This item is under embargo and not available online per the author's request. For access information, please visit http://libanswers.wustl.edu/faq/5640.

Date of Award

Spring 5-20-2021

Author's School

McKelvey School of Engineering

Author's Department

Mechanical Engineering & Materials Science

Degree Name

Master of Science (MS)

Degree Type

Thesis

Abstract

Endovascular catheter-based technologies have revolutionized the treatment of complex vascular pathology. Catheters and endovascular devices that can be maneuvered through tortuous arterial anatomy have enabled minimally invasive treatment in the peripheral arterial system. Although mechanical factors drive an interventionalist's choice of catheters and sheaths, these decisions are mostly qualitative and based on personal experience and procedural pattern recognition. The field currently lacks a definitive quantitative characterization of endovascular tools that are best suited for specific peripheral arterial beds. This approach gives rise to a phenomenon called catheter herniation, which occurs when a catheter is energetically displaced or buckles while a second coaxial device is passed over or through it. After deriving the mechanics of catheter herniation through an energy approach, results indicate that the ratio of device flexural rigidity dominates in causing this event. To establish a foundation for quantitative tool selection in the neurovascular and lower extremity peripheral arterial beds, a nonlinear beam theory method was developed to quantify catheter and sheath flexural rigidity. This was applied to assess a sampling of commonly utilized commercially available peripheral arterial catheters and sheaths. Results demonstrated that catheters and sheaths adopted for existing practice patterns to treat peripheral arterial disease in the lower extremities and neurovascular system have different but overlapping ranges of flexural rigidities that were not sensitive to luminal diameters within each procedure type. This approach provides an accurate and effective method for characterization of flexural rigidity properties of catheters and sheaths, and a foundation for developing a variable stiffness catheter technology tailored for alleviating catheter herniation concerns in peripheral arterial systems.

Language

English (en)

Chair

Dr. Guy Genin

Committee Members

Dr. Guy Genin, Dr. David Peters, Dr. Mohamed Zayed, Dr. Joshua Osbun

Available for download on Tuesday, April 26, 2022

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