Extracorporeal lithotripsy – ESWL

Extracorporeal lithotripsy

The operating principle of extracorporeal lithotrypsy (ESWL) is based on the existence of three components:

-> A source of energy that produces shock waves
-> Energy transfer mechanism in the body of the patient
-> Focus method of shock waves on the stone.

The energy sources are of three types: electrohydraulic, electromagnetic and piezoelectric. Stone fragmentation is achieved by focusing the shock waves on the stone which initially causes corrosion and subsequent cracking and splitting it. Energy source focus is either fluoroscopy (C-arm) or ultrasound.

Before ESWL application, there must be accurate knowledge of the position of the stone and the anatomy of the urinary tract by intravenous urography (IVU) or CT scan to rule out a possible blockage.

ESWL Contrandictions:
a) absolute:

-> Pregnancy

-> Clogging the drain fate

-> Abdominal aortic aneurysm or renal artery

-> Coagulopathy

b) related:

-> Obesity

-> Patients with arrhythmia or pacemaker

-> Disorders of the spine,

-> Chronic renal insufficiency

Complications of extracorporeal lithotripsy: perirenal hematoma, pyelonephritis, hematuria, renal colic, lithiasis chain (steinstrasse) in the ureter. Regarding the results of ESWL, gritty in the kidney has efficiency of 65-85% on average depending on the size of the stone, while on ureteral lithiasis 50-90% for the middle third and 75 to 90% on average upper third.

ESWL in children:

-> Small trend shock waves <17 kv>

-> Number of hits impact <2000

-> Indicated singleton noninflammatory pelvic stones <2cm.

-> Easier gritty calculi elimination compared with adults