Grants Funded

Abstract
Vascular anastomoses are common and essential in many surgical procedures. Cardiac and vascular surgeons bypass clotted vessels to restore blood flow to the heart and extremities. Microsurgeons move tissues around the body, reconstructing defects caused by trauma and cancer. Transplant surgeons replace nonfunctional kidneys and composite tissues with new parts. Each of these critical operations requires an anastomosis, which is a surgically created connection between blood vessels. Thousands of these operations are performed daily throughout the United States. Once the anastomosis is complete, the focus turns to maintaining patency and monitoring perfusion. Surgeons use different monitoring methods, ranging from hand-held Doppler evaluations to contrast enhanced computed tomography to no monitoring at all. If a clot goes unrecognized, heart attacks occur, limbs are amputated, organs fail, and tissue dies. Microsurgeons are particular about post-operative blood flow monitoring. The vessels used for these critical surgeries are usually less than 2mm. Their small caliber makes them more susceptible to minor insults. The goal of this project is to standardize, objectify, and simplify anastomosis monitoring. Specifically, this project seeks to evaluate a wireless, biodegradable sensor capable of detecting real-time changes in blood flow after microsurgery. The sensor could help expedite return to the operating room when necessary and optimize patient outcomes. With our colleagues in chemical engineering, we have developed a wireless, biodegradable, flexible, capacitive sensor. The sensor has been tested in an ex vivo environment designed to mimic post-operative conditions. In this proposal, we will assess the accuracy, tolerance, reliability, and degradation of the sensor in vivo. Aim 1 will evaluate device tolerance and accuracy over a short time period simulating a standard inpatient stay after microsurgery. We will assess the sensor's ability to detect small variations in blood flow as well as early thrombus formation. Aim 2 will evaluate continued device accuracy, degradation, and vessel inflammation until complete breakdown. In Aim 3, the sensor will be compared to the current commercially available wired, non-biodegradable sensor. The proposed work will create a new device that will enhance patient care by providing real-time objective data that will fundamentally change the way blood flow monitoring can be achieved after microsurgery.

Biography
In 2015, Dr. Fox joined the Plastic Surgery faculty at Stanford University. She sees patients at the Veterans Affairs-Palo Alto campus, and Lucille Packard Children’s Hospital as well. In addition to clinical responsibilities, she has a basic science lab examining the application of tissue engineering to wound care and upper extremity surgery. Her work has focused on collagen based scaffolds for treating tendon and ligament injuries. Most recently she has begun applying these scaffolds to wound healing models. Dr. Fox received a combined MD/PhD (Microbiology) from Virginia Commonwealth University in 2008. Her PhD research was related to antibiotic resistance in bacteria. She developed a number of critical bench skills during this time, including microscopy fixation and staining techniques, as well as quantitative RT-PCR and protein analysis. In summer 2008, Dr. Fox commenced a residency in Plastic Surgery at Stanford University. Following residency, she completed a fellowship in Hand Surgery at Mayo Clinic. During these training periods, she worked on multiple clinical research projects with the goal of using data to move the fields of plastic and hand surgery forward. These projects allowed her to continue thinking critically about the problems faced by patients and surgeons and how to improve the care of these patients. While at Stanford and Mayo Clinic, she gained the critical surgical knowledge and skills to allow her to be a translational researcher.