39 resultados para Hopf bifurcation


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The stress associated with providing care for a spouse diagnosed with Alzheimer's disease can have adverse effects on cardiovascular health. One potential explanation is that chronic caregiving stress may contribute to the development of atherosclerosis. The purpose of this study was to determine whether the duration that one has provided care is associated with the degree of atherosclerotic burden, as measured by carotid artery intima-media thickness (IMT). One hundred and ten Alzheimer caregivers [mean age 74 ± 8 (SD) years, 69% female] underwent in-home assessment of carotid artery IMT via B-mode ultrasonography. Data regarding medical history, blood pressure, and multiple indicators of caregiving stress were also collected. Multiple regression indicated that duration of care was positively associated with IMT measured in the internal/bifurcation segments of the carotid artery (β = 0.202, p = 0.044) independent of risk factors such as age, gender, body mass index, smoking history, sleep quality, hypertension status, and caregiving stressors. Duration of care was positively associated with IMT in the common carotid artery, but the relationship was not significant. These findings provide more evidence of the link between chronic caregiving stress and cardiovascular disease and indicate that enduring the experience of caregiving over a period of years might be associated with atherosclerotic burden.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

There is substantial variability in the extent of the node dissection performed during radical cystectomy for bladder cancer. Here, we review the diagnostic assessment of lymph node metastasis and the prognostic and therapeutic benefit for pelvic node dissection for bladder cancer. A review of the applicable urologic literature regarding the topics of lymphadenectomy for bladder cancer was conducted. Nodal metastasis above a limited or standard template is not uncommon, with up to 16% of all nodal metastasis detected proximal to the aortic bifurcation. However, skip metastasis is extremely rare. Proteins associated purely with epithelial tissue such as cytokeratin (CK)-19, CK-20, and uroplakin II have been observed in reportedly negative nodal specimens, which indicates that routine microscopic analysis of nodal tissue may miss small foci of metastatic cancer. In addition to the surgical technique, the total number of lymph nodes removed is influenced by patient anatomy and pathologic processing and therefore may be unsuitable as a procedural quality statement. Consecutively, meticulous removal of tissue within a defined and uniformly applied template may be more relevant than absolute nodal count. Observational cohort series indicate an improved oncologic outcome for patients undergoing extensive nodal dissection. The results of two randomized controlled trials addressing the extent of nodal dissection for bladder cancer are forthcoming.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND AND PURPOSE:Conventional platinum coils cause imaging artifacts that reduce imaging quality and therefore impair imaging interpretation on intraprocedural or noninvasive follow-up imaging. The purpose of this study was to evaluate imaging characteristics and artifact production of polymeric coils compared with standard platinum coils in vitro and in vivo.MATERIALS AND METHODS:Polymeric coils and standard platinum coils were evaluated in vitro with the use of 2 identical silicon aneurysm models coiled with a packing attenuation of 20% each. DSA, flat panel CT, CT, and MR imaging were performed. In vivo evaluation of imaging characteristics of polymeric coils was performed in experimentally created rabbit carotid bifurcation aneurysms. DSA, CT/CTA, and MR imaging were performed after endovascular treatment of the aneurysms. Images were evaluated regarding visibility of individual coils, coil mass, artifact production, and visibility of residual flow within the aneurysm.RESULTS:Overall, in vitro and in vivo imaging showed relevantly reduced artifact production of polymeric coils in all imaging modalities compared with standard platinum coils. Image quality of CT and MR imaging was improved with the use of polymeric coils, which permitted enhanced depiction of individual coil loops and residual aneurysm lumen as well as the peri-aneurysmal area. Remarkably, CT images demonstrated considerably improved image quality with only minor artifacts compared with standard coils. On DSA, polymeric coils showed transparency and allowed visualization of superimposed vessel structures.CONCLUSIONS:This initial experimental study showed improved imaging quality with the use of polymeric coils compared with standard platinum coils in all imaging modalities. This might be advantageous for improved intraprocedural imaging for the detection of complications and posttreatment noninvasive follow-up imaging.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A 51-year-old man was struck by the tip of a broomstick weighing 1000 g at the left side of the neck, upon which he collapsed. Intense but delayed cardiopulmonary resuscitation restored the circulation roughly 30 minutes after the incident. Upon admittance to a nearby hospital, an extensive hypoxic cerebral damage was diagnosed. Death due to the severe cerebral damage occurred 5 hours after the incident. An autopsy demonstrated a severe subcutaneous traumatization of the left side of the neck, with a hemorrhage compressing the carotid bifurcation. A prolonged excitation due to this ongoing compression of the baroreceptors in the carotid sinus was assumed to have led to a cardiac arrest. In this case report, the authors discuss the underlying pathophysiology of this potentially lethal and rare reflexogenic incident also known as the Hering reflex and discuss possible therapeutic measures.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Data on female patients with atherosclerotic peripheral arterial disease (PAD) are scarce, and limited primarily to the elderly population with multilevel disease. In this longitudinal observational study we compare female patients below 60 years of age with isolated lesions at the aortic bifurcation or focal superficial femoral artery disease. PATIENTS AND METHODS: Analysis is based on consecutive series of 43 female patients with PAD limited to the aortoiliac bifurcation (n = 28, group I) or an isolated femoral segment at the adductor channel (n = 15, group II) seen in a tertiary referral center between 1998 and 2000. The first assessment provided baseline data, with follow up data obtained at this study. Traditional risk factors, carotid artery disease and clinical outcome (mortality, cardiovascular events, vascular re-intervention rate, PAD progression) were evaluated over an interval of 5 (2 to 8) years. RESULTS: Female patients with aortic disease [group I] were younger (51.8 +/- 7.7 vs. 56.7 +/- 7.6 years in group II; p = 0.048), presented a more masculine phenotype, and smoked significantly more often (82% vs. 40%; p = 0.007). Arterial hypertension and diabetes mellitus were more common in group II, though it missed statistical significance (p = 0.068 and p = 0.085). Cardiovascular and limb outcome were comparable in both groups of female patients, while carotid artery disease was more severe in group I (i.e., carotid plaques in 71 vs. 53%). CONCLUSION: Our data support previous findings that cigarette smoking is a stronger risk factor for aortic disease as compared to femoral disease in younger female patients, with the strongest effect of smoking on a localized region of the aortic bifurcation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The use of drug-eluting stents (DES) in percutaneous coronary interventions (PCI) decreased the rate of restenosis and hence the need for repeat revascularization by 50-71%. DES have changed PCI. DES allow successful revascularization of anatomically challenging lesions, such as long, thin vessels, bifurcation lesions, and chronic total occlusions. A rare, but severe complication of coronary stenting is stent thrombosis, a partial or total thrombotic occlusion of the stent. The use of DES for increasingly more complex lesions, the prothrombotic effect of the antiproliferative substances, and a delayed endothelialization of DES all potentially prolong and increase the risk of stent thrombosis. Dual antiplatelet therapy for 1 year is therefore recommended after DES placement. There is currently no evidence for the efficacy and safety of routine dual antiplatelet therapy beyond 1 year. It is also recommended postponing elective surgery for 1 year and, if surgery cannot be deferred, considering continuation of acetylsalicylic acid during the perioperative period in high-risk patients with DES.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

AIMS: Recent studies of drug-eluting stents for unprotected left main coronary artery (LMCA) disease have been encouraging. We examined the performance of sirolimus-eluting stents (SES) for this indication. METHODS AND RESULTS: This retrospective study included 228 consecutive patients (mean age = 68 +/- 11 years, 80.6% men, 26.3% diabetics) who underwent implantation of SES for de novo LMCA stenoses. The mean additive and logistic EuroSCOREs were 5.2 +/- 3.9 and 8.2 +/- 13.2, respectively. The main objective of this study was to measure the rate of major adverse cardiac events (MACE), including death, myocardial infarction and target lesion revascularisation (TLR) at 12 months. Other objectives were to measure the rates of in-hospital MACE and 12-month TLR. Outcomes in 143 patients with (BIF+ group), versus 84 patients without (BIF-group) involvement of the bifurcation were compared. The pre-procedural percent diameter stenosis (%DS) was 60.1 +/- 11.2 in the BIF+ versus 54.7 +/- 12.2% in the BIF- group (p=0.008), and decreased to 18.0 +/- 9.7 and 13.9 +/- 11.3%, respectively (ns), after SES implant. The overall in-hospital MACE rate was 3.5%, and similar in both subgroups. The 1-year MACE rate was 14.5% overall, 16.8% in the BIF+ and 10.7% in the BIF- subgroup (ns). CONCLUSIONS: SES implants in high-risk patients with LMCA stenoses were associated with a low 1-year MACE rate. Stenting of the bifurcation was associated with significant increases in neither mortality nor 1-year MACE rate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Arterial puncture closure devices (APCD) are frequently used after cardiac catheterization. Here, the diagnosis and therapy of femoral artery complications after the use of the Angio-Seal APCD is reported. PATIENTS AND METHODS: The Angio-Seal APCD was deployed in 1600 patients undergoing transfemoral catheterization. RESULTS: In 7 of 1600 cases (0.4%) vascular complications occurred following Angio-Seal deployment. Diagnosis was made by duplex sonography. Intraoperative findings consisted of a complete occlusion with dissection of the femoral artery in all patients. In 6 cases, the femoral bifurcation had to be reconstructed after endarterectomy. Follow-up is complete with a mean of 6 months. CONCLUSION: The Angio-Seal device should not be used for closure of the superficial femoral artery and in patients with severe arteriosclerosis. The application of arteriography as well as the use of ultrasound-guided puncture is advisable. In all cases, surgical intervention was successful and an adequate therapy for management of complications.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND: Cardiac surgery is the reference treatment for patients with left main (LM) disease, although percutaneous coronary intervention with drug-eluting stents is emerging as a possible alternative. The objective of this registry was to evaluate the 2-year outcome of elective percutaneous coronary intervention for unprotected LM disease with paclitaxel-eluting stents. METHODS AND RESULTS: A total of 291 patients were prospectively included from 4 centers. Acute myocardial infarction and cardiogenic shock were the only exclusion criteria. Patients were 69+/-11 years old, 29% were diabetic, and 25% had 3-vessel disease. For distal LM lesions (78%), the provisional side-branch T-stenting approach was used in 92% of cases and final kissing balloon inflation in 97%. Angiographic success was obtained in 99.7% of cases. At 2-year follow-up, the total cardiac death rate was 5.4% (1 EuroSCORE point was associated with a 15% [95% confidence interval 2.9% to 28.2%, P=0.013] higher risk of cardiac death), target-lesion revascularization was 8.7%, and incidence of Q-wave or non-Q-wave myocardial infarction was 0.9% and 3.1%, respectively. The combined end point occurred in 15.8% of cases and stroke in 0.7%. The incidence of definite and probable LM stent thrombosis was 0.7%, whereas the incidence of any stent thrombosis was 3.8%, with a higher risk in patients with side-branch stenting in the presence of LM bifurcation lesions (hazard ratio 9.6, 95% confidence interval 1.2 to 77.7, P=0.035). CONCLUSIONS: Unprotected LM stenting with paclitaxel-eluting stents, with a strategy of provisional side-branch T-stenting for distal lesions, provides excellent acute angiographic results and good mid-term clinical outcomes, with a 15.8% rate of major adverse cardiac events at 2-year follow-up.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

CONTEXT: The presence of lymph node metastases and the extent of lymphadenectomy have both been shown to influence the outcome of patients with muscle-invasive bladder cancer. OBJECTIVE: Current standards for detection of lymph node metastases, lymph-node mapping studies, histopathologic techniques, and risk factors in relation to lymph node involvement are discussed. The impact of lymph node metastases and the extent of lymphadenectomy on the outcome of patients treated with radical cystectomy are analyzed. EVIDENCE ACQUISITION: A systematic literature review of bladder cancer and lymph nodes was performed searching the electronic databases Pubmed/Medline, Cochrane, and Embase. Articles were selected based on title, abstract, study format, and content by a consensus of all participating authors. EVIDENCE SYNTHESIS: Lymph node status is highly consequential in bladder cancer patients because the presence of lymph node metastases is predictive of poor outcome. Knowledge of primary landing sites of lymph node metastases is important for optimum therapeutic management. Accurate pathologic work-ups of resected lymph node tissue are mandatory. Molecular markers could potentially guide therapeutic decisions in the future because they may enable the detection of micrometastatic disease. In current series, radical cystectomy with an extended lymphadenectomy seems to provide a clinically meaningful therapeutic benefit compared with a limited approach. However, the anatomic boundaries of lymph node dissection are still under debate. Therefore, large prospective multicenter trials are needed to validate the influence of extended lymph node dissection on disease-specific survival. CONCLUSIONS: An extended pelvic lymph node dissection (encompassing the external iliac vessels, the obturator fossa, the lateral and medial aspects of the internal iliac vessels, and at least the distal half of the common iliac vessels together with its bifurcation) can be curative in patients with metastasis or micrometastasis to a few nodes. Therefore, the procedure may be offered to all patients undergoing radical cystectomy for invasive bladder cancer.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In a patient with staphylococcus lugdunensis prosthetic aortic valve endocarditis and coronary septic embolism accompanied by antero-lateral myocardial infarction, embolic material was successfully aspirated from the bifurcation of the left anterior descending coronary artery and the first diagonal branch. A good angiographic result was documented six months thereafter when the patient presented with a second complication, pulsatile compression of the left main coronary artery by an abscess cavity originating between the aortic and mitral annulus, leading to congestive heart failure. The patient underwent successful surgical replacement of the aortic valve prosthesis with concomitant patch reconstruction of the annulus as well as tricuspid annuloplasty.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Temporary transcoronary unipolar pacing is a validated simple, effective, and safe alternative to temporary transvenous pacing of the right ventricle for the treatment of relevant bradyarrhythmias complicating percutaneous coronary intervention. We describe the use of rapid transcoronary pacing to aid precise placement of a stent in the left main coronary artery bifurcation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper introduces a novel vision for further enhanced Internet of Things services. Based on a variety of data (such as location data, ontology-backed search queries, in- and outdoor conditions) the Prometheus framework is intended to support users with helpful recommendations and information preceding a search for context-aware data. Adapted from artificial intelligence concepts, Prometheus proposes user-readjusted answers on umpteen conditions. A number of potential Prometheus framework applications are illustrated. Added value and possible future studies are discussed in the conclusion.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Abstract PRINCIPLES: Computed tomography (CT) is inferior to the fibroscan and laboratory testing in the noninvasive diagnosis of liver fibrosis. On the other hand, CT is a frequently used diagnostic tool in modern medicine. The auxiliary finding of clinically occult liver fibrosis in CT scans could result in an earlier diagnosis. The aim of this study was to analyse quantifiable direct signs of liver remodelling in CT scans to depict liver fibrosis in a precirrhotic stage. METHODS: Retrospective review of 148 abdominal CT scans (80 liver cirrhosis, 35 precirrhotic fibrosis and 33 control patients). Fibrosis and cirrhosis were histologically proven. The diameters of the three main hepatic veins were measured 1-2 cm before their aperture into the inferior caval vein. The width of the caudate and the right hepatic lobe were divided, and measured horizontally at the level of the first bifurcation of the right portal vein in axial planes (caudate-right-lobe ratio). A combination of both (sum of liver vein diameters divided by the caudate-right lobe ratio) was defined as the ld/crl ratio. These metrics were analysed for the detection of liver fibrosis and cirrhosis. RESULTS: An ld/crl-r <24 showed a sensitivity of 83% and a specificity of 76% for precirrhotic liver fibrosis. Liver cirrhosis could be detected with a sensitivity of 88% and a specificity of 82% if ld/crl-r <20. CONCLUSION: An ld/crl-r <24 justifies laboratory testing and a fibroscan. This could bring forward the diagnosis and patients would profit from early treatment in a potentially reversible stage of disease.