Future of robotics in vascular surgery

摘要

For over a decade, there has been a paradigm shift to an endovascular, minimally invasive approach whilst treating diseases of the aorta and its branches, with clear advantages in terms of morbidity and mortality in certain vascular beds, especially in patients with multiple co-morbidities that would otherwise be deemed unsuitable for traditional open surgical approaches. Endovascular intervention however, has certain morphological and anatomical constraints. Difficult anatomical targets may lead to prolonged endovascular instrumentation carrying significant risks to the patient such as distal embolization and vessel trauma, with increased fluoroscopic exposure and long overall procedure times. Visualization and control of wire and catheter manipulation become less intuitive and less predictable as case complexity increases. Furthermore, complex endovascular tasks require a refined set of operator skills and technical finesse that is usually acquired after years of experience and standardized training. Conventional endovascular catheter technology contributes to these technical limitations; with a limited repertoire of shapes and sizes, they are difficult to steer and lack active maneuverability of the tip. This manual control can hinder overall stability and control at key target areas necessitating frequent catheter changes and risking loss of wire position in challenging cases. Catheter movement in itself consists of a series of interactions, which occur between the catheter, the guidewire and the vessel wall. Although effective, it is this wall interaction, which is responsible for many of the complications reported, as repeated instrumentation especially in the presence of vessel thrombus or calcification, increases the risk vessel dissection, perforation and distal embolization. Endovascular flexible robotic technology presents itself as an attractive option, with enhanced active maneuverability, catheter tip control and the promise of “off the wall”, center-line navigation remotely and away from the radiation source. CLINICAL ADVANTAGES OF ENDOVASCULAR ROBOTICS Experience with computerized robotically controlled catheter systems was initially obtained in cardiac mapping and ablation procedures via the transvenous route. Clinical experience with the Hansen Sensei robotic catheter system (Hansen Medical, USA) has demonstrated safety and efficacy as well as reduction in radiation exposure in electrophysiology.1–3 Remotely controlled steerable catheter navigation and vessel cannulation in the arterial tree constitutes a novel approach in the field of endovascular arterial intervention. Extensive pre-clinical studies have shown robotic cannulation to be an effective technique both in the visceral segment and fenestrated stent grafting techniques but also for the arch vessels,4,5 and animal studies have reported histological evidence in terms of its safety.6 Robotic cannulation seems to be significantly faster than standard cannulation using conventional endovascular catheters; the data suggested that the time taken to access target vessels may be reduced by 83% using robotic technology, with important implications for fluoroscopic exposure, radiation dose and overall procedure times. The number of movements at the catheter tip required to complete successful target vessel cannulation as well as vessel wall contact are also significantly reduced. This is likely a result of a greater range of motion with the robotic catheter and increased 3-dimensional (3D) control. With conventional catheters the operator is required to make a series of movements, adjusting the amount of manual torque in order to reach a given target. The benefits using robotic technology are particularly evident with the more challenging anatomical configurations, whereas one may argue that advantages during simplex endovascular tasks may be less clinically relevant. Mere target vessel catheterization however, does not necessarily reflect technical success i