PROJECT SUMMARY Endovascular surgeries (ES) increasingly augment or replace traditional open surgical treatment of brain, liver, heart, and vascular diseases due to their improved clinical outcomes, faster recovery times, and improved mor- tality rates. These surgeries are commonly performed by inserting endovascular equipment into the groin or arm and navigating to distal arteries through a combination of axial loading and rotation of the base of the tools, utilizing the curved tips to deflect into intended locations and vessels. Despite the many benefits of endovascular surgeries, vascular anatomy, particularly for elderly patients who represent a large portion of those undergoing such procedures, can demonstrate excessive tortuosity and severe angulation, leading to high-risk , time-intensive procedures that can only be performed by a select number of expertly trained specialists. The small number of specialists results in limited access to necessary treatment, and patients are forced to either wait and travel for treatment or to not receive treatment at all. There is therefore a critical need for new endovascular robotic surgical tools that are safe, e↵ective, and that enable more surgeons to successfully navigate challenging anatomies. To address this need, a new soft-robotic approach called VINE – Vascular Internal Navigation by Extension – will be used. When pressurized with fluid, these VINEs navigate via extension at their tip in a man- ner analogous to how plants grow, creating shapes with complex curvatures. These VINEs are inherently safer due to their soft structure and represent a fundamentally di↵erent method of movement. The overall objective of this work is to characterize the behavior and refine the design of the VINE for ES, including the shape control methods, and to validate its e"cacy and safety. The central hypothesis is that this new method of shape control and navigation via tip-extension enables VINEs to safely and e↵ectively traverse the vasculature. The central hypothesis will be tested by pursuing three specific aims: (1) characterize and refine small-scale, pre-shaped and steerable VINE designs for ES, (2) evaluate VINE e"cacy in bench-top models, and (3) validate the safety of the entire VINE system in an in vivo pig study. This work will serve as a first step towards achieving the long-term goal of creating a soft robotic catheterization system, operable by a large number of surgeons, to increase access to high-quality surgical treatment. This work is innovative in that the proposed VINE is the first everting, robotic catheter with shape control and represents a substantive departure from the status quo, which currently relies on pushing semi-rigid instruments from their proximal end. The expected contribution of this work is a preliminary soft, tip-extending robotic system capable of safely and e↵ectively navigating around acute turns and through winding paths of the vasculature, which is significant since it will ultimately lead to increased access to high-quality minimally invasive procedures.

PROJECT NARRATIVE We propose to develop new soft, tip-extending robotic catheters with shape control that have the potential to increase access to endovascular procedures by enabling navigation of vessels that can currently only be performed by a small number of specialists. Our approach represents a fundamentally di↵erent method of movement through the vasculature compared to typical manual and robotic methods that rely on axial loading of semi-rigid catheters, and our approach has the potential to improve safety and e↵ectiveness of endovascular surgical procedures. The proposed research is relevant to public health because it seeks to improve outcomes and ultimately increase access to high-quality minimally invasive surgical procedures.