ESWL on Disintegration of Renal Stones

Impact of Different Shock Wave Release Frequencies on Disintegration of Renal Stones in Assuit Urology & Nephrology University Hospital

The impact of different frequencies on pattern of disintegration of renal stones

• Prior to the introduction of extracorporeal shockwave lithotripsy (ESWL) in 1980, the only treatment available for calculi that could not pass through the urinary tract was open surgery. Since then, ESWL has become the preferred tool in the urologist's armamentarium for the treatment of renal stones, , ESWL is minimally invasive, exposes patients to less anaesthesia, and yields equivalent stone-free rates in appropriately selected patients.
• The efficacy of ESWL lies in its ability to pulverize calculi in vivo into smaller fragments, which the body can then expulse spontaneously. Shockwaves are generated and then focused onto a point within the body. The shockwaves propagate through the body with negligible dissipation of energy (and therefore damage) owing to the minimal difference in density of the soft tissues. At the stone-fluid interface, the relatively large difference in density, coupled with the concentration of multiple shockwaves in a small area, produces a large dissipation of energy. Via various mechanisms, this energy is then able to overcome the tensile strength of the calculi, leading to fragmentation. Repetition of this process eventually leads to pulverization of the calculi into small fragments that the body can pass spontaneously and painlessly.
• It is well recognized that the popularity of extracorporeal shock wave lithotripsy (SWL), despite its non-invasive character, has decreased during recent years. This is partly explained by the technological achievements in endoscopy and urologists' enthusiasm for such procedures. Another explanation is that many urologists have been insufficiently successful with SWL. The latter effect might to some extent be a result of the performance of the lithotripter used, but in too many cases, it is evident that the principles of how shock wave lithotripsy should be carried out are poorly appliedical aspect

Inclusion Criteria:

• Pelvic and upper ureteric stones
• Stone size less than 2 cm
• Stone density up to 1000 HU

Exclusion Criteria:

• Lower calycle stone
• Stone size 2 cm or more
• Stone denstiy more than 1000
• age group less than 18 y
• uncontrolled hypertension patient and bleeding disorder
• Pregnancy
• Patients with UPJ obstruction, ureteral strictures,
• Congenital anomalies
• Previous stented ureter
• Narrow neck of the calycx less than 30 %