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1.
Acta Chir Orthop Traumatol Cech ; 87(5): 363-366, 2020.
Artigo em Eslovaco | MEDLINE | ID: mdl-33146607

RESUMO

Tranexamic acid (TXA) is widely used to limit the blood loss during total joint arthroplasty without an increased risk of thromboembolic events. We present a case of acute limb ischaemia due to thrombotic occlusion of the superficial femoral artery on the non-operated limb following a total hip arthroplasty in a 64-year-old male patient. Untreated peripheral artery disease, intravenous TXA administration, surgery, obesity and hypertension were identified as predisposing factors of the occlusion. Good reperfusion of the limb was obtained after mechanical thrombectomy. Other cases report that antifibrinolytic agents such as TXA could be associated with arterial thrombosis. The necessity to detect the risk factors of thrombotic events in each patient scheduled for total joint arthroplasty is emphasized. Therefore, topical TXA administration could be a reasonable alternative in a high-risk patient. Key words: tranexamic acid complications, total hip arthroplasty, arterial thrombosis.


Assuntos
Antifibrinolíticos , Artroplastia de Quadril , Ácido Tranexâmico , Administração Tópica , Antifibrinolíticos/efeitos adversos , Artroplastia de Quadril/efeitos adversos , Perda Sanguínea Cirúrgica , Humanos , Isquemia/etiologia , Masculino , Pessoa de Meia-Idade , Ácido Tranexâmico/efeitos adversos
3.
Kyobu Geka ; 73(10): 783-788, 2020 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-33130766

RESUMO

Mesenteric malperfusion is reported as a complication associated with acute aortic dissection(AAD) in 3~5% cases, and one of the adverse risk factors for survival. The mortality rate associated with malperfusion due to AAD is higher than that without malperfusion. To improve the clinical outcome, it is important to address the mesenteric malperfusion appropriately. Mesenteric malperfusion remains a diagnostic challenge. Abdominal pain is the most common symptom, but a nonspecific of acute mesenteric ischemia. Computed tomography(CT) including CT angiography is the gold standard in the diagnosis of aortic dissection and the mesenteric malperfusion. No single serum marker, including lactate, is reliable enough to diagnosis mesenteric ischemia. The optimal treatment for mesenteric malperfusion due to AAD is to restore blood flow to the ischemic area as early as possible, while minimizing the risk of thoracic aortic rupture. Those patients with malperfusion but no significant organ ischemia should be treated with immediate surgical repair. Those patients with malperfusion and significant organ ischemia and hemodynamically stable should be treated with mesenteric reperfusion, followed by surgical repair. The management of mesenteric malperfusion associated with AAD requires a tailored approach to improve outcomes. After successful restoration of mesenteric perfusion, patients should be monitored closely, and the bowel should be inspected when there is doubt regarding its viability.


Assuntos
Aneurisma Dissecante , Aneurisma Aórtico , Procedimentos Endovasculares , Isquemia Mesentérica , Doença Aguda , Aneurisma Dissecante/complicações , Aneurisma Dissecante/diagnóstico por imagem , Aneurisma Dissecante/cirurgia , Aneurisma Aórtico/complicações , Aneurisma Aórtico/diagnóstico por imagem , Aneurisma Aórtico/cirurgia , Humanos , Isquemia/etiologia , Isquemia/cirurgia , Isquemia Mesentérica/diagnóstico por imagem , Isquemia Mesentérica/cirurgia , Resultado do Tratamento
4.
Chirurgia (Bucur) ; 115(5): 677-680, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33138906

RESUMO

The spread of SARS-CoV-2 in Italy has been rapid, with over 230.000 infections and 33.000 deaths (May 31st, 2020). The full impact of COVID19 on surgery is still unknown, as its effects on healthcare strategy, hospital infrastructure, staff, regional economy and colorectal disease progression, may not be evident before several months. No systematic reports are available about a higher incidence of COVID19 infections in patients with cancer. However, available data indicate that older people are more vulnerable, particularly when there are underlying health conditions such as chemotherapy or active cancer. Herein, we present the case of a patient with rectal cancer treated with pull-through technique low anterior rectal resection and coloanal anastomosis with protective loop ileostomy, complicated with Sars-CoV-2 infection and late (31st post-operative day) colic ischemia with colo-vaginal fistula. Late intestinal ischemia is a rare complication and can be secondary to several traditional factors, but certainly small vessel thrombosis related to Coronavirus disease must be taken into consideration.


Assuntos
Colo/patologia , Infecções por Coronavirus/complicações , Isquemia/cirurgia , Pneumonia Viral/complicações , Fístula Vaginal/cirurgia , Idoso , Betacoronavirus , Colo/cirurgia , Feminino , Humanos , Isquemia/complicações , Itália , Pandemias , Resultado do Tratamento , Fístula Vaginal/complicações
5.
Nat Commun ; 11(1): 4950, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009377

RESUMO

Necrotizing enterocolitis (NEC) is a devastating disease of premature infants with high mortality rate, indicating the need for precision treatment. NEC is characterized by intestinal inflammation and ischemia, as well derangements in intestinal microcirculation. Remote ischemic conditioning (RIC) has emerged as a promising tool in protecting distant organs against ischemia-induced damage. However, the effectiveness of RIC against NEC is unknown. To address this gap, we aimed to determine the efficacy and mechanism of action of RIC in experimental NEC. NEC was induced in mouse pups between postnatal day (P) 5 and 9. RIC was applied through intermittent occlusion of hind limb blood flow. RIC, when administered in the early stages of disease progression, decreases intestinal injury and prolongs survival. The mechanism of action of RIC involves increasing intestinal perfusion through vasodilation mediated by nitric oxide and hydrogen sulfide. RIC is a viable and non-invasive treatment strategy for NEC.


Assuntos
Enterocolite Necrosante/patologia , Intestinos/irrigação sanguínea , Intestinos/patologia , Isquemia/patologia , Microcirculação , Animais , Enterócitos/patologia , Humanos , Hipóxia , Mucosa Intestinal/patologia , Camundongos Endogâmicos C57BL , Microvilosidades/patologia , Microvilosidades/ultraestrutura
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1528-1531, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018282

RESUMO

Raynaud's phenomenon (RP) is a disease characterized by a transient ischemic process, in an exaggerated vascular response to cold or emotional stress. Thermography is a resource applied to support diagnosis of changes in the circulatory system. The aim of the study was to use the DistalDorsal Thermography Difference (DDD) in thermographic images to assess thermal behavior in individuals with secondary RP. The research was carried out in the period between 2018 and 2019. The sample means of the Distal-consisted of 44 individuals in a control group (Control) and 44 individuals in a pathological group (RP2). The participants, after acclimatization, were submitted to the cold stress protocol. The protocol consisted of immersing hands in a container of water at a temperature of 15°C for 60 seconds. The acquisition of thermographic images was performed at the pre-test moment and at the 1st, 3rd, 5th, 7th, 10th and 15th minute. At each time, the DDD values (of all fingers - minimum, maximum and sum) between the groups were analyzed. For statistical analysis, the independent t test and Cohen's d test were used. Regarding the results, there was a difference in relation to the rate of temperature recovery between the groups. The first group showed a rate of reheating just after the first minute subsequent to the cold stress test, while the RP2 group was unable to recover the temperature over 15 minutes. DDD, regardless of the selected criterion, proved to be a valid index for verifying the temperature gradient in the study with individuals identified with secondary RP.


Assuntos
Doença de Raynaud , Termografia , Temperatura Baixa , Dedos/irrigação sanguínea , Mãos , Humanos , Isquemia , Doença de Raynaud/diagnóstico
7.
JAMA ; 324(16): 1640-1650, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33107944

RESUMO

Importance: Current guidelines recommend ticagrelor as the preferred P2Y12 platelet inhibitor for patients with acute coronary syndrome (ACS), primarily based on a single large randomized clinical trial. The benefits and risks associated with ticagrelor vs clopidogrel in routine practice merits attention. Objective: To determine the association of ticagrelor vs clopidogrel with ischemic and hemorrhagic events in patients undergoing percutaneous coronary intervention (PCI) for ACS in clinical practice. Design, Setting, and Participants: A retrospective cohort study of patients with ACS who underwent PCI and received ticagrelor or clopidogrel was conducted using 2 United States electronic health record-based databases and 1 nationwide South Korean database from November 2011 to March 2019. Patients were matched using a large-scale propensity score algorithm, and the date of final follow-up was March 2019. Exposures: Ticagrelor vs clopidogrel. Main Outcomes and Measures: The primary end point was net adverse clinical events (NACE) at 12 months, composed of ischemic events (recurrent myocardial infarction, revascularization, or ischemic stroke) and hemorrhagic events (hemorrhagic stroke or gastrointestinal bleeding). Secondary outcomes included NACE or mortality, all-cause mortality, ischemic events, hemorrhagic events, individual components of the primary outcome, and dyspnea at 12 months. The database-level hazard ratios (HRs) were pooled to calculate summary HRs by random-effects meta-analysis. Results: After propensity score matching among 31 290 propensity-matched pairs (median age group, 60-64 years; 29.3% women), 95.5% of patients took aspirin together with ticagrelor or clopidogrel. The 1-year risk of NACE was not significantly different between ticagrelor and clopidogrel (15.1% [3484/23 116 person-years] vs 14.6% [3290/22 587 person-years]; summary HR, 1.05 [95% CI, 1.00-1.10]; P = .06). There was also no significant difference in the risk of all-cause mortality (2.0% for ticagrelor vs 2.1% for clopidogrel; summary HR, 0.97 [95% CI, 0.81-1.16]; P = .74) or ischemic events (13.5% for ticagrelor vs 13.4% for clopidogrel; summary HR, 1.03 [95% CI, 0.98-1.08]; P = .32). The risks of hemorrhagic events (2.1% for ticagrelor vs 1.6% for clopidogrel; summary HR, 1.35 [95% CI, 1.13-1.61]; P = .001) and dyspnea (27.3% for ticagrelor vs 22.6% for clopidogrel; summary HR, 1.21 [95% CI, 1.17-1.26]; P < .001) were significantly higher in the ticagrelor group. Conclusions and Relevance: Among patients with ACS who underwent PCI in routine clinical practice, ticagrelor, compared with clopidogrel, was not associated with significant difference in the risk of NACE at 12 months. Because the possibility of unmeasured confounders cannot be excluded, further research is needed to determine whether ticagrelor is more effective than clopidogrel in this setting.


Assuntos
Síndrome Coronariana Aguda/cirurgia , Clopidogrel/efeitos adversos , Intervenção Coronária Percutânea , Antagonistas do Receptor Purinérgico P2Y/efeitos adversos , Ticagrelor/efeitos adversos , Síndrome Coronariana Aguda/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Aspirina/administração & dosagem , Estudos de Casos e Controles , Causas de Morte , Clopidogrel/administração & dosagem , Bases de Dados Factuais/estatística & dados numéricos , Dispneia/induzido quimicamente , Feminino , Hemorragia/induzido quimicamente , Humanos , Isquemia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Metanálise em Rede , Pontuação de Propensão , Antagonistas do Receptor Purinérgico P2Y/administração & dosagem , Recidiva , República da Coreia , Estudos Retrospectivos , Acidente Vascular Cerebral/epidemiologia , Ticagrelor/administração & dosagem , Estados Unidos
8.
Rev Esp Anestesiol Reanim ; 67(9): 516-520, 2020 11.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33012537

RESUMO

Coronavirus associated severe acute respiratory syndrome (SARS-CoV-2) causes a worldwide syndrome called Covid-19 that has caused 5,940,441 infections and 362,813 deaths until May 2020. In moderate and severe stages of the infection a generalized swelling, cytokine storm and an increment of the heart damage biomarkers occur. In addition, a relation between Covid-19 and neurological symptoms have been suggested. The results of autopsies suggest thrombotic microangiopathy in multiple organs. We present 2 cases of patients infected with severe Covid-19 that were hospitalized in the Reanimation Unit that presented cerebrovascular symptoms and died afterwards. A high dose prophylaxis with antithrombotic medication is recommended in patients affected by moderate to severe Covid-19.


Assuntos
Betacoronavirus , Infecções por Coronavirus/complicações , Hemorragia/complicações , Isquemia/complicações , Pneumonia Viral/complicações , Acidente Vascular Cerebral/etiologia , Idoso , Evolução Fatal , Hemorragia/diagnóstico por imagem , Humanos , Isquemia/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Pandemias , Acidente Vascular Cerebral/diagnóstico por imagem , Microangiopatias Trombóticas/complicações , Microangiopatias Trombóticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X
9.
Vascular ; 28(6): 747-755, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33045944

RESUMO

OBJECTIVES: To compare perioperative outcomes related to atherectomy with percutaneous transluminal angioplasty versus percutaneous transluminal angioplasty alone for the treatment of lower extremity chronic limb threatening ischemia using a national patient database. METHODS: Patients with chronic limb threatening ischemia treated with atherectomy and percutaneous transluminal angioplasty or percutaneous transluminal angioplasty alone from 2011 to 2016 in the National Surgical Quality Improvement Program database were identified. Primary outcomes were major adverse limb events (30-day untreated loss of patency, major reintervention, major amputation) and major adverse cardiac events (cardiac arrest, composite outcome of myocardial infarction or stroke). Secondary outcomes included 30-day mortality, length of stay, and any unplanned readmission within 30 days. Multivariate regression analyses were performed to determine independent predictors of outcome. Propensity score matched cohort analysis was performed. A p-value <0.05 was considered statistically significant. Subgroup analyses of femoropopliteal and infrapopliteal interventions were performed. RESULTS: In total, 2636 (77.2%) patients were treated with percutaneous transluminal angioplasty and 778 (22.8%) were treated with atherectomy and percutaneous transluminal angioplasty. Multivariate analyses of the unadjusted cohort revealed no significant differences in major adverse cardiac events or major adverse limb events between the two groups (p-value >0.05). Subgroup analysis of femoropopliteal interventions demonstrated a significantly decreased likelihood of untreated loss of patency in 30 days in the atherectomy group compared to the percutaneous transluminal angioplasty group (1.1% vs. 2.7%, respectively; p-value = 0.034), which persisted on propensity score matched analysis (1.1% vs. 3.1%, respectively; p-value = 0.026). CONCLUSION: Atherectomy with balloon angioplasty of femoropopliteal disease provides a significant decrease in untreated loss of patency compared to balloon angioplasty alone.


Assuntos
Angioplastia com Balão , Aterectomia , Isquemia/terapia , Doença Arterial Periférica/terapia , Idoso , Amputação , Angioplastia com Balão/efeitos adversos , Angioplastia com Balão/mortalidade , Aterectomia/efeitos adversos , Aterectomia/mortalidade , Doença Crônica , Bases de Dados Factuais , Feminino , Humanos , Isquemia/diagnóstico por imagem , Isquemia/mortalidade , Isquemia/fisiopatologia , Salvamento de Membro , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/mortalidade , Doença Arterial Periférica/fisiopatologia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
10.
Wiad Lek ; 73(9 cz. 1): 1882-1887, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33099535

RESUMO

Morbidity and mortality associated with aortic aneurysm remains high. Aneurysms involving the thoracic and lumbar part of the aorta (TAAA) are particularly burdened with mortality. They are also one of the biggest challenges that vascular surgeons can face. Despite several dozen years of progress in surgical techniques, as well as the constant development of accompanying methods of spinal protection, ischemic spinal cord injury with subsequent paresis or pareresis is still one of the most serious complications of both open and closed surgical treatment of aortic aneurysms. Ischemic complications of the spinal cord occur immediately after the procedure, when the patient wakes up with a neurological deficit (according to some authors within the first day after the procedure) or in a deferred manner. In the case of open surgery, immediate damage is more common, in the case of endovascular surgery - deferred. Factors such as low blood pressure, arrhythmias, cardiovascular failure, sepsis and anemia due to anemia contribute to an increased risk of deferred complications. The rehabilitation of a patient with limb paralysis as a consequence of vascular spinal injury is laborious and requires a comprehensive approach. Proper treatment and prompt intervention in the form of rehabilitation is a great therapeutic challenge. The aim of the paper was to present the importance of the ischemic injuries of spinal cord following aortic stent graft implantation through a case report.


Assuntos
Aneurisma da Aorta Torácica , Traumatismos da Medula Espinal , Aneurisma da Aorta Torácica/etiologia , Aneurisma da Aorta Torácica/cirurgia , Humanos , Isquemia , Traumatismos da Medula Espinal/complicações , Stents/efeitos adversos
11.
Khirurgiia (Mosk) ; (10): 79-87, 2020.
Artigo em Russo | MEDLINE | ID: mdl-33047590

RESUMO

Active collagen type I successfully used in regenerative medicine. However, despite the large amount of material of cellular and molecular mechanisms underlying skin repair, the molecular mechanisms of wound healing with use collagen type I, not studied enough. PURPOSE OF THE STUDY: To study the mechanism of the native collagen type I wound-healing action of native type I collagen on the example of the medical device Collost (7% gel) in a model of the rats difficult-to-heal skin wounds. MATERIAL AND METHODS: Male rats in population SD (72 individuals) surgically formed an ischemic dorsal skin flap (3×10 cm) with two full-thickness skin wounds 6 mm in diameter.The trained animals divided into 2 groups: in the experimental group, medical device Collost (gel) applied once after the operation, in the control group - a standard medical device for comparison. The dynamics of wound healing assessed, the number of M2 macrophages, myofibroblasts, vascularization and expression of the main markers of the repair process in the wound tissues and time points for assessment were: after 3, 7 and 14 days after operation using macroscopic, immunohistochemical, and molecular methods. RESULTS: It has been established that the mechanism of action of native collagen type I is associated with the acceleration of the appearance of «progenitorous¼ M2-macrophages in the wound tissues, decrease in the severity of inflammation or reduction in the duration of the inflammatory stage of the repair process, change in the expression spectrum of number of growth factors, an acceleration of neovasculogenesis. CONCLUSION: In this work, on the modern experimental model shown regenerative efficiency of a medical device based on collagen type I and described the molecular and cellular processes of wound healing when using it It has been shown that the acceleration of wound healing processes occurs when using a medical device based on native collagen type 1, it is also accompanied by a better aesthetic closure of the damaged skin area.


Assuntos
Colágeno Tipo I/administração & dosagem , Fármacos Dermatológicos/administração & dosagem , Pele/efeitos dos fármacos , Lesões dos Tecidos Moles/tratamento farmacológico , Cicatrização/fisiologia , Animais , Materiais Biocompatíveis/administração & dosagem , Modelos Animais de Doenças , Géis , Isquemia/tratamento farmacológico , Masculino , Ratos , Pele/lesões , Lesões dos Tecidos Moles/terapia , Retalhos Cirúrgicos/irrigação sanguínea
12.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(9): 1149-1152, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33081909

RESUMO

Acute kidney injury (AKI) is a common clinical critical illness, and ischemic kidney injury is the main type. The mortality rate of ischemic kidney injury is high, because the efficacy of treatment is limited due to symptomatic and supportive treatment. Establishing a reliable animal model of ischemic AKI is an important prerequisite for conducting research on physiological, pathological and pharmacological researches, so as to explore effective prevention methods and strategies. In recent years, the establishment methods of animal models of ischemic AKI have been continuously improved. The article summarizes the common methods and model characteristics of animal models of ischemic AKI in order to provide a reference for researchers to choose a reasonable modeling method.


Assuntos
Lesão Renal Aguda , Animais , Estado Terminal , Modelos Animais de Doenças , Isquemia , Rim
13.
Angiol Sosud Khir ; 26(3): 37-43, 2020.
Artigo em Russo | MEDLINE | ID: mdl-33063750

RESUMO

Critical ischaemia of lower limbs is a cause of death and invalidity in the whole world. Stem cells and products of their secretion find wide application in treatment of vascular diseases, including critical ischaemia of the lower limbs. Erythropoietin promotes an increase in the angiogenic potential of stem cells. The authors examined the therapeutic potential of a biomedical cellular product (mesenchymal stem cells and products of their secretion) and mesenchymal stem cells with erythropoietin on the processes of restoration of vessels in the hind legs of Wistar male rats following induction of lower limb critical ischaemia. Mesenchymal stem cells were derived from the bone marrow of male Wistar rats. Critical ischaemia of hind legs was modulated by transaction of the femoral artery. The parameters of microcirculation in the foot were assessed with the help of laser Doppler flowmetry. In the blood serum and crural muscles by means of solid-phase enzyme immunoassay we examined the levels of cytokines, growth factors, and persistent metabolites of nitrogen oxide - nitrites. Muscles morphology and the number of blood vessels were assessed by the findings of histological examination. It was shown that the biomedical cellular product alone and in combination with erythropoietin stimulated angiogenesis. The results of Doppler flowmetry revealed restoration of the parameters of microcirculation in the lower limb by 35-75% of the baseline values. Besides, we observed a decrease of muscle necrosis, connective tissue proliferation, and an increase in the number of the vessels supplying the muscles in the experimental groups. It was also determined that the biomedical cellular product influenced the levels of cytokines in blood serum and crural muscles. Hence, the obtained findings proved the therapeutic potential of the biomedical cellular product in critical ischaemia of lower limbs.


Assuntos
Isquemia , Doenças Vasculares Periféricas , Animais , Modelos Animais de Doenças , Humanos , Isquemia/tratamento farmacológico , Extremidade Inferior , Masculino , Ratos , Ratos Wistar
14.
Angiol Sosud Khir ; 26(3): 116-121, 2020.
Artigo em Russo | MEDLINE | ID: mdl-33063758

RESUMO

Presented herein is original experience in using a technique of arterialization in patients with critical lower limb ischaemia on the background of diffuse multilevel occlusive lesions of femoral, crural arteries and arteries of the foot in 214 patients. We used a new method of treatment by means of oxygenation of the sural group of muscles and the foot through the small saphenous vein and indirect communicating veins. This method does not require destruction of the valvular apparatus of the communicants themselves, promoting opening of previously not functioning ones, as well as appears to be a powerful stimulus for the development of collateral circulation of the extremity. Alterations introduced into the design characteristics of a valvulotome make it possible to avoid lateral injury of the venous wall in the area of confluence of tributaries, preventing incomplete resection of the valve. The method expands the boundaries of operability of patients with the absence of the receiving arterial bed of the calf and foot. It may be combined with arterial primary and repeat reconstructions in patients with depleted receiving channel of the calf as an effective additional path of outflow. It also makes it possible to lower the level of amputation in the developed necrosis of the distal part of the foot. Based on clinical laboratory and instrumental findings, the patients were diagnosed by the aetiological factor of the occlusive process and its extension, substantiating the indications for operative treatment with the use of one or another venous basin. Comparative assessment of reversion of arterial blood flow through the great saphenous vein, small saphenous vein, and posterior tibial vein, according to the findings of bioelectromagnetic diagnosis of reactivity of tissues demonstrated that the most effective method was that of arterialization thought the small saphenous vein. With the help of the questionnaire of quality of life in patients with performed arterialization of the calf and foot through the small saphenous vein for critical lower limb ischaemia we obtained 5-year remote results. Upon completion of this period, 87.3% of the limbs were saved and composite measures of the patients' quality of life proved to be high, ranging from 53 to 69 points.


Assuntos
Doenças Vasculares Periféricas , Qualidade de Vida , Humanos , Isquemia/diagnóstico , Isquemia/etiologia , Isquemia/cirurgia , Perna (Membro) , Veia Safena
15.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2434-2437, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018498

RESUMO

Dialysis causes blood flow defects in the heart that may augment electrophysiological heterogeneity in the form of increased number of ischemic zones in the human left ventricle. We computationally tested whether a larger number of ischemic zones aggravate arrhythmia using a 2D electrophysiological model of the human ventricle.A human ventricle cardiomyocyte model capable of simulating ischemic action potentials was adapted in this study. The cell model was incorporated into a spatial 2D model consisting of known number of ischemic zones. Inter-cellular gap junction coupling within ischemic zones was reduced to simulate slow conduction. Arrhythmia severity was assessed by inducing a re-entry, and quantifying the ensuing breakup and tissue pacing rates.Ischemia elevated the isolated cardiomyocyte's resting potential and reduced its action potential duration. In the absence of ischemic zones, the propensity in the 2D model to induce multiple re-entrant waves was low. The inclusion of ischemic zones provided the substrate for initiation of re-entrant waves leading to fibrillation. Dominant frequency, which measured the highest rate of pacing in the tissue, increased drastically with the inclusion of multiple ischemic zones. Re-entrant wave tip maximum numbers increased from 1 tip (no ischemic zone) to 34 tips when a large number (20) of ischemic zones were included. Computational limiting factors of our platform were identified using software profiling.Clinical significance. Dialysis may promote deleterious arrhythmias by increasing tissue level action potential dispersion.


Assuntos
Arritmias Cardíacas , Diálise Renal , Arritmias Cardíacas/etiologia , Eletrofisiologia Cardíaca , Simulação por Computador , Humanos , Isquemia
16.
J Vasc Interv Radiol ; 31(11): 1831-1835, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32958378

RESUMO

PURPOSE: To review the immediate flow response and incidence of steal syndrome after taper reduction of tapered dialysis grafts. MATERIAL AND METHODS: This was a retrospective review of a quality assurance database of all hemodialysis access interventions performed between 2005 and 2017. It identified 77 patients who underwent a taper reduction procedure, involving angioplasty of the arterial limb of the graft and the arterial anastomosis for graft thrombosis/poor flow. A subset of patients underwent 5-, 6-, or 7-mm balloon taper reduction angioplasty coupled with intravascular direct flow measurement (n = 15 with 16 dialysis grafts). A two-tailed Wilcoxon matched-pairs signed-rank test was used to compare pre- and post-taper reduction flows. Mean duration of follow-up was 3.5 years (range, 0-12.5 years). RESULTS: Mean access survival after taper reduction was 20.2 months (range, 0.10-94.4 months). Pre- and post-taper reduction access flows (mean Qb ± standard deviation) were 574 ± 315 ml/min and 929 ± 352 ml/min, respectively (P < .0001). The mean ratio of post- to pre-taper reduction flows was 1.6 (range, 1.1-10.2). No patients developed steal syndrome within 6 months after taper reduction. CONCLUSIONS: Dialysis graft arterial anastomotic taper reduction did not result in the development of steal syndrome within 6 months. In the subset of patients who underwent flow measurements, taper reduction was associated with nearly a 2-fold improvement in access flow, which is a key predictor of access function.


Assuntos
Angioplastia com Balão , Derivação Arteriovenosa Cirúrgica/instrumentação , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Oclusão de Enxerto Vascular/terapia , Diálise Renal , Trombose/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Angioplastia com Balão/efeitos adversos , Derivação Arteriovenosa Cirúrgica/efeitos adversos , Velocidade do Fluxo Sanguíneo , Implante de Prótese Vascular/efeitos adversos , Bases de Dados Factuais , Feminino , Oclusão de Enxerto Vascular/diagnóstico por imagem , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/fisiopatologia , Humanos , Isquemia/etiologia , Isquemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Estudos Retrospectivos , Fatores de Risco , Trombose/diagnóstico por imagem , Trombose/etiologia , Trombose/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
17.
Acta Cir Bras ; 35(9): e202000901, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32996998

RESUMO

PURPOSE: To evaluate the effects of treatment with Indigo Carmine (IC) on rat livers subjected to ischemia-reperfusion injury. METHODS: The animals were subdivided into 4 groups: 1.SHAM group(SH) - saline; 2.SHAM group with IC-2mg/Kg(SHIC); 3.IR group - rats submitted to ischemia and reperfusion with saline(IR); 4.IR group with IC-2mg/Kg(IRIC). The IR protocol consists of liver exposure and administration of drug or saline intravenously, followed by 60 minutes of ischemia and 15 of reperfusion. Liver samples were collected for biochemical analysis. RESULTS: State 3 of mitochondrial respiration showed a significant worsening of the IRIC group in relation to all others. State 4 showed a difference between IRIC and SHIC. The Respiratory Control Ratio showed statistical decrease in IR and IRIC versus Sham. The osmotic swelling showed significant difference between SHxIR; SHICxIRIC and SHxIRIC. There was a significant increase in ALT in the IRIC group in relation to all the others. Concerning the nitrate dosage, there was a decrease in the group treated with IC(IRxIRIC). There was no difference regarding the dosage of Malondialdehyde. CONCLUSION: IC was not able to protect mitochondria from IR injury and proved to be a potentiating agent, acting in synergy with the IR injury promoting damage to the hepatocyte membranes.


Assuntos
Índigo Carmim , Isquemia , Traumatismo por Reperfusão , Animais , Aspartato Aminotransferases , Índigo Carmim/uso terapêutico , Isquemia/tratamento farmacológico , Isquemia/prevenção & controle , Masculino , Ratos , Ratos Wistar , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/prevenção & controle
20.
Acta Chir Plast ; 62(1-2): 40-44, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32911941

RESUMO

The key point for microvascular reconstruction is to preserve patency of flap vessels. Despite great improvement in reconstruction success rates in the last 30 years, ischemic complications are still an undesirable event. The authors assessed recent as well as older literature and compared progression in perioperative pharmacology interventions in antithrombotic prevention.


Assuntos
Anastomose Cirúrgica , Humanos , Isquemia , Microcirurgia , Retalhos Cirúrgicos
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