• Journal of Chest Surgery
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• v.31 no.10
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• pp.919-923
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• 1998

Background: Calcific degeneration is unavoidable in either homo- or heterografts implanted in the human body. We have developed a calcification-resistant cardiovascular tissue patch using a novel technique of anticalcification. Materials and methods: Fresh bovine pericardium was harvested at the slaughter house and transfered to the laboratory in Hank's solution. After trimming and fixing the pericardium, it was embedded in 4$^{\circ}C$ 0.65% glutaraldehyde for a week and then washed by phosphate-buffered saline(PBS) of pH 7.4. This prepared pericardium was then stored in 2.5% sulphonated polyethyleneoxide(PEO-SO3) solution for 2 days at room temperature and reversed by 4$^{\circ}C$ NaBH4 solution for 16 hours. To evaluate the calcification-resistance of surface modified bovine pericardium with PEO-SO3, either glutaraldehyde- treated(GA group, n=4) or PEO-SO3-treated pericardial patch(PEO-SO3 group, n=4) was implanted into adult mongrel dog to reconstruct the main pulmonary artery and the descending aorta using a partial clamp technique. After 1 month follow-up, the implanted patches were retrieved to evaluate the pathologic findings and the content of calcium and phosphorous. Results: The PEO-SO3 group showed substantially less retraction and significantly less calcium deposition than the GA group in both aortic(7.10$\pm$1.05 vs. 13.81$\pm$2.33 mg/g of dried tissue) and pulmonary positions(1.55$\pm$0.29 vs. 6.72$\pm$0.70 mg/g)(p<0.01). Phosphorous contents were also less in the PEO-SO3 group than the GA group significantly, 8.11$\pm$1.07 mg/g vs. 19.33$\pm$4.31 mg/g in the aortic and 2.58$\pm$0.40 vs. 12.60$\pm$3.40 mg/g in thepulmonary position(p<0.01). Conclusions: These findings suggest that PEO-SO3 modified bovine pericardium is highly calcification-resistant but further study is needed to evaluate the long-term biological safety and compatibility of the prosthesis.

• 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.36 no.8
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• pp.602-605
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• 2003

A patch design using bovine pericardial patch for aortic enlargement in the Nowood procedure has been introduced to avoid problems related to homograft availability. We report 2 successful cases of Norwood procedure with home-made bovine pericardial patch. The first case was a 23-day-old (2.2 kg) patient with multi-level left ven-tricular outflow tract obstruction with ductal-dependent systemic circulation. The other case was a 9-day-old (3 kg) patient with hypoplastic lefi heart syndrome. This technique was relatively easy to perform, reproducible and quite effective like homograft patch.

• Journal of Chest Surgery
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• v.22 no.5
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• pp.724-730
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• 1989

The development of severe pericardial adhesion after cardiovascular surgical procedures often increases the risk of injuring the heart, great vessels, or extracardiac grafts during resternotomy. Several pericardial substitutes have been tested in an attempt to facilitate reoperation with inconclusive results. This study was designed to evaluate the applicability of two different materials as pericardial substitutes to minimize the pericardial adhesion and epicardial reaction. A procedure for induction of pericardial adhesion was carried out in 30 rabbits. Rabbits were divided into three groups of ten rabbits each: Group 1[control, simple pericardial closure]: Group 2[bovine pericardium as pericardial substitute]: Group 3[e-polytetrafluoroethylene surgical membrane, e-PTFE as a pericardial substitute]. Bovine pericardium or e-PTFE surgical membrane was interposed between the sternum and the heart. Rabbits were sacrificed at 4 weeks after operation. The development of adhesions and epicardial reactions were graded as: none [I]; minimal[II]; moderate[Ill]; and severe[1V]. Histologic studies of the substitute, the pericardium, and the epicardium were performed. The results were as follows; l. In group 1[control group], the degree of pericardial adhesions were grade I in none, grade II in 1, grade III in 3, and grade 1V in 6 animals. Epicardial reactions were grade I in none, grade II in 3, grade K in 4, grade 1V in 3 animals respectively. 2. In group 2[bovine pericardium], the degree of pericardial adhesions were grade I in 1, grade II in 5, grade III in 3, and grade 1V in 1 animal. Epicardial reactions were grade I in 1, grade II in 2, grade III in 4, and grade 1V in 3 animals respectively. 3. In group 3[e-PTFE], the degree of pericardial adhesions were grade I in 7 animals, grade II in 2, grade III in 1, and grade g in none. Epicardial reactions were grade I in 4, grade II in 3, grade III in 2, and grade IV in 1 animal respectively. Pericardial adhesions more than grade II were 90.9% in group 1, 40 % in group 2, and 10% in group 3. Pericardial adhesions were significantly reduced in group 3 compared to group 1 or 2. Epicardial reactions more than grade II were 70 % in group 1, 70 % in group 2 and 30 % in group 3. We concluded that this 0.1mm thick polytetrafluoroethylene surgical membrane is a suitable pericardial substitute to minimize the development of pericardial adhesion or epicardial reaction following cardiovascular surgery.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.148-156
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• 2009

Background: As cardiovascular operations become more complex and sophisticated, there is an increasing need for various bioprostheses for use as components of blood vessels and heart valves. We developed a fatigue stimuli test instrument to objectively evaluate the mechanical durability of a bioprosthesis, and we tested several currently known processing methods for bovine pericardium and we then compared the results. Material and Method: Fresh bovine pericardium was collected at the butcher shop with using aseptic technique, and each piece of pericardium was fixated and/or decellularized by 16 representative methods. We measured the permeability and compliance of the processed bovine pericardium samples, and measured them again after exposure to the fatigue stimuli. All the pieces of pericardium underwent microscopic examinations before and after the fatigue stimuli. Result: A mixture of glutaraldehyde and solvent treatment showed better mechanical durability than did the single glutaraldehyde treatment. High concentration glutaraldehyde treatment showed equal or no worse results than did low concentration glutaraldehyde treatment. After SDS (sodium dodecylsulfate) decellularization, the mechanical property of the bioprosthesis became much worse ($20{\sim}190$ times) and the mechanical durability to the fatigue stimuli was also very poor. Conclusion: We obtained the basic durability data after various fixation methods with using a home-made fatigue test instrument.

• Journal of Chest Surgery
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• v.37 no.4
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• pp.307-312
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• 2004

With the development of cardiac surgical technique, we need more prosthetic materials for repairing the intra- and extracardiac defects. Although bovine pericardial bioprosthesis treated with glutaraldehyde (GA) solution is one of the most popular materials, it has a drawback of later calcific degeneration. The purpose of this study is to investigate the effectiveness of several materials and methods in reducing the calcific degeneration of bovine pericardium. Material and Method: Forty square-shaped pieces of bovine pericardia were fixed in 0.625% GA solution with 4 g/L MgCl$_2$ㆍ6$H_2O$ as a control group (group 1). Other 40 pieces pre-treated with 1 % SDS(group 2) and 40 pieces post-treated with 8% glutamate (group 3) and 2% chitosan (group 4) were also fixed in the same GA solution. Other 40 pieces pre-treated with 1% SDS and post-treated with 8% glutamate and 40 pieces post-treated with 2% chitosan were also fixed in the same GA solution (group 5, 6). The pericardial pieces were implanted into the belly of 40 Fisher 344 rats subdermally and were extracted 1 month, 2 months, 3 months, and 6 months after the implantation. With an atomic absorption spectrophotometry, we measured the calcium amount deposited and examined the tissue with microscope. Result: The calcium deposition in 1 month was less in group 2, 5, 6 than that in group 1 (p＜0.05). It was most prominent in group 5 (p＜0.01). This finding continued in 2 month. In 3 month, the calcium deposition was less in group 3 and 4 as well as group 2, 5, and 6 than in group 1. In 6 month, the calcium deposition in group 2, 3, 4, 5, and 6 was less than that in group 1 and the difference was more than that of 1, 2, and 6 month. The microscopic calcium deposition was also less in group 2 and 5. Calcium deposition developed in the whole layer of pericardium, beginning with the surrounding the collagen fiber and progressing inwardly. Conclusion: Pre-treatment with SDS, post-treatment with glutamate or chitosan, and SDS pre-treatment and post-treatment with glutamate or chitosan were effective in reducing the calcium deposition in bovine pericardium. Moreover, the combined method of SDS pre-treatment and glutamate post-treatment was more effective than other methods.

• Journal of Chest Surgery
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• v.35 no.2
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• pp.133-136
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• 2002

A 28 year-old male who had received Konno procedure twelve years ago with 23mmmechanical aortic valve and bovine pericardium with which his small aortic annulus, ventricular septum and right ventricular outflow tract had been enlarged was transferred due to sudden congestive heart failure. There were perforations on aortic and interventricular portion of bovine pericardial patch above and below the aortic valve, respectively, which was calcified and denaturated severely. The perforations seemed to be attributed to the cracks, resulting from mobility of mechanical aortic valvc itself and stiffness of calcified and denaturated bovine patch. We performed a redo Konno procedure applying PTFE patch.

• Journal of Chest Surgery
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• v.44 no.2
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• pp.99-107
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• 2011

Background: Calcification is the most frequent cause of clinical failure of bioprosthetic tissues fabricated from GA-fixed porcine valves or bovine pericardium. A multi-factorial approach using different mechanisms was recently developed to reduce the calcification of bioprosthetic tissues. The purpose of the present study was to evaluate the synchronized synergism of using L-arginine and $NaBH_4$, compared with ethanol and L-lysine, in glutaraldehyde treated porcine pericardium from the standpoint of calcification and tissue elasticity. Materials and Methods: Porcine pericardium was fixed at 0.625% GA (7 days at room temperature after 2 days at $4^{\circ}C$). An interim step of ethanol (80%; 1 day at room temperature) or L-lysine (0.1 M; 2 days at $37^{\circ}C$) or L-arginine (0.1 M; 2 days at $37^{\circ}C$) was followed by completion of the GA fixation. A final step of NaBH4 (0.1 M; 2 days at room temperature) was followed. Their tensile strength, thickness, and thermal stability were measured. Treated pericardia were implanted subcutaneously into three-week-old Sprague-Dawley rats for 8 weeks. Calcium content was assessed by atomic absorption spectroscopy and histology. Results: L-arginine and $NaBH_4$ pretreatment ($1.81{\pm}0.39$ kgf/5 mm p=0.001, $0.30{\pm}0.08$ mm p<0.001) significantly increased tensile strength and thickness compared with the control ($0.53{\pm}0.34$ kgf/5 mm, $0.10{\pm}0.02$ mm). In a thermal stability test, L-arginine and $NaBH_4$ pretreatment ($84.25{\pm}1.12^{\circ}C$, p=0.023) caused a significant difference from the control ($86.25{\pm}0.00^{\circ}C$). L-lysine and $NaBH_4$ pretreatment ($183.8{\pm}42.6$ ug/mg, p=0.804), and L-arginine and $NaBH_4$ pretreatment ($163.3{\pm}27.5$ ug/mg, p=0.621) did not significantly inhibit calcification compared to the control ($175.5{\pm}45.3$ ug/mg), but ethanol and $NaBH_4$ pretreatment did ($38.5{\pm}37.3$ ug/mg, p=0.003). Conclusion: The combined pretreatment using L-arginine and $NaBH_4$ after GA fixation seemed to increase the tensile strength and thickness of porcine pericardium, fixed with GA. Additionally, it seemed to keep thermal stability. However it could not decrease the calcification of porcine pericardium fixed with GA. $NaBH_4$ pretreatment seemed to decrease the calcification of porcine pericardium fixed with GA, but only with ethanol.

• Journal of Chest Surgery
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• v.25 no.11
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• pp.1327-1336
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• 1992

Between Jan. 1986 and Aug. 1992. 72 patients underwent Rastelli procedure. There were 43 male and 29 female, aged 46 days to 16 years [mean age, 5.2 years] with 18 patients less than 2 years of age. All patients had complex defect, 27 pulmonary atresia with ventricular septal defect, 18 corrected transposition of great arteries with pulmonary atresia or punmonary stenosis, 10 truncus arteriosus, 10 double outlet right ventricle with pulmonary atresia or stenosis, 7 complete transposition of great artersia with pulmonary atresia or pulmonary stenosis. The types of extracardiac valved conduit used were prosthetic valve[n=47, 24 car-bomedics, 19 Ionescu-Shiley, 4 Bjork-shiley] and hand-made trileaflet valve using pericardium. [n=23, 20 bovine pericardium, Z autologous pericardium, 1 equine pericardium] The mean size of valved cinduit was 5.25mm larger in diameter than the size of main pulmonary artery. [normalized to the patient`s body surface area] There were 17 hospital death[24%] and 4 late deaths[5.6%]. Postoperative complication rate was 38.9%a, none of which was conduit-related. All patients were followed pos-toperatively for 1 to 73 months. [mean 25.8 months] During follow-up period, reoperation was done in 6 patients due to stenosis of valved conduit. Mean interval between intial repair and reoperation was 20.3 months. In our experience, li recently extracardaic valved conduits between right ventricle [or pulmonary ventricle] and pulmonary artery were inserted with increasing frequency in infants less than 2 year, but hospital mortality was decreased, 2] Risk of reoperation due to conduit stenosis is low, so that the effect of graft failure on overall survival is minimized. 3] Nevertheless, because any type of extracardaic valved conduit is not ideal in children, we recommended that Lecompte should be done if cardiac anatomy is permitted.

• Journal of Chest Surgery
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• v.43 no.1
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• pp.1-10
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• 2010

Background: Bioprosthetic materials have been made using glutaraldehyde fixation of porcine or bovine pericardium during cardiovascular surgery. But these bioprostheses have the problems of calcification and mechanical failure. We determined changes in tensile strength and elasticity of pericardium after glutaraldehyde, solvent, decellularization and detoxification. Material and Method: Tissues were allocated to four groups: glutaraldehyde with and without solvent, decellularization, and detoxification. We studied tensile strength and strain on tissues. We measured the tensile strength of fresh pericardium stretched in six directions (with 5 mm width), and % strain, which we calculated from the breaking point when we pulled the pericardium in two directions. Result: Tensile strength was reduced when we used the usual concentrated glutaraldehyde fixation (n=83, $MPa=11.47{\pm}5.40$, p=0.006), but there was no change when we used solvent. Elasticity was increased after glutaraldehyde fixation (n=83, strain $(%)=24.55{\pm}9.81$, p=0.00), but there was no change after solvent. After decellularization of pericardium, the tensile strength was generally reduced. The decrease in tensile strength after concentrated glutaraldehyde fixation for a long time was significantly greater less than after concentrated solvent (p=0.01, p=0.00). After detoxification, the differences in strength and strain were not significant. Conclusion: After glutaraldehyde treatment of pericardium there is no loss in tensile strength (even though we did the glutaraldehyde, solvent and detoxification treatments LOGIC IS UNCLEAR). Also, these treatments had a tendency to increase elasticity. Although post-treatment decellularization led to a significant loss in strength, this effect could be attenuated using a low concentration of solvent or hypertonic solution.