CTO in contemporary PCI

: Percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) represents the most challenging procedure in modern endovascular treatments. In recent years, the success rate of CTO PCI has substantially improved, owing to increasing operator expertise and advancements in CTO equipment and algorithms as well as the development of expert consensus documents. In this review, we summarize existing evidence for CTO PCI, its success/ risk prediction scoring tools, procedural principles and complications and provide an insight into the future role of CTO PCI.

Flat morphological operators from non-increasing set operators, I: general theory

Flat morphology is a general method for obtaining increasing operators on grey-level or multivalued images from increasing operators on binary images (or sets). It relies on threshold stacking and superposition; equivalently, Boolean max and min operations are replaced by lattice-theoretical sup and inf operations. In this paper we consider the construction a flat operator on grey-level or colour images from an operator on binary images that is not increasing. Here grey-level and colour images are functions from a space to an interval in ℝ m or ℤ m (m ≥ 1). Two approaches are proposed. First, we can replace threshold superposition by threshold summation. Next, we can decompose the non-increasing operator on binary images into a linear combination of increasing operators, then apply this linear combination to their flat extensions. Both methods require the operator to have bounded variation, and then both give the same result, which conforms to intuition. Our approach is very general, it can be applied to linear combinations of flat operators, or to linear convolution filters. Our work is based on a mathematical theory of summation of real-valued functions of one variable ranging in a poset. In a second paper, we will study some particular properties of non-increasing flat operators.

Guidewire perforation and compartment syndrome after lower extremity angioplasty

Summary: Chronic total occlusion remains one of the most challenging lesions to treat despite continuing developments in medical devices and increasing operator experience. Guidewire perforation complications are being increasingly observed. Early recognition and timely institution of appropriate treatment are essential to prevent potentially devastating sequelae.

Positive Solutions for a Hadamard Fractional p-Laplacian Three-Point Boundary Value Problem

This article is to study a three-point boundary value problem of Hadamard fractional p-Laplacian differential equation. When our nonlinearity grows ( p − 1 ) -superlinearly and ( p − 1 ) -sublinearly, the existence of positive solutions is obtained via fixed point index. Moreover, using an increasing operator fixed-point theorem, the uniqueness of positive solutions and uniform convergence sequences are also established.

Singular value inequalities for Hilbert space operators

In this paper we show that if Ai,Bi,Xi are Hilbert space operators such that Xi is compact i = 1,2,..., n and f,g are non-negative continuous functions on [0,?) with f (t)g(t)=t for all t?[0,?), also h is non-negative increasing operator convex function on [0,?), then h(Sj(?n,i=1 ?iAi*Xi*Bi)) ? Sj(?n,i=1 ?ih(Ai* f(|Xi*|)2Ai) ? ?n,i=1 ?ih(Bi* g(|Xi|)2Bi)) for j = 1,2,... and ?n,i=1 ?i = 1. Also, applications of some inequalities are given.

Does Accountability and an Automation Decision Aid’s Reliability Affect Human Performance in a Visual Search Task?

Some automation aids are not 100% reliable and can therefore provide incorrect information to users. If humans trust and comply with faulty automation aids, performance errors may result. In combat identification, performance errors may include fratricide or failure to identify enemies. In operator-automation teams, human accountability may reduce errors resulting from over-compliance and automation bias. The goal of the proposed study was to evaluate if reliability of an automation aid (60%, 80%) and accountability level (accountability, non-accountability) would influence human performance on a visual search task. Fifty-two undergraduate students performed a simulated combat identification task, aided by automation. Those in the 60% reliability condition committed more identification errors. However, this difference was eliminated for accountable participants. The findings suggest increasing operator accountability may improve identification performance and meliorate the adverse effects of unreliable automation.

The effect of increasing operator experience on procedure-related characteristics in patients undergoing carotid artery stenting

Objectives To evaluate the efficacy and safety of carotid artery stenting for the treatment of severe carotid artery disease in our department and to investigate the effect of increasing operator experience on perioperative and procedure-related characteristics. Methods From January 2007 to February 2015 200 patients underwent 207 endovascular procedures for carotid artery stenosis. Of all, 113 arteries (56.5%) were symptomatic. Significant changes across time were calculated with the use of Change Point analysis using bootstrap and mean squared error estimates. Results The technical success was 98.6% (204/207 cases). Thirty-day neurological events included stroke in four patients (2%) and transient ischemic attack in two (1%). None of the patients died during the first 30 days. The most significant change of radiation duration occurred after the 33rd patient with a decrease from 25.31 min to 12.31 min, while for the total operative time that change occurred between the 31st and 33rd patient where mean operation time decreased from 88.89 min to 49.22 min. The most significant change of contrast media used occurred at the 40th patient with a decrease from 91.58 ml to 62 ml. During a mean follow-up period of 42 ± 20.02 months none of the patients experienced any cerebrovascular event. There was one case of significant recurrent stenosis, which was successfully treated by endovascular means. Conclusions Endovascular treatment of carotid artery stenosis performed in a single center with the use of a cerebral protection device seems to consist a safe therapeutic choice with acceptable results, within the referenced benchmarks proposed in the latest guidelines. Certain perioperative parameters such as the amount of contrast media used, the fluoroscopy and operation time, seem to decline overtime indicating increasing operator’s experience. A number of performed cases above 40 was related to the significant decrease of those parameters and may represent the learning curve of the procedure.

SIGN-CHANGING SOLUTIONS OF (e1, B)-LIMIT INCREASING OPERATOR EQUATION

In this paper, by using the fixed point index method first we obtain some existence and multiplicity results for sign-changing solutions of an (e1, B)-limit increasing operator equation. The main results can be applied to many non-linear boundary value problems to obtain the existence and multiplicity results for sign-changing solutions. We also give a clear description of locations of these sign-changing solutions through strict lower and upper solutions. As an example, in the last section we obtain some existence and multiplicity results for sign-changing solutions of some Sturm–Liouville differential boundary value problems.

Introduction: Endovascular approaches to cerebral ischemia

Thetreatment of stroke has rapidly evolved over the past decade, particularly as data concerning the natural history have emerged and endovascular treatment options have matured. Therapies for acute stroke have expanded as intraarterial thrombolysis and mechanical clot retrieval have been validated. Furthermore, angioplasty and stenting of intra- and extracranial vessels have evolved with the development of new devices coupled with increasing operator experience. Endovascular therapy is now a widely accepted treatment option for cerebral ischemia in many clinical situations.