BACKGROUND: Using animal models in experimental medicine requires mapping of their anatomical variability. Porcine common carotid arteries (CCA) are often preferred for the preclinical testing of vascular grafts due to their anatomical and physiological similarity to human small-diameter arteries. Comparing the microscopic structure of animal model organs to their human counterparts reveals the benefits and limitations of translational medicine. METHODS: Using quantitative histology and stereology, we performed an extensive mapping of the regional proximodistal differences in the fractions of elastin, collagen, and smooth muscle actin as well as the intima-media and wall thicknesses among 404 segments (every 1 cm) of porcine CCAs collected from male and female pigs (n = 21). We also compared the microscopic structure of porcine CCAs with segments of human coronary arteries and one of the preferred arterial conduits used for the coronary artery bypass grafting (CABG), namely, the internal thoracic artery (ITA) (n = 21 human cadavers). RESULTS: The results showed that the histological structure of left and right porcine CCA can be considered equivalent, provided that gross anatomical variations of the regular branching patterns are excluded. The proximal elastic carotid (51.2% elastin, 4.2% collagen, and 37.2% actin) transitioned to more muscular middle segments (23.5% elastin, 4.9% collagen, 54.3% actin) at the range of 2-3 centimeters and then to even more muscular distal segments (17.2% elastin, 4.9% collagen, 64.0% actin). The resulting morphometric data set shows the biological variability of the artery and is made available for biomechanical modeling and for performing a power analysis and calculating the minimum number of samples per group when planning further experiments with this widely used large animal model. CONCLUSIONS: Comparison of porcine carotids with human coronary arteries and ITA revealed the benefits and the limitations of using porcine CCAs as a valid model for testing bioengineered small-diameter CABG vascular conduits. Morphometry of human coronary arteries and ITA provided more realistic data for tailoring multilayered artificial vascular prostheses and the ranges of values within which the conduits should be tested in the future. Despite their limitations, porcine CCAs remain a widely used and well-characterized large animal model that is available for a variety of experiments in vascular surgery.
- MeSH
- arteriae carotides anatomie a histologie chirurgie MeSH
- cévní protézy * klasifikace normy MeSH
- imunohistochemie MeSH
- koronární bypass metody MeSH
- lidé MeSH
- modely u zvířat MeSH
- mrtvola MeSH
- pilotní projekty MeSH
- prasata MeSH
- srdce anatomie a histologie MeSH
- tkáňové inženýrství MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- Bentallova operace,
- MeSH
- aortální insuficience * chirurgie MeSH
- cévní protézy normy MeSH
- kardiochirurgické výkony * metody MeSH
- kardiologie metody MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
Cardiovascular prosthetic bypass grafts do not endothelialize spontaneously in humans, and so they pose a thrombotic risk. Seeding with cells improves their performance, particularly in small-caliber applications. Knitted tubular polyethylene-terephthalate (PET) vascular prostheses (6 mm) with commercial type I collagen (PET/Co) were modified in the lumen by the adsorption of laminin (LM), by coating with a fibrin network (Fb) or a combination of Fb and fibronectin (Fb/FN). Primary human saphenous vein endothelial cells were seeded (1.50 × 10(5)/cm(2)), cultured for 72 h and exposed to laminar shear stress 15 dyn/cm(2) for 40 and 120 min. The control static grafts were excluded from shearing. The cell adherence after 4 h on PET/Co, PET/Co +LM, PET/Co +Fb and PET/Co +Fb/FN was 22 %, 30 %, 19 % and 27 % of seeding, respectively. Compared to the static grafts, the cell density on PET/Co and PET/Co +LM dropped to 61 % and 50 %, respectively, after 120 min of flow. The cells on PET/Co +Fb and PET/Co +Fb/FN did not show any detachment during 2 h of shear stress. Pre-coating the clinically-used PET/Co vascular prosthesis with LM or Fb/FN adhesive protein assemblies promotes the adherence of endothelium. Cell retention under flow is improved particularly on fibrin-containing (Fb and Fb/FN) surfaces.
- MeSH
- časové faktory MeSH
- cévní protézy normy MeSH
- endoteliální buňky fyziologie MeSH
- kolagen typu I aplikace a dávkování MeSH
- lidé MeSH
- mechanický stres MeSH
- pevnost ve smyku fyziologie MeSH
- polyestery normy MeSH
- skot MeSH
- vena saphena cytologie fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Vascular accesses (especially polytetrafluoroethylene grafts) with a permanently low flow (Qa <600 ml/min) are prone to thrombosis and thus have short patency. The reason for a permanently low flow is usually medial calcinosis of the inflow artery in diabetics. We retrospectively studied the long-term patency of low-flow grafts with careful ultrasound surveillance and preemptive interventions. METHODS: Twenty subjects with Qa permanently <600 ml/min were included. Ultrasound surveillance was performed every 3 months in addition to classical monitoring techniques. Significant stenosis was strictly defined as the combination of B-mode narrowing >50% + >2-fold peak systolic velocity increase + 1 additional criterion (residual diameter <2.0 mm or flow volume decrease by >20%). Such stenoses were treated by preemptive percutaneous intervention. Primary and secondary patencies were calculated. RESULTS: The primary patency was 357 ± 316 days and the secondary (cumulative) patency was 996 ± 702 days. The number of interventions was 2.09/patient year, but >10 in 6 (33%) subjects. 93 and 80% of grafts were patent 1 and 2 years after access creation, respectively. CONCLUSION: Low-flow accesses undergoing ultrasound surveillance with strict diagnostic criteria and preemptive interventions had patencies similar to accesses with normal Qa in our study. This was enabled by a relatively high rate of interventions.
- MeSH
- cévní protézy normy trendy MeSH
- dospělí MeSH
- kardiovaskulární nemoci chirurgie ultrasonografie MeSH
- lidé středního věku MeSH
- lidé MeSH
- polytetrafluoroethylen normy MeSH
- retrospektivní studie MeSH
- rychlost toku krve * fyziologie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The authors summarize historical findings from the literature on the success of microsurgical vascular prostheses in experimental practice with regard to different production and construction technologies. They reference authors and surgeons using Gore-Tex, polyurethane, polyactide, silicone and woven vascular microprostheses.
The authors have been concerned for six years with the development of woven microsurgical prostheses in ex- periments on laboratory rats, beagle dogs and domestic white pigs. In rats, in 224 experiments employing 38 types of prostheses with an inner diameter of 2 mm, a reliable prosthesis was selected, described as No. 36, with a 100% patency after insertion of a 1 cm long portion into a defect in the abdominal aorta in 40 experiments. The follow-up of this type of prosthesis lasted 12 months. In large animals this type of prosthesis was implanted into a defect of the radial artery and cephalic vein in dogs and into the femoral artery and the artery of a vascular pedicle of groin and lateral thigh flap. These experiments on large animals are not yet complete and will be the subject of a separate paper.
- MeSH
- cévní protézy ekonomika normy zásobování a distribuce MeSH
- dospělí MeSH
- implantace protézy normy statistika a číselné údaje MeSH
- kolagen MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci cév chirurgie MeSH
- pooperační komplikace MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- hodnotící studie MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- cévní protézy * mikrobiologie normy MeSH
- lidé MeSH
- odběr tkání a orgánů metody MeSH
- uchovávání tkání * metody MeSH
- Check Tag
- lidé MeSH
