Experimental results and clinical impact of using autologous rectus fascia sheath for vascular replacement

2008 ◽  
Vol 56 (3) ◽  
pp. 411-420 ◽  
Author(s):  
László Kóbori ◽  
Tibor Németh ◽  
Péter Nagy ◽  
Gábor Dallos ◽  
Péter Sótonyi ◽  
...  
Keyword(s):  
Patency Rate ◽  
Graft Failure ◽  
Histological Analysis ◽  
Vascular Grafts ◽  
Vascular Complications ◽  
Clinical Impact ◽  
Clinical Use ◽  
Rectus Fascia ◽  
Vascular Replacement

Vascular complications are major causes of graft failure in liver transplantation. The use of different vascular grafts is common but the results are controversial. The aim of this study was to create an ‘ideal’ arterial interponate for vascular replacements in the clinical field. An autologous, tubular graft prepared from the posterior rectus fascia sheath was used for iliac artery replacement in dogs for 1, 3, 6 and 12 months. Forty-one grafts were implanted and immunosuppression was used in separate groups. The patency rate was followed by Doppler ultrasound. Thirty-seven grafts remained patent, 2 cases with thrombosis and 2 cases with stenosis occurred. There was no evidence of necrosis or aneurysmatic formation. The histological analysis included conventional light microscopic and immunohistochemical examinations for CD34 and factor VIII. The explanted grafts showed signs of arterialisation, appearance of elastin fibres, and smooth muscle cells after 6 months. Electron microscopy showed intact mitochondrial structures without signs of hypoxia. In conclusion, the autologous graft presents acceptable long-term patency rate. It is easy to handle and the concept of beneficial presence of the anti-clot mesothelium until endothelialisation seems to work. The first clinical use was already reported by our group with more than 2 years survival.

scholarly journals EXPERIMENTAL AUTOLOGOUS SUBSTITUTE VASCULAR GRAFT FOR TRANSPLANTATION SURGERY

2000 ◽  
Vol 48 (3) ◽  
pp. 355-360 ◽  
Author(s):  
L. Kóbori ◽  
G. Dallos ◽  
Anette S. H. Gouw ◽  
Tamás Németh ◽  
B. Nemes ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Smooth Muscle ◽  
Flow Rate ◽  
Vascular Graft ◽  
Patency Rate ◽  
Graft Failure ◽  
Vascular Complications ◽  
Transplantation Surgery ◽  
Rectus Fascia

Vascular complications in liver transplantation are a major cause of graft failure and mortality. The aim of the study was to create autologous vascular graft without risk of rejection. Posterior rectus fascia sheath lined with peritoneum was used for iliac artery replacement in seven mongrel dogs. The patency was followed by palpation and Doppler ultrasound. The grafts were removed after one month. Five grafts remained patent. The Doppler showed good, relatively increased flow (median flow rate: 383 cm/sec) after one month in all of the cases. Slight increase in diameter was present in all cases. By microscopy the five patent grafts showed viable morphology, fibroblasts, smooth muscle cells and thin fibrin layer in the wall. The grafts were lined partially with a neoendothelial monolayer and a thin fibrin layer. In conclusion, this graft presents an acceptable patency rate and low thrombogenicity, and could be useful in transplantation. Further investigations are needed to study the effect of immunosuppression and rejection on long-term morphology and patency of the grafts.

Experimental vascular graft for liver transplantation

2003 ◽  
Vol 51 (4) ◽  
pp. 529-537 ◽  
Author(s):  
L. Kóbori ◽  
T. Németh ◽  
B. Nemes ◽  
G. Dallos ◽  
P. Sótonyi Jr. ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Vascular Graft ◽  
Patency Rate ◽  
Graft Failure ◽  
Tissue Oxygenation ◽  
Radical Production ◽  
Artery Thrombosis ◽  
One Year ◽  
Rectus Fascia

Hepatic artery thrombosis is a major cause of graft failure in liver transplantation. Use of donor interponates are common, but results are controversial because of necrosis or thrombosis after rejection. Reperfusion injury, hypoxia and free radical production determinate the survival. The aim of the study was to create an 'ideal' arterial interponate. Autologous, tubular graft lined with mesothelial cells, prepared from the posterior rectus fascia sheath, was used for iliac artery replacement in eight mongrel dogs for six months under immunosuppression. Patency rate was followed by Doppler ultrasound. Eight grafts remained patent and another two are patent after one year. The patency rate was good (median Doppler flow: 370 cm/sec) and there was no necrosis, thrombosis or aneurysmatic formation. The grafts showed viable morphology with neoangiogenesis, appearance of elastin, smooth muscle and endothelial cells. Electron microscopy showed intact mitochondrial structures without signs of hypoxia. Tissue oxygenation was good in all cases with normal (< 30 ng/ml) myeloperoxidase production. In conclusion, this autologous graft presents good long-term patency rate. Viability, arterialisation and low thrombogenicity are prognostic factors indicating usability of the graft in the clinical practice without the risk of rejection. Further investigations such as cell cultures and standardisation are necessary.

Coating Small-Diameter ePTFE Vascular Grafts with Tunable Poly(diol-co-citrate-co-ascorbate) Elastomers to Reduce Neointimal Hyperplasia

2021 ◽  
Author(s):  
Lu Yu ◽  
Emily R. Newton ◽  
David C. Gillis ◽  
Kui Sun ◽  
Brian C. Cooley ◽  
...  
Keyword(s):  
Neointimal Hyperplasia ◽  
Vascular Grafts ◽  
Small Diameter ◽  
Clinical Use

Lack of long-term patency has hindered the clinical use of small-diameter prosthetic vascular grafts with the majority of these failures due to the development of neointimal hyperplasia. Previous studies by...

scholarly journals OP0146 LONG TERM OUTCOME AND PROGNOSIS FACTORS OF ISOLATED AORTITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 93.1-93
Author(s):  
Y. Ferfar ◽  
S. Morinet ◽  
O. Espitia ◽  
C. Agard ◽  
M. Vautier ◽  
...  
Keyword(s):  
Multivariate Analysis ◽  
Giant Cell Arteritis ◽  
Takayasu Arteritis ◽  
Vascular Complications ◽  
Event Free Survival ◽  
Prognosis Factors ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Free Survival

Background:Aortitis is a group of disorders characterized by the inflammation of the aorta. The most common causes of aortitis are the large-vessel vasculitis i.e. giant cell arteritis (GCA) and Takayasu arteritis (TA). However, aortitis may be isolated. Because of the wide variation in the course of aortitis, predicting outcome is challenging. The optimal management strategy of isolated aortitis (IA) is still unclear as IA is poorly defined, with data consisting of small retrospective and case control studies.Objectives:To assess the long-term outcome and prognosis factors for vascular complications in patients with isolated aortitis.Methods:Retrospective multicenter study of 353 patients with non-infectious aortitis including 136 giant cell arteritis (GCA), 96 Takayasu arteritis (TA) and 73 isolated aortitis (IA). Factors associated with event-free survival, vascular event-free survival and revascularization-free survival were assessed. Risk factors for vascular complications were identified in multivariate analysis.Results:After a median follow up of 52 months, vascular complications were observed in 32.3 %, revascularization in 30 % and death in 7.6%. The 5-year cumulative incidence of vascular complications was 58% (41; 71), 20% (13; 29), and 19 % (11; 28) in IA, GCA and TA, respectively. In multivariate analysis, IA [HR, 1.85 (1.19 to 2.88), p=0.017] and male gender [1.77 (1.26 to 2.49), p<0.0001] were independently associated with vascular events. The 5-year surgery-free survival was 45% (31; 65), 71% (62; 81) and 76% (68; 86) in IA, TA and GCA, respectively.Conclusion:IA has a worse vascular prognosis than GCA and TA. Sixty percent of IA patients will experience a vascular complication within 5 years from diagnosis.Disclosure of Interests:None declared

scholarly journals Collagen analogs with phosphorylcholine are inflammation-suppressing scaffolds for corneal regeneration from alkali burns in mini-pigs

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Fiona C. Simpson ◽  
Christopher D. McTiernan ◽  
Mohammad Mirazul Islam ◽  
Oleksiy Buznyk ◽  
Philip N. Lewis ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Nerve Regeneration ◽  
Graft Failure ◽  
Corneal Stroma ◽  
Advanced Stage ◽  
Term Survival ◽  
Corneal Regeneration ◽  
Type V ◽  
Mini Pigs

AbstractThe long-term survival of biomaterial implants is often hampered by surgery-induced inflammation that can lead to graft failure. Considering that most corneas receiving grafts are either pathological or inflamed before implantation, the risk of rejection is heightened. Here, we show that bioengineered, fully synthetic, and robust corneal implants can be manufactured from a collagen analog (collagen-like peptide-polyethylene glycol hybrid, CLP-PEG) and inflammation-suppressing polymeric 2-methacryloyloxyethyl phosphorylcholine (MPC) when stabilized with the triazine-based crosslinker 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The resulting CLP-PEG-MPC implants led to reduced corneal swelling, haze, and neovascularization in comparison to CLP-PEG only implants when grafted into a mini-pig cornea alkali burn model of inflammation over 12 months. Implants incorporating MPC allowed for faster nerve regeneration and recovery of corneal sensation. CLP-PEG-MPC implants appear to be at a more advanced stage of regeneration than the CLP-PEG only implants, as evidenced by the presence of higher amounts of cornea-specific type V collagen, and a corresponding decrease in the presence of extracellular vesicles and exosomes in the corneal stroma, in keeping with the amounts present in healthy, unoperated corneas.

scholarly journals Assessment of Electrospun Pellethane-Based Scaffolds for Vascular Tissue Engineering

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3678
Author(s):  
Vera Chernonosova ◽  
Alexandr Gostev ◽  
Ivan Murashov ◽  
Boris Chelobanov ◽  
Andrey Karpenko ◽  
...  
Keyword(s):  
Vascular Tissue ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Wistar Rat ◽  
Graft Occlusion ◽  
Suitable Candidate ◽  
Large Animals ◽  
Cell Adhesion And Proliferation

We examined the physicochemical properties and the biocompatibility and hemocompatibility of electrospun 3D matrices produced using polyurethane Pellethane 2363-80A (Pel-80A) blends Pel-80A with gelatin or/and bivalirudin. Two layers of vascular grafts of 1.8 mm in diameter were manufactured and studied for hemocompatibility ex vivo and functioning in the infrarenal position of Wistar rat abdominal aorta in vivo (n = 18). Expanded polytetrafluoroethylene (ePTFE) vascular grafts of similar diameter were implanted as a control (n = 18). Scaffolds produced from Pel-80A with Gel showed high stiffness with a long proportional limit and limited influence of wetting on mechanical characteristics. The electrospun matrices with gelatin have moderate capacity to support cell adhesion and proliferation (~30–47%), whereas vascular grafts with bivalirudin in the inner layer have good hemocompatibility ex vivo. The introduction of bivalirudin into grafts inhibited platelet adhesion and does not lead to a change hemolysis and D-dimers concentration. Study in vivo indicates the advantages of Pel-80A grafts over ePTFE in terms of graft occlusion, calcification level, and blood velocity after 6 months of implantation. The thickness of neointima in Pel-80A–based grafts stabilizes after three months (41.84 ± 20.21 µm) and does not increase until six months, demonstrating potential for long-term functioning without stenosis and as a suitable candidate for subsequent preclinical studies in large animals.

Alternative Donor Transplantation for Aplastic Anemia

Hematology ◽  
2010 ◽  
Vol 2010 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Mary Eapen ◽  
Mary M. Horowitz
Keyword(s):  
Cord Blood ◽  
Aplastic Anemia ◽  
Umbilical Cord ◽  
Umbilical Cord Blood ◽  
Graft Failure ◽  
Hla Typing ◽  
Unrelated Donor ◽  
Term Survival ◽  
Alternative Donor

AbstractPatients with severe aplastic anemia who do not have a human leukocyte antigen (HLA)-identical sibling generally receive immunosuppressive therapy as a first-line therapy, with allogeneic transplantation being reserved for those who do not have an adequate sustained response. Barriers to the use of unrelated-donor transplantation for aplastic anemia include identifying a suitable alternative donor, and risks of graft failure, regimen-related toxicity, and graft-versus-host disease (GVHD). Despite the more than 14 million adults registered with donor registries worldwide, only approximately 50% of patients of Caucasian descent will have an available and fully HLA-matched unrelated adult donor; the rate is substantially lower for non-Caucasians. While umbilical cord blood allows transplantation with greater donor-recipient HLA disparity (without excessive risk of GVHD), risks of graft failure and transplant-related mortality are higher than after transplantation of adult donor grafts. Among patients with a suitable donor, recent changes in pre-transplant conditioning regimens have lowered the risks of organ toxicity and graft failure. Although advances in donor HLA typing and selection practices and improved GVHD prophylaxis have lowered the risk, GVHD remains an important obstacle to long-term symptom-free survival. Despite these limitations, unrelated-donor transplantation offers the best chance of long-term survival for many patients in whom current immunosuppression strategies are not effective. Wider applicability of alternative-donor transplantation for aplastic anemia will require better approaches to prevent graft failure and GVHD and to expand the pool of unrelated-donor grafts. This includes exploring strategies to effectively use alternative grafts such as umbilical cord blood.

scholarly journals Framework for patient-ventilator asynchrony during long-term non-invasive ventilation

Thorax ◽  
2019 ◽  
Vol 74 (7) ◽  
pp. 715-717 ◽  
Author(s):  
Jesus Gonzalez-Bermejo ◽  
Jean-Paul Janssens ◽  
Claudio Rabec ◽  
Christophe Perrin ◽  
Frédéric Lofaso ◽  
...  
Keyword(s):  
Present Report ◽  
Time Windows ◽  
Clinical Impact ◽  
Positive Pressure ◽  
Systematic Analysis ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Polygraphic Recordings ◽  
Bench Testing

Episodes of patient-ventilator asynchrony (PVA) occur during acute and chronic non-invasive positive pressure ventilation (NIV). In long-term NIV, description and quantification of PVA is not standardised, thus limiting assessment of its clinical impact. The present report provides a framework for a systematic analysis of polygraphic recordings of patients under NIV for the detection and classification of PVA validated by bench testing. The algorithm described uses two different time windows: rate asynchrony and intracycle asynchrony. This approach should facilitate further studies on prevalence and clinical impact of PVA in long-term NIV.

THE EFFICACY OF TRANSURETHRAL BIOPSY FOR PREDICTING THE LONG-TERM CLINICAL IMPACT OF PROSTATIC INVASIVE BLADDER CANCER

2001 ◽  
Vol 165 (5) ◽  
pp. 1580-1584 ◽  
Author(s):  
S. MACHELE DONAT ◽  
DAVID C. WEI ◽  
MICHAEL S. McGUIRE ◽  
HARRY W. HERR
Keyword(s):  
Bladder Cancer ◽  
Clinical Impact ◽  
Invasive Bladder Cancer

scholarly journals Cancer Epigenetics: New Therapies and New Challenges

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Eleftheria Hatzimichael ◽  
Tim Crook
Keyword(s):  
Dna Methylation ◽  
Epigenetic Modification ◽  
Hdac Inhibitors ◽  
Clinical Impact ◽  
Clinical Use ◽  
Cancer Epigenetics ◽  
Dnmt Inhibitors ◽  
Epigenetic Effects ◽  
New Challenges ◽  
Neoplastic Disorders

Cancer is nowadays considered to be both a genetic and an epigenetic disease. The most well studied epigenetic modification in humans is DNA methylation; however it becomes increasingly acknowledged that DNA methylation does not work alone, but rather is linked to other modifications, such as histone modifications. Epigenetic abnormalities are reversible and as a result novel therapies that work by reversing epigenetic effects are being increasingly explored. The biggest clinical impact of epigenetic modifying agents in neoplastic disorders thus far has been in haematological malignancies, and the efficacy of DNMT inhibitors and HDAC inhibitors in blood cancers clearly attests to the principle that therapeutic modification of the cancer cell epigenome can produce clinical benefit. This paper will discuss the most well studied epigenetic modifications and how these are linked to cancer, will give a brief overview of the clinical use of epigenetics as biomarkers, and will focus in more detail on epigenetic drugs and their use in solid and blood cancers.

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