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Farmacorresistência Bacteriana Múltipla , Infecções por Enterobacteriaceae , Enterobacteriaceae , Transplante de Pulmão , Transplantados , Humanos , Transplante de Pulmão/efeitos adversos , Transplantados/estatística & dados numéricos , Fatores de Risco , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/epidemiologia , Pessoa de Meia-Idade , Masculino , Feminino , Estudos de Coortes , Adulto , Idoso , Portador Sadio/microbiologia , Portador Sadio/epidemiologia , Trato Gastrointestinal/microbiologiaRESUMO
BACKGROUND: Prior studies have assessed the impact of the pretransplantation recipient body mass index (BMI) on patient outcomes after lung transplantation (LT), but they have not specifically addressed early postoperative complications. Moreover, the impact of donor BMI on these complications has not been evaluated. The first aim of this study was to assess complications during hospitalization in the ICU after LT according to donor and recipient pretransplantation BMI. METHODS: All the recipients who underwent LT at Bichat Claude Bernard Hospital, Paris, between January 2016 and August 2022 were included in this observational retrospective monocentric study. Postoperative complications were analyzed according to recipient and donor BMIs. Univariate and multivariate analyses were also performed. The 90-day and one-year survival rates were studied. P < 0.05 was considered to indicate statistical significance. The Paris-North Hospitals Institutional Review Board approved the study. RESULTS: A total of 304 recipients were analyzed. Being underweight was observed in 41 (13%) recipients, a normal weight in 130 (43%) recipients, and being overweight/obese in 133 (44%) recipients. ECMO support during surgery was significantly more common in the overweight/obese group (p = 0.021), as were respiratory complications (primary graft dysfunction (PGD) (p = 0.006), grade 3 PDG (p = 0.018), neuroblocking agent administration (p = 0.008), prone positioning (p = 0.007)), and KDIGO 3 acute kidney injury (p = 0.036). However, pretransplantation overweight/obese status was not an independent risk factor for 90-day mortality. An overweight or obese donor was associated with a decreased PaO2/FiO2 ratio before organ donation (p < 0.001), without affecting morbidity or mortality after LT. CONCLUSION: Pretransplantation overweight/obesity in recipients is strongly associated with respiratory and renal complications during hospitalization in the ICU after LT.
Assuntos
Transplante de Pulmão , Sobrepeso , Humanos , Índice de Massa Corporal , Sobrepeso/complicações , Estudos Retrospectivos , Obesidade/complicações , Fatores de Risco , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Transplante de Pulmão/efeitos adversos , Sobrevivência de Enxerto , Resultado do TratamentoRESUMO
BACKGROUND: The French national protocol for controlled donation after circulatory determination of death (cDCD) includes normothermic regional perfusion (NRP) in case of abdominal organ procurement and additional ex-vivo lung perfusion (EVLP) before considering lung transplantation (LT). METHODS: We made a retrospective study of a prospective registry that included all donors considered for cDCD LT from the beginning of the program in May 2016 to November 2021. RESULTS: One hundred grafts from 14 donor hospitals were accepted by 6 LT centers. The median duration of the agonal phase was 20 minutes [2-166]. The median duration from circulatory arrest to pulmonary flush was 62 minutes [20-90]. Ten lung grafts were not retrieved due to prolonged agonal phases (n = 3), failure of NRP insertion (n = 5), or poor in situ evaluation (n = 2). The remaining 90 lung grafts were all evaluated on EVLP, with a conversion rate of 84% and a cDCD transplantation rate of 76%. The median total preservation time was 707 minutes [543-1038]. Seventy-one bilateral LTs and 5 single LTs were performed for chronic obstructive pulmonary disease (n = 29), pulmonary fibrosis (n = 21), cystic fibrosis (n = 15), pulmonary hypertension (n = 8), graft-versus-host disease (n = 2), and adenosquamous carcinoma (n = 1). The rate of PGD3 was 9% (n = 5). The 1-year survival rate was 93.4%. CONCLUSION: After initial acceptance, cDCD lung grafts led to LT in 76% of cases, with outcomes similar to those already reported in the literature. The relative impacts of NRP and EVLP on the outcome following cDCD LT should be assessed prospectively in the context of comparative studies.
Assuntos
Transplante de Pulmão , Obtenção de Tecidos e Órgãos , Humanos , Estudos Retrospectivos , Preservação de Órgãos/métodos , Perfusão/métodos , Pulmão , Doadores de Tecidos , Morte , Sobrevivência de EnxertoRESUMO
INTRODUCTION: The number of lung transplantations performed is increasing worldwide. With an improved experience and outcomes, the age of the recipient on its own has ceased to be an absolute contra-indication. We report our first experience with lung transplantation in patients aged 65 years or older. METHODS: From January 2014 to March 2019, the files of patients aged 65 years or older undergoing lung transplantation were retrospectively reviewed. RESULTS: During the study period, 241 patients underwent lung transplantation in Bichat hospital (Paris, France), including 25 recipients aged 65 years or older. Underlying diagnoses were interstitial (72%) and obstructive (28%) disease. The rate of single lung transplantation was 80%. Sixteen patients required ECMO assistance during the procedure. Early complications were mostly grade III primary graft dysfunction (12%) and cellular rejection (20%). Overall one-year survival rate was 76%. CONCLUSION: After a careful selection of the recipients, the early results of our retrospective single center series are encouraging. We continue to consider lung transplantation in rigorously selected recipients of aged 65 years and more.
Assuntos
Doenças Pulmonares Intersticiais/epidemiologia , Doenças Pulmonares Intersticiais/terapia , Pneumopatias Obstrutivas/epidemiologia , Pneumopatias Obstrutivas/terapia , Transplante de Pulmão , Fatores Etários , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Feminino , França/epidemiologia , Sobrevivência de Enxerto , Humanos , Doenças Pulmonares Intersticiais/mortalidade , Pneumopatias Obstrutivas/mortalidade , Transplante de Pulmão/efeitos adversos , Transplante de Pulmão/métodos , Transplante de Pulmão/mortalidade , Transplante de Pulmão/estatística & dados numéricos , Masculino , Paris/epidemiologia , Período Pós-Operatório , Disfunção Primária do Enxerto/epidemiologia , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Acute kidney injury (AKI) is associated with increased short-term and long-term mortality and morbidity after lung transplantation (LT). The primary objective of this study was to analyze the perioperative factors associated with AKI according to Kidney Disease: Improving Global Outcome (KDIGO) criteria during hospitalization in an intensive care unit (ICU) after LT. METHODS: This was a single-center, observational, prospective study. AKI was defined according to KDIGO criteria. Results are expressed as median, interquartile range, absolute numbers, and percentages. Statistical analyses were performed using χ2 test, Fisher exact test, and Mann-Whitney U test. P < .05 was considered to be significant. Multivariate analysis was performed to identify independent risk factors. RESULTS: Between January 2016 and April 2018, 94 patients underwent LT (70% bilateral LT). AKI occurred during ICU stay in 46 patients (49%). KDIGO 1 AKI was observed in 16 patients (17%), KDIGO 2 in 14 patients (15%), and KDIGO 3 in 16 patients (17%), including 12 patients (75%) who required renal replacement therapy. AKI occurred before the fifth day after surgery for 38 patients (82% of the AKI patients). On multivariate analysis, independent factors associated with AKI were bilateral LT and mechanical ventilation >3 days (odds ratio [OR] 4.26, 95% confidence interval [CI] [1.49; 13.63] P = .010 and OR 5.56 [1.25; 11.47] P = .018, respectively). AKI and the need for renal replacement therapy were significantly associated with ICU mortality, 28-day mortality, and 1-year mortality. CONCLUSION: AKI is common during ICU stay after LT, especially after bilateral LT, and is associated with prolonged mechanical ventilation and increased short-term and long-term mortality.
Assuntos
Injúria Renal Aguda/etiologia , Transplante de Pulmão/efeitos adversos , Injúria Renal Aguda/epidemiologia , Adulto , Idoso , Feminino , Humanos , Incidência , Transplante de Pulmão/mortalidade , Masculino , Pessoa de Meia-Idade , Razão de Chances , Período Perioperatório , Estudos Prospectivos , Terapia de Substituição Renal , Respiração Artificial , Fatores de RiscoRESUMO
BACKGROUND: Fungus-positive respiratory samples (FPRS) are common in the intensive Care unit (ICU) and are usually considered to correspond to colonization. The management of FPRS during the early postoperative course after lung transplantation (LT) remains unclear. The epidemiology, clinical consequences, and prognosis of FPRS were assessed in LT recipients. METHODS: Over a 6-year period, we analyzed the postoperative ICU course of 176 LT recipients with a specific focus on microbiological results of routine respiratory samples and clinical course. The outcomes during the ICU stay at day 28 and at 1 year were compared in patients with or without FPRS. Results are expressed as median and interquartile range. RESULTS: In the pretransplantation period, Candida spp were reported in 17% of patients. No routine post-LT antifungal prophylaxis was initiated. In the post-LT period, at least 1 FPRS was observed in 69% of patients (93% Candida spp, 7% Aspergillus spp). Double LT (odds ratio = 4.15, 95% confidence interval [1.67-11.80], P = .0007) was the only risk factor associated with Candida spp in respiratory samples. Antifungal therapy was administered in 58% of patients with post-LT Candida-positive samples. Candida spp in post-LT respiratory samples were not associated with increased ICU, 28-day, or 1-year mortality rates. CONCLUSION: A high prevalence of FPRS is reported after LT, mainly with Candida spp. The lack of association between post-LT FPRS and mortality and morbidity suggests avoiding antifungal therapy in the absence of clinical signs of invasive infection.
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Transplante de Pulmão , Micoses/epidemiologia , Micoses/etiologia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/microbiologia , Candida , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Prognóstico , Sistema Respiratório/microbiologia , Fatores de RiscoAssuntos
Dor no Peito/diagnóstico , Equinococose Hepática/diagnóstico , Equinococose Pulmonar/diagnóstico , Adulto , Dor no Peito/etiologia , Diagnóstico Diferencial , Equinococose Hepática/complicações , Equinococose Pulmonar/complicações , Feminino , Humanos , Imageamento por Ressonância Magnética , Radiografia Torácica , UltrassonografiaRESUMO
Surgery is still the main treatment in early-stage of non-small cell lung cancer with 5-year survival of stage IA patients exceeding 80%, but 5-year survival of stage II patients rapidly decreasing with tumor size, N status, and visceral pleura invasion. The major metastatic risk in such patients has supported clinical research assessing systemic or loco-regional perioperative treatments. Modern phase 3 trials clearly validated adjuvant or neo-adjuvant platinum-based chemotherapy in resected stage I-III patients as a standard treatment of which value has been reassessed several independent meta-analyses, showing a 5% benefit in 5y-survival, and a decrease of the relative risk for death around from 12 to 25%. Conversely perioperative treatments were not validated for stage IA and IB patients. In more advanced stage patients, neo-adjuvant radio-chemotherapy has not been validated either. Adjuvant radiotherapy for N2 patients is currently tested in the large international phase 3 trial Lung-ART/IFCT-0503. The development of video-assisted thoracic surgery (VATS) has helped adjuvant chemotherapies for elderly patients. Perioperative targeted treatments in NSCLC with EGFR or ALK molecular alterations is currently assessed in the U.S. ALCHEMIST prospective trial. Finally, the role of immune check-points inhibitors is currently evaluated in a large international phase 3 trial testing adjuvant anti-PD-L1 monoclonal antibody, the BR31/IFCT-1401 trial, while a proof-of principle neo-adjuvant trial IONESCO/IFCT-1601, has just begun by the end of the 2016 year, with survival results of both trials expected in 5 to 7 years.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Assistência Perioperatória/métodos , Assistência Perioperatória/tendências , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Quimioterapia Adjuvante , Terapia Combinada , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Radioterapia Adjuvante , Cirurgia Torácica VídeoassistidaRESUMO
Information about the prevalence and nature of liver disorders in adults with alpha1-antitrypsin deficiency is scarce. At our center, systematic liver biopsy screening is part of the evaluation before lung transplantation (LT) in the emphysema patients with the PiZZ phenotype. Our aim was to report our experience with this prospective screening. Clinical, liver function, and imaging parameters as well as liver histology data were analyzed for 23 consecutive adult patients with PiZZ severe emphysema referred to our center for consideration of LT from 2006 to 2014. Overall 20 (87%) featured chronic liver disease characterized by a chronic inflammation and/or a significant portal fibrosis on histology. Two of the 23 patients (8.7%) had septal fibrosis according to the Metavir and Ishak scores and met our definition of severe chronic liver disease. They were both clinically asymptomatic with normal liver function tests. On abdominal ultrasonography, the liver appeared normal in one patient and with abnormal contours in the other. Our data indicate that in adults with PiZZ-related emphysema being evaluated for LT, most patients had some histologic involvement. The prevalence of severe liver dysfunction is <10%.
Assuntos
Fígado/fisiopatologia , Transplante de Pulmão , Enfisema Pulmonar/cirurgia , Deficiência de alfa 1-Antitripsina/complicações , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Estudos Prospectivos , Enfisema Pulmonar/etiologia , Estudos Retrospectivos , Fatores de Risco , Adulto JovemRESUMO
BACKGROUND: Multidrug-resistant (MDR) bacteria are a growing concern worldwide. The aim of this study was to describe the epidemiology and risk factors of MDR bacteria detected in respiratory invasive samples during hospitalization in the intensive care unit (ICU) after lung transplantation (LT). METHODS: This study was based on a retrospective analysis of 176 patients hospitalized in the ICU after LT in 2006-2012. Respiratory invasive samples were performed according to a routine protocol. MDR pathogens were defined according to in vitro susceptibility tests. RESULTS: A total of 1176 bacteria were cultured. Susceptibility testing was performed on 1046 strains and 404 (39%) MDR were detected in 90 (51%) patients. Pseudomonas aeruginosa, coagulase-negative staphylococci, and Enterobacteriaceae (mainly Enterobacter species) were the most common MDR pathogens. On multivariate analysis, an ICU stay >14 days, presence of a tracheostomy, and previous exposure to broad-spectrum antibiotics were associated with MDR acquisition (odds ratio [OR] 3.7; 95% confidence interval [1.69-8.12]; OR 3.28 [1.05-10.28]; and OR 2.25 [1.17-4.34], respectively). We consistently observed an increasing emergence of resistance to several antibiotics, from week 1 to week 4 of ICU hospitalization: for ticarcillin, piperacillin-tazobactam, ceftazidime, imipenem/cilastatin, amikacin, and ciprofloxacin in P. aeruginosa; and for piperacillin-tazobactam, cefepime, and amikacin in Enterobacteriaceae. CONCLUSION: A large proportion of MDR bacteria are detected on respiratory invasive samples in LT patients, and the risk of their emergence is mainly determined by the previous exposure to broad-spectrum antibiotics and the length of ICU stay. Adequate treatment requires broad-spectrum empiric antibiotic therapy.
Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/epidemiologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Transplante de Pulmão/efeitos adversos , Infecções Bacterianas/microbiologia , Enterobacter/efeitos dos fármacos , Enterobacteriaceae/efeitos dos fármacos , Feminino , Hospitalização , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Estudos Retrospectivos , Fatores de RiscoRESUMO
OBJECTIVES/BACKGROUND: ECAR (Endovasculaire ou Chirurgie dans les Anévrysmes aorto-iliaques Rompus) is a prospective multicentre randomized controlled trial including consecutive patients with ruptured aorto-iliac aneurysms (rAIA) eligible for treatment by either endovascular (EVAR) or open surgical repair (OSR). Inclusion criteria were hemodynamic stability and computed tomography scan demonstrating aorto-iliac rupture. METHODS: Randomization was done by week, synchronously in all centers. The primary end point was 30 day mortality. Secondary end points were post-operative morbidity, length of stay in the intensive care unit (ICU), amount of blood transfused (units) and 6 month mortality. RESULTS: From January 2008 to January 2013, 107 patients (97 men, 10 women; median age 74.4 years) were enrolled in 14 centers: 56 (52.3%) in the EVAR group and 51 (47.7%) in the OSR group. The groups were similar in terms of age, sex, consciousness, systolic blood pressure, Hardman index, IGSII score, type of rupture, use of endoclamping balloon, and levels of troponin, creatinine, and hemoglobin. Delay to treatment was higher in the EVAR group (2.9 vs. 1.3 hours; p < .005). Mortality at 30 days and 1 year were not different between the groups (18% in the EVAR group vs. 24% in the OSR group at 30 days, and 30% vs. 35%, respectively, at 1 year). Total respiratory support time was lower in the EVAR group than in the OSR group (59.3 hours vs. 180.3 hours; p = .007), as were pulmonary complications (15.4% vs. 41.5%, respectively; p = .050), total blood transfusion (6.8 vs. 10.9, respectively; p = .020), and duration of ICU stay (7 days vs. 11.9 days, respectively; p = .010). CONCLUSION: In this study, EVAR was found to be equal to OSR in terms of 30 day and 1 year mortality. However, EVAR was associated with less severe complications and less consumption of hospital resources than OSR.
Assuntos
Aneurisma Roto/cirurgia , Aneurisma da Aorta Abdominal/cirurgia , Ruptura Aórtica/cirurgia , Implante de Prótese Vascular , Procedimentos Endovasculares , Aneurisma Ilíaco/cirurgia , Idoso , Idoso de 80 Anos ou mais , Aneurisma Roto/diagnóstico , Aneurisma Roto/economia , Aneurisma Roto/mortalidade , Aneurisma da Aorta Abdominal/diagnóstico , Aneurisma da Aorta Abdominal/economia , Aneurisma da Aorta Abdominal/mortalidade , Ruptura Aórtica/diagnóstico , Ruptura Aórtica/economia , Ruptura Aórtica/mortalidade , Transfusão de Sangue , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/economia , Implante de Prótese Vascular/mortalidade , Análise Custo-Benefício , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/economia , Procedimentos Endovasculares/mortalidade , Feminino , França , Custos Hospitalares , Mortalidade Hospitalar , Humanos , Aneurisma Ilíaco/diagnóstico , Aneurisma Ilíaco/economia , Aneurisma Ilíaco/mortalidade , Estimativa de Kaplan-Meier , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Complicações Pós-Operatórias/terapia , Estudos Prospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
We report a case of a 54-year-old woman presenting a symptomatic focal atherosclerotic abdominal aortic stenosis. Computed tomographic angiography allowed to study the lesion, the abdominal aorta and its main branches. The patient was treated via an endovascular approach using a covered stent. The postoperative course was uneventful and the patient was asymptomatic with a patent reconstruction after 18 months. Improvement in endovascular technology has totally modified the treatment of focal atherosclerotic abdominal aortic stenosis. However, many technical points remain to be determined including the necessity of systematic stenting, the type of stent to use, and the steps of the procedure.
Assuntos
Doenças da Aorta , Aterosclerose , Aorta Abdominal , Doenças da Aorta/diagnóstico por imagem , Doenças da Aorta/cirurgia , Aterosclerose/diagnóstico por imagem , Aterosclerose/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , RadiografiaAssuntos
Aneurisma/diagnóstico por imagem , Veia Poplítea , Aneurisma/cirurgia , Angiografia , Antifibrinolíticos/administração & dosagem , Antifibrinolíticos/uso terapêutico , Feminino , Humanos , Pessoa de Meia-Idade , Cuidados Pós-Operatórios , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Ultrassonografia Doppler , Vitamina K/administração & dosagem , Vitamina K/uso terapêuticoRESUMO
Traumatic rupture of the aortic isthmus is a rare lesion occurring in patients subjected to violent deceleration. Because of the forces involved, it is frequently associated with concomitant life-threatening injuries. Non-invasive examinations such as CT and transesophageal echocardiography aid greatly in making the diagnosis. Urgent conventional repair is still considered the gold standard technique for cases of isolated rupture, or rupture without severe concomitant lesion where aortic clamping and heparinization will not impair post-operative outcomes. Urgent endovascular repair has been shown to be a feasible and efficient technique which may be proposed as a therapeutic option for patients with multiple trauma instead of delayed classical surgical repair after stabilization. Long-term results of endovascular repair need to be assessed before enlarging the indications of this technique in the emergency setting.
Assuntos
Aorta Torácica/cirurgia , Ruptura Aórtica/diagnóstico , Ruptura Aórtica/cirurgia , Doença Aguda , Algoritmos , Aorta Torácica/lesões , Prótese Vascular , Diagnóstico por Imagem , HumanosRESUMO
Hereditary multiple exostoses is an autosomal dominant bone disorder characterized by multiple cartilaginous tumors growing outward from metaphyses of long bones. These tumors are usually located in long bones of the limbs. Exostosis also called osteochondroma can cause many complications, the most serious being malignant transformation as chondrosarcoma. We report a rare phenotype of this disease in a young male patient who presents digestive symptoms caused by a voluminous degenerated lumbar exostosis with anterior abdominal development.
Assuntos
Exostose Múltipla Hereditária/complicações , Obstrução Intestinal/etiologia , Adulto , Exostose Múltipla Hereditária/diagnóstico , Humanos , Obstrução Intestinal/diagnóstico , MasculinoRESUMO
Veno-occlusive disease (VOD) of the liver is mainly described after chemo-irradiation conditioning regimens during haematopoietic stem cell transplantation (SCT) and has been sporadically reported after kidney and liver transplantation. In the latter cases, it is commonly attributed to azathioprine and/or tacrolimus. One case of tacrolimus-induced hepatic VOD developing after lung transplantation (LT) has been recently reported. Here we describe another case of VOD occurring after LT, but in which the causative role was played by azathioprine.
Assuntos
Azatioprina/efeitos adversos , Rejeição de Enxerto/tratamento farmacológico , Hepatopatia Veno-Oclusiva/induzido quimicamente , Imunossupressores/efeitos adversos , Transplante de Pulmão , Azatioprina/uso terapêutico , Biópsia , Seguimentos , Rejeição de Enxerto/patologia , Hepatopatia Veno-Oclusiva/patologia , Humanos , Imunossupressores/uso terapêutico , Fígado/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
Arteriovenous fistulas (AVFs) are usually used for vascular access in the provision of hemodialysis, but AVFs have a 1-year patency rate of only about 60% owing to stenosis. As the molecular mechanisms behind AVF neointimal hyperplasia remain largely unknown, representative models in transgenic mice could be useful to study this process at the genetic level. Hence, we characterized neointimal lesion formation in a model of AVF recently developed in the mouse, where the common carotid artery was end-to-side sutured to jugular vein in C57BL/6J mice. At the site of anastomosis, arterial wall thickening was observed as early as 1 week after surgery (fourfold) and progressed to six- and 10-fold original thickness in carotid arteries after 2 and 3 weeks, respectively. The lumen of the carotid artery was significantly narrowed owing to neointima hyperplasia, and thrombosis was observed in the vein wall opposite to the anastomosed artery. Histological and immunohistochemical analyses revealed that 3-week neointimal lesions consisted of abundant smooth muscle cells (alpha-actin(+)) and a small number of membrane attack complex-1+ macrophages. Furthermore, using chimeric mice receiving bone marrow from transgenic mice expressing the LacZ gene in smooth muscle (SM-LacZ), it was found that bone marrow stem cells did not contribute to smooth muscle cell accumulation in neointimal lesions of AVF arteries. Thus, this model, which reproduces many of the features of human AVF, should prove useful for our understanding of the mechanism of neointimal formation and to evaluate the effects of drugs and gene therapy on this disease.
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Fístula Arteriovenosa/patologia , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Modelos Animais de Doenças , Camundongos Transgênicos , Túnica Íntima/patologia , Animais , Células da Medula Óssea/patologia , Artérias Carótidas/patologia , Artérias Carótidas/cirurgia , Células-Tronco Hematopoéticas/patologia , Veias Jugulares/patologia , Veias Jugulares/cirurgia , Óperon Lac , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/patologiaRESUMO
Blood vessels are permanently subjected to mechanical forces in the form of stretch, encompassing cyclic mechanical strain due to the pulsatile nature of blood flow and shear stress. Significant variations in mechanical forces, of physiological or physiopathological nature, occur in vivo. These are accompanied by phenotypical modulation of smooth muscle cells and endothelial cells, producing structural modifications of the arterial wall. In all the cases, vascular remodelling can be allotted to a modification of the tensional strain or shear, and underlie a trend to reestablish baseline mechanical conditions. Vascular cells are equipped with numerous receptors that allow them to detect and respond to the mechanical forces generated by pressure and shear stress. The cytoskeleton and other structural components have an established role in mechanotransduction, being able to transmit and modulate tension within the cell via focal adhesion sites, integrins, cellular junctions and the extracellular matrix. Mechanical forces also initiate complex signal transduction cascades, including nuclear factor-kappaB and mitogen-activated protein kinase pathways, leading to functional changes within the cell.