First Results on a Flexible Variable Stiffness Endoport for Single-Site Partial Nephrectomy

Amanov, E; Nguyen, Thien-Dang; Imkamp, Florian; Burgner-Kahrs, J
The Hamlyn Symposium on Medical Robotics, pp. 91–92, 2017
First Results on a Flexible Variable Stiffness Endoport for Single-Site Partial Nephrectomy


Minimally invasive surgery gains increasing importance in treating localized renal tumours. Improvements in diagnosis of earlier stages, of haemostats, clips, and barbed sutureslead to an increasing number of organ-preserving partial nephrectomies. While laparo-endoscopic single-site surgery (LESS) is the preferable approach, today’sinstrumentsstill require mobilisation of the kidney to ensure visualisation and accessibility of many tumours. Thisincreases invasiveness, stress for the patient,and prolongssurgery. It would thus be desirable to have a dexterous and flexible port system,which allows single site access and reconfiguration such that a tumourcan be visualised from various orientations.Adjustable stiffness of the port can further enhance manipulability of the tumourwith various instruments through working channels.Thakkar et al.proposed a snake-like flexible single port platformfor distal pancreatectomy enabling deployment of several instruments [1].Dynamic motion of thisplatform for reorientationis challengingand working channels for instrumentation are limited to 2.34mm. Ranzani et al.introduceda multi-segment robotic soft manipulator with variable stiffnessfor single port surgery[2]. However,thedesign does not include working channelsfor varying instrumentation.Comparable approachesto variable stiffnessmanipulatorswith granular jamming wereproposed (e.g. [3]),yet instrumentation was not considered.In this paper, weextend our initial investigations towarda flexible variable stiffness endoport for partial nephrectomy [4].We introduce our first prototype robotic endoport with 2tendon-actuated segments and 3working channels, which is flexible and can stiffenreversibly by granular jamming. We further present qualitative results on the accessibility tothe kidney and renal tumoursin an in vitrohuman abdomen.