A Novel Chorioallantoic Membrane (CAM) Setup to Investigate Angiogenic Effects of Extracorporeal Shock Wave Therapy (ESWT)

Extracorporeal shock wave therapy (ESWT) is a well-known biophysical therapy that offers several beneficial effects, including a presumed increase in the growth of blood vessels. The chorioallantoic membrane (CAM) assay is a well-established in vivo model for studying angiogenesis. The aim of this study was to develop an experimental setup to apply ESWT to CAM in a three-step process and investigate the vascular response. First, we conducted virtual simulations of various shock-wave application setups to CAM and subsequently tested them in preliminary studies to evaluate their feasibility. In the final stage, we employed the most suitable protocol to investigate the angiogenic effects of shock wave therapy in practical applications. Our findings suggest that ESWT increases the number of vessels in CAM. In the final biological experiment (n = 16 CAM per group), ESWT increased vessel number by approximately 14.3% (p = 0.050) and branching points by approximately 13.5% (p = 0.070), while mean vessel thickness decreased by approximately 8.0% (p = 0.047); total vascular area per image remained unchanged (p = 0.760). These effects were concentrated in short-to-medium, thinner-caliber vessels rather than reflecting a uniform increase in vascularity, consistent with the emergence of a denser microvascular network. This new experimental setup paves the way for future research into the angiogenic effects of ESWT and provides a multifaceted model as an intermediate step between in vitro mechanistic studies and clinical translation.