Coronary Angioscopy Findings before and after Excimer Laser Coronary Angioplasty for Bare-Metal Stent In-Stent Restenosis

No abstract available.

Advances in Intravascular Imaging: New Insights into the Vulnerable Plaque from Imaging Studies

The term “vulnerable plaque” denotes the plaque characteristics that are susceptible to coronary thrombosis. Previous post-mortem studies proposed 3 major mechanisms of coronary thrombosis: plaque rupture, plaque erosion, and calcified nodules. Of those, characteristics of rupture-prone plaque have been extensively studied. Pathology studies have identified the features of rupture-prone plaque including thin fibrous cap, large necrotic core, expansive vessel remodeling, inflammation, and neovascularization. Intravascular imaging modalities have emerged as adjunctive tools of angiography to identify vulnerable plaques. Multiple devices have been introduced to catheterization laboratories to date, including intravascular ultrasound (IVUS), virtual-histology IVUS, optical coherence tomography (OCT), coronary angioscopy, and near-infrared spectroscopy. With the use of these modalities, our understanding of vulnerable plaque has rapidly grown over the past several decades. One of the goals of intravascular imaging is to better predict and prevent future coronary events, for which prospective observational data is still lacking. OCT delineates microstructures of plaques, whereas IVUS visualizes macroscopic vascular structures. Specifically, plaque erosion, which has been underestimated in clinical practice, is gaining an interest due to the potential of OCT to make an in vivo diagnosis. Another potential future avenue for intravascular imaging is its use to guide treatment. Feasibility of tailored therapy for acute coronary syndromes (ACS) guided by OCT is under investigation. If it is proven to be effective, it may potentially lead to major shift in the management of millions of patients with ACS every year.

Practical Application of Coronary Imaging Devices in Cardiovascular Intervention

The significant morbidity and mortality associated with coronary artery disease has spurred the development of intravascular imaging devices to optimize the detection and assessment of coronary lesions and percutaneous coronary interventions. Intravascular ultrasound (IVUS) uses reflected ultrasound waves to quantitatively and qualitatively assess lesions; integrated backscatter and virtual histology IVUS more precisely characterizes plaque composition; angioscopy directly visualize thrombus and plaque; optical coherence tomography using near-infrared (NIR) light with very high spatial resolution provides more accurate images; and the recently introduced NIR spectroscopy identifies chemical components in coronary artery plaques based on differential light absorption in the NIR spectrum. This article reviews usefulness of these devices and hybrids thereof.

Treatment for chronic venous ulceration of the leg by subfascial endoscopic perforator vein surgery / 中南大学学报(医学版)

OBJECTIVE@#To observe the effect of subfascial endoscopic perforator vein surgery (SEPS) in the treatment of chronic venous ulceration of the legs.@*METHODS@#Chronic venous ulceration for 91 patients with 102 limbs was treated by SEPS from January 2005 to July 2008. The effect of SEPS on chronic venous ulceration of the leg, the symptoms during and after the operation, and the durations of hospital treatment were analyzed.@*RESULTS@#The symptoms of the 102 legs conducted by SEPS operation, except the pigmentation, were obviously improved (P<0.01). Its cicatrisation rate, the recrudesce rate, and the cut infection rate were 93.1%, 1.96%, and 1.0%, respectively. The time of the operation was short and the hemorrhage was small during the surgery. The durations of hospitalization and the cicatrisation time of ulceration were (6.5+/-3.4) d and (12.2+/-13.7) d, respectively.@*CONCLUSION@#SEPS is simple and effective in treating chronic venous ulceration of the leg, and particularly effective for patients classified into C5 and C6 in clinical-etiological-anatomical-pathophysiology (CEAP).

Exploration on the relationship between thrombosis and stability of coronary atherosclerotic plaque in patients with unstable angina pectoris / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the correlation between thrombosis and stability of atherosclerotic plaque within criminal vessels in patients with unstable angina pectoris (UAP) by coronary angioscopy, to explore the clinical pathological basis for acute coronary syndromes (ACS).</p><p><b>METHODS</b>Sixty-eight patients with UAP were enrolled, the patients with post-infarction angina pectoris and variant angina pectoris were excluded. There were 48 males and 20 females, aged from 40 to 73 (average 62.4 +/- 8.6) years. The criminal vessels of there patients were observed by coronary angioscopy during percutaneous coronary intervention (PCI) therapy.</p><p><b>RESULTS</b>There were 68 criminal vessels in 68 patients. Atherosclerotic plaques were observed in all criminal vessels. Among criminal vessels, thrombi and intimae lesions were detected in 63 cases and 46 cases, respectively. Among 68 cases with atherosclerotic plaques, there were 48 cases of yellow plaques (70.5%), 18 cases of light yellow plaques (26.5%) and 2 cases of white plaques (2.94%). Sixty-three thrombi cases were mural and on-occlusive, which included 11 cases of red or mixed thrombi (17.5%) and 52 cases of white or pink thrombi (82.5%). All intimae lesions were accompanied by thrombosis, which included 11 cases of red or mixed thrombi (23.9%) and 35 cases of white or pink thrombi (76.1%).</p><p><b>CONCLUSION</b>The study has shown that the rupture of unstable yellow plaque and its thrombosis were the pathological basis of UAP. Therefore, stabilizing yellow plaque before its rupture may play critical role in prevention and treatment of ACS.</p>

Clinical Usefulness of Virtual Angioscopy Using 3D MR Angiography DICOM Images / 대한의료정보학회지

OBJECTIVE: To evaluate of virtual angioscopy was implemented using MR(magnetic resonance) angiography image of carotid artery. METHODS: The endoscopy system provides a 3D volume rendered image as a navigation map and has the multi planar reformation image along the path and a 2D axial image as a reference image. We segmented the common carotid artery and internal, external carotid artery from the MR angiography image. We used the coordinates as a navigation path for virtual camera that were calculated from medial axis transformation. We used the perspective projection and marching cube algorithm to render the surface from volumetric MR angiography image data. RESULTS: The virtual angioscopy is highly recommended as a diagnosis tool with which the specific place of stenosis can be identified and the degree of stenosis can be measured qualitatively. CONCLUSION: Virtual angioscopy is one of the powerful tool for non-invasive carotid artery and many in-vitro, in-vivo studies have shown the artery stenosis detection. Inside of the carotid artery is one of the body region not accessible by real optical endoscopy but can be visualized with virtual endoscopy.

Vulnerable plaques, inflammation and newer imaging modalities.

Currently, inflammation is considered to be the central player in the pathogenesis of atherosclerosis. It leads to the formation of multiple plaques in the arterial beds including coronary vasculature. Recent studies using the latest imaging techniques have shown that in patients with acute coronary syndromes (ACS) multiple plaques are ruptured and have thrombus formation on them. Various factors make these plaques unstable, these include structural components of plaque like thin fibrous cap, high lipid content of the plaque core and inflammation, both localized and generalized. It has been shown that most of the ACS are caused by plaques causing non-critical stenosis as seen on traditional X-ray angiography. Also, the phenomenon of remodelling makes angiography a poor technique for plaque visualization. Hence newer modalities are required to identify these "vulnerable plaques". Intravascular ultrasound (IVUS), thermography and Magnetic Resonance Imaging (MRI) are a few such promising techniques. Here we review the invasive and non-invasive modalities that can be helpful in the identification of these plaques before they become unstable and cause ACS, and also the available therapies to stabilize these plaques.

Aspectos hemodinâmicos da ruptura da placa e implicações para o tratamento percutâneo / Hemodynamic aspects of the atherosclerotic plaque ruptureand implications for percutaneous intervention

São abordados os mecanismos que contribuem para a instabilização da placa aterosclerótica, assim como são conceituadas as lesões angiograficamente complexas, as placas particularmente vulneráveis à ruptura e as placas estáveis. As limitações da coronariografia na definição prognóstica dos ateromas são justificadas e, dentre as novas modalidades diagnósticas intravasculares, discutiu- se a importância da angioscopia coronária. Finalmente, do ponto de vista terapêutico, são enfatizadas a aplicabilidade e a eficácia da intervenção coronária percutânea nos quadros relacionados a síndromes isquêmicas miocárdicas instáveis...

The recent study and key technologies of an aided endoscopic surgical robot system / 中国医疗器械杂志

This paper introduces the recent study and development of an aided endoscopic surgical robot system, and discusses its future trends--teleoperative robot system and telesurgery system. In addition, their key technologies are analyzed here in the paper.

Derivación aorta torácica descendente bifemoral para salvamento de extremidades inferiores / Descending thoracic aortabifemoral bypass to save lower extremities

Cuando la aorta abdominal no es un sitio con flujo adecuado o es técnicamente inaccesible para derivar el flujo a las extremidades inferiores por representar un alto riesgo secundario a múltiples situaciones complejas, se justifica el recurso de las derivaciones extraanatómicas en pacientes apropiadamente seleccionados con resultados de baja morbilidad y mortalidad, mejor calidad de vida y menores costos en comparación con la amputación de extremidades inferiores.Presentamos el caso de un paciente sometido a derivación aorta torácica descendente bifemoral (DATDB) como una alternativa satisfactoria de manejo diferente a las derivaciones extraanatómicas convencionales utilizadas en nuestro medio, con mayor permeabilidad reportada por tener flujo directo de la aorta y sin incremento de la morbilidad y de la mortalidad.

Clinical Study of Acute Arterial Occlusion of Lower Extremities

PURPOSE: The major source of acute peripheral arterial occlusion has been embolization from the heart. However overall improvement in medical care have increased life spans, resulting in significant increase in the incidence of systemic atherosclerosis and thrombotic occlusion of peripheral vessels. Recently, occlusion from in situ thrombosis has surpassed occlusion from embolization as the major cause of acute arterial occlusion. The introduction of the balloon catheter technique in 1963 dramatically simplified the technical aspect of surgical therapy for acute arterial occlusion and it became the main modality of the therapy. Recently, numerous reports have documented increased identification of intraluminal defects after arterial surgery using angioscopy as compared with those using intraoperative arteriography, and for this reason, the use of intraluminal angioscopy has grown in popularity. METHODS: We analyzed clinical characteristics and treatment results in patients with acute arterial occlusion. The variables studied include location, etiology, time interval from occurrence of occlusion to performance of thromboembolectomy. RESULTS: There were 41 men and 4 women and most prevalent age group was in 7th decades. The causes of acute arterial occlusion were embolism in 21 cases (46.7%), thrombosis in 24 cases (53.3%). The primary source of embolism was heart in 20 cases as a result of ischemic heart disease (n=11, 52.4%) and atrial fibrillation (n=9, 42.9%). Two patients in embolic group died of cardiogenic shock and were in shorter duration group (<24 hours). Iliac arterial occlusion group was associated with highest amputation rate (23.1%). Amputation rates were 12.5% for thromboembolectomy performed within 24 hours of onset of symptoms, and 17.4% when performed after 48 hours. We used angioscopic technique in limited cases of 5 patients to detect residual thrombus, intimal flap and other intraluminal defects. CONCLUSION: To improve outcome, early diagnosis and early treatment are essential. Direct visualization of the arterial lumen with angioscopy during thromboembolectomy procedure would provide a more reliable method of assessing luminal morphologic characteristics than angiography alone.

Agregación globular: consistecia y validéz de la "Oftalmoangioscopia conjuntival" / Globular aggregation: congesteme and validity of the \"Oftalmoangyoscopy conjunctival\"

Evaluar la consistencia y validez de la "Oftalmoangioscopia conjuntival" en el diagnóstico de agregación globular en vasos conjuntivales, como evidencia clínica de Velocidad de Sedimentación Globular (VSG) aumentada. Estudio de Corte Transversal. Se evaluaron dos muestras de 32 pacientes de ambos sexos, hospitalizados en los Servicios de Medicina Interna del Hospital Universitario de Caracas. La primera muestra está compuesta de 20 pacientes femeninos y 12 masculinos, la segunda 17 y respectivamente. Los treinta y dos pacientes de cada muestra fueron seleccionados por azar simple por un clínico independiente quien registró: identificación, datos demográficos y último valor de VSG. los pacientes fueron evaluados individualmente por seis observadores: Dos médicos Especialistas en Medicina Interna, dos médicos Generales Residentes del primer año del Postgrado de Medicina, dos estudiantes de Pregrado del quinto año del régimen anual. La"oftalmoangioscopia conjuntival" fue demostrada y estandarizada previamente entre los seis observadores (Siguiendo la descripción de Muci-Mendoza), las dos muestras fueron evaluadas con un lapso entre ellas de quince días, utilizando para el entrenamiento individual en la técnica. La consistencia se estudió como variabilidad interobservador, calculada a través del estadístico Kappa pesado, la validez de la técnica fue explorada con el cálculo de las probabilidades intermedias (sensibilidad, especificidad) y probabilidades posteriores (valores predictivos positivos y negativos). El acuerdo de los seis observadores estimado a través del Kappa pesado entre mínimo y regular, independientemente del nivel de experiencia de los observadores; con amplias variaciones en los valores de sensibilidad, especificidad y valores predictivos positivos y negativos. la "oftalmoangioscopia conjuntival" como técnica semiológica para el diagnóstico de agregación globular en los vasos conjuntivales y marcador clínico de VSG elevada resultó inconsistente y poco válida independientemente del nivel de experiencia del observador

Angioscopía coronaria percutánea: su contribución a la interpretación fisiopatológica de los síndromes isquémicos agudos: estudio prospectivo / Percutaneous coronary angioscopy: its contribution to the physiopathological interpretation of the acute ischemic syndromes: prospective study

Con objeto de determinar mediante angioscopía coronaria la prevalencia de ruptura de placa y trombo en angina inestable e infarto agudo del miocardio transmural, y de correlacionar los hallazgos angioscópicos con las modalidades de presentación clínica de la angina inestable, estudiamos, prospectivamente, 23 pacientes, 18 hombres y 5 mujeres, de 58 ñ 9,5 años, 19 de ellos con angina inestable y 4 con infarto agudo de miocardio transmural

Cateter óptico para aplicaçöes espectroscópicas / Optic catheter for spectroscopic applications

Neste trabalho é apresentada a caracterização de cateteres utilizando fibras ópticas para aplicações de espectroscopia in vivo. Estes cateteres apresentam a configuração de seis fibras em torno de uma fibra central de mesmo diâmetro, sendo estas fibras do tipo multimodo com diâmetro de núcleo de 100 mum. A eficiência de coleta de radiação para este tipo de cateter é da ordem de 0,05 por cento, variando em função da distância ao tecido e da distribuição de intensidade de sinal retroespalhado na superfície do mesmo.

ln this work we describe the characterization of fiber optic catheters for in vivo spectroscopy applications. This type of catheters have the geometry of one central fiber sun-ounded by six 100 µm diameter multimode fibers. The collection efficiency of these type of catheter is about 0.05% and it changes with the distance to the tissue surface and the signal intensity distribution on it.