• Journal of Chest Surgery
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• v.55 no.1
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• pp.69-76
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• 2022

Background: While the use of bioprosthetic valves for mitral valve replacement (MVR) is increasing, very few studies have compared bovine pericardial and porcine valves in the mitral position to help guide bioprosthetic selection. Methods: In the present study, patients who underwent MVR using bovine pericardial valves were compared with those who underwent MVR with porcine bioprostheses between January 1996 and July 2018. Those with prior MVR, infective endocarditis, congenital mitral valve disease, or ischemic mitral regurgitation were excluded. The primary outcomes were structural valve deterioration (SVD) and mitral valve reoperation from any cause, and death was regarded as a competing risk. Competing risk analysis and propensity score-matching were used for comparisons. Results: Among the 388 patients enrolled, pericardial and porcine bioprostheses were implanted in 217 (55.9%) and 171 (44.1%), respectively. Propensity score-matching yielded 122 pairs of patients that were well-balanced for all baseline covariates. No significant differences were observed between the groups in unadjusted (p=0.09) and adjusted overall survival (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.72-1.76; p=0.60). Competing risk analysis revealed no significant differences in the risks of mitral reoperation (HR, 1.07; 95% CI, 0.50-2.27; p=0.86) and development of SVD (HR, 1.57; 95% CI, 0.56-4.36; p=0.39) between the groups. Matched population analysis confirmed similar results regarding reoperation (HR, 0.99; 95% CI, 0.40-3.22; p=0.98) and SVD (HR, 1.39; 95% CI, 0.41-4.73; p=0.60). Conclusion: No significant differences in survival or valve durability were observed between bovine pericardial and porcine bioprosthetic MVR. These findings require further validation through studies with larger sample sizes.

• Journal of Chest Surgery
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• v.32 no.11
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• pp.1042-1045
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• 1999

Background: Recently, open heart surgerys using homograft are progressively increasing in complex cardiac anomalies, and even though the use of homograft tissues harvested from hearts of transplant recipients and brain-death patients are allowed and their use is increasing, the supply of homograft tissue is very limited. Material and Method: The large diameter homografts are difficult to apply directly for RVOT reconstruction of small neonatal and infant hearts due to the size mismatching. Therefore, were surgically down-sized the large diameter tricuspid homograft into bicuspid conduits by means of a longitudinal incision of the oversized homograft, excision of one cusp, and oversewing of the“Bicuspid homograft”wrapped around a Hega dilator of the appropriate size. Result: 3 patients(Male 1, Female 2: tetralogy of Fallot with pulmonary atresia), ranging in age from 5 months to 4 years and ranging in weight from 5.5Kg to 12.95Kg underwent reconstruction of the RVOT with bicuspid conduits obtained by appropriate tailoring from large-diameter homografts. The mean follow-up period was 4.3 months(range, 2 to 6 months). There were no complications related to the homograft tissues. Conclusion: In the short term follow-up, the bicuspid homografts provided good competence and excellent hemodynamics although a long term follow-up is needed to assess the functions of the bicuspid homografts in RVOT. We believe this technique may be a more effective alternative than the use of synthetic conduits when the use of an appropriate-sized homograft is not possible.

• Journal of Chest Surgery
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• v.27 no.1
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• pp.1-8
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• 1994

Allograft cardiac valves have been used for over 30 years to replace diseased cardiac valves, reconstruct right or left ventricular outflow tract. With increasing its requirement, the establishment of a viable bank capable of maintaining the viability of graft over a prolonged period would be desirable. The method for determining the viability of allograft by metabolic assay technique using radiolabeled aminoacids has been used recently. An experimental study was done for evaluation of viability of cardiac allograft which was preserved for 14 days at 4oC in nutrient medium[fresh preservation] by metabolism assay technique using 3H-glycine. Also, the effectiveness of low concentration antibiotic solution[CLPV] for sterilization was evaluated. The effectiveness of CLPV solution for sterilization of allograft was perfect. Pre-treatment cultured organisms were not cultured after treatment at all in every cases. The viability of allograft after sterilization was reduced to 66.4%[aortic wall], 74.7%[pulmonary wall], 76.3%[aortic valve], 67.9%[aortic wall]. And after the fresh preservation for 14 days, the viability was reduced to 14.7%, 18.5%, 17.7%, 19.0%, respectively.In conclusion, viability of allograft was reduce to 71.3[66.4-76.3]% after sterilization and 17.5[14.7-19.0]% after fresh preservation. And sterilization effect of CLPV solution was satisfactory.

• Journal of Chest Surgery
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• v.47 no.4
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• pp.333-343
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• 2014

Background: A preclinical study was conducted for evaluating a valved conduit manufactured with a glutaraldehyde (GA)-fixed bovine pericardium treated using an anticalcification protocol. Methods: Bovine pericardia were decellularized, fixed with GA in an organic solvent, and detoxified. We prepared a valved conduit using these bovine pericardia and a specially designed mold. The valved conduit was placed under in vitro circulation by using a mock circulation model, and the durability under mechanical stress was evaluated for 2 months. The valved conduit was implanted into the right ventricular outflow tract of a goat, and the hemodynamic, radiologic, histopathologic, and biochemical results were obtained for 6 months after the implantation. Results: The in vitro mock circulation demonstrated that valve motion was good and that the valved conduit had good gross and microscopic findings. The evaluation of echocardiography and cardiac catheterization demonstrated the good hemodynamic status and function of the pulmonary xenograft valve 6 months after the implantation. According to specimen radiography and a histopathologic examination, the durability of the xenografts was well preserved without calcification at 6 months after the implantation. The calcium and inorganic phosphorus concentrations of the explanted xenografts were low at 6 months after the implantation. Conclusion: This study demonstrated that our synergistic employment of multiple anticalcification therapies has promising safety and efficacy in the future clinical study.

• Journal of Chest Surgery
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• v.53 no.5
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• pp.285-290
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• 2020

Background: This study was conducted to evaluate the hemodynamic performance and the incidence of prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) using bovine pericardial valves (Carpentier-Edwards Perimount Magana and Magna Ease). Methods: In total, 216 patients (mean age, 70.0±10.5 years) who underwent AVR using stented bovine pericardial valves and had follow-up echocardiography between 3 months and 2 years (mean, 12.0±6.6 months) after surgery were enrolled. The implanted valve sizes were 19, 21, 23, and 25 mm in 32, 56, 99, and 29 patients, respectively. Results: On follow-up echocardiography, the mean transvalvular pressure gradients for the 19-mm, 21-mm, 23-mm, and 25-mm valves were 13.3±4.4, 12.6±4.2, 10.5±3.9, and 10.2±3.7 mm Hg, respectively. The effective orifice area (EOA) was 1.25±0.26, 1.54±0.31, 1.81±0.41, and 1.87±0.33 ㎠, respectively. These values were smaller than those suggested by the manufacturer for the corresponding sizes. No patients had PPM, when based on the reference EOA. However, moderate (EOA index ≤0.85 ㎠/㎡) and severe (EOA index ≤0.65 ㎠/㎡) PPM was present in 56 patients (11.8%) and 9 patients (1.9%), respectively, when using the measured values. Conclusion: Carpentier-Edwards Perimount Magna and Magna Ease bovine pericardial valves showed satisfactory hemodynamic performance with low rates of PPM, although the reference EOA could overestimate the true EOA for individual patients.

• Journal of Chest Surgery
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• v.32 no.11
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• pp.1023-1030
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• 1999

This is a retrospective study of 42 pregnancies from 33 women with prosthetic heart valves who were on anticoagulation regimen prior to or during their pregnancy. Material and Method: Of the 17 women with bioprosthesis, 15 had 21 pregnancies following cessation of the anticoagulation therapy which resulted in the delivery of 20 healthy babies and 1 abortion. Remaining 2 had 3 pregnancies maintained with heparin, resulting in 2 healthy babies and 1 spontaneous abortion. Result: Among 16 women with mechanical heart valves, there were 7 pregnancies during which warfarin was used and this was associated with 4 fetal wastages(2 therapeutic abortion, 1 spontaneous abortion and 1 stillbirth with cerebral hemorrhage). However, in pregnancies where heparin was used, there was no fetal wastage. A patient who did not take anticoagulant for the first trimester and took warfarin for the remaining period and a patient who did not take anticoagulant during pregnancy delivered normal babies. There was an other fetal wastage in a patient on anti-platelet therapy for the first trimester and warfarin therapy for the remaining periods. There was 1 minor petechial complication in a heparin administered group. Conclusion: The study indicates that woman with bioprosthetic heart valves can go through pregnancy without undue risks or complications. On the other hand, the use of warfarin during pregnancy in women with mechanical heart valves, was shown to be associated with unacceptable high risk for the fetus. However, in the same group of women, judicious use of heparin during pregnancy was accompanied by a much reduced risk. The safety and adequate therapeutic range of heparin usage under such circumstances are subject to further studies.

• Journal of Chest Surgery
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• v.51 no.1
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• pp.1-7
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• 2018

Background: Sutureless aortic valve replacement (SU-AVR) has been developed as an alternative surgical treatment for patients with symptomatic severe aortic stenosis (AS). The aim of this study was to evaluate the clinical outcomes of SU-AVR through an assessment of hemodynamic performance and safety. Methods: From December 2014 to June 2016, a total of 12 consecutive patients with severe AS underwent SU-AVR. The endpoints were overall survival and valve-related complications (paravalvular leakage, valve thrombosis, migration, endocarditis, and permanent pacemaker implantation). The mean follow-up duration was $18.1{\pm}8.6months$. Results: The mean age of the patients was $77.1{\pm}5.8years$ and their mean Society of Thoracic Surgeons score was $9.2{\pm}17.7$. The mean cardiopulmonary bypass and aortic cross-clamp times were $94.5{\pm}37.3$ minutes and $54.9{\pm}12.5minutes$, respectively. Follow-up echocardiography showed good prosthesis function with low transvalvular pressure gradients (mean, $13.9{\pm}8.6mm\;Hg$ and peak, $27.2{\pm}15.0mm\;Hg$) at a mean of $9.9{\pm}4.2months$. No cases of primary paravalvular leakage, valve thrombosis, migration, or endocarditis were reported. A new permanent pacemaker was implanted in 1 patient (8.3%). The 1-year overall survival rate was $83.3%{\pm}10.8%$. Conclusion: Our initial experience with SU-AVR demonstrated excellent early clinical outcomes with good hemodynamic results. However, there was a high incidence of permanent pacemaker implantation compared to the rate for conventional AVR, which is a problem that should be solved.

• Journal of Chest Surgery
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• v.43 no.2
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• pp.156-160
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• 2010

The Bentall-DeBono operation is the technique of choice for aortic root replacement. When the patients have contraindications for lifelong anticoagulation, the biologic Bentall operation may be a good option. However, complex reoperation may be required when bioprosthetic degeneration occurs. For this reason, a new technique for simple reoperation after the Bentall operation has recently been performed by some surgeons. We performed a similar technique in two patients with aortic root dilation and for whom aortic valve sparing techniques could not be performed because of an unrepairable valve contour, we think this modification seems to be simple and reproducible for reoperation.

• Journal of Periodontal and Implant Science
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• v.47 no.6
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• pp.388-401
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• 2017

Purpose: The physicochemical properties of a xenograft are very important because they strongly influence the bone regeneration capabilities of the graft material. Even though porcine xenografts have many advantages, only a few porcine xenografts are commercially available, and most of their physicochemical characteristics have yet to be reported. Thus, in this work we aimed to investigate the physicochemical characteristics of a porcine bone grafting material and compare them with those of 2 commercially available bovine xenografts to assess the potential of xenogenic porcine bone graft materials for dental applications. Methods: We used various characterization techniques, such as scanning electron microscopy, the Brunauer-Emmett-Teller adsorption method, atomic force microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and others, to compare the physicochemical properties of xenografts of different origins. Results: The porcine bone grafting material had relatively high porosity (78.4%) and a large average specific surface area (SSA; $69.9m^2/g$), with high surface roughness (10-point average roughness, $4.47{\mu}m$) and sub-100-nm hydroxyapatite crystals on the surface. Moreover, this material presented a significant fraction of sub-100-nm pores, with negligible amounts of residual organic substances. Apart from some minor differences, the overall characteristics of the porcine bone grafting material were very similar to those of one of the bovine bone grafting material. However, many of these morphostructural properties were significantly different from the other bovine bone grafting material, which exhibited relatively smooth surface morphology with a porosity of 62.0% and an average SSA of $0.5m^2/g$. Conclusions: Considering that both bovine bone grafting materials have been successfully used in oral surgery applications in the last few decades, this work shows that the porcinederived grafting material possesses most of the key physiochemical characteristics required for its application as a highly efficient xenograft material for bone replacement.

• Journal of Chest Surgery
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• v.44 no.3
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• pp.197-207
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• 2011

Background: In cardiac surgery, especially in the reconstruction of vascular structures and intracardiac defects, glutaraldehyde has usually been used as the reagent for fixing porcine or bovine pericardial tissues. But the well-known problem of calcification or cytotoxicity of glutaraldehyde motivates the search for a replacement. The aim of this study is to investigate the physical, mechanical, and biochemical characteristics of bovine pericardial tissues fixed with genipin, which is known to be a less toxic and more natural fixing reagent. Materials and Methods: Bovine pericardial tissues were fixed with different concentrations and conditions of glutaraldehyde and genipin. To determine the physical, mechanical, and biochemical differences among different concentrations and conditions, we divided the tissue into 18 groups by concentration, the addition of organic solvents, and the timing of adding the organic solvents, and compared the characteristics of each group. Results: Tensile strength, physical activity, and thermal stability tests revealed that the tissues fixed with glutaraldehyde were better with regard to mechanical strength and biochemical durability. However, the difference was not significant statistically. Conclusion: Genipin can be used as an alternative crosslinking agent for pericardial tissue, considering given its physical, mechanical, biochemical characteristics and low cytotoxicity comparable to glutaraldehyde. However, further studies are needed on the immune reaction and the long term changes in genipin-fixed tissues in the human body.