Advances in ultrasonic tracking devices, designed for tracking catheters within vessels, may provide an opportunity for image-guided endovascular procedures. This study evaluates the positional accuracy of an ultrasonic navigation system for tracking an endovascular catheter when different stents and graft materials have been deployed in an in vitro system.
Methods: Stent and graft materials commonly used in endovascular procedures were used for this study in combination with a custom three-head ultrasonic transducer navigation system. The stents; evaluated were composed
of Dacron/nitinol, polytetrafluoroethylene (PTFE)/nitinol, and bare nitinol. They were deployed check details into excised porcine tissue cannulized with a rotary drill, and a catheter with a custom microtransducer probe was inserted. The distance from each ultrasonic tracking module to a probe mounted on an endovascular catheter was measured using time of flight
techniques, and the catheter position in three-dimensions Saracatinib was calculated using triangulation.
Results: The measured position was compared to the actual catheter position determined by a precision translation stage. The PTFE/nitinol, bare nitinol, and Dacron/nitinol stent materials were evaluated and resulted in a maximum error of 1.7, 3.0, and 3.6 mm and an SD of 0.7, 1.2, and 1.4 mm, respectively. A reduction in signal intensity of up to 6x was observed during passage of the endovascular probe through the stent materials, but no reduction in the accuracy of the ultrasonic navigation system was evident.
Conclusion: The use of an ultrasonic-based navigation system is feasible in endovascular procedures, even in the presence of common stent materials. It may have promise as a navigational tool for endovascular procedures. (J Vasc Surg 2009;50:1143-8.)”
“OBJECTIVE: To report an operative
technique using 2 microcatheters placed in different arterial pedicles for Onyx (ev3 Neurovascular, Inc, Bafilomycin A1 purchase Irvine, CA) embolization of cerebral arteriovenous malformations (AVMs).
TECHNIQUE: Two cases illustrate this approach to embolization of AVMs. Microcatheters are placed in 2 different arterial pedicles of the AVM. Subsequently, the embolic material is injected in an alternate fashion between the microcatheters until occlusion of the AVM.
CONCLUSION: The 2-microcatheter technique for embolization of AVMs with Onyx was performed safely. The technique allowed for less interruptions of injection and better control of the reflux of Onyx in the arterial pedicle during treatment. This technique presents an alternate approach to conventional AVM embolization.”
“Objective: The theory of primary venous dilatation leading to secondary valvular incompetence and varicose vein formation has received more attention nowadays. Although many studies have investigated the role of the main components of the venous wall in the development of varicose veins, the leading cause remains unknown.