Objective Vascular surgeons perform numerous highly sophisticated and delicate procedures. Due to restrictions in training time and the advent of endovascular techniques, new concepts including ...alternative environments for training and assessment of surgical skills are required. Over the past decade, training on simulators and synthetic models has become more sophisticated and lifelike. This study was designed to evaluate the impact of a 3-day intense training course in open vascular surgery on both specific and global vascular surgical skills. Methods Prospective observational cohort analysis with various parameter measurements of both surgical skills and the technical quality of the finished product, performed before and after 3 days of simulator training of 10 participants (seven male and three female) in a vascular surgery training course. The simulator model used was a conventional carotid endarterectomy with a Dacron patch plasty on a lifelike carotid bench model under pulsatile pressure. The primary end points were assessment of any changes in the participants' surgical skills and in the technical quality of their completed carotid patches documented by procedure-based assessment forms. Scores ranging from 1 (inadequate) to 5 (excellent) were compared by a related-sample Wilcoxon signed test. Interobserver reliability was estimated by Cronbach's alpha (CA). Results A significant improvement in surgical skills tasks was observed ( P < .001). The mean score increased significantly by 21.5% from fair (3.43 ± 0.93) to satisfactory (4.17 ± 0.69; P < .001). The mean score for the quality of the carotid patch increased significantly by 0.96 (27%) from fair (3.55 ± 0.87) to satisfactory (4.51 ± 0.76; P < .01). The median interassessor reliability for the quality of the carotid patch was acceptable (CA = 0.713) and for surgical skills was low (CA = 0.424). Conclusions This study shows that lifelike simulation featuring pulsatile flow can increase surgical skills and technical quality in a highly sophisticated multistep vascular intervention. This training provides comparatively inexpensive and lifelike training possibilities for the adoption and assessment of surgical skills required to perform delicate vascular surgical procedures.
Background: Stroke is one of the leading causes of morbidity and mortality. Thromboembolism, as a major cause of carotid artery-related stroke, can be caused by plaque rupture which is associated ...with neoangiogenesis within the carotid plaque. Aim: We sought to investigate a possible correlation between angiogenesis-related factors and preoperative neurological manifestations in patients with internal carotid artery stenosis, for a better understanding of thromboembolism in internal carotid artery stenosis-related stroke. Methods: This study included 54 patients (asymptomatic, n = 20 and symptomatic, n = 34) undergoing carotid endarterectomy for high-grade internal carotid artery stenosis. In the retrieved carotid plaques, angiogenesis-related factors (vascular endothelial growth factor VEGF, hypoxia inducible factor-1 alpha HIF-1α, and Clusterin) were measured by immunohistochemistry and quantified by real-time polymerase chain reaction. Results: We demonstrated the expression of VEGF, HIF-1α, and Clusterin by endothelial cells and smooth muscle cells in the carotid plaques. Noteworthy, mRNA VEGF levels were .7-fold higher in symptomatic patients (P = .017) compared to asymptomatic patients. In contrast, mRNA Clusterin levels were 1.8-fold lower (P = .021). Levels of mRNA HIF-1α were 1.5-fold higher in asymptomatic patients, but no statistical significance was reached between the 2 groups. Conclusions: Our results show an association between VEGF and Clusterin and neurological symptoms of patients with high-grade carotid artery stenosis.
The IgE-mediated and Th2-dependent late-phase reaction remains a mechanistically enigmatic and daunting element of human allergic inflammation. In this study, we uncover the FcεRI on dendritic cells ...(DCs) as a key in vivo component of this form of allergy. Because rodent, unlike human, DCs lack FcεRI, this mechanism could be revealed only by using a new transgenic mouse model with human-like FcεRI expression on DCs. In the presence of IgE and allergen, FcεRI(+) DCs instructed naive T cells to differentiate into Th2 cells in vitro and boosted allergen-specific Th2 responses and Th2-dependent eosinophilia at the site of allergen exposure in vivo. Thus, FcεRI on DCs drives the cascade of pathogenic reactions linking the initial allergen capture by IgE with subsequent Th2-dominated T cell responses and the development of late-phase allergic tissue inflammation.
Vascular surgical training currently has to cope with various challenges, including restrictions on work hours, significant reduction of open surgical training cases in many countries, an increasing ...diversity of open and endovascular procedures, and distinct expectations by trainees. Even more important, patients and the public no longer accept a “learning by doing” training philosophy that leaves the learning curve on the patient's side. The Vascular International (VI) Foundation and School aims to overcome these obstacles by training conventional vascular and endovascular techniques before they are applied on patients. To achieve largely realistic training conditions, lifelike pulsatile models with exchangeable synthetic arterial inlays were created to practice carotid endarterectomy and patch plasty, open abdominal aortic aneurysm surgery, and peripheral bypass surgery, as well as for endovascular procedures, including endovascular aneurysm repair, thoracic endovascular aortic repair, peripheral balloon dilatation, and stenting. All models are equipped with a small pressure pump inside to create pulsatile flow conditions with variable peak pressures of ∼90 mm Hg. The VI course schedule consists of a series of 2-hour modules teaching different open or endovascular procedures step-by-step in a standardized fashion. Trainees practice in pairs with continuous supervision and intensive advice provided by highly experienced vascular surgical trainers (trainer-to-trainee ratio is 1:4). Several evaluations of these courses show that tutor-assisted training on lifelike models in an educational-centered and motivated environment is associated with a significant increase of general and specific vascular surgical technical competence within a short period of time. Future studies should evaluate whether these benefits positively influence the future learning curve of vascular surgical trainees and clarify to what extent sophisticated models are useful to assess the level of technical skills of vascular surgical residents at national or international board examinations. This article gives an overview of our experiences of >20 years of practical training of beginners and advanced vascular surgeons using lifelike pulsatile vascular surgical training models.
Objective The benefit of carotid surgery in asymptomatic patients with high-grade internal carotid artery stenosis (ICAS) is subject of intense debate, and thus improved preoperative risk ...stratification is mandatory. This study aimed to investigate the predictive value of contralateral ICAS (cl-ICAS) for the preoperative clinical presentation of patients with ipsilateral ICAS (primary outcome). Methods This study was a post hoc analysis of a prospective cohort comprising 485 consecutive patients undergoing carotid endarterectomy for high-grade ICAS. Patients were classified by their clinical presentation, ie, asymptomatic (n = 213) or symptomatic (within 6 months of surgery; n = 272, comprising both transient ischemic attack TIA; n = 163 and stroke n = 109). We investigated the association of cl-ICAS with the primary outcome in adjusted regression models. Results Mean ipsilateral degrees of ICAS were similar in both groups (84% ± 10% vs 84% ± 11%; P = .92), whereas contralateral degrees were significantly higher in the symptomatic group (29% ± 34% vs 38% ± 39%; P = .008). After multivariable regression analysis, cl-ICAS >60% conferred a three times higher preoperative stroke risk (odds ratio, 3.31; 95% confidence interval, 1.98-5.54; P < .001). Inclusion of cl-ICAS significantly improved ( P = .001) ipsilateral combined TIA and stroke risk prediction based on established risk factors (area under the curve, 0.66; 95% confidence interval, 0.60-0.72; P < .001). Conclusions Our study identifies a high contralateral degree of ICAS as an independent predictor of preoperative ipsilateral TIA and stroke in patients with ipsilateral high-grade ICAS. Therefore, such patients might rather benefit from elective carotid surgery and intensive postoperative medical care.
Background Both deficiency and, according to recent reports, excess of vitamin B12 (B12) are associated with increased mortality. Thus, it is difficult to estimate the effect of B12 on overall ...survival, which also depends on folate (FA) in homocysteine lowering. This study aimed to assess FA and B12 serum concentrations associated with long-term survival of vascular surgery patients by means of a prognostic index (PI). Methods This single-center, prospective cohort study comprised 485 consecutive carotid surgery patients. B-vitamin baseline concentrations of B12 and FA were used to compute a PI for postoperative overall survival from January 2003 to January 2012 (mean observation period 102.3 months). Results Increasing B12 serum concentrations showed a nonlinear association with overall survival ( P = .033). A B vitamin-based PI significantly predicted overall (hazard ratio HR per standard deviation = 1.97, confidence interval CI 1.37-2.82; P < .001), cardiovascular (HR = 3.03, CI 1.78-5.14; P < .001), and stroke-free survival (HR = 2.20, CI 1.22-3.98; P = .009), and revealed that the highest adverse event-free survival was predicted by high FA (16.3 ± 12.9 ng/mL) but only moderate B12 (360.3 ± 156.0 pmol/L) baseline concentrations. Conclusions Prediction of increased long-term overall, cardiovascular, and stroke-free survival is based on high FA but only moderate B12 serum concentrations. Excessive B12 concentrations might harbor a potential harm and are no requisite for low homocysteine concentrations. The association between B vitamins and survival might serve either as a tool for risk stratification or, if causative, as effective therapy, if optimal dosing of B vitamins is provided and on-treatment concentrations, including homocysteine and renal functions, are closely monitored.
Background Carotid endarterectomy (CEA) is commonly performed for asymptomatic high-grade internal carotid artery (ICA) stenosis to prevent stroke. However, despite advancing age of the society, for ...patients older than 75 years, there is no recommendation by the European guidelines for CEA, as this age group might not benefit from this intervention due to a limited life expectancy. Objective We assessed N-terminal pro B-type natriuretic peptide (NT pro-BNP) as a predictive marker for long-term survival in this particular patient population in order to stratify patients for an improved surgical outcome. Methods In a nonrandomized single-center clinical trial, we prospectively studied mortality rates of 205 consecutive patients (80 women, 125 men; mean age, 75 ± 10 years) with asymptomatic high-grade ICA stenosis in relation to preoperative plasma NT pro-BNP levels. We estimated cumulative survival over 5 years by Kaplan-Meier curves and established a proportional hazard-model by Cox regression. Results In male patients, higher levels of preoperative NT pro-BNP levels were associated with a significantly increased long-term mortality. Those 75 years or older had the same survival rate as younger patients, if NT pro-BNP levels were low, making them thus eligible for CEA. Conclusions The results of our study suggest that preoperative plasma levels of NT pro-BNP are a valuable tool for the stratification of male patients. Male patients older than 75 years with low levels of NT pro-BNP should be referred for carotid revascularization, as they will most likely enjoy the benefit of surgery.
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