The objective of this Phase I SBIR proposal is to demonstrate the feasibility of a device designed to connect two small vessels together simply and easily and that would replace the hand suturing technique currently used to connect vessels in microsurgery and macrovascular end-to-end vascular repair surgeries. This completely biodegradable vascular coupling device (VCD) being developed by Microsurgical Innovations Inc. (MSI), Salt Lake City, Utah will be applied towards both arteries and veins. This approach would reduce the time required in the surgery suite, reduce costs associated with surgery, and reduce the likelihood of failure of the arterial connections, by minimizing human error and stenting open the anastomosis. According to the American Society of Plastic Surgeons there were 17,163 microsurgery procedures in the US performed by plastic surgeons in 2010. This does not include breast microsurgical procedures (around 15,000) and hand microsurgery procedures. Including all of the other subspecialties that perform these types of procedures (neurosurgery, orthopedics, urology, ENT); a reasonable estimate of the number of these surgeries surpasses 100,000. Current microsurgical techniques require the use of intraoperative magnification and ultrafine nylon suture (50-150 m needles) to successfully complete the anastomosis. These operations are time consuming (20-60 min/artery) and expensive (operating room costs of $1000s/hr). Successful implementation of VCD will expand the pool of surgeons that can perform such operations without microsurgical specialization thus bringing ?microsurgery? from tertiary to primary care settings and potentially allow for battlefield surgeries as well. MSI product development is led by Dr. Jay Agarwal, Assistant Professor of Surgery and Dr. Bruce Gale, Associate Professor of Mechanical Engineering at the University of Utah. This SBIR project will be directed by Dr. Huizhong Li, who has more than 4 years of experience with implantable medical device development. MSI also has access to the additional expertise and facilities at the University of Utah core research facilities for mechanical testing, 3D printing, animal studies, histology and imaging at the University of Utah. In this project, Microsurgical Innovations will build a series of vascular coupling device designs and test them first in the lab and then in pigs to determine if they are safe and effective. Design modifications will be made as needed to improve the design of the couplers and to enable inexpensive and efficient manufacturing. The following specific aims detail the goals of Microsurgical Innovations? efforts in this Phase I project.
Specific Aim 1. To evaluate the functionality of biodegradable coupling devices ex vivo. New prototypes will be built from PLA using 3D printing. The goal of this task is to evaluate mechanical strength (yield strength) of the biodegradable prototypes at simulated physiological conditions (in FBS at 37 C). Manufacture 20 3- mm PLA prototypes of the VCD for testing using arterial and cadaver tissues: 1) demonstrate the ability of the couplers to hold at least 5 psi in 90% of tested devices and 2) demonstrate no noticeable or measurable loss of function after 3 months in FBS at 37 C.
Specific Aim 2. To evaluate the effectiveness and performance of the biodegradable VCD in vivo. To evaluate the functionality of the VCDs in vivo, anastomosis procedures will be performed on porcine model for 15 days and 90 days after refinement using the coupling device and accompanying installation tools. Longer term patency, device degradation, and foreign body reaction evaluations will be conducted.
Vascular anastomoses are an expensive and time consuming surgical procedure performed over 100,000 times each year in the US. The proposed project would develop a device to rapidly perform the anastomosis, thereby significantly reducing costs and challenges associated with these surgeries. The proposed device will be more effective and efficient than current methods, and will therefore significantly improve medical treatment while reducing costs in the US.
