ABSTRACT
Endovascular procedures provide surgeons and other interventionalists with minimally invasive methods to treat vascular diseases by passing guidewires, catheters, sheaths and treatment devices into the vasculature to and navigate toward a treatment site. The efficiency of this navigation affects patient outcomes, but is frequently compromised by catheter "herniation", in which the catheter-guidewire system bulges out from the intended endovascular pathway so that the interventionalist can no longer advance it. Here, we showed herniation to be a bifurcation phenomenon that can be predicted and controlled using mechanical characterizations of catheter-guidewire systems and patientspecific clinical imaging. We demonstrated our approach in laboratory models and, retrospectively, in patients who underwent procedures involving transradial neurovascular procedures with an endovascular pathway from the wrist, up in the arm, around the aortic arch, and into the neurovasculature. Our analyses identified a mathematical navigation stability criterion that predicted herniation in all of these settings. Results show that herniation can be predicted through bifurcation analysis, and provide a framework for selecting catheter-guidewire systems to avoid herniation in specific patient anatomy.
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 made qualitative and based on personal experience and procedural pattern recognition. However, a definitive quantitative characterization of endovascular tools that are best suited for specific peripheral arterial beds is currently lacking. To establish a foundation for quantitative tool selection in the neurovascular and lower extremity peripheral arterial beds, we developed a nonlinear beam theory method to quantify catheter and sheath flexural rigidity. We applied this assessment to a sampling of commonly utilized commercially available peripheral arterial catheters and sheaths. Our 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. Our approach provides an accurate and effective method for characterization of flexural rigidity properties of catheters and sheaths, and a foundation for developing future technologies tailored for specific peripheral arterial systems.
