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Regis Rieu

Publications and source records attributed to Regis Rieu.

2 recordsLinked to original sources

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. This Chapter presents an overview of what is available currently, such as laparoscopic aortic clamps or laparoscopic intestinal retractors; others are in the experimental stage, such as laparoscopic aortic staplers, anastomotic devices, and robotic surgical systems. This important technologic challenge should lead to 2 major orientations: development of qualitative in vitro and in vivo experiments to test these new products, and training courses to teach their use. Minimally aggressive techniques are well adapted to a western population growing older and has access to constantly improving medical care; however, only specific and ergonomic instruments will allow these new techniques to be widely embraced by the vascular surgical community.

Aortic Aneurysm↗

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). The final objective is to give leads to understand, from the hemodynamic point of view, complications in case of AF. METHODS AND RESULTS: An atrio-ventricular dual activation system is used to simulate physiological flow in the left atrium. The cavities are compliant and transparent. Velocity measurements are performed with Particle Image Velocimetry. Systolic peak of the pulmonary venous flow is about 0.4 m s(-1) and diastolic peak 0.6 m s(-1) in magnitude. Vortices appear during diastasis and systole and are of normal size and duration. In early and late diastole, the ventricular filling (in NC and AF) and the atrial contraction (in NC only) create a characteristic flow pattern that consists in directed flow towards the mitral valve. In AF an increased resident time (500 ms versus 300 ms) and a slow helical flow pattern (about 0.1 m s(-1)), similar to what is measured using ultrasound echocardiography are observed. CONCLUSION: This study uses atrial flow dynamics description to help understand why thromboembolisms occur in AF.

Atrial Fibrillation↗