Investigating Biomechanical Properties & Structural Changes Post-Stretch in Neonatal Brachial Plexus
Friday, April 29, 2022
10:00 AM-12:00 PM
BIOMED PhD Research Proposal
Title:
Investigating Biomechanical Properties and Structural Changes Post-Stretch in Neonatal Brachial Plexus
Speaker:
Virginia Orozco, PhD Candidate
School of Biomedical Engineering, Science and Health Systems
Drexel University
Advisors:
Sriram Balasubramanian, PhD
Associate Professor
School of Biomedical Engineering, Science and Health Systems
Drexel University
Anita Singh, PhD
Chair of Biomedical Engineering
Associate Professor
Department of Biomedical Engineering
School of Engineering
Widener University
Abstract:
The brachial plexus (BP) is an intricate network of nerves responsible for providing motor and sensory innervation to the upper extremities. A common BP nerve injury in infants is neonatal brachial plexus palsy (NBPP), which is defined as over-stretching of the BP during complicated birthing scenarios. Despite obstetric care improvements, NBPP continues to significantly impact infants’ lives, with a worldwide incidence of 1 to 4 per 1000 live births. While 70–90% of NBPP cases reported spontaneous recovery, 30–40% reported permanently reduced range of motion with decreased strength, size, and girth of affected upper extremity. Reported spontaneous recovery incidence of NBPP is less than previously expected, thereby increasing the need to improve preventative obstetric maneuvers that help reduce BP injury.
Despite available BP biomechanical properties, a major limitation is the lack of available human neonatal BP data. Due to ethical limitations, no studies have reported the stretch-injury response of human neonatal BP. Therefore, an alternative would be a clinically relevant neonatal large animal model, such as a piglet. In addition, previous studies have reported injury thresholds of histological changes using adult small animal models; however, such limits are yet to be reported in neonatal BP tissue. Injury outcome relies on the extent of damage, hence studying structural changes at varying degrees of mechanical stretch injury in neonatal BP tissue will further help characterize the NBPP injury mechanism.
The overall objective of this study is to characterize the neonatal BP biomechanical properties and corresponding structural changes during stretch using a clinically relevant neonatal large animal model. BP nerve segments of neonatal piglets (3–5 days old) will stretched to pre-determined strains of <10%, 10–20%, and >20% to represent mild, moderate, and severe stretch injury, respectively. BP tissues will be harvested, fixed, and embedded for Hematoxylin-Eosin and immunofluorescence staining to quantify vascular and neurofilament damage and axoplasmic transport impairment.
This study is the first to report in vivo biomechanical properties and structural changes of neonatal BP tissue subjected to stretch using a clinically relevant neonatal large animal model. Data obtained from the current study will enhance the biofidelic responses of existing computational models that simulate neonatal BP injuries. This research will further our understanding of neonatal BP and advance preventative strategies by creating a framework for many future studies that could be conducted, including injury-site modeling or surgical planning.
Contact Information
Natalia Broz
njb33@drexel.edu