Thesis (Ph. D.)--University of Washington, 1996. / Includes bibliographical references (leaves [97]-104).

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 5 uppsatser.

Thesis (D.P.H.)--University of Michigan.

Dissertation (D.P.H.)--University of Michigan.

Orientador: Ana Terezinha Guillaumon / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-28T09:17:18Z (GMT). No. of bitstreams: 1 Siqueira_LeticiaCristinaDalledone_M.pdf: 5041737 bytes, checksum: 615b5b4269f2f46490565662d28dfb21 (MD5) Previous issue date: 2015 / Resumo: Introdução: A espectroscopia próxima ao infra-vermelho (NIRS) é uma técnica não invasiva e de baixo custo que detecta as alterações hemodinâmicas teciduais. O NIRS pode monitorar de forma contínua as informações fisiológicas vasculares intracranianas. Por ser portátil, ele pode ser utilizado a beira do leito e no centro cirúrgico. Objetivo: Avaliar o comportamento das possíveis alterações hemodinâmicas cerebrais, durante a endarterectomia, em pacientes com estenoses maiores que 70%, utilizando NIRS. Casuística e métodos: Foram avaliados 10 voluntários portadores de doença carotídea aterosclerótica com indicação de endarterectomia. Após a seleção dos pacientes que responderam um questionário com dados epidemiológicos e informações referentes a presença de comorbidades, a doença foi confirmada por métodos diagnósticos. No procedimento cirúrgico utilizou-se o NIRS para monitorização. Foram avaliadas as variáveis saturação de oxigênio (Sat O2) hemoglobina total (HbT), hemoglobina reduzida (HbR) e hemoglobina oxigenada (HbO) nos três tempos cirúrgicos pré, trans e pós-clampeamento carotídeo. Resultados: Utilizou-se p<0,05 como nivel de significância. A avaliação dos resultados obtidos através das medidas registradas pelo NIRS permite afirmar que as etapas da cirurgia diferem quanto ás variável HbR e SatO2. Durante a etapa do clampeamento, a variável HbR mostra valores mais elevados que nas outras duas etapas da cirurgia. De outra parte, a variável SatO2 mostra redução durante o clampeamento. Conclusão: O NIRS é um método viável e aplicável de monitorização intracerebral, não-invasivo e em tempo real, durante a endarterectomia carotídea, capaz de medir de forma precisa as mudanças das condições hemodinâmicas capilares intra-cerebrais / Abstract: Introduction: Near-infrared spectroscopy (NIRS) is a low-cost, non-invasive technique that detects tissue hemodynamic alterations. It enables continuous monitoring of the intracerebral vascular physiologic information. Due to its portable nature, NIRS may be used beside a bed or in the operating room. Objective: To evaluate the use of NIRS for intra-surgical monitoring of the brain hemodynamic response, during an endarterectomy procedure of the atherosclerotic carotid artery. Casuistry and Methods: 10 patients with atherosclerotic carotid disease and recommended endarterectomy were evaluated. They were identified in a survey which provided epidemiologic data and the presence of comorbidities. Disease was confirmed by diagnostic methods. NRIS monitoring was used during the surgical procedure. Oxygen saturation (O2 Sat), total hemoglobin (THb), reduced hemoglobin (RHb), and oxyhemoglobin (OHb) were the variables analyzed at the three carotid clamp stages: pre-, trans- and post-. Results: A p<0.05 value was considered statistically significant. The results obtained from the NIRS data reveal that the surgical stages differ in relation to the RHb and O2Sat variables. RHb presents higher levels during clamping when compared with the other two surgical stages. On the other hand, O2Sat is decreased during clamping. Conclusion: NIRS is a feasible, realtime and non-invasive intracranial monitoring method, during carotid endarterectomy, which measures accurately and reliably the changes of the intracerebral capillary hemodynamic conditions / Mestrado / Cirurgia / Mestra em Ciências

<p>UVOD: Vilisov poligon predstavlja najznačajniju rezervu kolateralnog protoka između ekstrakranijalnih arterija koje vaskularizuju mozak i ima sposobnost razvoja kolateranih puteva kod ekstrakranijalne karotidne bolesti. Ova anatomska struktura podložna je varijacijama koje uključuju i prekid kontinuiteta i nekompletnost kolateralizacije. CILJEVI: Cilj je bio da se utvrdi da li nekompletnost Vilisovog poligona utiče na če&scaron;će pojavljivanje neurolo&scaron;ke simptomatologije i ishemijske moždane lezije kod pacijenata sa ekstrakranijalnom karotidnom bolesti. Takođe cilj je bio i da se utvrdi da li cerebrovaskularna reaktivnost kod pacijenata sa asimptomatskom ekstrakranijalnom karotidnom bolesti zavisi od kompletosti Vilisovog poligona i na koji način hirur&scaron;ki tretman utiče na parametre cerebrovaskularne rezerve kod pacijenata sa kompletnim i nekompletnim Vilisovim poligonom. METOD: U retrospektivnoj studiji analiziran je nalaz MRA kod 211 pacijenata sa ekstrakranijalnom karotidnom bolesti i 102 pacijenta iz kontrolne grupe. U prospektivnoj studiji je kod 98 pacijenata sa asimptomatskom karotidnom bolesti pored MRA nalaza određivana cerebrovaskularna reaktivnost putem određivanja &bdquo;breath hold index&ldquo;-a (BHI) pre i nakon operativnog tretmana. REZULTATI: Nekompletan Vilisov poligon nađen je kod 25% asimptomatskih, 47,5% simptomatskih pacijenata sa karotidnom bolesti i kod 59% kontrolne grupe pacijenata, pri čemu su se razlike pokazale kao statistički značajne. Kod asimptomatskih pacijenata sa nekompletnim Vilisovim poligonom BHI preoperativno iznostio je 0,62 a postoperativno 1,01 na strani lezije. U slučaju nekompletnog Vilisovog poligona preoperativna vrednost BHI iznostila je 0,88 a postoperativna 1,09 na strani lezije. Razlike su se pokazale kao statistički značajne između grupa i pre i posle operativnog tretmana. Porast je bio statistički značajno izraženiji u grupi asimptomatskih pacijenata sa nekompletnim Vilisovim poligonom. Nisu zabeležene major operativne komplikacije (perioeprativni moždani udar,smrtni ishod) a na pojavu hiperperfuzionog sindroma najvi&scaron;e su uticali kompletnost Vilisovog poligona, vrednost BHI i preoperativni tretman hipertenzije. ZAKLJUČCI: Nekompletan Vilisov poligon predstavlja faktor rizika za pojavu neurolo&scaron;ke simptomatologije ili ishemijske moždane lezije kod pacijenata sa ekstrakranijalnom karotidnom bolesti. Kod asimptomatskih pacijenata nekompletan Vilisov pologon utiče na smanjenu cerebrovaskularnu reaktivnost i veći rizik od moždanog udara. Parametri cerebrovaskularne reaktivnosti signifikantno se pobolj&scaron;avaju nakon operativnog tretmana.</p> / <p>INTRODUCTION: Circle of Willis is the most important reserve of collateral flow between the extracranial arteries that supply the brain and has the ability to develop collateral pathways in extracranial carotid disease. This anatomical structure is subject to variations which include a disruption in the continuity and incompleteness of collateralisation. OBJECTIVES: was to determine whether the incompleteness of the Circle of Willis is more often associated with neurological symptoms and ishemic cerebral lesions in patients with extracranial carotid artery disease. Also, the objective was to determine whether cerebrovascular reactivity in patients with asymptomatic extracranial carotid artery disease depends on the completeness Circle of Willis and how surgical treatment affects the parameters of cerebrovascular reserve in patients with complete and incomplete Circle of Willis. METHODS: This study analyzed the findings of MRA in 211 patients with extracranial carotid artery disease and 102 patients in the control group. In prospective study in 98 patients with asymptomatic carotid artery disease in addition to the MRA findings cerebrovascular reactivity was determined by determining the &quot;breath hold index&quot; -a (BHI) before and after surgical treatment. RESULTS: Incomplete Circle of Willis was found in 25% of asymptomatic, 47.5% of symptomatic patients with carotid artery disease, and 59% of the control group patients, where the difference proved to be statistically significant. In asymptomatic patients with incomplete Circle of Willis BHI values were 0.62 preoperatively and 1.01 postoperatively on the side of the lesion. In the case of incomplete Circle of Willis preoperative BHI values were 0.88 preopertively and 1.09 postoperatively in asymptomatic patients. The differences are shown to be statistically significant between the groups before and after surgical treatment. The increase was significantly more pronounced in the group of asymptomatic patients with incomplete Circle of Willis. There were not recorded major operative complications (perioeprativni stroke, mortality) and the occurrence hyperperfusion syndrome was most affected by completeness of the Circle of Willis, a value BHI and preoperative treatment of hypertension. CONCLUSIONS: Incomplete Circle of Willis is a risk factor for the occurrence of neurological symptoms or ischemic brain lesions in patients with extracranial carotid artery disease. In asymptomatic patients incomplete Circle of Willis affects the reduced cerebrovascular reactivity and a higher risk of stroke. The parameters of cerebrovascular reactivity significantly improved after surgical treatment.</p>

<p>TCD apnea test kao neinvazivna i bezbedna neuroultrasonografska metoda pruža korisne informacije o vazomotornoj reaktivnosti (VMR) u procesu indirektnog sagledavanja funkcionisanja moždane autoregulacije. Vazomotorna reaktivnosti podrazumeva sposobnost dilatacije ili konstrikcije moždanih arteriola nastale kao odgovor na određeni vazoaktivni stimulus, najče&scaron;će ugljen dioksid. Cilj ove doktorske disertacije bio je ispitivanje i analiziranje promene karotidne hemodinamike kod bolesnika sa ishemijskim moždanim udarom (IMU) ili tranzitornim ishemijskim atakom (TIA) i simptomatskom karotidnom stenozom u preoperativnom i tromesečnom postoperativnom periodu, kao i procena revaskularizacionog efekta karotidne endarterektomije (KEA).U istraživanje je uključeno 60 hospitalizovanih bolesnika koji su doživeli prvi IMU i TIA u zoni vaskularizacije arterije cerebri anterior (ACA) i arterije cerebri medije (ACM), svi sa karotidnom stenozom, ACI &ge;70%. Bolesnici su bili hospitalizovani na Klinici za neurologiju, Kliničkog Centra Vojvodine, Klinici za kardiovaskularnu hirurgiju, Instituta za kardiovaskularne bolesti Vojvodine i Klinici za vaskularnu hirurgiju, u Novom Sadu. U odnosu na kliničke manifestacije bolesni i su podeljeni u tri grupe: bolesnici sa TIA i amaurosis fugax, sa parcijalnim infarktom u zoni ACA ili ACM i sa lakunarnim infarktom. Istraživanje je analiziralo uticaj promenljivih i nepromenljivih vaskularnih faktora rizika na pojavu IMU i TIA, ali i na VMR, procenjivanu kroz indeks zadržavanja daha (Breath Holding Index, BHI) ipsilateralno i kontralateralno u odnosu na karotidnu stenozu. Analizirana je povezanost stepena karotidne stenoze sa vrednostima BHI preoperativno, povezanost BHI sa težinom kliničke slike, uticaj kolateralnog krvotoka na VMR, distribucija BHI u pojedinim tipovima IMU i TIA kao i komparacija BHI u pre i u postoperativnom periodu od 30 i 90 dana. Na osnovu sprovedenog istraživanja, do&scaron;lo se do zaključaka da je redukovana VMR preoperativna karakteristika karotidne stenoze ipsilateralno kao i karakteristika različitih tipova IMU i TIA ipsilateralno; postoji negativna korela ija izmeĐu stepena karotidne stenoze i BHI vrednosti. Nije potvrđena hipoteza da veći roj razvijenih kolateralnih puteva uslovljava očuvanu VMR; utvrđena je pozitivna korelacija između BHI vrednosti u preoperativnom i postoperativnom periodu; redukovana VMR ima negativan uticaj na težinu kliničke slike. Prepoznavanje vrednosti TCD apnea testa, koji se može koristiti kao komplementarna metoda drugim vazoaktivnim testovima u praćenju karotidne hemodinamike, od posebne je važnosti neurologu i vaskularnom hirurgu. Time bi se doprinelo daljoj evaluaciji mehanizma nastanka IMU, planiranju terapijskog pristupa i determinisanju prognoze operisanih bolesnika. Činjenica da većina neurolo&scaron;kih odeljenja poseduje TCD aparat, apnea test postaje dostupan svakom neurologu u kliničkom radu, posebno u na&scaron;im uslovima, kada se do drugih drugih, skupljih metoda, te&scaron;ko stiže ili nam ostaju nedostižne.</p> / <p>TCD apnea test, as a noninvasive and safe neuroultrasonographic method, provides useful information about vasomotor reactivity (VMR) in the indirect evaluation of cerebral autoregulation. Vasomotor reactivity is the ability of cerebral arterioles to constrict or to dilate in response to a vasoactive stimulus, mainly carbon dioxide. The aim of this doctoral thesis was to investigate and analyze changes in carotid hemodynamics in patients with ischemic stroke (IS) or transient ischemic attack (TIA) and symptomatic carotid stenosis in the preoperative and three-month postoperative period as well as the assessment of revascularisation effect of carotid endarterectomy (CEA). The study included 60 hospitalized patients who experienced a first ischemic stroke or TIA in the vasularisation area of anterior cerebral artery (ACA) and middle cerebral artery (MCA), all with carotid stenosis &ge;70% ACI. Patients were hospitalized at the Clinic of Neurology, Clinical Center of Vojvodina, Department of Cardiovascular Surgery, Institute of Cardiovascular Diseases and the Department of Vascular Surgery in Novi Sad. Considering clinical manifestations of stroke, the patients were divided into three groups: patients with TIA and amaurosis fugax, with partial infarction in area ACA or ACM and with lacunar infarct. The study analyzed the impact of variabile and unvariable vascular risk factors on the incidence of ischemic stroke and TIA, but also on VMR, evaluated through Breath Holding Index (Breath Holding Index, BHI) on the ipsilateral and contralateral side from carotid stenosis. We analysed the correlation between the degree of carotid stenosis with preoperative values of BHI, BHI correlation to the severity of clinical findings, the impact of collateral circulation to the VMR, distribution of BHI in certain types of ischemic stroke and TIA as well as comparison of BHI in the pre and postoperative period of 30 and 90 days. On the basis of this research came the conclusion that reduced VMR is characteristic of ipsilateral carotid stenosis in preoperative period as well as number of developed collateral characteristics of different types of ipsilateral ischemic stroke and TIA; there is a negative correlation between the degree of carotid stenosis and BHI values. The hypothesis that the greater pathways causes preservation of VMR was not confirmed, while the positive correlation between BHI values in the preoperative and postoperative period was established. Reduced VMR has a negative impact on the degree of clinical picture severity. Recognizing the importance of TCD apnea test method, that can be used as a complementary method to other vasoactive tests in monitoring of carotid hemodynamics, is of special importance to the neurologists and vascular surgeons. This would contribute to the further evaluation of mechanism of ischemic stroke, planning of therapeutic approach and determining the prognosis of treated patients. The fact that most of neurological department has TCD device, apnea test becomes available to every neurologist in clinical work, specially in our conditions, when other methods remain unattainable.</p>

Background. Carotid stenosis is an important cause of stroke. Carotid endarterectomy is a means of reducing the burden of stroke but is of marginal benefit in individuals with asymptomatic carotid stenosis. The identification of factors associated with increased risk of cerebral ischemic events would help select individuals who may obtain a greater benefit. / Methods. A comprehensive search was performed to identify studies examining risk factors for cerebral ischemic events in patients with asymptomatic carotid stenosis. Inclusion criteria were defined a priori. Relevant studies were reviewed, assessed for quality, and data were extracted. / Results. Thirty-four studies met the inclusion criteria. There was a suggestion of increasing neurological events with increasing severity and progression of carotid stenosis. There was some evidence for an association with carotid plaque morphology. No consistent association was found with clinical factors, impaired cerebral vasoreactivity, or cerebral embolic signals. / Conclusions. The evidence is insufficient to reliably identify individuals with asymptomatic carotid stenosis who are at a higher risk of cerebral ischemic events.

No description available.

<p>Ciljevi: Cilj ove studije je da ispita bezbednost rane karotidne endarterektomije (CEA) u odnosu na odložene CEA nakon akutnog ishemijskog neurolo&scaron;kog deficita (TIA/CVI). Drugi cilj je da istražimo da li postoji razlika u brzini neurolo&scaron;kog oporavka između navedenih grupa. Metode: Ukupno 157 ispitanika u prospektivnoj studiji je praćeno 30 dana postoperativno. Grupa I ili rana CEA, je imala 50 ispitanika operisanih od 3. do 14. dana po TIA/CVI događaju. Grupa II ili odložena CEA, je imala 107 ispitanika operisanih od 15. do 180. dana nakon TIA/CVI. Praćen je proceduralni op&scaron;ti i specifični morbiditet i mortalitet u 30-dnevnom postoperativnom periodu. Rankin skor (mRS) smo koristili za procenu neurolo&scaron;kog invaliditeta. U odnosu na vrednost mRS skora smo formirali dve podgrupe mRS&lt;3 i mRS3. U statističkoj analizi koristili smo Pirsonov hi test, Studentov test, ANOVU analizu varijanse, Boniferonijev test i multiplu analizu varijanse za ponovljena merenja (GLM- general line model), kao i parametarsku i neparametarsku korelaciju i regresiju. Nivo značajnosti je bio 0,05. Rezultati: Prosečna starost ispitanika je bila 66,72 godine uz 66,2% osoba mu&scaron;kog pola. U grupi I je prosečno vreme do intervencije bilo 9,5 dana, a u grupi II 72,22 dana. Grupe su homogene u odnosu na faktore rizika i komorbiditet. Grupa I je imala 54% nestabilnih aterosklerotskih plakova u poređenju sa grupom II gde ih je bilo 31,8% (&chi;2 = 7.084; p &lt; 0.01). U grupi I TIA je imalo 50% ispitanika, a u grupi II CVI nalaza je bilo 68,2% (&chi;2 =4.825; p &lt;0.05). CVI do 1 cm veličine je statistički značajno vi&scaron;e zastupljen u grupi I , a CVI do 2 cm u grupi II (&chi;2 = 6.913; p &lt;0.05). Stopa CVI je u grupi I bila 2.0% a u grupi II je 2.8% (F = 0.083; p &gt; 0.05). Stopa postoperativnog infarkta miokarda (IM) je u grupi I je 2.0% a u grupi II je 1.9%. Stopa specifičnog hirur&scaron;kog morbiditeta je u grupi I 4.0% a u grupi II 3.7%. U grupi I ukupni morbiditet bio 6.0% a u grupi II 7.5%, razlika nije bila statistički značajna (F =0.921; p &gt; 0.05). Mortaliteta u obe grupe nije bilo. CVI/IM/smrt stopa je u grupi I bio 4.0% a u grupi II je bio 4.7% (F = 0.122; p &gt;0.05). Hiperlipidemija je signifikantan faktor rizika za CVI/IM/smrt (&chi;2 = 4.083; p &lt; 0.05). Pobolj&scaron;anje mRS je u grupi I imalo 52%, a u grupi II 31,8% pacijenata (&chi;2 = 5.903; p &lt;0.01). Relativni rizik je 2,4 odnosno toliko puta je veća &scaron;ansa da kod bolesnika dođe do promene mRS ako je bolesnik u grupi I. Pad mRS koji nastupa između trećeg i desetog dana nakon CEA je statistički visoko značajno izraženiji u grupi ranih CEA ( F 3,701 df 1 p=0,029). Kod bolesnika sa TIA u preko 60% slučajeva do&scaron;lo je do pada mRS, a kod onih koji su imali CVI u oko 25.5% (&chi;2 = 18.050; p &lt; 0.01). Kod Rankin skora podgrupe mRS&lt;3 i mRS3 je pad bio značajan i po vremenu (F 18,774; df 6; p=0,000) i po podgrupi ali je daleko brži pad zapažen u podgrupi mRS&lt;3(F 6,010; df 1; p=0,003). Zaključak: Rana CEA je jednako bezbedna kao i odložena CEA u pogledu incidence perioperativnog morbiditeta i mortaliteta. Ranom CEA se postiže znatno brži neurolo&scaron;ki oporavak pacijenata, naročito onih sa TIA i mRS&lt;3 skorom.</p> / <p>Objectives: The aim of this study was to investigate the safety of early carotid endarterectomy (CEA) in relation to the delayed CEA after acute ischemic neurological events (TIA / CVI). The second objective was to investigate whether there is a difference in speed of neurological recovery between these groups. Methods: A total of 157 patients in the prospective study followed 30 days postoperatively. Group I or early CEA, had 50 patients operated from 3 to 14 days after TIA / CVI event. Group II or delayed CEA, had 107 patients operated from 15 to 180 days after the TIA / CVI. Accompanied by the general and specific procedural morbidity and mortality in 30-day postoperative folow up. Rankin score (mRS) were used for evaluation of neurologic disability. In relation to the value of mRS score we formed two subgroups mRS &lt;3 i mRS3. In the statistical analysis we used the Pearson chi test, Student&#39;s test, ANOVA analysis of variance, Boniferony test and multiple analysis of variance for repeated measures (GLM- general line model), as well parametric and nonparametric correlation and regression. The significance level was 0.05. Results: The mean age was 66.72 years with 66.2% of males. In Group I is the average time to intervention was 9.5 days, and in group II 72.22 days. The groups were homogeneous in relation to risk factors and comorbidities. Group I had 54% of unstable atherosclerotic plaques compared with group II, where it was 31.8% (&chi;2 = 7.084; p &lt;0.01). In the group I TIA had 50% of respondents, while in group II CVI was 68.2% (&chi;2 = 4.825; p &lt;0.05). CVI to 1 cm in size were significantly more frequent in the group I, a CVI to 2 cm in group II (&chi;2 = 6.913; p &lt;0.05). CVI rate in the group I was 2.0%, and in group II was 2.8% (F = 0.083, p&gt; 0.05). Postoperative myocardial infarction (MI) in the group I is 2.0%, and in group II was 1.9%. Specific surgical morbidity rate in the group I and 4.0% in the group II 3.7%. In group I total morbidity was 6.0% in group II 7.5%, the difference was not statistically significant (F = 0.921; p&gt; 0.05). Mortality in both groups was not. CVI/IM/death rate in group I was 4.0% in group II was 4.7% (F = 0.122; p&gt; 0.05). Hyperlipidemia is a significant risk factor for CVI/IM/death (&chi;2 = 4.083; p&lt;0.05). Improving mRS in the group I had 52% and in group II 31.8% of patients (&chi;2 = 5.903; p &lt;0.01). The relative risk was 2.4 times as much and is more likely to occur in patients mRS changes if the patient in group I. Improving mRS that occurs between the third and tenth days after CEA was highly statistically significantly greater in the group of early CEA (F 3,701 df 1 p = 0.029). In patients with TIA in 60% of cases there was a decline mRS, and those had CVI in about 25.5% (&chi;2 = 18.050; p &lt;0.01). In Rankin score subgroups mRS &lt;3 i mRS 3 the decline was significant and time (F 18,774; df 6; p =0.000) and in the subgroup but it is far more rapid decline observed in the subgroup mRS &lt;3 (F 6.010; df 1; p = 0.003). Conclusions: Early CEA is as safe as the delayed CEA in respect incidence of perioperative morbidity and mortality. Early CEA is achieved significantly faster recovery of neurological patients, especially those with TIA and mRS &lt;3 compared with delayed CEA.</p>