Longitudinal compression behaviour of coronary stents: a bench-top comparative study.

Aims: The aim of this study was to characterise the coronary stent longitudinal resistance of new coronary stents under worst case clinical crossing simulated configurations.

Methods And Results: Six coronary balloon-expandable stents were evaluated using two different tests. The first was a direct parallel plates longitudinal crush resistance test: it was conducted on stents deployed to 3 mm diameter, and three samples of each model were used.

Laparoscopic aortic surgery: recent development in instrumentation.

In addition to conventional and endovascular techniques, laparoscopic surgery is becoming a third way to treat patients with aortoiliac occlusive or aneurysmal diseases. Several different laparoscopic techniques are available, but most authors are stressing the need for development of specific laparoscopic aortic instruments, to decrease the operative and clamping times and reduce the learning curve. Our experience of more than 150 patients who underwent a laparoscopic abdominal or thoracic aortic reconstruction, has lead us to imagine the instruments that may facilitate these procedures, and then to create a society with Vascular Surgeons and Biomedical Engineers, called PROTOMED, which may conceive, develop, and test new medical instruments.

In vitro atrial flow dynamics: normal conditions versus atrial fibrillation.

Aims: The flow dynamics in the atrium is poorly described. The reasons are principally due to the complicated geometry of the cavity and its contractility. The present in vitro study focuses on the description of the flow in the left atrium in normal conditions (NC) and in atrial fibrillation (AF).

Assessment of the trackability, flexibility, and conformability of coronary stents: a comparative analysis.

The efficacy and safety of coronary stent implantation depend on the mechanical features of these devices when deployed in atheromatous lesions of various morphologies. We evaluated the trackability, flexibility, and conformability of 17 coronary stents using specific mechanical bench tests. The quantifications used a dynamometer for assessment of trackability (maximal strength) and flexibility (stiffness) and a 3D optical gauging machine for assessment of conformability (distance between stent and arterial wall in a curvature).

Independent contribution of left ventricular ejection time to the mean gradient in aortic stenosis.

Background And Aims Of The Study: Transvalvular mean pressure gradients (MPG) are important in the evaluation of aortic stenosis, but surprisingly they often differ in patients having similar valve effective orifice area (EOA) and stroke volume (SV). The study aim was to determine if these differences could be explained by variations in left ventricular ejection time (LVET).

Methods: A pulse duplicator system with a constant SV of 75 ml and incremental increases of LVET from 250 to 450 ms was used to measure MPG by Doppler echocardiography in three fixed stenoses (0.