scholarly journals Immunological and functional features of decellularized xenogeneic heart valves after transplantation into GGTA1-KO pigs

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Robert Ramm ◽  
Tobias Goecke ◽  
Peter Köhler ◽  
Igor Tudorache ◽  
Serghei Cebotari ◽  
...  
Keyword(s):  
Heart Valves ◽  
Immune Reaction ◽  
Inflammatory Cells ◽  
Giant Cells ◽  
Large Animal Model ◽  
Large Animal ◽  
Wild Type ◽  
Foreign Body Giant Cells ◽  
Antibody Titers ◽  
Functional Features

Abstract Decellularization of xenogeneic heart valves might lead to excellent regenerative implants, from which many patients could benefit. However, this material carries various xenogeneic epitopes and thus bears a considerable inherent immunological risk. Here, we investigated the regenerative and immunogenic potential of xenogeneic decellularized heart valve implants using pigs deficient for the galactosyltransferase gene (GGTA1-KO) as novel large animal model. Decellularized aortic and pulmonary heart valves obtained from sheep, wild-type pigs or GGTA1-KO pigs were implanted into GGTA1-KO pigs for 3, or 6 months, respectively. Explants were analyzed histologically, immunhistologically (CD3, CD21 and CD172a) and anti-αGal antibody serum titers were determined by ELISA. Xenogeneic sheep derived implants exhibited a strong immune reaction upon implantation into GGTA1-KO pigs, characterized by massive inflammatory cells infiltrates, presence of foreign body giant cells, a dramatic increase of anti-αGal antibody titers and ultimately destruction of the graft, whereas wild-type porcine grafts induced only a mild reaction in GGTA1-KO pigs. Allogeneic implants, wild-type/wild-type and GGTA1-KO/GGTA1-KO valves did not induce a measurable immune reaction. Thus, GGTA1-KO pigs developed a ‘human-like’ immune response toward decellularized xenogeneic implants showing that immunogenicity of xenogeneic implants is not sufficiently reduced by decellularization, which detracts from their regenerative potential.

Abstract 657: A New Translational Model of Hypercholesterolemia and Atherosclerosis: Effect of Statins on LDLR KO Miniature Swine

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Dale E Mais ◽  
Thomas Vihtelic ◽  
Chidozie Amuzie ◽  
Steven Denham ◽  
John R Swart ◽  
...  
Keyword(s):  
High Fat Diet ◽  
Clinical Chemistry ◽  
Small Animal ◽  
Normal Diet ◽  
Large Animal Model ◽  
Control Group ◽  
Large Animal ◽  
Wild Type ◽  
High Fat ◽  
Miniature Swine

Small animal models of atherosclerosis are commonly used in drug studies; however, the results often fail to translate into the clinic. A large animal model that more accurately reflects the human disease is needed. We recently developed a transgenic Yucatan pig model in which the LDL receptor (LDLR) gene is knocked out. Five groups of Yucatan pigs (N=4 per group), either wild type (LDLR+/+) or heterozygote (LDLR+/-) were fed a normal diet or a high fat diet for a six month period. One of the heterozygote/high fat diet groups in addition received a daily dose of a statin (atorvastatin) at 3 mg/kg. Every two weeks during the study a variety of clinical chemistry parameters were measured. At study termination, select arteries were collected, stained for lipid deposits and quantitated. In addition, sections of these arteries were prepared for immunohistochemistry to detect selected markers of macrophage infiltration into the atherosclerotic plaques. As expected, pigs fed a high fat diet gained significantly more weight at six months whether they were wild type or LDLR+/-. Atorvastatin appeared to attenuate this weight gain. There were significant increases in total cholesterol, HDL and LDL in pigs fed the high fat diet compared to their corresponding control group. The group receiving the atorvastatin had reduced values of these parameters compared to controls showing that a statin had a beneficial effect on lipid levels even in a high fat diet scenario. VLDL levels were not affected but there were triglyceride changes across the groups. Liver function was unchanged based on total bilirubin and AST while ALT measurements were altered in some of the groups. Immunohistochemistry and histomorphometry was performed on some arteries. Atorvastatin-induced amelioration of hypercholesterolemia in this model underscores its translational utility.

361 GROWTH HORMONE RECEPTOR MUTANT PIGS PRODUCED BY USING THE CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR) AND CRISPR-ASSOCIATED SYSTEMS IN IN VITRO-PRODUCED ZYGOTES

2015 ◽  
Vol 27 (1) ◽  
pp. 269 ◽  
Author(s):  
M. Kurome ◽  
M. Dahlhoff ◽  
S. Bultmann ◽  
S. Krebs ◽  
H. Blum ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Receptor ◽  
Growth Hormone Receptor ◽  
Large Animal Model ◽  
Large Animal ◽  
Single Mutation ◽  
Wild Type ◽  
Ghr Gene ◽  
Normal Fertilization

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) technology is considered as an efficient strategy for generating gene edited large animals, such as pigs. Compared to somatic cell nuclear transfer, this new technology offers a relatively simple way to generate mutant pigs by direct injection of RNA into the cytoplasm of zygotes. Moreover, the use of in vitro produced zygotes would provide a highly effective and practical method for the production of porcine disease models for biomedical research. Here we examined the production efficiency of growth hormone receptor (GHR) mutant pigs by the combination of the CRISPR/Cas system and in vitro produced zygotes. In vitro maturation (IVM) of oocytes was performed as described previously (Kurome et al., Meth. Mol. Biol., in press). In all experiments, the same batch of frozen sperm was used. After IVM, around 20 oocytes with expanded cumulus cells were incubated with 5 × 104 spermatozoa in a 100-μL drop of porcine fertilization medium for 7 h. In vitro-produced embryos were assessed by the ratio of normal fertilization (eggs with 2 pronuclei) and blastocyst formation at Day 7. The Cas9 mRNA and a single guide RNA, recognising a short sequence of 20 base pairs in exon 3 of the GHR gene, were injected directly into the cytoplasm of the embryos 8.5 to 9.5 h after IVF. Injected embryos were transferred laparoscopically to recipient pigs, and 86.4% (57/66) of sperm-penetrated oocytes (66/96) exhibited normal fertilization. Incidence of polyspermy was relatively low (9/66, 13.6%). Developmental ability of in vitro-produced embryos to the blastocyst stage was 17.4% (24/138). In total, 426 RNA-injected embryos were transferred into 2 recipients, one of which became pregnant and gave birth to 8 piglets. All piglets were clinically healthy and developed normally. In 3 out of 8 piglets (37.5%), mutations were introduced. Next-generation sequencing revealed that all of them were mosaics: one with a single mutation (22% wild-type/78% mutant) and 2 piglets with 2 different mutations (80% wild-type/2% mutant_1/18% mutant_2 and 94% wild-type/4% mutant_1/2% mutant_2). Four out of 5 mutations caused a frameshift in the GHR gene. Our study reports for the first time generation of GHR mutant pigs by the use of the CRISPR/Cas system in in vitro-produced zygotes. Because all GHR mutant offspring were mosaic, Cas9 activation probably occurred after the 1-cell stage under our experimental conditions. The founder animal with the highest proportion of mutant GHR alleles will be used for breeding to establish a large animal model for Laron syndrome.This work is supported by the German Research Council (TR-CRC 127).

scholarly journals A systematic evaluation on reporting quality of modern studies on pulmonary heart valve implantation in large animals

2020 ◽  
Vol 31 (4) ◽  
pp. 437-445
Author(s):  
Marcelle Uiterwijk ◽  
Annemijn Vis ◽  
Iris de Brouwer ◽  
Debora van Urk ◽  
Jolanda Kluin
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Animal Experiments ◽  
Reporting Quality ◽  
Systematic Evaluation ◽  
Large Animal Model ◽  
Large Animal ◽  
Before And After ◽  
Large Animals

Abstract OBJECTIVES Before new heart valves can be implanted safely in humans, animal experiments have to be performed. These animal experiments have to be clearly designed, analysed and reported to assess the accuracy and importance of the findings. We aimed to provide an overview of the reporting and methodological quality of preclinical heart valve research. METHODS We conducted a systematic literature search on biological and mechanical pulmonary valve implantations in large animals. We used the Animals in Research: Reporting In Vivo Experiments (ARRIVE) guidelines to score the quality of reporting in each article. We compared the scores before and after the introduction of the ARRIVE guidelines (2010). RESULTS We screened 348 articles, of which 31 articles were included. The included articles reported a mean of 54.7% adequately scored ARRIVE items (95% confidence interval 52.2–57.3%). We did not identify a difference in reporting quality (54.7% vs 54.8%) between articles published before and after 2010. We found an unclear (lack of description) risk of selection bias, performance bias and detection bias. CONCLUSIONS The reporting quality of studies that implanted bioprosthetic or mechanical valves in the pulmonary position in the large animal model is not on the desired level. The introduction of the ARRIVE guidelines in 2010 did not improve the reporting quality in this field of research. Hereby, we want to emphasize the importance of clearly describing the methods and transparently reporting the results in animal experiments. This is of great importance for the safe translation of new heart valves to the clinic. Clinical trial registration number PROSPERO (CRD42019147895).

5 DISRUPTION OF THE HIGH MOBILITY GROUP AT-HOOK 2 (HMGA2) GENE IN SWINE REDUCES POSTNATAL GROWTH

2014 ◽  
Vol 26 (1) ◽  
pp. 117 ◽  
Author(s):  
J. Chung ◽  
X. Zhang ◽  
B. Colins ◽  
K. Howard ◽  
S. Simpson ◽  
...  
Keyword(s):  
Cell Lines ◽  
Mutant Cell ◽  
High Mobility ◽  
Postnatal Growth ◽  
High Mobility Group ◽  
Large Animal Model ◽  
Large Animal ◽  
Wild Type ◽  
Adult Growth ◽  
Fetal Fibroblasts

The high mobility group AT-hook 2 (HMGA2) protein has been shown to be a crucial gene for cell growth, proliferation, and apoptosis; HMGA2 is also a strong biological candidate for growth, because mutations in this gene alter body size in mice and humans. Compared with wild-type controls, adult mice lacking HMGA2 are 60% smaller, and adult heterozygous mutants are 20% smaller. In humans, HMGA2 has been associated with adult and childhood height without any other deleterious effect. Additionally, a microdeletion in the HMGA2 gene in a human patient resulted in short stature, with no dysmorphologies and normal puberty. In order to determine the effect of HMGA2 on fetal and adult growth in pigs, a transgenic pig line deficient in HMGA2 expression was generated by gene targeting in fetal fibroblasts (FF). Using a targeting vector carrying a reporter gene, and homology arms specific to HMGA2, heterozygous mutant cell lines were generated. The cell lines were then used to generate 6 heterozygous females by somatic cell nuclear transfer (SCNT). Bodyweights and lengths from snout to base of tail were measured every 2 weeks for a year for mutant (n = 6) and wild-type farm gilts (n = 6). Data were analysed by one-way ANOVA. As in mice, disruption of one allele of the HMGA2 gene resulted in 25% reduction in weight (P < 0.0001) and 14% reduction in length (P < 0.0001). Early in postnatal growth (2 months), weights of mutants were not different than wild-type. However, mutants were 20 to 35% lighter (P < 0.05) during mid stages (6 months) and 25 to 30% (P < 0.0001) in late stages (3 months). The same insertional mutation generated 8 heterozygous male clones by SCNT. In addition, 7 nontransgenic males from the same FF line were generated as SCNT controls. Bodyweights and lengths were measured every 2 weeks for 30 weeks for HMGA2 heterozygous mutants (n = 8), control SCNT (n = 7) and wild-type farm boars (n = 5). The weight curve of boars showed similar pattern as for mutant gilts. At 30-week postnatal stage, mutants were 17% (P < 0.05) and 16% (P < 0.05) lighter in weight compared with littermate and wild-type animals, respectively. We are presently developing homozygous HMGA2 mutant lines. Currently, 3 of 6 heterozygous gilts have been bred with heterozygous boars, with 1 confirmed pregnancy. The expectation is that the homozygous animals will, like mice, be 60% smaller than the wild-type animals. The approach described here will result not only in a valuable large-animal model of dwarfism, but also in a tool to reduce the size of existing transgenic and nontransgenic swine lines. This, in turn, will increase the receptivity of valuable transgenic lines by the biomedical community. Funding for this work was provided by NIH grant R21-OD010553 to JP.

Cholesterol Granuloma of the Maxillary Sinus

2002 ◽  
Vol 126 (2) ◽  
pp. 217-219 ◽  
Author(s):  
Marino E. Leon ◽  
Carlos Chavez ◽  
Billie Fyfe ◽  
Matthew J. Nagorsky ◽  
Fernando U. Garcia
Keyword(s):  
Foreign Body ◽  
Maxillary Sinus ◽  
Surgical Excision ◽  
Inflammatory Cells ◽  
Lymphatic Drainage ◽  
Giant Cells ◽  
Resected Specimen ◽  
Cholesterol Granuloma ◽  
Arterial Blood ◽  
Foreign Body Giant Cells

Abstract Cholesterol granuloma is usually associated with chronic middle ear disease and is common in the mastoid antrum and air cells of the temporal bone. It has also been reported in other parts of the skull, such as the frontal and maxillary sinuses and orbit. Cholesterol granuloma is rare in the paranasal sinuses. We report a new case of cholesterol granuloma in the maxillary sinus of a 38-year-old man who underwent surgical excision. We also review the literature and discuss the mechanism of development for this lesion. The resected specimen showed fragments of respiratory mucosa with cholesterol clefts surrounded by multinucleated foreign-body giant cells. Some multinucleated foreign-body giant cells showed asteroid bodies. Hemorrhagic areas, hemosiderin-laden macrophages, chronic inflammatory cells, and dilated lymphatics vessels were seen as well. Increased intrasinus pressure due to drainage obstruction may affect venous and lymphatic drainage from the sinus cavity, leading to venule microhemorrhages while still allowing arterial blood into the sinus mucosa and further contributing to a large localized hemorrhage. Lymphatic drainage may be insufficient to completely remove the lipid components of the red blood cells, and the lipid accumulation may contribute to the formation of cholesterol crystals and their esters.

scholarly journals Role of Toll-like receptors in diabetic renal lesions in a miniature pig model

2015 ◽  
Vol 1 (5) ◽  
pp. e1400183 ◽  
Author(s):  
Yuanyuan Feng ◽  
Shulin Yang ◽  
Yuxiang Ma ◽  
Xue-Yuan Bai ◽  
Xiangmei Chen
Keyword(s):  
Immune System ◽  
Signaling Pathway ◽  
Inflammatory Cells ◽  
Large Animal Model ◽  
Large Animal ◽  
Toll Like Receptors ◽  
Metabolic Inflammation ◽  
Renal Lesions ◽  
Miniature Pigs ◽  
Downstream Signaling

The mechanisms of diabetic renal injury remain unclear. Recent studies have shown that immunological and inflammatory elements play important roles in the initiation and development of diabetic nephropathy (DN). Toll-like receptors (TLRs) comprise a superfamily of innate immune system receptors. The roles and mechanisms of TLRs in the pathogenesis of diabetic renal lesions are mostly unknown. Compared with rodents, miniature pigs are more similar to humans with respect to metabolism, kidney structure, and immune system, and therefore represent an ideal large-animal model for DN mechanistic studies. A diabetes model was established by feeding miniature pigs with high-sugar and high-fat diets. Functional and pathological markers, expression and activation of endogenous TLR ligands [HSP70 (heat shock protein 70) and HMGB1], TLR1 to TLR11 and their downstream signaling pathway molecules (MyD88, IRAK-1, and IRF-3), nuclear factor κB (NF-κB) signaling pathway molecules (IKKβ, IκBα, and NF-κBp65), inflammatory cytokines [IL-6 (interleukin-6), MIP-2, MCP-1, CCL5, and VCAM-1 (vascular cell adhesion molecule–1)], and infiltration of inflammatory cells were systematically evaluated. The expression of HSP70 was significantly increased in diabetic pig kidneys. The expression of MyD88-dependent TLR2, TLR4, TLR5, TLR7, TLR8, and TLR11 and their downstream signaling molecules MyD88 and phospho–IRAK-1 (activated IRAK-1), as well as that of MyD88-independent TLR3 and TLR4 and their downstream signaling molecule phospho–IRF-3 (activated IRF-3), was significantly up-regulated. The expression and activation of NF-κB pathway molecules phospho-IKKβ, phospho-IκBα, NF-κBp65, and phospho-NF-κBp65 were significantly increased. Levels of IL-6, MIP-2, MCP-1, CCL5, VCAM-1, and macrophage marker CD68 were significantly increased in diabetic pig kidneys. These results suggested that the metabolic inflammation activated by TLRs might play an important role in diabetic renal injuries.

scholarly journals The efficacy and safety of pinocembrin in a sheep model of bleomycin-induced pulmonary fibrosis

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260719
Author(s):  
Habtamu B. Derseh ◽  
Jason Q. D. Goodger ◽  
Jean-Pierre Y. Scheerlinck ◽  
Chrishan S. Samuel ◽  
Ian E. Woodrow ◽  
...  
Keyword(s):  
Animal Model ◽  
Pulmonary Fibrosis ◽  
Inflammatory Cells ◽  
Lung Parenchyma ◽  
Lung Compliance ◽  
Large Animal Model ◽  
Large Animal ◽  
Lung Pathology ◽  
Sheep Model ◽  
Anti Inflammatory

The primary flavonoid, pinocembrin, is thought to have a variety of medical uses which relate to its reported anti-oxidant, anti-inflammatory, anti-microbial and anti-cancer properties. Some studies have reported that this flavonoid has anti-fibrotic activities. In this study, we investigated whether pinocembrin would impede fibrosis, dampen inflammation and improve lung function in a large animal model of pulmonary fibrosis. Fibrosis was induced in two localized lung segments in each of the 10 sheep participating in the study. This was achieved via two infusions of bleomycin delivered bronchoscopically at a two-week interval. Another lung segment in the same sheep was left untreated, and was used as a healthy control. The animals were kept for a little over 5 weeks after the final infusion of bleomycin. Pinocembrin, isolated from Eucalyptus leaves, was administered to one of the two bleomycin damaged lung segments at a dose of 7 mg. This dose was given once-weekly over 4-weeks, starting one week after the final bleomycin infusion. Lung compliance (as a measure of stiffness) was significantly improved after four weekly administrations of pinocembrin to bleomycin-damaged lung segments. There were significantly lower numbers of neutrophils and inflammatory cells in the bronchoalveolar lavage of bleomycin-infused lung segments that were treated with pinocembrin. Compared to bleomycin damaged lung segments without drug treatment, pinocembrin administration was associated with significantly lower numbers of immuno-positive CD8+ and CD4+ T cells in the lung parenchyma. Histopathology scoring data showed that pinocembrin treatment was associated with significant improvement in inflammation and overall pathology scores. Hydroxy proline analysis showed that the administration of pinocembrin did not reduce the increased collagen content that was induced by bleomycin in this model. Analyses of Masson’s Trichrome stained sections showed that pinocembrin treatment significantly reduced the connective tissue content in lung segments exposed to bleomycin when compared to bleomycin-infused lungs that did not receive pinocembrin. The striking anti-inflammatory and modest anti-fibrotic remodelling effects of pinocembrin administration were likely linked to the compound’s ability to improve lung pathology and functional compliance in this animal model of pulmonary fibrosis.

Rectal Pulse Granuloma

2001 ◽  
Vol 125 (6) ◽  
pp. 822-823 ◽  
Author(s):  
Telma C. Pereira ◽  
Jeffrey W. Prichard ◽  
Mushtaq Khalid ◽  
David S. Medich ◽  
Jan F. Silverman
Keyword(s):  
Foreign Body ◽  
Oral Cavity ◽  
Microscopic Examination ◽  
Foreign Body Reaction ◽  
Inflammatory Cells ◽  
Giant Cells ◽  
Mass Lesion ◽  
Delay In Diagnosis ◽  
Foreign Body Giant Cells ◽  
Histopathologic Features

Abstract Pulse granuloma is a rare benign entity, most likely representing a foreign body reaction to vegetable particles. We report a case of a pulse granuloma involving the rectum. The patient presented with a submucosal and intramuscular mass lesion found at routine rectal examination and subsequent colonoscopy. The mass was excised and the microscopic examination revealed acute and chronic inflammatory cells, foreign-body giant cells, vegetable matter, and convoluted hyaline rings and scattered circular structures containing basophilic granules, consistent with pulse granuloma. There are a few reports in the literature of pulse granulomas, with most occurring in the oral cavity or lungs. To the best of our knowledge, this is the first reported example of pulse granuloma in the rectum. Although rare, familiarity with this entity's distinctive histopathologic features may avoid a delay in diagnosis and prevent the expense of distinguishing it from its histologic lookalikes.

scholarly journals Regeneration of Subcutaneous Cartilage in a Swine Model Using Autologous Auricular Chondrocytes and Electrospun Nanofiber Membranes Under Conditions of Varying Gelatin/PCL Ratios

2021 ◽  
Vol 9 ◽  
Author(s):  
Rui Zheng ◽  
Xiaoyun Wang ◽  
Jixin Xue ◽  
Lin Yao ◽  
Gaoyang Wu ◽  
...  
Keyword(s):  
Cartilage Regeneration ◽  
Inflammatory Cells ◽  
Large Animal Model ◽  
Swine Model ◽  
Large Animal ◽  
Nude Mouse Model ◽  
Cartilage Formation ◽  
Nanofiber Membranes ◽  
Large Animals

The scarcity of ideal biocompatible scaffolds makes the regeneration of cartilage in the subcutaneous environment of large animals difficult. We have previously reported the successful regeneration of good-quality cartilage in a nude mouse model using the electrospun gelatin/polycaprolactone (GT/PCL) nanofiber membranes. The GT/PCL ratios were varied to generate different sets of membranes to conduct the experiments. However, it is unknown whether these GT/PCL membranes can support the process of cartilage regeneration in an immunocompetent large animal model. We seeded swine auricular chondrocytes onto different GT/PCL nanofiber membranes (GT:PCL = 30:70, 50:50, and 70:30) under the sandwich cell-seeding mode. Prior to subcutaneously implanting the samples into an autologous host, they were cultured in vitro over a period of 2 weeks. The results revealed that the nanofiber membranes with different GT/PCL ratios could support the process of subcutaneous cartilage regeneration in an autologous swine model. The maximum extent of homogeneity in the cartilage tissues was achieved when the G5P5 (GT: PC = 50: 50) group was used for the regeneration of cartilage. The formed homogeneous cartilage tissues were characterized by the maximum cartilage formation ratio. The extents of the ingrowth of the fibrous tissues realized and the extents of infiltration of inflammatory cells achieved were found to be the minimum in this case. Quantitative analyses were conducted to determine the wet weight, cartilage-specific extracellular matrix content, and Young’s modulus. The results indicated that the optimal extent of cartilage formation was observed in the G5P5 group. These results indicated that the GT/PCL nanofiber membranes could serve as a potential scaffold for supporting subcutaneous cartilage regeneration under clinical settings. An optimum GT/PCL ratio can promote cartilage formation.

Histopathological follow-up study of 66 cerebral arteriovenous malformations after therapeutic embolization with polyvinyl alcohol

1992 ◽  
Vol 76 (4) ◽  
pp. 607-614 ◽  
Author(s):  
Isabelle M. Germano ◽  
Richard L. Davis ◽  
Charles B. Wilson ◽  
Grant B. Hieshima
Keyword(s):  
Polyvinyl Alcohol ◽  
Arteriovenous Malformations ◽  
Inflammatory Cells ◽  
Therapeutic Embolization ◽  
Giant Cells ◽  
Content Type ◽  
Foreign Body Giant Cells ◽  
Foreign Materials ◽  
Pva Particles

✓ Embolization with polyvinyl alcohol (PVA) is an accepted method of rendering complex arteriovenous malformations (AVM's) more amenable to surgery, but its effects on human vascular tissues have not been adequately documented. The authors reviewed the histopathology of 66 intracranial AVM's resected 1 to 76 days after embolization with PVA. The mean age of the patients was 36 years, and their AVM's were located in the cerebral hemispheres (92%), the cerebellum (6%), or the corpus callosum (2%). In 79% of cases, at least one vessel contained PVA particles; in most cases, the vessel was filled with sharp, angular PVA particles in a serpiginous pattern. Polyvinyl alcohol particles indented the endothelium in 69% of cases but were rarely found subendothelially. Clotted blood and fibroblasts were present among the particles, and abundant intraluminal mononuclear and polymorphonuclear inflammatory cells were found in all vessels containing PVA particles. Foreign-body giant cells appeared 2 to 14 days after embolization in the majority of cases. Patchy mural angionecrosis and necrotizing vasculitis were found in 39% of the cases. Recanalized lumina were seen in 18% of PVA-embolized vessels. Foreign materials resembling cotton fibers and other particulate substances, which were probably contaminants of the contrast solution or the embolic material, were found in 65% of the cases. These findings suggest a specific chain of events in the interaction between PVA and vessel wall components and may explain some important sequelae of embolization therapy.

Sign in / Sign up

Export Citation Format

Share Document