Reconstruction of right ventricular outflow tract in patients with congenital heart disease in various age groups remains a controversial issue. Currently, a little is known about the fate of secondary and subsequent conduit. The aim of the study was to determine risk factors of conduit failure, evaluate long-term conduit survival, find out which type of conduit should be preferred in case of reoperations. We performed a retrospective analysis of a total of 249 records of valved conduit secondary and subsequent replacement in right ventricular outflow tract in 197 patients. Median follow-up was 5.7 years. The study endpoints were defined as conduit explants; balloon dilatation of the graft (excluding balloon dilatation of left/right pulmonary artery), transcatheter pulmonary valve implantation; heart transplantation or death of the patient. There were total of 21 deaths (11% mortality) among 197 patients during the follow-up, 2 patients underwent heart transplant, in 23 implanted conduits pulmonary angioplasty or/including transcatheter pulmonary valve implantation was afterwards performed due to graft failure, conduit had to be explanted in 46 cases. After 28 years follow-up, freedom from graft failure after 5 years was 77%, 48% after 10 years and 21% after 15 years. Reoperative right ventricular outflow tract reconstruction demonstrates good mid-term and acceptable long-term outcomes regardless of the type of conduit implanted. Worse long-term graft survival of secondary and further conduits is associated with younger age of the recipient at implantation, small size of the conduit, younger age of donor and male donor in case of allograft implantation.
INTRODUCTION: Cryopreserved allograft heart valves (CAHV) show longer event-free survival compared to other types of protheses. However, all patients develop early and/or late allograft failure. Negative predictors are clinical, and there is a lack of evidence whether they correspond with the microscopic structure of CAHV. We assessed histopathological signs of structural degeneration, degree of cellular preservation, and presence of antigen-presenting cells (APC) in CAHV and correlated the changes with donor clinical characteristics, cryopreservation times, and CAHV types and diameters. METHODS: Fifty-seven CAHV (48 pulmonary, nine aortic) used for transplantation between November/2017 and May/2019 were included. Donor variables were age, gender, blood group, height, weight, and body surface area (BSA). Types and diameters of CAHV, cold ischemia time, period from decontamination to cryopreservation, and cryopreservation time were recorded. During surgery, arterial wall (n=56) and valvar cusp (n=20) samples were obtained from the CAHV and subjected to microscopy. Microscopic structure was assessed using basic staining methods and immunohistochemistry (IHC). RESULTS: Most of the samples showed signs of degeneration, usually of mild degree, and markedly reduced cellular preservation, more pronounced in aortic CAHV, correlating with arterial APC counts in both basic staining and IHC. There was also a correlation between the degree of degeneration of arterial samples and age, height, weight, and BSA of the donors. These findings were independent of preservation times. CONCLUSION: CAHV show markedly reduced cellular preservation negatively correlating with the numbers of APC. More preserved CAHV may be therefore prone to stronger immune rejection.
- MeSH
- alografty MeSH
- aortální chlopeň chirurgie patologie MeSH
- dárci tkání * MeSH
- homologní transplantace MeSH
- kryoprezervace * MeSH
- lidé MeSH
- srdeční chlopně transplantace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Pozadí studie: Kryoprezervované chlopenní alografty (CAHV) v současné době představují konduity volby vykazující delší dobu přežití v porovnání s jinými typy chlopenních protéz. Nicméně téměř všichni pacienti v průběhu času rozvinou časné nebo pozdní selhání alograftu. Přesný mechanismus selhání či případná role buněčné nebo humorální rejekce však zůstávají nejasné. V této studii jsme se zaměřili na mikroskopickou strukturu CAHV s ohledem na dobu trvání implantace, hodnotili stupeň degenerativních změn a pátrali po známkách celulární rejekce. Metodika: Do studie bylo prospektivně zařazeno 24 pacientů s CAHV a jeden pacient s chlopenním xenograftem, kteří podstoupili explantaci konduitu v období od listopadu 2017 do května 2020. Zaznamenán byl věk pacientů v době implantace, doba trvání implantace, typ konduitu, hlavní diagnóza příjemce a počet předchozích implantací. Mikroskopická struktura konduitů byla hodnocena pomocí světelné mikroskopie s užitím základních barvicích metod i imunohistochemie. Výsledky: Všechny konduity byly kompletně avitální, s úseky nekróz, hyalinizace, kalcifikací, metaplastické kosti a přerůstání fibrózním pannem. Ve třech případech byly zastiženy okrsky zánětu rejekčního charakteru. Tři další pacienti vykazovali v průběhu operace i následně mikroskopicky známky subakutní infekční endokarditidy. Jak tíže mikroskopických změn, tak i přítomnost rejekčních infiltrátů byly nezávislé na době trvání implantace či jakékoliv jiné klinické proměnné. Závěry: Histopatologické hodnocení explantovaných konduitů může přispět k objasnění přesného patogenetického mechanismu selhání alograftu. Nicméně mikroskopická struktura dlouhodobých explantátů je často nespecifická a známky celulární rejekce jsou mírné. Přínosnější tak může být mikroskopické vyšetření krátkodobých explantátů.
Background: Cryopreserved allograft heart valves (CAHV) currently represent conduits of choice showing longer event-free survival compared to other types of prostheses. However, almost all patients develop early or late allograft failure. The exact mechanism of the failure and eventual role of cellular or antibody-mediated rejection remain uncertain. In this study, we targeted the microscopical structure of CAHV in correlation to the duration of implantation, assessed the degree of degenerative changes and searched for signs of cellular rejection.Methods: 24 patients with CAHV and one patient with xenograft heart valve who required conduit explan-tation in the period of 11/2017-5/2020 were prospectively enrolled in the study. Age of the patients at the time of implantation, duration of implantation, type of conduit, main diagnosis and number of previous implantations were recorded. Conduits were subjected to light microscopy and the microscopic structure was assessed using basic staining methods and immunohistochemistry. Results: All conduits were completely non-vital, with areas of necrosis, hyalinization, calcifi cation, meta-plastic bone formation and pannus overgrowth. Foci of rejection-type infl ammatory infi ltrate were noted in three cases. Three other patients showed perioperative and microscopical signs of subacute infective endocarditis. Both severity of the microscopical changes and presence of rejection-type infiltrate were inde-pendent of duration of implantation or any other clinical variable. Conclusions: Histopathological assessment of explanted conduits may contribute to understanding of exact pathogenic mechanisms of allograft failure. However, the microscopic appearance of long-term explants is often non-specifi c and signs of cellular rejection are sparse. Examination of short-term and intermediate--term explants may be more beneficial.
- Klíčová slova
- kryoprezervované chlopenní alografty,
- MeSH
- alografty MeSH
- chirurgická náhrada chlopně * MeSH
- histologické techniky MeSH
- klinická studie jako téma MeSH
- lidé MeSH
- rejekce štěpu MeSH
- selhání protézy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Despite the wide choice of commercial heart valve prostheses, cryopreserved semilunar allograft heart valves (C-AHV) are required, and successfully transplanted in selected groups of patients. The expiration limit (EL) criteria have not been defined yet. Most Tissue Establishments (TE) use the EL of 5 years. From physiological, functional, and surgical point of view, the morphology and mechanical properties of aortic and pulmonary roots represent basic features limiting the EL of C-AHV. The aim of this work was to review methods of AHV tissue structural analysis and mechanical testing from the perspective of suitability for EL validation studies. Microscopic structure analysis of great arterial wall and semilunar leaflets tissue should clearly demonstrate cells as well as the extracellular matrix components by highly reproducible and specific histological staining procedures. Quantitative morphometry using stereological grids has proved to be effective, as the exact statistics was feasible. From mechanical testing methods, tensile test was the most suitable. Young's moduli of elasticity, ultimate stress and strain were shown to represent most important AHV tissue mechanical characteristics, suitable for exact statistical analysis. C-AHV are prepared by many different protocols, so as each TE has to work out own EL for C-AHV.
- MeSH
- alografty MeSH
- aorta MeSH
- aortální chlopeň * chirurgie MeSH
- kryoprezervace * MeSH
- lidé MeSH
- modul pružnosti MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Východisko a cíl: Regresivní změny přítomné v biopsii nulté hodiny mohou ovlivnit potransplantační funkci štěpu.Metody: V retrospektivní studii jsme semikvantitativně (0 až 3+) zhodnotili morfologické nálezy na cévách, glomerulech, tubulech a intersticiu a procento sklerotizovaných glomerulů v klínovité biopsii nulté hodiny u 42 „ideálních“ dárců ledvin určených pro transplantaci u dětí. Výsledky: Změny arteriol glomerulárního hilu jsme nalezli u poloviny dárců. Větší arteriální větve byly v normě u 3/4 dárců, u zbylé 1/4 byly změny rovnoměrně distribuovány mezi obě pohlaví. Pokročilá stenozující fibróza arteriálních větví byla výjimečná a vyskytla se jen u jednoho muže. Významnou tubulární atrofii a intersticiální sklerózu jsme u žádného z dárců nenalezli, v mírném stupni však byly přítomny u 17 (40 %) dárců s rovnoměrnou distribucí mezi muži a ženami. U více než poloviny štěpů (58 %) nebyly nalezeny sklerotizované glomeruly. V celé skupině 42 dárců činilo procento sklerotizovaných glomerulů 2,9 ± 3,5 % (medián 1,4), poněkud více u mužů než u žen a s přímým vztahem k věku.U 42 transplantovaných dětí (21 chlapců, ve věku 3–18 roků), jimž byla transplantována ledvina od ideálního dárce, jsme hledali vztahy mezi regresivními změnami v biopsii nulté hodiny a úrovní glomerulární filtrace (eGFR): a) při ukončení hospitalizace po transplantaci, b) za půl roku po transplantaci, c) po roce, d) při poslední kontrole (medián 2,5 roku po transplantaci). Průměrná eGFR byla ve všech časových obdobích vyšší u ledvin bez insudátů arteriol a s intaktními většími arteriemi. Za nepřítomnosti tubulointersticiální regrese byla eGFR statisticky významně vyšší za 1/2 roku po transplantaci (p < 0,05) a při poslední kontrole (p < 0,001). Ve všech sledovaných intervalech byla eGFR nesignifikantně vyšší u pacientů, jimž byla transplantována ledvina bez sklerotizovaných glomerulů.Závěr: Tubulární atrofie a intersticiální skleróza v biopsii nulté hodiny se projevily ve snížené potransplantační funkci štěpu.
Background and aim: Morphological regressive changes in zero-time biopsy may influence the graft function in post-transplant period. Methods: In a retrospective study of 42 ideal deceased kidney donors for pediatric transplantation, we semiquantitavely (0-3+) evaluated morphological regressive changes of the vessels, tubuli, interstitium, and the percentage of sclerotized glomeruli by light microscopy in a wedge zero-time biopsy.Results: Regressive changes of the glomerular hilar arteries were twice more frequent in men than in women. Their progressed regression (3+) was present only in 2 men, but never in women. The larger arteries were normal in ¾ of the donors, in remaining ¼ the pathology was distributed equally between men and women. A progressed stenosing arterial lesion was exceptional and was found in one man only. The advanced tubular atrophy and interstitial sclerosis were never found and their mild degree was discovered in 17 (40 %) donors, and was equally distributed between genders. There were no sclerotized glomeruli in more than half donors (58 %). In the all group of 42 donors, a proportion of sclerotized glomeruli was 2.9± 3.5 % (median 1.4). The glomerular sclerosis directly correlated with age and was more frequent in men. In 42 renal grafted children from these donors, 21 boys, aged 3-18, we evaluated relations between these regressive changes and glomerular filtration rate (eGFR) at a) discharge from the hospital after surgery, b) 6 month after transplantation, c) one year, and d) at the end of follow-up (mean 2.5 y).In all time-intervals, eGFR was higher in grafts without arteriolar insudate (P<0.05, half year after transplantation), in grafts with intact larger arteries, and in grafts without tubulointerstitial regression six month after surgery and at the end of follow-up (P<0.05 and P<0.001, respectively). The eGFR was also higher in patients receiving grafts without sclerotized glomeruli, but the difference did not reach statistical significance.Conclusion: The tubulointerstitial regressive changes present in zero-time biopsy were associated with lower graft function in the post-transplant period.
- MeSH
- biopsie * MeSH
- dárci tkání MeSH
- dítě MeSH
- hodnoty glomerulární filtrace MeSH
- lidé MeSH
- mladiství MeSH
- odběr tkání a orgánů * MeSH
- předškolní dítě MeSH
- retrospektivní studie MeSH
- transplantace ledvin MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- kardiologie * MeSH
- mezinárodní spolupráce * MeSH
- Check Tag
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- Geografické názvy
- Česká republika MeSH
- Spojené království MeSH
The aortic and pulmonary allograft heart valves (AHV) are used in the cardiac surgery for replacing the impaired semilunar valves. They are harvested from donor hearts and cryostored in tissue banks. The expiration period was set to 5 years arbitrarily. We hypothesized that their mechanical and structural properties do not deteriorate after this period. A total of 64 human AHV (31 aortic and 33 pulmonary) of different length of cryopreservation (fresh, 0-5, 5-10, over 10 years) were sampled to different tissue strips (artery, leaflet, ventriculo-arterial junction) and tested by tensile test with loading velocity 10 mm/min until tissue rupture. Neighbouring regions of tissue were processed histologically and evaluated for elastin and collagen area fraction. The results were evaluated statistically. In aortic AHV, the physical deformation response of wall samples to stress did not changed significantly neither during the process of cryopreservation nor during the first 10 years of storage. In pulmonary AHV, the ultimate strain dropped after 5 years of cryopreservation indicating that pulmonary artery was significantly less deformable at the time of rupture. On the other hand, the ultimate stress was equal during the first 10 years of cryostorage. The changes in collagen and elastin amount in the tissue samples were not associated with mechanical impairment. Neither elasticity, stiffness and solidity nor morphology of aortic and pulmonary AHV did not change reasonably with cryopreservation and in the first 10 years of cryostorage. This evidence suggests that the expiration period might be extended in the future.
- MeSH
- aortální chlopeň transplantace MeSH
- dospělí MeSH
- elastin analýza MeSH
- homologní transplantace MeSH
- kolagen analýza MeSH
- kryoprezervace metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- plicní chlopeň transplantace MeSH
- tkáňové banky * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Two decontamination solutions, commercially produced BASE•128 and laboratory decontamination solution (LDS), with analogous content of antibiotic and antimycotic agents, were compared in their antimicrobial efficiency and stability (pH and osmolarity). Both solutions were compared immediately after thawing aliquots frozen for 1, 3 or 6 months. Agar well diffusion method was used to test their antimicrobial efficiency against five human pathogens: Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli and Enterococcus faecalis. The difference in the inhibition of growth between the two decontamination solutions was mostly not statistically significant, with few exceptions. The most pronounced difference between the LDS and BASE•128 was observed in their decontamination efficacy against E. coli and E. faecalis, where the LDS showed to be more efficient than BASE•128. The osmolarity value of LDS decreased with cold-storage, the osmolarity values of the BASE•128 could not be measured as they were below the range of the osmometer. Slight changes were found in pH of the less stable LDS solution, whose pH increased from initial value 7.36 ± 0.07 to 7.72 ± 0.19 after 6 m-storage. We verified that BASE•128 and LDS are similarly efficient in elimination of possible placental bacterial contaminants and may be used for decontamination of various tissues.
The transplantation of fresh or cryopreserved vascular allografts in patients with a prosthetic graft infection or critical limb ischemia is necessary for their limb salvage and, in many cases, represents a lifesaving procedure. While transplantation of fresh allografts has a long history in the Czech Republic, the standard use of cryopreserved vascular allografts was introduced into the clinical practice in 2011 as a result of the implementation of EU Directive 2004/23/EC into national legislation (Human Cell and Tissue Act No. 296/2008 Coll.). The authors present an organizational model based on cooperation between the majority of Czech Transplant Centers with a tissue establishment licensed by the national competent authority. In various points, we are addressing individual aspects of experimental and clinical studies which affect clinical practice. Based on experimental and clinical work, the first validation of cryopreserved arterial and venous grafts for clinical use was performed between 2011 and 2013. The growing number of centers participating in this programme led to a growing number of patients who underwent transplantation of vascular allografts. In 2015 the numbers of transplanted fresh versus cryopreserved allografts in the Czech Republic were almost equal. Cooperation of the participating centers in the Czech Republic with the licensed Tissue Establishment made it possible to achieve a full compliance with the European Union Directives, and harmonized national legal norms and assured a high quality of cryopreserved vascular allografts.
- MeSH
- cévy fyziologie transplantace MeSH
- homologní transplantace ekonomika zákonodárství a právo metody MeSH
- kryoprezervace * ekonomika metody MeSH
- lidé MeSH
- řízení kvality MeSH
- transplantace cév * ekonomika zákonodárství a právo metody MeSH
- uchovávání tkání ekonomika metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH