BACKGROUND: This study was designed to develop a Korean version of the heparin-coated vascular bypass shunt by using a physical dispersing technique. The safety and effectiveness of the thrombo-resistant shunt were tested in experimental animals. MATERIAL AND METHOD: A bypass shunt model was constructed on the descending thoracic aorta of 21 adult mongrel dogs(17.5-25 kg). The animals were divided into groups of no-treatment(CONTROL group; n=3), no-treatment with systemic heparinization(HEPARIN group; n=6), Gott heparin shunt (GOTT group; n=6), or Korean heparin shunt(KIST group; n=6). Parameters observed were complete blood cell counts, coagulation profiles, kidney and liver function(BUN/Cr and AST/ ALT), and surface scanning electron microscope(SSEM) findings. Blood was sampled from the aortic blood distal to the shunt and was compared before the bypass and at 2 hours after the bypass. RESULT: There were no differences between the groups before the bypass. At bypass 2 hours, platelet level increased in the HEPARIN and GOTT groups(p<0.05), but there were no differences between the groups. Changes in other blood cell counts were insignificant between the groups. Activated clotting time, activated partial thromboplastin time, and thrombin time were prolonged in the HEPARIN group(p<0.05) and differences between the groups were significant(p<0.005). Prothrombin time increased in the GOTT group(p<0.05) without having any differences between the groups. Changes in fibrinogen level were insignificant between the groups. Antithrombin III levels were increased in the HEPARIN and KIST groups(p<0.05), and the inter-group differences were also significant(p<0.05). Protein C level decreased in the HEPARIN group(p<0.05) without having any differences between the groups. BUN levels increased in all groups, especially in the HEPARIN and KIST groups(p<0.05), but there were no differences between the groups. Changes of Cr, AST, and ALT levels were insignificant between the groups. SSEM findings revealed severe aggregation of platelets and other cellular elements in the CONTROL group, and the HEPARIN group showed more adherence of the cellular elements than the GOTT or KIST group. CONCLUSION: Above results show that the heparin-coated bypass shunts(either GOTT or KIST) can suppress thrombus formation on the surface without inducing bleeding tendencies, while systemic heparinization(HEPARIN) may not be able to block activation of the coagulation system on the surface in contact with foreign materials but increases the bleeding tendencies. We also conclude that the thrombo-resistant effects of the Korean version of heparin shunt(KIST) are similar to those of the commercialized heparin shunt(GOTT).
Adult ; Animals ; Antithrombin III ; Aorta ; Aorta, Thoracic ; Blood Cell Count ; Blood Platelets ; Fibrinogen ; Hemorrhage ; Heparin ; Humans ; Kidney ; Liver ; Partial Thromboplastin Time ; Protein C ; Prothrombin Time ; Thrombin Time ; Thrombosis

BACKGROUND: Calcific degeneration is the major cause of clinical failure of glutaraldehyde (GA) crosslinked bioprosthetic tissues implanted in the body and necessitates the reoperation or causes death. Surface modification of biologic tissues using sulfonated polyethyleneoixde (PEO-SO3) has been suggested to significantly enhance blood compatibility, biostability and calcification-resistance by means of the synergistic effect of highly mobile and hydrophilic PEO chains and electrical repulsion of negatively charged sulfonate groups. This study was designed to evaluate the anticalcification effect of surface-modification of biologic arteries by direct coupling of PEO-SO3 after GA fixation and changes of calcification according to the implantation period through the quantitative investigation of the deposited calcium and phosphorous contents of the biologic arterial tissues in the canine circulatory implantation model. MATERIAL AND METHOD: Total of 16 fresh canine carotid arteries were harvested from eight adult dogs and divided in to GA group(n =8) and PEO-SO3 group(n=8). Sulfonation of diamino-terminated PEO was performed using propane sultone. Canine carotid arteries were only crosslinked with 0.65% GA solution in GA group and modified by direct coupling 5% PEO-SO3 solution after GA crosslinkage for 2 days and stabilized by NaBH4 solution for 16 hours in PEO-SO3 group. In both groups the resected segment of bilateral carotid arteries were reconstructed. Reconstructed segments of the two groups were analysed the quantities of calcium and phosphorous contents after 3(n=4) and 6(n=4) weeks in vivo. RESULT: After implantation of 3 seeks, PEO-SO3 group showed significantly less depositions.
Adult ; Animals ; Arteries* ; Calcium ; Carotid Arteries ; Dogs ; Glutaral ; Humans ; Polyethylene Glycols* ; Propane ; Reoperation

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 4degree 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 4degree 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+/-1.05 vs. 13.81+/-2.33 mg/g of dried tissue) and pulmonary positions (1.55+/-0.29 vs. 6.72+/-0.70 mg/g) (p<0.01). Phosphorous contents were also less in the PEO-SO3 group than the GA group significantly, 8.11+/-1.07 mg/g vs. 19.33+/-4.31 mg/g in the aortic and 2.58+/-0.40 vs. 12.60+/-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.
Adult ; Animals ; Aorta* ; Aorta, Thoracic ; Calcinosis ; Calcium ; Dogs ; Follow-Up Studies ; Glutaral ; Heterografts ; Hominidae ; Human Body ; Humans ; Hydrogen-Ion Concentration ; Pericardium* ; Polyethylene Glycols ; Prostheses and Implants ; Pulmonary Artery*

No abstract available.
Animals ; DNA* ; Mice* ; Vaccination*

BACKGROUND: Calcific degeneration limits durabilities of the bioprosthetic tissues implanted in the human body. The direct coupling sulphonated polyethyleneoxide (PEO-SO3) to the bioprosthetic tissues after glutaraldehyde (GA) fixation and the removal of residual aldehyde groups from the tissues can augment the effect of calcification-resistance. MATERIALS AND METHODS: To study the anti-calcification effect by PEO-SO3 modification and the removal of the residual aldehyde groups of tissues, surface modified bovine pericardia (BP-PEO-SO3) were preserved in aseptic saline to wash out GA (saline group) and 0.65% GA solution (GA group). And then above two groups and PERIGUARD (Bio-vascular. Co.) (product group) were evaluated with respects to calcium contents and microscopic findings using in vivo implantation models at carotid and femoral artery and peritoneum of 8 adult dogs. RESULTS: In the tissues retrieved from carotid artery, calcium content was significantly decreased in saline group than in other two groups (saline; 2.89+/-0.31 vs. GA; 6.14+/-1.08 vs. product; 22.82+/-5.00 mg/g of dried tissue; p<0.05). In the tissues retrieved from femoral artery and peritoneum, calcium amount was also decreased in saline group than in other two groups, but not reached the significant difference between groups. On the other hand, the pathologic findings of pericardial tissues showed marked destructuction in GA group compared to the other two groups. CONCLUSIONS: In this study, covalently PEO-SO3 bound to bovine pericardium decreased calcifications and the anti-calcification effect of BP-PEO-SO3 could be augmented by the washing out the residual aldehyde groups using saline after GA fixation. Conclusively, the PEO-SO3 modified bovine pericardium is highly resistant to calcification and can be useful for the development of calcification-resistant cardiovascular patches and valves.
Adult ; Animals ; Arteries* ; Calcinosis ; Calcium ; Carotid Arteries ; Dogs ; Femoral Artery ; Glutaral ; Hand ; Human Body ; Humans ; Pericardium* ; Peritoneum* ; Polyethylene Glycols

Background: Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. Methods: From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation–Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. Results: Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence inter val [CI], 0.55– 0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% 0.56–0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79–1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65–2.17; P = 0.582). Conclusion In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.