Robotics in Interventional Oncology: Articles From the Official Show Daily for Synergy 2015

Intravascular robotics represent the latest advancement in the evolution of endovascular interventions. One of the primary objectives of this novel technology is the facilitation of guidewire and catheter navigation, especially in the setting of tortuous and challenging anatomy. A wide variety of angles and catheter shapes can be created with precision and allows the operator to utilize a single catheter to obtain stable positioning and drive interventions. The robotic system provides advantages to the physician in terms of decreasing radiation exposure and operator fatigue as the physician is comfortably seated at a workstation away from the image intensifier (Figure 1). During long arduous cases, performance may be ameliorated as the operator is less prone to fatigue. Although we are in the learning curve with this technology, there is the potential to increase procedural efficiency with continued technical improvements.

Our experience with vascular robotics began in 2012, very soon after we acquired the Magellan robotic system (Hansen Medical) at Miami Cardiac and Vascular Institute (Figures 2 and 3). We have performed a variety of interventions utilizing the Magellan robot, including embolization, carotid stenting, mesenteric stenting, treatment of peripheral arterial disease, endovascular aneurysm repair, and treatment of renal aneurysms. With regard to interventional oncology, we have utilized the robotic catheter to assist with hepatic chemoembolization and yttrium-90 radioembolization.

We have at least 18-month follow-up on chemoembolization procedures performed with the robotic system. We have had 100% technical success in performing hepatic chemoembolization and radioembolization. Although there are not sufficient patients or follow-up to determine outcomes in terms of tumor response and survival, I believe that the results would be similar to conventional manual embolization procedures because the actual embolic is equivalent.

The robotic catheter can be especially helpful in the setting of very tortuous aortoiliac anatomy with significant angulation of the celiac axis or superior mesenteric artery that can make manual catheterization difficult or impossible. Although these represent a minority of cases, such cases sometimes necessitate utilization of an upper-extremity approach. The robotic catheter allows for excellent stability from a femoral approach, enabling stable catheterization of targeted vessels because of the ability to manipulate the catheter into different shapes and angles (Figures 4 and 5).

We have not encountered any complications with robot-assisted hepatic embolization procedures. In fact, we have not encountered any complications with the robot for any vascular procedure. Prior to the FDA clearance of the 6 Fr robotic catheter (Figure 6), we performed chemoembolization with the 9 Fr catheter. The clearance of the 6 Fr catheter was a significant advancement as it allowed the procedure to be performed via a smaller profile 6 Fr sheath, which is the size catheter that we generally use. Although we did not encounter any groin complications when utilizing a 9 Fr sheath, the smaller 6 Fr catheter is likely safer. The 6 Fr robotic catheter is designed to catheterize and intervene in smaller vessels. Robotic catheterization is currently limited for smaller vessels for which the smaller 6 Fr system is often still too large and often requires delivery of a microcatheter through the robotic system. Hansen Medical is currently investigating smaller catheters that would be valuable in selecting and tracking into smaller vessels in this setting. We are excited about the future of robotic-guided microcatheters, which will further increase the utility of this system for embolization procedures as well as other peripheral interventions. 

We are currently obtaining data with regard to fluoroscopy time and radiation dose as a part of the ROVER registry. I predict that radiation dose will be reduced with the robotic system; however, the data are not yet available. Sandeep Rao, MD, MBA, gave an abstract presentation of a study at the 2015 Society of Interventional Radiology meeting demonstrating a greater than 80% reduction in radiation dose to the operating physician compared to a bedside control.¹

The purpose of the ROVER registry is to gather both retrospective and prospective case data on the use of the commercially available Magellan Robotic System and Magellan Robotic Catheters in accordance with the approved intended use. For prospective cases, follow-up patient data are collected at 14 days (±5 days) post procedure to assess treatment success, primary patency of intended targeted vessel region, radiation exposure, and adverse events. Intra-procedural radiation at the bedside (typical primary operator position) and actual primary operator using RaySafe is measured.

In terms of nonvascular robotics, there are some preliminary data that show that robotic-assisted biopsies can be performed with CT guidance with a high level of accuracy. In addition, studies have demonstrated the feasibility of robot-assisted ablation and the ability to accurately place ablation probes into tumors.^2,3 Procedures that require very precise placement of probes such as IRE may be very well suited to robot-guided intervention.

Robotic technology offers the potential to make some interventional procedures more precise and safer. Currently approved devices are in the early stages of clinical evaluation. There are some data suggesting there is less vascular trauma when utilizing a robotic catheter when compared to manual catheterization.⁴ With technical improvements and further research, robotic technology may provide some real clinical benefit, however, a comparison of the clinical outcomes of robot-assisted interventions compared to conventional techniques in a randomized clinical trial is necessary.  

References

1. Rao S. Radiation (reduction) in the interventional lab. Abstract presented at the 2015 Annual Scientific Meeting of the Society of Interventional Radiology, March 2, 2015.
2. Patriciu A, Awad M, Solomon SB, et al. Robotic assisted radio-frequency ablation of liver tumors--randomized patient study. Med Image Comput Comput Assist Interv. 2005;8(Pt 2):526-533.
3. Koethe Y, Xu S, Velusamy G, Wood BJ, Venkatesan AM. Accuracy and efficacy of percutaneous biopsy and ablation using robotic assistance under computed tomography guidance: a phantom study. Eur Radiol. 2014;24(3):723-730. 
4. Duran C, Lumsden AB, Bismuth J. A randomized, controlled animal trial demonstrating the feasibility and safety of the Magellan endovascular robotic system. Ann Vasc Surg. 2014;28(2):470-478.