Bovine Pericardial Valve Research Articles

One-year outcome with a bovine pericardial valve.

ObjectivesTo evaluate the safety and effectiveness of a novel surgical bovine pericardial valve for aortic and mitral valve replacements.MethodsBetween March 2016 and October 2017, 197 patients (mean age, 66.9 ± 4.9 years; 40.6% were women) underwent aortic valve replacement and mitral valve replacement and were implanted with the Cingular bovine pericardial valve (Shanghai Cingular Biotech Corporation, Shanghai, China) in a prospective, multicenter, single-arm trial in China. A total of 161 aortic and 49 mitral prostheses were implanted. Patients were followed up to 1 year. The primary end point was the 1-year overall rate of valve-related complications, including thromboembolic event, valve thrombosis, major hemorrhage event, major perivalvular leak, and prosthetic valve endocarditis.ResultsThe 1-year overall rate of valve-related complications was 0.5% (95% confidence interval, 0.1%-3.7%). The 1-year survival was 96.4%. The mean gradient and effective orifice area for aortic prostheses at 1 year postoperatively were 12.8 ± 4.4 mm Hg and 1.9 ± 0.3 cm2, respectively. Particularly, the mean gradients and effective orifice area for 19 mm and 21 mm sizes of aortic prostheses at 1 year were 17.0 ± 3.8 mm Hg and 1.6 ± 0.2 cm2, 13.1 ± 4.0 mm Hg and 1.8 ± 0.1 cm2, respectively. Patient–prosthesis mismatch occurred in only 1.3% patients for aortic valve implantation at 1 month. No structural valve deterioration and no endocarditis occurred.ConclusionsThe Cingular bovine pericardial valve was safe and effective for surgical aortic and mitral valve replacement. The 1-year rate of valve-related complications was very low. Early hemodynamic performance was excellent even for the small aortic root.

Perpendicular and turbulent flow after aortic valve replacement: paravalvular or transvalvular leakage? \u2013 a case report

BackgroundPerpendicular transvalvular leakage (TVL) is occasionally observed after aortic valve replacement (AVR) in biological valves with a stent post, often originating from the base of the stent post. However, an observed perpendicular jet flow is not always a TVL. In rare cases, paravalvular leakages (PVLs) can be perpendicular and are present behind a TVL. In the present case, both PVL and TVL existed simultaneously as unusual perpendicular jet flows that originated from sites in close proximity to the stent post.Case presentationA 73-year-old man underwent AVR with a biological valve in the supra-annular position using the non-everting mattress suture technique with pledgets. After weaning from cardiopulmonary bypass (CPB), transesophageal echocardiography (TEE) revealed an unfamiliar perpendicular turbulent flow, similar to reported TVL, originating from the anterior stent post. Further TEE examination revealed a PVL had originated from the site between the sewing ring at the anterior stent post and native annulus attached to a pledget. The space between the sewing ring and annular retained native portion caused the perpendicular turbulent jet. Consequently, two types of perpendicular turbulent flows, TVL and PVL, existed adjacent to each other.After reinstitution of CPB, inspection of the prosthesis itself indicated it to be normal, but there was a region adjacent to the anterior stent post near the right coronary ostium where the tip of the curved Pean forceps entered between the sewing ring and the native annulus. The region was consistent with TEE findings. AVR was performed with the same prosthesis again. After weaning from CPB, immediate TEE revealed that the unusual perpendicular turbulent flows had disappeared and only a few small TVLs were observed. Regarding the disappearance of TVL, we considered that the fabric region of the prosthetic valve was covered with cellular elements to prevent the leak, as it was already used in AVR once and soaked in blood.ConclusionsPerpendicular turbulent flow raises the possibility of both TVL and PVL in the case of AVR with stented bovine pericardial valves. For a differential diagnosis of TVL or PVL, it is important to know the surgical procedures and valve morphology.

Long-Term Outcomes of Mosaic Versus Perimount Mitral Replacements: 17-Year Follow-Up of 940 Implants

The objective of this study was to compare long-term outcomes of Mosaic (Medtronic, Minneapolis, MN) porcine mitral valves to Carpentier-Edwards (Edwards Lifesciences, Irving, CA) bovine pericardial mitral valves. From 2001 through 2017 at a single institution, 940 patients received a mitral bioprosthesis, of which 463 (49.3%) were porcine and 477 (50.7%) were bovine pericardial. Retrospective review of the procedure and the postoperative clinical course, including echocardiography, through August 2018 were analyzed. All consecutive mitral valve replacements over the study period were included. Follow-up was 99% (929 patients) complete for a total of 6045 patient-years (mean, 6.4 ± 4.5 years). A propensity-matched cohort of 802 mitral bioprosthesis was used for outcome analyses. Operative mortality of the 940 patients was 5.4% (n= 51) and incidence of postoperative stroke was 2.1% (n= 20). Overall survival of the propensity-matched patients at 10 and 15 years was 49.7% (95% confidence interval [CI] 45.5%-53.7%) and 23.3% (95% CI 17.9%-29.3%), respectively. Survival at 15 years was 24.0% (95% CI 18.0%-30.5%) for porcine and 16.5% (95% CI 5.5%-32.6%) for bovine implants, which was not significantly different (P= .67). Overall cumulative incidence for reoperative structural valve deterioration at 15 years was 7.9% (95% CI 4.7%-12.3%) for porcine valves versus 13.2% (95% CI 8.1%-19.5%) for pericardial valves (P< .001). For patients age younger than 65 years, structural valve deterioration at 15 years was 15.8% (95%CI 7.4%-27.0%) versus 30.2% (95% CI 15.1%-46.8%) for porcine and pericardial valves, respectively (P= .009). Overall average time to reoperation for structural valve deterioration for porcine valves was 11.1 ± 2.3 years vs 6.8 ± 2.3 years for bovine pericardial valves (P < .001). In long-term follow-up, of patients younger than 65 years of age undergoing mitral valve replacement, bovine pericardial valves experienced earlier and more frequent structural valve deterioration than porcine valves.

Durability and clinical experience using a bovine pericardial prosthetic aortic valve

ObjectivesTo report the implant experience and long-term outcomes from a large tertiary care referral center on surgical aortic valve replacement (SAVR) with a contemporary stented pericardial bioprosthesis with anticalcification treatment. MethodsPatients underwent SAVR using the Trifecta valve at a single institution. Endpoints included procedural outcomes, adverse events, prosthesis–patient mismatch (PPM), long-term survival, and valve durability. Follow-up included 30-day, 6-month, and annual assessments. Treatment for structural valve deterioration (SVD) included surgical explant and valve-in-valve (V-in-V) transcatheter aortic valve implantation (TAVI). ResultsSAVR was performed in 1241 patients (median age, 73.5 ± 6.4 years; 54% male; median logistic EuroSCORE, 7.8) with concomitant procedures in 713 cases (57.5%). Intraprocedural mortality was 1.4%, and 30-day mortality was 6.0%. At hospital discharge, 68 patients (5.5%) had moderate PPM, and no patients had severe PPM. Adverse events included cardiac arrhythmias (44.7%, mostly atrial fibrillation), respiratory failure (22.9%), acute renal failure requiring temporary renal replacement therapy (12.9%), and low cardiac output syndrome (3.3%). Follow-up data were available over a total of 5469 patient-years (median duration of follow-up, 4.7 years). Freedom at 8 years from all-cause mortality, valve-related mortality, reoperation for SVD (redo SAVR or V-in-V TAVI), and endocarditis were 78.4%, 98.0%, 93.3%, and 96.5%, respectively. Of the 30 patients with SVD, 17 were treated by V-in-V TAVI and 13 underwent surgical explant. ConclusionsOutcomes from this large single-center cohort at increased surgical risk demonstrate excellent long-term durability of the Trifecta valve for SAVR and feasibility of treating SVD by V-in-V TAVI.

Optimizations of stent and tissue leaflets in a new surgical bovine pericardial valve.

Compared with mechanical valves, bovine pericardial valves have satisfactory hemodynamic performance, low risk of infective endocarditis, and low incidence of thromboembolism without long-term anticoagulation treatment (1). Even after decades of continues improvements in tissue leaflets and bioprosthetic valve structure, the existing bioprosthetic valves still have some drawbacks. Although mid- and long-term clinical outcomes of bovine pericardial valves are satisfactory in the literature, the durability is still a major concern because of structural valve deterioration (SVD) (2-6).

Native-valve Enterococcus hirae endocarditis: a case report and review of the literature

BackgroundEnterococcus hirae is rarely identified in humans and may be a commensal pathogen in psittacine birds. We present the fifth known case of E. hirae endocarditis.Case presentationA 64-year-old Caucasian female presented with fever, hypotension, atrial fibrillation with rapid ventricular response, and a two-week history of lightheadedness. Her previous medical history included COPD, recurrent DVT, atrial fibrillation (on warfarin), hypertension, hypothyroidism, and Hodgkin’s lymphoma. Physical exam was notable for expiratory wheezes and a 2/6 systolic ejection murmur at the right sternal border. 2D echocardiogram revealed severe aortic stenosis. The patient underwent right and left heart catheterization, where she was found to have severe aortic stenosis and mild pulmonary hypertension. She subsequently underwent minimally invasive aortic valve replacement with a bovine pericardial valve, bilateral atrial cryoablation, and clipping of the left atrial appendage. Her aortic valve was found to have a bicuspid, thickened appearance with calcifications, multiple small vegetations, and a root abscess beneath the right coronary cusp. With a new suspicion of infective endocarditis, the patient was placed on broad-spectrum IV antibiotics. Intra-operative blood cultures were negative. A tissue culture from the aortic valve vegetations identified Enterococcus hirae susceptible to ampicillin through MALDI-TOF. Antibiotic treatment was then switched to IV ampicillin and ceftriaxone; she declined aminoglycoside treatment due to toxicity concerns. The patient had an uncomplicated postoperative course and was discharged with 6 weeks of antibiotics. To date, she continues to be followed with no signs of relapsing disease.ConclusionsTo our knowledge, this case constitutes the fifth known case of E. hirae endocarditis, and the second case to have been identified with MALDI-TOF and treated with ampicillin and ceftriaxone. This case reinforces the efficacy of ampicillin and ceftriaxone for the treatment of E. hirae endocarditis.

Discussion

Dr Song Wan (Shatin, Hong Kong). Your 2-year outcome analysis indicated excellent safety, efficacy, and hemodynamic performance of this newly developed bovine pericardial valve. I have 2 related questions and 1 comment.

THE AVALUS MEDTRONIC BOVINE PERICARDIAL VALVE SHOWS SIGNIFICANT OPENING RESERVE AT EXERCISE SUPPORTING GOOD CLINICAL OUTCOMES

The Avalus Medtronic valve is a novel low profile stented bovine pericardial valve. The FDA investigational PERIGON trial reported good clinical outcomes although a significant proportion of patients presented moderate to severe PPM at rest. To study this ‘conundrum’, an exercise-based protocol was designed to evaluate the Avalus valve performance

Safety, efficacy, and hemodynamic performance of a stented bovine pericardial aortic valve bioprosthesis: Two-year analysis

ObjectivesThe study objectives were to evaluate the safety, efficacy, and hemodynamic performance of a novel stented bovine pericardial aortic valve bioprosthesis 2 years after implantation. MethodsThe PERIcardial SurGical AOrtic Valve ReplacemeNT Pivotal Trial enrolled patients with symptomatic moderate/severe aortic stenosis or regurgitation at centers in Canada, Europe, and the United States. We report the outcomes and hemodynamic performance in patients with up to 2 years of follow-up. ResultsA total of 1273 patients were enrolled, and 1110 underwent implantation. Among patients undergoing implantation, the mean age was 70.2 ± 8.9 years; 833 (75.0%) were male. Risk of mortality (Society of Thoracic Surgeons) was 2.0% ± 1.4%. At the time of analysis, 604 patients had completed the 2-year follow-up visit. Linearized late event rates were as follows: all death, 2.68%; valve-related death, 0.42%; valve thrombosis, 0.05%; endocarditis, 0.94%; thromboembolism, 1.68%; all hemorrhage, 2.94%; major hemorrhage, 1.99%; all paravalvular leak, 0.26%; and major paravalvular leak, 0.05% per patient-year. Mean 2-year aortic gradient and effective orifice area were 13.4 ± 5.0 mm Hg and 1.5 ± 0.37 cm2, respectively. Moderate and severe prosthesis–patient mismatch were observed in 43.5% and 34.8% of patients at 2 years, respectively. Improvement in New York Heart Association class compared with baseline was observed in 73.0% with moderate mismatch and 74.1% with severe mismatch. ConclusionsThe Avalus (Medtronic, Minneapolis, Minn) bovine pericardial valve demonstrates good clinical and safety outcomes at 2 years. Hemodynamic performance shows mean gradients comparable to currently available bovine pericardial aortic valves. There was no clinical impact of moderate to severe mismatch at 2 years. Further follow-up is required to evaluate midterm to long-term clinical outcome.

Pulmonary versus aortic pressure behavior of a bovine pericardial valve

BackgroundThe Carpentier Edwards Perimount Magna Ease aortic valvular prosthesis (Edwards Lifesciences, Irvine, Calif) has been among the most frequently and successfully used tissue prosthetic cardiac valves. Furthermore, this prosthesis has been used off-label in the pulmonary position. Until now, there has been a paucity of data regarding the functioning of tissue prosthetic valves under pulmonary conditions. MethodsUsing a pulse duplicator, hydrodynamic characteristics of a 21-mm and 25-mm Magna Ease valve were evaluated. Among parameters evaluated were leakage orifice area, closing time (ie, time required to close), and leakage duration. This procedure was performed under different pulmonic pressure conditions (15/5 mm Hg, 28/11 mm Hg, 73/32 mm Hg) and normal aortic pressure (120/80 mm Hg) as a reference. Moving images were obtained using a Phantom MIRO M320S high-speed camera (Vision Research Inc, Wayne, NJ) at 600 frames per second and used to analyze valve area in closed position. ResultsUnder normal pulmonic conditions (28/11 mm Hg) the leakage orifice area was 0.020 ± 0.012 mm2 for the 21-mm valve and 0.054 ± 0.041 mm2 for the 25-mm valve (P = .03). Hydrodynamic characteristics of the valves differed between pulmonary and aortic testing condition. Valve closing volumes were significantly lower under pulmonary hypotension and normal pulmonary conditions than under normal aortic conditions (P < .05). ConclusionsUnder normal pulmonary pressure conditions, the hydrodynamic characteristics of Magna Ease valves are significantly different compared with aortic conditions. Further research is needed to determine whether these results are associated with prosthetic valve failure.

Evaluation of Hybrid Surgical Access Approaches for Pulmonary Valve Implantation in an Acute Swine Model.

Percutaneous implantation of the pulmonary valve through peripheral vascular access can be limited due to poor venous access, low patient weight, hemodynamic or rhythmic instability, and size constraints related to the valve. In such cases, hybrid procedures may provide alternatives. Because the most commonly used median sternotomy is unsuitable for chronic trials in large animals, we evaluated several hybrid approaches for pulmonary valve replacement in a swine model. We tested the feasibility of hybrid pulmonary valve implantation in pigs by using inhouse-generated valves containing bare-metal or nitinol stents. Valves consisted of bovine jugular veins, bovine pericardial valves, or sprayed polyurethane valves. Access was achieved through median sternotomy, lower partial sternotomy, transverse sternotomy, or right lateral thoracotomy. The delivery device was introduced in a transventricular manner. Implantation took place under fluoroscopic and epicardial echocardiographic guidance. We achieved implantation of the stented valve in 12 (92.3%) pigs, of which 5 (41.7%) of the implanted valves were in an optimal position. Paravalvular leakage occurred in 2 trials (16.7%). Lower partial sternotomy provided the best trade-off between feasibility and minimized trauma for long-term animal trials. Here we describe our experience with hybrid pulmonary valve implantation in an acute large-animal (swine) model. We demonstrate the feasibility of the procedure in terms of surgical technique and the perioperative management and preparation of the field for a chronic trial.

Immunoproteomic Identification of Noncarbohydrate Antigens Eliciting Graft-Specific Adaptive Immune Responses in Patients with Bovine Pericardial Bioprosthetic Heart Valves.

This case-control retrospective discovery study is to identify antigenic bovine pericardium (BP) proteins that stimulate graft-specific humoral immune response in patients implanted with glutaraldehyde fixed bovine pericardial (GFBP) heart valves. Banked serum is collected from age- and sex-matched patients who received either a GFBP or mechanical heart valve replacement. Serum IgG is isolated and used to generate poly-polyclonal antibody affinity chromatography columns from each patient. Native and deglycosylated BP protein extracts are separately added to individual patient affinity chromatography columns, with unbound proteins washed through the column. Proteins captured in the affinity chromatography columns are submitted for proteomic identification. Differences between GFBP and mechanical heart valve replacement recipients are analyzed with Gaussian linearized modeling. Carbohydrate antigens overwhelm protein capture in the column, requiring BP protein deglycosylation prior to affinity chromatography. Nineteen BP protein antigens, which stimulated graft-specific IgG production, are identified in patients who received GFBP valve replacements. Identified antigens are significantly over-represented for calcium-binding proteins. Patients implanted with GFBP valves develop a graft-specific humoral immune response toward BP protein antigens, with 19 specific antigens identified in this work. The molecular functions of over-represented antigens, specifically calcium-binding proteins, may aid in understanding the underlying factors that contribute to structural valve deterioration.

Trifecta Aortic Bioprosthesis: Midterm Results in 1,953 Patients From a Single Center

The St. Jude Medical Trifecta bioprosthesis (St. Jude Medical, St. Paul, MN) is a bovine pericardial valve mounted on a titanium stent. The objective of this study was to report a single-center experience with the Trifecta aortic valve. Patients undergoing aortic valve replacement (AVR) with the Trifecta valve between 2011 and 2017 at a single center were included. The primary outcome was overall survival. Secondary outcomes included operative mortality and morbidity, aortic valve reoperations, and reoperation for structural valve deterioration. Echocardiographic outcomes were evaluated. Multivariable logistic regression models were created to identify predictors of death. The study included 1,953 Trifecta valve implants. Operations included isolated AVR (45% [n= 869]), AVR plus coronary artery bypass grafting (40% [n= 771]), and AVR plus mitral valve operation (13% [n= 254]). Overall survival at 30 days, 1 year, and 5 years was 94.9%, 89.7%, and 69.8%, respectively. Overall freedom from aortic valve reintervention was 96.4% at 5 years, with an overall freedom from reoperation for structural valve deterioration of 98.7% at 5 years. For elective isolated AVRs, survival was 98.6%, 94.1%, and 77.5% at 30 days, 1 year, and 5 years, respectively. The 5-year freedom from aortic valve reintervention and reoperation for structural valve deterioration for elective isolated AVRs was 97.6% and 99.1%, respectively. Overall mean gradients were 6.8 ± 5.3 mm Hg postoperatively and remained low at 10.1 ± 6.2 mm Hg at 1 year. This is the largest series reporting on outcomes of the Trifecta valve. Our results demonstrate that this valve can be safely implanted in the aortic position with excellent midterm durability and hemodynamics.

Prospective US investigational device exemption trial of a sutureless aortic bioprosthesis: One-year outcomes

ObjectivesWe performed a prospective, single-arm clinical trial approved under a Food and Drug Administration Investigational Device Exemption to assess safety and efficacy of Perceval, a sutureless bovine pericardial aortic valve representing the initial US experience. MethodsFrom June 2013 to January 2015, 300 patients (mean age 76.7 ± 7.7 years, 54.3% men, 37.3% ≥80 years, median Society of Thoracic Surgeons Predicted Risk of Mortality 2.8%), underwent Perceval valve implantation at 18 centers across the United States. Twenty patients (6.7%) had a bicuspid aortic valve and 5 (1.7%) patients had previous aortic valve replacement. A minimally invasive approach was used in 80 (26.7%) and concomitant procedures were performed in 113 (37.8%) patients. ResultsTwo hundred eighty-nine patients (96.3%) were successfully implanted. Operative mortality (≤30 days) was 1.3% (n = 4) (observed to expected ratio of 0.40). One-year results included all-cause mortality in 5.2% (n = 15), stroke in 1% (n = 3), and endocarditis in 1.7% (n = 5). New permanent periprocedural pacemaker rate was 10.7% (n = 30/281); 2.5% (n = 7/281) resulted from third-degree atrioventricular block. One-year valve-related reoperation was 2.1% (n = 6). At 1-year follow-up, 98% of patients were in New York Heart Association class I/II, left ventricular mass index decreased from 103.5 ± 30.1 g/m2 at discharge to 95.8 ± 27.1 g/m2 (P = .001), and 3 (1.3%) moderate paravalvular leaks were identified. Health-related quality of life score increased from 62.7 ± 21.8 before surgery to 85.5 ± 17.8 at 1 year (P < .001). ConclusionsThese results confirm the safety and effectiveness of the Perceval sutureless aortic valve replacement in study patients with lower mortality than expected from a risk prediction model. Persistent hemodynamic benefit and improvement in quality of life at 1 year support the importance of this device in the management of aortic valve disease.

Impact of Clinically Relevant Elliptical Deformations on the Damage Patterns of Sagging and Stretched Leaflets in a Bioprosthetic Heart Valve.

After implantation of a transcatheter bioprosthetic heart valve its original circular circumference may become distorted, which can lead to changes in leaflet coaptation and leaflets that are stretched or sagging. This may lead to early structural deterioration of the valve as seen in some explanted transcatheter heart valves. Our in vitro study evaluates the effect of leaflet deformations seen in elliptical configurations on the damage patterns of the leaflets, with circular valve deformation as the control. Bovine pericardial tissue heart valves were subjected to accelerated wear testing under both circular (N = 2) and elliptical (N = 4) configurations. The elliptical configurations were created by placing the valve inside custom-made elliptical holders, which caused the leaflets to sag or stretch. The hydrodynamic performance of the valves was monitored and high resolution images were acquired to evaluate leaflet damage patterns over time. In the elliptically deformed valves, sagging leaflets experienced more damage from wear compared to stretched leaflets; the undistorted leaflets of the circular valves experienced the least leaflet damage. Free-edge thinning and tearing were the primary modes of damage in the sagging leaflets. Belly region thinning was seen in the undistorted and stretched leaflets. Leaflet and fabric tears at the commissures were seen in all valve configurations. Free-edge tearing and commissure tears were the leading cause of valve hydrodynamic incompetence. Our study shows that mechanical wear affects heart valve pericardial leaflets differently based on whether they are undistorted, stretched, or sagging in a valve configuration. Sagging leaflets are more likely to be subjected to free-edge tear than stretched or undistorted leaflets. Reducing leaflet stress at the free edge of non-circular valve configurations should be an important factor to consider in the design and/or deployment of transcatheter bioprosthetic heart valves to improve their long-term performance.

One-year outcomes associated with a novel stented bovine pericardial aortic bioprosthesis

ObjectivesThe study objectives were to evaluate the safety, effectiveness, and hemodynamic performance of a new stented bovine pericardial aortic valve. MethodsThis trial enrolled patients with symptomatic moderate or severe aortic stenosis or chronic, severe aortic regurgitation. We assessed death, valve-related adverse events, functional recovery, and hemodynamic performance at discharge, 3 to 6 months, and 1 year, as required by the US Food and Drug Administration for regulatory approval. The primary analysis compared late linearized rates of valve-related adverse events after implantation with Food and Drug Administration–specified objective performance criteria to determine whether the adverse event rates associated with the valve are within acceptable limits. Adverse events included thromboembolism, thrombosis, all and major hemorrhage, all and major paravalvular leak, and endocarditis. ResultsThe primary analysis included 864 patients who received an implant and 904.1 valve-years of follow-up. A total of 577 patients completed the 1-year evaluation. The primary end point was met for death, thromboembolism, thrombosis, all and major paravalvular leak, and endocarditis, but not for all and major hemorrhage. At 1 year, freedom from all death and from valve-related death was 96.4% and 99.7%, respectively. From baseline to 1 year, New York Heart Association class changed as follows: I, 10.8% to 73.7%; II, 48.9% to 22.6%; III, 38.0% to 3.5%; and IV, 2.3% to 0.2%. Effective orifice area increased from 0.9 ± 0.5 to 1.5 ± 0.4 (P < .0001), and mean aortic gradient decreased from 42.7 ± 16.5 to 12.5 ± 4.3 (P < .0001). ConclusionsThis analysis of a new stented bovine pericardial aortic valve demonstrated low overall mortality and valve-related adverse events, and hemodynamic performance comparable to that of other surgical aortic valves.

Modified technique for Melody valve implantation in the mitral position

Modified technique for Melody valve implantation in the mitral position

A novel tissue treatment to reduce mineralization of bovine pericardial heart valves

ObjectiveWith the increasing use of bioprostheses worldwide, continuous efforts have been made to improve tissue durability. We introduce a new treatment for bovine pericardium combining octanediol-ethanol based phospholipid removal with taurine-based glutaraldehyde neutralization and storage in an aldehyde-free solution (FREE). MethodsTreated tissues were evaluated by mechanical and biochemical characterization, phospholipid content, aldehyde levels, cell cultures on pericardial samples (L929 fibroblasts and human umbilical vein endothelial cells), rat subcutaneous implantations, and long-term juvenile sheep mitral valve implantations (n = 3). Comparisons were made to glutaraldehyde-fixed bovine pericardium or to samples from commercially available biological valves (ie, Trifecta [St Jude Medical, Saint Paul, Minn] and Perimount Magna Ease [Edwards Lifesciences, Irvine, Calif]). ResultsFREE-treated pericardium had similar mechanical strength and biochemical properties as commercially available valves. Compared with glutaraldehyde-only samples, FREE-treated samples showed lower phospholipid levels (P < .01), significantly better growth of L929 fibroblasts, and lower calcification levels in rat subcutaneous implants (P < .01). Compared with samples from Linx- (Trifecta) and ThermaFix-treated (Perimount Magna Ease) valves, similar low levels of phospholipids were observed as were similar low calcification levels in subcutaneous implants, but tissue extractions from FREE-treated samples showed the lowest levels of extracted aldehydes (P < .01). Mitral implants of FREE-treated valves in juvenile sheep had excellent hemodynamic behavior without any sign of degeneration or calcification at 5 months. ConclusionsThe new FREE treatment combines an adequate phospholipid reduction and aldehyde neutralization with storage in an aldehyde-free solution. This combination enhances the anticalcification properties and may thereby improve long-term durability of the tissue.

Transcatheter Mitral Valve Replacement With a Novel Dual Stent Bioprosthesis

There has been great interest in transcatheter mitral valve replacement (TMVR) as a potential therapy for high-risk patients with severe mitral regurgitation, with several distinct device systems undergoing first-in-man clinical studies. The Intrepid TMVR (Medtronic Inc, Redwood City, CA), designed for transapical delivery, comprises 2 interconnected self-expanding nitinol stents: (1) an inner stent that houses a bovine pericardial tissue trileaflet valve and; (2) an outer ring that fixes to the mitral annulus by radial force in a cork-like effect (Figure 1).1 The outer fixation ring is designed to conform to the dynamic anatomy of the mitral valve throughout the cardiac cycle, avoiding distortion of the inner stent and valve. Figure 1. The Intrepid transcatheter mitral valve replacement with en face and side on views showing atrial brim, fixation …

Outcome of bioprosthetic valve replacement in dogs with tricuspid valve dysplasia.

To describe the short-term and long-term outcome in dogs with tricuspid valve dysplasia undergoing tricuspid valve replacement under cardiopulmonary bypass. Data were collected from the hospital records of all dogs that had undergone tricuspid valve replacement under cardiopulmonary bypass between 2006 and 2012. Dogs were considered candidates for tricuspid valve replacement if they had severe tricuspid valve regurgitation associated with clinical signs of cardiac compromise. Nine dogs of six different breeds were presented. Median age was 13 months (range 7 to 61 months), median weight 26·5 kg (range 9·7 to 59 kg). Eight bovine pericardial valves and one porcine aortic valve were used. One non-fatal intraoperative complication occurred. Complications during hospitalisation occurred in six dogs, four of which were fatal. Of the five dogs discharged, one presented dead due to haemothorax after minor trauma seven days later. The four remaining dogs survived a median of 533 days; all of these dogs received a bovine pericardial valve. Based on our results, tricuspid valve replacement with bovine or porcine prosthetic valves is associated with a high incidence of complications.