Michael Chang, M.D., Ph.D., CMD
Department of Rehabilitation Medicine
"Physical and Biological Responses to Shockwave Therapy: Potential for Multiple Clinical Applications"


ABSTRACT

For over 25 years, extracorporeal shockwave lithotripsy (ESWL) has become the treatment of
choice for kidney or ureteral stone. More than 4 million patients worldwide have been treated
successfully. It is now well understood that both shear stress and cavitations generated by the
shockwave work synergistically to disintegrate the stone. However, ESWL-related complications,
some are life-threatening, have been reported in the literature, such as subcapsular or
perinephric hematomas, abdominal aorta dissection, kidney infection or rupture, arterial pseudo
aneurysm, bowel perforation or intra-abdominal bleeding, and abdominal wall abscess, etc. There
are lots can be learned from these previous ESWL complications to help prevent future potential
tissue injuries from shockwave therapy.

For over last 10 years, extracorporeal shockwave therapy (ESWT) has been safely and effectively
applied to treat many chronic musculoskeletal conditions such as tendonopathy, enthesopathy,
non-unions, etc with minimally reported complications. Shockwave has been demonstrated, both
in-vitro and in-vivo, to lead an up-regulation of various tissue growth/angiogenic factors. It
is speculated that shockwaves physical effects initiate mechano-transduction via cellular
matrix and/or membrane proteins. ESWT has recently been further demonstrated to accelerate
healing of chronic wound, increase perfusion in ischemic myocardium, reverse clinical course
for femoral avascular necrosis, and increase survival of skin graft. Other potential
therapeutic biological responses from the shockwave also include analgesia, resolution of
chronic pain, collagen parallelism, bactericidal effects, anti-spasticity and reversal of
heterotopic ossifications.

Growing number of clinical ESWT applications to treat variety of tissues at different
anatomical regions requires our thorough understanding of the interplay between physical and
biological responses from shockwave therapy. The goal for future ESWT research and clinical
service is to achieve optimal desired therapeutic efficacy at the target tissue while avoiding
any potential complication.