According to a study published in the Journal of Surgical Research, more than 80 percent of people who suffer traumatic injury to a major artery or vein die from rapid blood loss. The window for saving lives of people with other potentially fatal afflictions may be hours, days, or even weeks, but the outcome of a non-compressible hemorrhage within the torso is determined in mere minutes.
The United States Department of Defense has granted $2.5 million in funds for a 4-year research collaboration between the University of Pittsburgh Swanson School of Engineering and UPMC Division of Vascular Surgery. The research team will develop a removable, collapsible, and biocompatible trauma stent to prevent internal bleeding from the aorta. The “Rescue Stent” will have both military and civilian applications and could greatly reduce fatalities caused by gunshot wounds, stabbings, and other related torso injuries.
McGowan Institute for Regenerative Medicine faculty member Bryan Tillman, MD, PhD, assistant professor of vascular surgery at Pitt’s School of Medicine, will serve as principal investigator and provide clinical insight and lead the testing. Joining Dr. Tillman on the study are three engineering professors from Pitt’s Swanson School: Youngjae Chun, PhD, Sung Kwon Cho, PhD, and William Clark, PhD. Parthasarathy Thirumala, MD, co-director of the Center of Clinical Neurophysiology at UPMC, will also assist the study as a co-investigator to ensure the Rescue Stent avoids the paralysis associated with other current approaches for hemorrhage control.
“If there is internal bleeding, applying pressure to the wound won’t stop it,” said Dr. Chun. The current treatment involves essentially placing a balloon somewhat randomly inside the patient’s artery to block blood loss. However, use of the balloon can result in organ failure and paralysis because it causes a complete stoppage of blood flow. In about 4 minutes, we can implant our stent, redirect blood flow, and stabilize a patient.”
McGowan Institute for Regenerative Medicine affiliated faculty member Dr. Chun, assistant professor in the Departments of Industrial Engineering and Bioengineering, will be responsible for designing, modeling, and fabricating the stent. He will investigate various design methods and advanced manufacturing processes to create functional rescue stents, including geometric/stress analyses, micro laser welding, thermal treatment, mechanical-chemical joining processes, and biocompatible surface treatments.
Dr. Cho, associate professor of mechanical engineering and materials science, will work on the fabrication of radio-frequency identification (RFID) and vital sign monitoring sensors. The RFID sensor—which is wireless, inexpensive, and more portable than the equipment used for internal positioning in hospitals—will allow Dr. Cho to position the device inside the body without X-rays or ultrasound imaging.
“An RFID sensor can be used to make sure we position the stent exactly at the point of trauma without restricting blood flow from the undamaged blood passageways,” said Dr. Cho. “It is the same technology used in a grocery store scanner; and an emergency room physician, general surgeon, or resident can easily track the stent to ensure it’s properly placed.”
Dr. Clark, professor of mechanical engineering and materials science, will participate in the sensor development and take the lead on their integration and data analysis, while working with Dr. Cho to make sure the sensors can be identified and interpreted once inside the body.
“In addition to accurately positioning the stent, the sensors we are developing will allow us to monitor the patient’s vitals,” said Dr. Clark. “The individual placing the stent will have a clear idea of what’s going on inside the patient and can drastically open the window of time the patient has to survive before being treated by a vascular surgeon.”
“The intersection of medicine, industrial engineering, and mechanical engineering has been very important to the development of the Rescue Stent,” added Dr. Tillman. “It requires a great deal of engineering expertise to ensure the stent is compatible with the needs of the medical community. The interdisciplinary environment at Pitt lends itself to these kinds of collaborations in a really spectacular way.”