An analytical method for studying DNA degradation by electrophoresis after cell lysis and visualization of DNA fragments with fluorescent dye, comet assay, was used to evaluate the viability of the endothelial layer of human arterial grafts with the aim of identifying the procedure that will least damage the tissue before cryopreservation. Four groups of samples were studied: cryopreserved arterial grafts that were thawed in two different ways, slowly lasting 2 hours or rapidly for approx. 7 minutes. Arterial grafts that were collected as part of multiorgan procurement with minimal warm ischemia time. Cadaveric grafts were taken as part of the autopsy, so they have a more extended period of warm ischemia. The HeadDNA (%) parameter and others commonly used parameters like TailDNA (%). TailMoment, TailLength, OliveMoment, TailMoment to characterize the comet were used to assess viability in this study. The ratio of non-decayed to decayed nuclei was determined from the values found. This ratio for cadaveric grafts was 0.63, for slowly thawed cryopreserved grafts 2.9, for rapidly thawed cryopreserved grafts 1.9, and for multi-organ procurement grafts 0.68. The results of the study confirmed the assumption that the allografts obtained from cadaveric donors are the least suitable. On the other hand, grafts obtained from multiorgan donors are better in terms of viability monitored by comet assay. Keywords: Arterial grafts, Cryopreservation, Cadaveric, Multiorgan procurement, Viability, Comet assay.

• MeSH
• Arteries transplantation   MeSH
• Comet Assay * MeSH
• Cryopreservation * MeSH
• Humans MeSH
• Cadaver MeSH
• Graft Survival physiology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

INTRODUCTION: Vascular graft infection is a life threatening situation with significant morbidity and mortality. Bacterial graft infection can lead to false aneurysms, bleeding and sepsis. There are a lot of risky situations where grafts can become infected. It is therefore highly desirable to have a vascular graft that is resistant to infection. In this retrospective clinical study, a silver-impregnated vascular graft was evaluated in various indications. METHODS: Our study included a total of 71 patients who received a silver-impregnated vascular graft during the period from 2013 to 2018. Patients had an aortoiliac localization of vascular graft in 61 cases (86%), and a peripheral localization on the lower limbs in 10 cases (14%). Indications for the use of these special vascular grafts were trophic lesions or gangrene in the lower limbs in 24 cases (34%), suspicious mycotic abdominal aortic aneurysm (mAAA) in 4 cases (5.5%), salmonela aortitis or aneurysms in 4 cases (5.5%), infection of the previous vascular graft in 11 cases (15.5%), other infections in 12 cases (17%), AAA rupture in 10 cases (14%) and other reasons (pre-transplant condition, multiple trauma, graft-enteric fistula) in 6 cases (8.5%). Thirty-day mortality, morbidity, the need for reintervention and amputation, primary and secondary graft patency, and finally the presence of a proven vascular graft infection were evaluated. RESULTS: The 30-day mortality was 19.7%, and morbidity was 42.2%. The primary patency of the vascular graft was 91.5%. Reoperation was necessary in 10 cases (14%) and amputation was necessary in 10 cases (14%). The median length of hospital stay was 13 days and the mean follow-up period was 48 ± 9 months. During the follow-up period, six patients (8.5%) died from reasons unrelated to surgery or without any relation to the vascular graft. Secondary patency after one year was 88%. Infection of the silver graft was observed in three patients (4.2%). CONCLUSIONS: Based on our results, the silver graft is a very suitable alternative for solving infectious, or potentially infectious, situations in vascular surgery. In particular, in urgent or acute cases, a silver graft is often the only option.

• Keywords
• antibiotics, graft patency, silver-impregnated vascular graft, vascular graft infection,
• Publication type
• Journal Article MeSH

The authors present their contribution to the improvement of methods suitable for the detection of the freezing and thawing damage of cells of cryopreserved venous grafts used for lower limb revascularization procedures. They studied the post-thaw viability of cells of the wall of cryopreserved venous grafts (CVG) immediately after thawing and after 24 and 48 h culture at +37 °C in two groups of six CVG selected randomly for slow thawing in the refrigerator and rapid thawing in a water bath at +37 °C. The grafts were collected from multi-organ and tissue brain-dead donors, cryopreserved, and stored in a liquid nitrogen vapor phase for five years. The viability was assessed from tissue slices obtained by perpendicular and longitudinal cuts of the thawed graft samples using in situ staining with fluorescence vital dyes. The mean and median immediate post-thaw viability values above 70% were found in using both thawing protocols and both types of cutting. The statistically significant decline in viability after the 48-h culture was observed only when using the slow thawing protocol and perpendicular cutting. The possible explanation might be the "solution effect damage" during slow thawing, which caused a gentle reduction in the graft cellularity. The possible influence of this phenomenon on the immunogenicity of CVG should be the subject of further investigations.

• Keywords
• Thawing method, cell viability, confocal microscopy, cryopreservation, fluorescence vital dyes, vascular allograft,
• MeSH
• Allografts diagnostic imaging   drug effects   MeSH
• Apoptosis drug effects   MeSH
• Tissue Donors MeSH
• Dimethyl Sulfoxide pharmacology   MeSH
• Fluorescent Dyes * MeSH
• Microscopy, Confocal methods   MeSH
• Cryopreservation methods   MeSH
• Cryoprotective Agents pharmacology   MeSH
• Humans MeSH
• Optical Imaging methods   MeSH
• Vascular Grafting methods   MeSH
• Femoral Vein diagnostic imaging   drug effects   MeSH
• Saphenous Vein diagnostic imaging   drug effects   MeSH
• Cell Survival drug effects   MeSH
• Freezing * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Dimethyl Sulfoxide MeSH
• Fluorescent Dyes * MeSH
• Cryoprotective Agents MeSH

INTRODUCTION: The rate of thawing of cryopreserved human iliac arteries allografts (CHIAA) directly affects the severeness of structural changes that occur during this process. METHOD: The experiment was performed on ten CHIAA. The 10% dimethylsulphoxide in 6% hydroxyethyl starch solution was used as the cryoprotectant; all CHIAA were cooled at a controlled rate and stored in the vapor phase of liquid nitrogen (-194°C). Two thawing protocols were tested: (1) placing the CHIAA in a water bath at 37°C, and (2) the CHIAA were thawed in a controlled environment at 5°C. All samples underwent analysis under a scanning electron microscope. Testing of the mechanical properties of the CHIAA was evaluated on a custom-built single axis strain testing machine. Longitudinal and circumferential samples were prepared from each tested CHIAA. RESULTS: Ultrastructural analysis revealed that all five CHIAA thawed during the thawing protocol 1 which showed significantly more damage to the subendothelial structures when compared to the samples thawed in protocol 2. Mechanical properties: Thawing protocol 1-longitudinal UTS 2, 53 ± 0, 47 MPa at relative strain 1, 27 ± 0, 12 and circumferential UTS 1, 94 ± 0, 27 MPa at relative strain 1, 33 ± 0, 09. Thawing protocol 2-longitudinal ultimate tensile strain (UTS) 2, 42 ± 0, 34 MPa at relative strain 1, 32 ± 0, 09 and circumferential UTS 1, 98 ± 0, 26 MPa at relative strain 1, 29 ± 0, 07. Comparing UTS showed no statistical difference between thawing methods. CONCLUSION: Despite the significant differences in structural changes of presented thawing protocols, the ultimate tensile strain showed no statistical difference between thawing methods.

• MeSH
• Allografts drug effects   physiology   MeSH
• Iliac Artery drug effects   physiology   MeSH
• Dimethyl Sulfoxide pharmacology   MeSH
• Adult MeSH
• Cryopreservation methods   MeSH
• Cryoprotective Agents pharmacology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Dimethyl Sulfoxide MeSH
• Cryoprotective Agents MeSH

OBJECTIVES AND DESIGN: At the present time there are two waiting list for patients with vascular prosthetic infection indicated for arterial transplantation in the Czech Republic. The inclusion of each patient for cold-stored or cryopreserved arterial transplantation is the preference of indicating surgeon. In this experimental work we studied the immunogenicity of rat aortal allografts treated by our new clinical cryopreservation/slow thawing protocol. MATERIAL AND METHODS: Brown-Norway (BN) (N = 6, 203-217 g) or Lewis (LEW) (N = 6, 248-254 g) abdominal aortal grafts treated in accordance with our new clinical cryopreservation/slow thawing protocol were orthotopically transplanted to Lewis recipients (N = 12, 191-245 g). Aortal wall histology and infiltration by recipient immune cells, as well as donor specific anti MHC class I and II antibodies in recipient serum were studied in both isografts and allografts on day 30 postransplant. Core data of cryopreserved allografts were compared to our previous data of cold-stored aortal allografts treated in accordance with our clinical cold-storage protocol. RESULTS: Cryopreserved allografts showed regular morphology of aortal wall with clear differentiation of all three basic anatomical layers on day 30 postransplant. Intimal layer showed no hyperplasia, luminal surface was covered by endothelial cells. No statistical difference was observed in tunica media thickness between isografts and allografts. The medial layer showed no necrosis, shrinkage or immunoglobuline G deposition in any experimental group. The adventitial infiltration by immune cells was significantly higher (P<0.05) in allografts. Cryopreserved allografts showed significant lower activation of both cell- and antibody mediated immunity compared to historical data of cold-stored allografts. CONCLUSION: Aortal wall histology of rat allografts treated by our new standardized clinical cryopreservation/slow thawing protocol was comparable to that of the cryopreserved isografts on day 30 posttranspant. The immunogenicity of cryopreserved aortal allografts was significantly lower compared to that of cold-stored aortal allografts.

• MeSH
• Allografts physiology   MeSH
• Aorta transplantation   MeSH
• Arteries transplantation   MeSH
• Transplantation, Homologous methods   MeSH
• Cryopreservation methods   standards   MeSH
• Rats MeSH
• Models, Animal MeSH
• Rats, Inbred BN MeSH
• Rats, Inbred Lew MeSH
• Graft Rejection immunology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH