of rupture in a chamber of the heart or in the pericardium. Although this case represents a consensus of experts' opinion, the recognition of these specific cases in which the risk of dissection, rupture or death is at its highest, would allow to operate at the appropriate time, improving the outcomes.
The ascending aorta is an uncommon site for non-infective thrombus. In non-aneurysmal and non-atherosclerotic vessels this condition becomes extremely rare, while it represents a source of potential ...cerebral and peripheral embolic events. Currently, there is no consensus in the guidelines on how to treat a free floating thrombus in ascending aorta, therefore we present our decision making process and therapeutic strategy.
A healthy 48-year-old man was hospital admitted with acute abdominal pain. CT-scan showed a right renal embolism in presence of a defect in the distal ascending aorta suggestive for thrombus. After heart team discussion the patient was scheduled for surgery and successfully underwent an emergent thrombus removal. Also, owing to multiple aortic wall insertions, the ascending aorta was replaced. The patient's recovery was uneventful and histological examination showed no signs of connective tissue disorders of aortic wall while confirmed the thrombotic nature of the mass.
We present a patient with a floating thrombus in the ascending aorta who underwent an ascending aorta replacement. While angio-CT scan led to a prompt diagnosis, intraoperative epi-aortic echocardiography allowed to define precise location of thrombus, minimizing operative risk. This case demonstrates that multi-disciplinary heart team discussion is essential to define a successful strategy, that surgical treatment is feasible with specific tools such as epi-aortic echocardiography.
Powder bed fusion (PBF) of ceramics is often limited because of the low absorptance of ceramic powders and lack of process understanding. These challenges have been addressed through a co-development ...of customized ceramic powders and laser process capabilities. The starting powder is made of a mix of pure alumina powder and alumina granules, to which a metal oxide dopant is added to increase absorptance. The performance of different granules and process parameters depends on a large number of influencing factors. In this study, two methods for characterizing and analyzing the PBF process are presented and used to assess which dopant is the most suitable for the process. The first method allows one to analyze the absorptance of the laser during the melting of a single track using an integrating sphere. The second one relies on in-situ video imaging using a high-speed camera and an external laser illumination. The absorption behavior of the laser power during the melting of both single tracks and full layers is proven to be a non-linear and extremely dynamic process. While for a single track, the manganese oxide doped powder delivers higher and more stable absorptance. When a full layer is analyzed, iron oxide-doped powder is leading to higher absorptance and a larger melt pool. Both dopants allow the generation of a stable melt-pool, which would be impossible with granules made of pure alumina. In addition, the present study sheds light on several phenomena related to powder and melt-pool dynamics, such as the change of melt-pool shape and dimension over time and powder denudation effects.
Objective
To report the early and mid-term results of patients who underwent minimally invasive aortic valve replacement (MI-AVR) with a sutureless prosthesis from an international prospective ...registry.
Methods
Between March 2011 and September 2018, among 957 patients included in the prospective observational SURE-AVR (Sorin Universal REgistry on Aortic Valve Replacement) registry, 480 patients underwent MI-AVR with self-expandable Perceval aortic bioprosthesis (LivaNova PLC, London, UK) in 29 international institutions through either minithoracotomy (n = 266) or ministernotomy (n = 214). Postoperative, follow-up, and echocardiographic outcomes were analyzed for all patients.
Results
Patient age was 76.1 ± 7.1 years; 64.4% were female. Median EuroSCORE I was 7.9% (interquartile range IQR, 4.8 to 10.9). Median cardiopulmonary bypass and cross-clamp times were 81 minutes (IQR 64 to 100) and 51 minutes (IQR 40 to 63). First successful implantation was achieved in 97.9% of cases. Two in-hospital deaths occurred, 1 for noncardiovascular causes and 1 following a disabling stroke. In the early (≤30 days) period, stroke rate was 1.4%. Three early explants were reported: 2 due to nonstructural valve dysfunction (NSVD) and 1 for malpositioning. One mild and 1 moderate paravalvular leak were reported. In 16 patients (3.3%) pacemaker implantation was needed. Mean follow-up was 2.4 years (maximum = 7 years). During follow-up 5 explants were reported, 3 due to endocarditis and 2 due to NSVD. Follow-up stroke rate was 2.5%. Three structural valve deteriorations not requiring reintervention were reported. Five-year survival was 91.45%.
Conclusions
In this large prospective international registry, MI-AVR with Perceval valve confirmed to be safe, reproducible, and effective in an intermediate-risk population, providing excellent clinical recovery both in early and mid-term follow-up.
Abstract
OBJECTIVES
The liquid–solid interactions have attracted broad interest since solid surfaces can either repel or attract fluids, configuring a wide spectrum of wetting states (from ...superhydrophilicity to superhydrophobicity). Since the blood–artificial surface interaction of bileaflet mechanical heart valves essentially represents a liquid–solid interaction, we analysed the thrombogenicity of mechanical heart valve prostheses from innovative perspectives. The aim of the present study was to modify the surface wettability of standard St. Jude Medical Regent™ occluders.
METHODS
Four pyrolytic carbon occluders were irradiated by means of ultra-short pulse laser, to create 4 different nanotextures (A–D), the essential prerequisite to achieve superhydrophobicity. The static surface wettability of the occluders was qualified by the contact angle (θ) of 2 µl of purified water, using the sessile drop technique. The angle formed between the liquid–solid and the liquid–vapour interface was the contact angle and was obtained by analysing the droplet images captured by a camera. The morphology of the occluders was characterized and analysed by a scanning electron microscope at different magnifications.
RESULTS
The scanning electron microscope analysis of the textures revealed 2 different configurations of the pillars since A and B showed well-rounded shaped tops and C and D flat tops. The measured highest contact angles were comprised between 108.1° and 112.7°, reflecting an improved hydrophobicity of the occluders. All the textures exhibited, to different extents, an orientation (horizontal or vertical), which was strictly related to the observed anisotropy.
CONCLUSIONS
In this very early phase of our research, we were able to demonstrate that the intrinsic wettability of pyrolytic carbon occluders can be permanently modified, increasing the water repellency.
Valvular heart diseases represents a major public-health problem and a burden of the upcoming years 1.
Objective: Mitral valve surgery for organic mitral regurgitation (MR) in the elderly has been debated. In the elderly, quality of life is a better indicator of surgical success than survival. We ...assessed quality of life of elderly patients submitted to surgery for MR using the Minnesota Living with Heart Failure (MLHF) questionnaire. Methods: Between August 2003 and August 2006, 225 consecutive patients >70 years old underwent surgical treatment of organic MR. Mean age was 77 ± 3.3 years (range 71–87 years). Mean EF was 50 ± 11%. Degenerative disease was the most prevalent (77%) etiology. CABG was associated in 25% of patients. Mean Charlson score was 4.3 ± 1.5 and 101 patients (45%) were NYHA class III and IV. Hospital survivors were followed up and quality of life by MLHF score was assessed. Results: Mitral repair and replacement were equally distributed in this population. Hospital mortality was 2.7%. Late survival was 91 ± 1.9% at 3 years. MLHF was obtained from 204 patients at mean 2 ± 1 years of follow-up. MLHF score was 38 ± 18; there were 135 (66%) patients with MLHF >30. MLHF tended to increase with age at follow-up (p = 0.007). Multivariable predictors of MLHF were preoperative atrial fibrillation (p = 0.019), diabetes (p = 0.03), higher creatinine level (p = 0.0009), higher EuroSCORE (p = 0.02), residual mitral regurgitation grade at follow-up echocardiography (p ≪ 0.0001) and systolic pulmonary artery pressure at follow-up (p = 0.04). Type of surgical treatment (repair vs replacement and choice of prosthesis) did not predict MLHF at follow-up, although those who had recurrent MR after repair had the highest scores compared to patients who had repair and durable result and those treated by replacement (MLHF was 51 ± 21, vs 34 ± 16, vs 39 ± 18, respectively, p = 0.0013). Conclusions: Quality of life following mitral valve surgery is suboptimal in more than half of elderly patients. MLHF score at follow-up is mostly related to preoperative conditions. Type of surgery does not influence MLHF score, however, quality of life is worse in patients with recurrent/residual MR following repair.
Annular dilation is a common feature of chronic degenerative mitral regurgitation caused by leaflet prolapse. Accordingly, patients undergoing surgical repair usually undergo concomitant reductive ...annuloplasty to restore a normal annular-to-leaflet relation. With the evolution of transcatheter valve repair technologies, patient selection criteria for those who do not require annuloplasty are needed. A series of patients undergoing mitral repair was analyzed, and the role of annular-to-leaflet mismatch in identifying patients requiring reductive annuloplasty was explored. Preoperative data for 82 patients undergoing mitral repair with annuloplasty for degenerative mitral regurgitation were prospectively collected, including annular intercommissural (IC) and septolateral (SL) dimensions and heights of anterior (ALH) and posterior leaflets. An SL/ALH ratio >1.4 was used to define annular-to-leaflet mismatch. After mitral repair, the ratio between preoperative IC distance and the size of the implanted annular prosthesis (Seguin ring SR, IC/SR <1.2) was used to identify patients for whom annuloplasty was nonreductive. All patients underwent successful mitral repair. Mean preoperative IC was 46 ± 6 mm, SL was 42 ± 5 mm, and ALH was 31 ± 5 mm. Mean SR was 34 ± 3 mm, with a mean IC/SR ratio of 1.34 ± 0.14. Sixteen patients (19%) had an IC/SR ratio <1.2. IC/SR ratio <1.2 was predicted by a SL/ALH ratio ≤1.4 (p = 0.009). In conclusion, annular dilation is negligible in <20% of surgical candidates. In this subgroup, an isolated leaflet repair may be indicated. SL/ALH ratio is a good indicator of annular-to-leaflet mismatch and could be used as an adjunct to other methods of annular function assessment to select patients for ringless mitral repair.
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