Technical Journal, Vol. 8 No. 2, 2014.
Professional paper
Technical aspects of lithotripters and application of shock wave therapy /ESWL/ in the treatment of urinary tract stones
Branka Glavaš
; Klinička bolnica Dubrava, Zagreb, Hrvatska
Zoran Peršec
; Klinička bolnica Dubrava, Zagreb, Hrvatska
Abstract
Nowadays, the treatment using shock wave lithotripsy (ESWL) is becoming the first choice for the treatment of stones in kidneys, ureter, and renal pelvis. Compared with open and endoscopic methods, ESWL is a minimally invasive method which does not require anaesthesia, and achieves high success rates in patients with urolithiasis. The effectiveness of ESWL lies in its specifics of fragmenting calculi "in vivo" which are upon treatment spontaneously eliminated through the urinary tract. All lithotripsy devices consist of four basic components: (1) shock wave generator, (2) focusing system, (3) linking mechanism, and (4) units for image/localization of stones.
Shock wave generators can be electrohydraulic, electromagnetic or piezoelectric. The mechanism of activity that allows stones be fragmented the moment when the power of shock waves exceeds the tensile strength of the stone. Although incompletely explained, fragmentation of stones is performed by the combination of mechanisms, while the strength of shock waves and cavitation are considered to be the most important. In Clinical Hospital Dubrava nowadays LITHOSKOP ®, a multifunctional lithotripter made by Siemens, is used. It has a flexible impact head to perform lithotripsy in positions above and below the table, and there is no need for repositioning the patient during the procedure. Frequency of the head shock waves is 60-120 pulses/min with a penetration depth up to 16 cm and the energy is adjustable to 38 levels. The X-ray C-arm is used for localization and it synchronously follows the automatic movement of the therapeutic head. In addition to the localization of X-ray system it is also equipped with advanced software to automatically move patients in therapeutic focus after selecting the stone and with Color Doppler ultrasound device that enables "inline" ultrasound localization.
Keywords
therapy with shock waves; technical aspects of lithotripters; mechanism of lithotripter activity; ways and reasons for medical applications
Hrčak ID:
124889
URI
Publication date:
15.6.2014.
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