Low-intensity Pulsed Ultrasound to Mitigate Skull Flap Resorption Following Cranioplasty
BACKGROUND: Bone flap resorption occurs in up to half of children undergoing an autologous cranioplasty (replacement of the bone flap) following initial removal of the bone for severe traumatic brain injury. Additional procedures are often required to provide adequate bony coverage of the underlying brain. GAP: While clinical risk factors for bone flap resorption have been identified in pediatric patients, therapeutic strategies for mitigating the resorption process following cranioplasty have not been explored in depth. HYPOTHESIS: Among pediatric patients, the growing brain places mechanical, tensile strain on the overlying immature dura, which induces the secretion of growth factors that contribute to osteogenesis. Low-intensity ultrasound has been shown to produce mechanical forces that have biological effects, and may impact bone formation / resorption following cranioplasty. METHODS: Aim 1: Cytokine levels will be measured in vitro in patient-derived dural samples exposed to mechanical loading via low-intensity ultrasound. Aim 2: The degree of bony fusion and integration following replacement of the bone flap will be measured in an in vivo rodent model of decompressive craniectomy following exposure of the dura to mechanical loading via low-intensity ultrasound. RESULTS: Pending. IMPACT: Bone flap resorption following cranioplasty can result in cosmetic issues, a decreased quality of life, and an increased risk of injury to the underlying brain. This typically requires additional surgery, exposing the child to further risks, more time spent in the hospital, and increased costs. A successful method of reducing bone flap resorption in a noninvasive manner would mitigate these issues.