1st supervisor: Thomas Booth, King’s College London
2nd supervisor: Kawal Rhode, King’s College London
3rd supervisor: Christos Bergeles, King’s College London
Stroke is the second leading cause of death across the world, annually killing approximately 6 million people and the third leading cause of disability. In England, Wales and Northern Ireland, 85,000 people are hospitalised with stroke each year[2]. Time from onset to treatment is known to be especially critical, with the effectiveness of treatment declining rapidly in the first few hours after stroke[1]. More recently, thrombectomy has shown substantially improved clinical outcomes in patients with large vessel occlusion present in approximately 40% of patients with acute ischaemic stroke[3,4]. Thrombectomy may be effective up to 6 h or more after stroke onset (depending on patient selection) but also demonstrates reducing effect size with increasing time from stroke onset[2]. The proportion of patients eligible for thrombectomy in the UK has been estimated at about 10%[6]. Providing thrombectomy presents a significant challenge for health services. The procedure is typically carried out by a neuro-interventionist.
Robotically-assisted angiography in the cerebral vasculature has only recently been described by three groups[7,8,9]. For neurointerventional applications, the lack of a platform specifically designed to accommodate very small devices and microcatheters— and the technically demanding “micromovements” required to successfully navigate these tools through the cerebral vasculature — has left neurointerventional robotics virtually unexplored[9]. This is a limitation of the Magellan system which is now no longer commercially available[7].
Two basic mechanisms have been developed to perform robotic surgery in general. Some robotic systems are telemanipulators, which means that they essentially copy the operator’s movements directly. Other systems transform the movements of the operator such that a joystick can manipulate a guidewire or microcatheter[7,8,9]. These systems are motivated by improving the neurointerention procedure itself.
Given that the motivation of this project is to develop tele-operated robotic thrombectomy to allow local treatment to be performed remotely from a specialist neuroscience centre, the emphasis is on the former system i.e. developing robotic systems that are telemanipulators. The key advantage compared to the three systems described above[7,8,9] is that operators would perform tasks in a way that is identical with their current practice with little new learning required (i.e. pushing and rotating catheters and wires as opposed to using a joystick). The large amount of delicate manipulation of the tiny catheter (2.1 Fr) and wire (0.014 inch) that occurs during the procedure demand that a major focus of the project would be on haptic feedback which is a major concern in the current joystick-controlled systems[7,8,9].
Months 1-4: Review of literature on robotic systems and kinematics; start animal project & personal licence permissions; exposure to thrombectomy procedures (King’s College Hospital)
Months 5-9: Develop an in vitro vascular model[10] using 3D printing. Exposure to in vivo porcine models.
Months 10-21: Develop kinematic robotic solutions; validate; reiterate until the accuracy and reliability of the steering is suitable for in vivo porcine model testing. In vivo porcine model training.
Months 21-30: In vivo porcine model set-up and testing. Develop 5G telecommunications for remote location. Develop HRA/REC permissions for human feasibility study.
Months 31–42: Submit paper 1.
If faster than anticipated progress: feasibility study set-up and recruitment of 5 patients who will be unable to reach a specialist neuroscience centre within time window.
Months 42-48: Write up thesis. Submit final paper.
References
- Saver et al. Time to Treatment With Endovascular Thrombectomy and Outcomes From Ischemic Stroke: A Meta-analysis. JAMA 2016 Sep 27;316(12):1279-88.
- Sentinel Stroke Audit Programme (SSNAP). Apr 2015– Mar 2016 –Annual Results Portfolio. National Results April 2015–Mar 2016, www.strokeaudit.org/Documents/Results/National/Apr2015Mar2016/Apr2015Mar2016 AnnualResults Portfolio.aspx (2016, accessed 1 January 2018).
- Flynn D et al. Intra-arterial mechanical thrombectomy stent retrievers and aspiration devices in the treatment of acute ischaemic stroke: a systematic review and meta- analysis with trial sequential analysis. Eur Stroke J 2017; 2: 308–318.
- Smith WS et al. Significance of large vessel intracranial occlusion causing acute ischemic stroke and TIA. Stroke 2009; 40: 3834–3840.
- Goyal M et al. Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials. Lancet 2016; 387: 1723–1731.
- McMeekin P et al. Estimating the number of UK stroke patients eligible for endovascular thrombectomy: estimating the number of UK stroke patients eligible for endovascular thrombectomy. Eur Stroke J 2017; 2: 319–326.
- Vuong SM et al Applications of emerging technologies to improve access to ischemic stroke care. Neurosurg Focus 2017 42 (4) E8
- Lu WS et al. Clinical application of a vascular interventional robot in cerebral angiography. Int J Med Robot 12:132–136, 2016
- Britz et al. Feasibility of Robotic-Assisted Neurovascular Interventions: Initial Experience in Flow Model and Porcine Model. Neurosurgery 2019 Apr 17. pii: nyz064. doi: 10.1093/neuros/nyz064. [Epub ahead of print]
- Crossley R et al. Validation studies of virtual reality simulation performance metrics for mechanical thrombectomy in ischemic stroke. J Neurointervent Surg 2019 Jan 17. pii: neurintsurg-2018-014510. doi: 10.1136/neurintsurg-2018-014510. [Epub ahead of print]