Debulking from within: a robotic steerable cannula for intracerebral hemorrhage evacuation

New approaches to intracerebral hemorrhage management are motivated by its high incidence and 40% mortality rate. Surgery is sometimes attempted to decompress the brain, although patient outcomes are similar regardless of whether surgery occurs. We hypothesize that surgical decompression is not more effective because current open surgical techniques disrupt healthy brain tissue to access the clot formed by the hemorrhage, offsetting the benefits of surgery. To address this, we propose a less invasive needle-based approach in which the clot is debulked from within using a superelastic, precurved aspiration cannula that is deployed from a needle. The tip of this aspiration cannula is controlled by coordinated insertion and retraction of the cannula and needle, as well as axial rotation of the cannula. We describe the design of a sterilizable and biocompatible robot that can control the three degrees of freedom of the needle and cannula. Image guidance is achieved by adapting an approach originally developed for brain biopsy. We provide an optimization method for the selection of the precurvatures of one or more sequentially used aspiration cannulas to maximize hemorrhage evacuation, based on preoperative medical image data. In vitro experiments demonstrate the feasibility of evacuating 83-92% of hemorrhage volume, depending on the number of tubes and deployment method used.