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Bioprostheses are prone to structural valve degeneration, resulting in limited long-term durability. A significant challenge when comparing the durability of different types of bioprostheses is the lack of a standardized terminology for the definition of a degenerated valve. This issue becomes especially important when we try to compare the degeneration rate of surgically inserted and transcatheter bioprosthetic valves. This document, by the VIVID (Valve-in-Valve International Data), proposes practical and standardized definitions of valve degeneration and provides recommendations for the timing of clinical and imaging follow-up assessments accordingly. Its goal is to improve the quality of research and clinical care for patients with deteriorated bioprostheses by providing objective and strict criteria that can be utilized in future clinical trials. We hope that the adoption of these criteria by both the cardiological and surgical communities will lead to improved comparability and interpretation of durability analyses., (© 2018 American Heart Association, Inc.)

Background: The reliability of the biophysical properties of skin equivalents (SEs) remains a challenge for medical applications and for product efficacy tests following the European Directive 2003/15/EC2 on the prohibition of animal experiments for cosmetic products., Methods: We propose to adapt the biophysical in vivo testing techniques to compare full thickness model growth vs. time. The interest in using such techniques lies in possible comparisons between in vivo and in vitro skin as well as monitoring samples over the culture time., Results: High frequency ultrasound technique, optical coherence tomography (OCT), and laser scanning microscopy were used to analyze SEs morphology at days D42 and D60 whereas their microstructure was assessed through transmission electron microscopy and classical histology. A correlation between these observations and mechanical measurements has been proposed so as to underline the consequence of both the development of the dermis elastic fibers and the epidermis differentiation., Conclusion: Ultrasounds measurements show a highly homogeneous dermis whereas the OCT technique clearly distinguishes the stratum corneum and the living epidermis. The increase in the thicknesses of these layers as well as the growth in elastin and collagen fibers results in strong modifications of the samples mechanical properties., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Transcatheter aortic valve implantation is an accepted and established alternative to surgical aortic valve replacement for patients with severe symptomatic aortic valve stenosis and multiple comorbidities that would make open surgery a high-risk option. It has also evolved as a suitable treatment option for degenerative surgical heart valve disease, with considerable experience in the aortic and mitral positions. To enable a successful procedure, avoiding malposition, valve embolization and coronary obstruction, clinicians should be familiar with the design, fluoroscopic appearances and implantation technique of the degenerated surgical bioprosthetic valve in situ, as well as its compatibility with currently available transcatheter valves., (© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

As originally described by Bentall and De Bono, aortic root replacement with reimplantation of the coronary arteries using a composite valved conduit represents the gold standard intervention in patients with aneurysmal disease or dissection involving the aortic root. Over the last decade, the number of Bentall procedures performed using biological valved conduit has dramatically expanded mainly due to the increased incidence of aortic disease in the aging population. Here, we sought to describe the commercially available biological composite grafts and the techniques that, to the best of our knowledge, are most frequently used in this setting., (© The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

An 85-year-old woman was admitted to our institution for effort dyspnea. She had a history of mitral valve replacement with a 29 mm Carpentier-Edwards bioprosthesis (Edwards Lifesciences). Transthoracic echocardiography (TTE) showed aortic stenosis and senescence of the mitral bioprosthesis. The heart team opted for a transapical transcatheter aortic valve implantation (TAVI) and mitral valve-in-valve implantation (m-ViV). Two Edwards Sapien XT (ESXT) 29 mm devices were selected. To our knowledge, this is the first description of the concomitant transapical implantation of two 29 mm ESXTs for a combination of failed mitral bioprosthesis and native aortic stenosis.

Objectives: Durability of bioprosthetic valves in the pulmonary position is not well defined. We examined the durability of bioprosthetic valves in the pulmonary position and risk factors associated with bioprosthetic pulmonary valve failure., Methods: Between 1993 and 2004, 181 patients underwent pulmonary valve replacement using bioprostheses. Patients who underwent valved conduit or homograft implantation were excluded. Mean age was 14.2 ± 9.8 years and median valve size was 23 mm (range, 19-27 mm). Types of bioprosthesis used were Hancock II (n = 83), Perimount (n = 53), Freestyle (n = 23), Carpentier-Edwards porcine valve (n = 18), and others (n = 4)., Results: There were 3 early and 7 late deaths. Follow-up completeness was 88.6% and mean follow-up duration was 7.3 ± 2.9 years. Forty-three patients underwent redo pulmonary valve replacement. Overall freedom from redo pulmonary valve replacement at 5 and 10 years was 93.9% ± 1.9% and 51.7% ± 8.6%, respectively. Overall freedom from both valve failure and valve dysfunction at 5 and 10 years was 92.2% ± 2.1% and 20.2% ± 6.7%, respectively. In multivariable analysis, younger age at operation, diagnosis of pulmonary atresia with ventricular septal defect, and use of stentless valve were identified as risk factors for redo pulmonary valve replacement., Conclusions: Durability of bioprosthetic valves in the pulmonary position was suboptimal. Valve function was maintained stable until 5 years after operation. By 10 years, however, about 80% will require reoperation or manifest valve dysfunction. In our experience, the stentless valve was less durable than stented valves., (Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Background: Selection of the best tissue valve is an essential step before percutaneous aortic valve replacement (PAVR) becomes a clinical reality. The aim of this study was to evaluate in vitro three different tissue valves mounted within the same endovascular stent., Methods: Thirty stented valves (10 aortic porcine, 10 pulmonary porcine, and 10 pericardial tubular) were sutured within a 32-mm long by 23-mm diameter cobalt-nickel stent. The porcine valves were trimmed down close to the cusps. All valves were delivered with a percutaneous valvuloplasty catheter and placed orthotopically in a latex root that was cast from a sheep's aorta. The roots were tested in a pulse duplicator at a rate of 60 beats per minute and 3.5 liters per minute. The transvalvular gradient, maximum valve orifice area, and presence of central and paravalvular leaks were recorded echocardiographically., Results: Within the limitations of implantation in a synthetic, noncalcified annulus, the pericardial valve performed best in terms of orifice area, transvalvular gradients, and tissue bulk; but four of the ten valves showed a central leak due to the type of stent used., Conclusion: The ideal valve for PAVR should collapse with minimal bulk to avoid coronary obstruction and central and paravalvular leaks. The tubular pericardial valve showed the lowest pressure gradients and was the most compressible, but was more open to manufacturing errors.

Aim: Retrospective analysis of the post-op hearing results in stapes surgery using different types of materials for stapes prosthesis after 12 months follow up., Material and Methods: The total number of 350 otosclerosis patients who underwent surgical treatment at the Otosurgery Department, Medical University of Lodz from 1980-2002. All patients included in the study were divided into 4 groups: group 1 (N=54)--Portmann's method interposition, group 2 (N=160)--stapes replaced with the Shea-type prosthesis, group 3 (N=60)--platinum wire prosthesis (Zini-type), group 4 (N=76)--teflon-piston operation (Fisch-type)., Results: The 12 months post-op mean value for air-bone gap (500, 1000, 2000 Hz) presented the following values: group 1-19 dB, group 2-15.9 dB, group 3-18.4 dB, group 4-13.5 dB. The percentage of patients with the mean air-bone gap value of 15 dB or less (500, 1000, 2000 Hz) has the following values in each group: group 1-75%, group 2-81.3%, group 3-83%, group 4-85%., Conclusions: 12 months post-op hearing results compared between the 4 studied groups showed statistically not significant differences. Our experience with teflon-piston prosthesis shows the lowest post-op mean value of the air-bone gap.

Background: Aortic valve replacement (AVR) with a 21-mm sized bioprothesis is still discussed controversially. Since better results have been reported for pericardial valves, the aim of the current study was to analyze the hemodynamic performance as well as clinical parameters in our patients and to compare pericardial and standard porcine valves in particular., Methods: 342 patients underwent AVR with a bioprosthesis between 1987 and 2000. A 21 mm prosthesis was used in 39 patients (group S), while 303 patients received at least a 23-mm sized valve (group L). Group S was further divided into 19 patients with a pericardial valve (group S1) and 20 patients with a standard porcine valve (group S2). The hemodynamic and clinical parameters were studied in all three groups., Results: The peak and mean transprosthetic gradients were significantly lower in the pericardial group than in the porcine group, particularly between patients with 21 mm valves (peak/mean: S1: 24 +/- 9/20.8 +/- 6.5 mm Hg vs. S2: 38 +/- 15/33 +/- 9 mm Hg, p < 0.05) at discharge. We could also observe that the peak transprosthetic gradient 7 days postoperatively was not significantly higher in patients with a 21 mm pericardial valve compared to group L patients. Comparing clinical parameters, we found significantly more cerebral ischemic events, a prolonged mechanical ventilation, a higher mortality and a longer stay in hospital in the group S2 compared to the group S1., Conclusion: The current study shows that pericardial valves perform well, particularly in patients with small aortic roots. Postoperative hemodynamics and clinical results were better than for comparable standard porcine valves. As the outcome of patients with a 21 mm pericardial valve was no worse than that in patients with bigger valves, enlarging procedures for the aortic root are not necessary in the majority of these patients.

Long-term experience with first generation porcine valve xenografts enabled identification of the major limitations to their durability: (1) prosthetic-ventricular mismatch due to the high profile of the stent in patients with mitral stenosis and a small left ventricle; (2) high-pressure fixation with loss of natural collagen crimping in the fibrosa, and wash-out of proteoglycans in the spongiosa; (3) xenograft tissue autolysis, due to the long interval between animal slaughter and aortic valve removal fixation; (4) muscle shelf in the right coronary cusp, which created a gradient and could undergo accelerated calcification and/or spontaneous perforation with time; (5) a flexible polypropylene stent, which could creep or even fracture with consequent inward bending of the stent; (6) progressive time-related dystrophic calcification; (7) host fibrous tissue ingrowth. An awareness of these limitations stimulated technical modifications, which frequently brought about distinct improvements: (1) the reduction of the stent profile eliminated the problem of mismatch, but resulted in a higher tendency towards cusp prolapse and earlier commissural tearing; (2) natural collagen waviness, proteoglycans and cusp extensibility were preserved by employing low or even zero pressure during the fixation process; (3) earlier valve fixation enabled preservation of cell integrity; (4) a new orifice for small valves was designed by replacing the right muscular cusp, thus achieving less gradient and avoiding muscle-shelf-related complications; (5) polypropylene was replaced by Delrin as stent material; (6) calcium-retarding agents like T6 and toluidine blue were applied during commercial processing and storage in order to mitigate tissue mineralization.(ABSTRACT TRUNCATED AT 250 WORDS)

The most frequent valve-related complications are thromboembolic problems (including anticoagulant-related hemorrhage), infective endocarditis, paravalvular leak, intrinsic degradative dysfunction, and extrinsic interference with function, including tissue overgrowth. Tissue overgrowth, endocarditis, and paravalvular leak are largely prosthesis-independent. Thrombosis, the major cause of mechanical valve dysfunction, is infrequent with bioprostheses; in contrast, the overwhelming cause of bioprosthetic valve failure is primary tissue degeneration.

Recent studies suggest that all prosthetic valves are at least mildly stenotic and may cause relatively high pressure gradients despite normal prosthesis function; such gradients could be due to a mismatch between prosthesis effective orifice area and patient's body size. In order to address this problem more directly, we derived, using a physiologic pulse duplicator system, the theoretical relations between transprosthetic pressure gradients and prosthesis effective orifice areas indexed for body surface area, assuming a normal resting cardiac index of 3.0 l/min m-2 and 10-50% increases in stroke volume such as may occur during maximal upright exercise. These exponential relations show that a small decrease in indexed effective orifice area produces a large increase in pressure gradient, and that the indexed effective orifice area should ideally be not less than 0.9-1.0 cm2/m2 for aortic prostheses and 1.3-1.5 cm2/m2 for mitral prostheses in order to minimize postoperative gradients. Thus, high postoperative gradients do not necessarily indicate intrinsic prosthesis dysfunction but may also be due to patient prosthesis mismatch. Intrinsic prosthetic performance is best assessed by comparing in vivo calculated effective orifice areas to in vitro measurements for same type and size of prosthesis. Patient prosthesis mismatch can be avoided by calculating before operation the projected indexed effective orifice area of the prosthesis being implanted.

An attempt is made to analyse the factors which are expected to influence clinical results following implantation of a stentless porcine bioprosthesis. Long experience with implantation of allograft aortic valves provides a meaningful basis for comparison with a glutaraldehyde-fixed device. Morphological differences between the two valves involve the aortic wall and muscle shelf, and differences in valve preparation include the strength and stiffness of the aorta and the extensibility of the valve leaflets. As a result of these differences, sizing of the porcine valve is expected to be more critical than the allograft valve and the porcine valve is also expected to be more obstructive. Methods for reducing the obstructive element include the use of a composite aortic valve, a porcine pulmonary valve, or a valve in which the aorta is glutaraldehyde-fixed under pressure while the leaflets are pressure-free. The techniques available for implantation, namely freehand insertion, total root replacement and mini-root replacement, are examined.

This report is concerned with the dynamic interplay between glutaraldehyde preserved tissue valves (bioprostheses) and mechanical valves. These two classes of valve replacement devices are not competitive, but provide some nonoverlapping characteristic advantages and disadvantages. By proper selection, it may be possible to tailor the kind of device used for a particular patient, thus improving the overall results of bioprosthetic and mechanical valve replacement. Careful selection of patients according to age and the safety of anticoagulation should achieve a series of patients with mechanical and bioprosthetic valves that would be superior to a series in which all patients received a single device. Thus, these devices should be viewed as complimentary rather than competitive since the value of properly matching a prosthesis to the patient will be reflected in improved overall results with each class of prosthesis.

Heart valve bioprostheses are most commonly analyzed as a group rather than individualized. Mechanical valves are usually referred to by specific name and manufacturer, while bioprostheses are pooled together as "tissue valves". Each specific bioprosthesis has its own structural characteristics and therefore a different level of performance and durability. Most large centers have an adequate number of these implants and a follow-up long enough to warrant separate analysis of each valve type. This review analyzes the differences among the most commonly used bioprostheses and reaffirms the reasons for their separate analysis. Authors, reviewers and editors must standardize their criteria to prevent this problem from recurring or escalating. New bioprostheses are now being released and unless we simplify their evaluation our questions will remain unanswered.

We reviewed the incidence of dysfunction of the Smeloff-Cutter mechanical prosthetic valve and the Hancock porcine prosthetic valve in the mitral position. The Smeloff-Cutter valve was implanted from 1966 to 1972; 107 patients were discharged from the hospital and were at risk for dysfunction. Follow-up averaged 10 +/- 0.7 years SD. The Hancock valve was implanted from 1971 through 1984; 473 patients were at risk and follow-up averaged 4.7 +/- 3.4 years SD. Dysfunction of the Smeloff-Cutter valve occurred as thrombosis with incomplete poppet opening in 13 patients. Dysfunction of the Hancock valve occurred as primary tissue failure in 47 patients. At 10 years the freedom from dysfunction of the Smeloff-Cutter valve was 84 +/- 5% SE and that for the Hancock valve was 71 +/- 4% SE (p greater than .06). The mortality associated with dysfunction of the Smeloff-Cutter valve was 46%; mortality associated with dysfunction of the Hancock valve was 15% (p less than .02). At 10 years the Hancock valve had a greater incidence of dysfunction than the Smeloff-Cutter valve but this difference was not statistically significant. The mortality associated with dysfunction of the Smeloff-Cutter valve, however, was three times that associated with dysfunction of the Hancock valve.