Extra-corporal Shockwave Lithotripsy - for Urolithiasis Dr. Chan Shu Yin Eddie Urology Division, Department of Surgery PYNEH

Agenda History and basic principle of ESWL Challenges and Complications of ESWL Take home messages

ESWL ESWL Easy, simple, thing that nothing need to learn REALLY???

History of ESWL 1951SW for treatment of brain tumours 1971 in-vitro disintegration of kidney stones 1974 in-vivo trials 10/19831st ESWL machine HM3 installed 1984FDA approval 19911st ESWL machine in HA hospital

Components of ESWL Machine Generator & focusing system  Electrohydraulic  Electromagnetic  Piezoelectric Coupling mechanism  Water Bath  Semi-water Bath  Water Cushion Localization system  Fluoroscopy vs. Ultra-sonography

HM3 machine

The New Generation ESWL Machine Principles of shockwave generation Focusing system Coupling Localization Aim as low cost, pain-free application, multifunctional use and easy handling

Lithostar

“The cellular phone… was introduced in 1984, the same year as the Dornier HM3 lithotriptor, an equally revolutionary device from a medical technology perspective. Cellular phone initially weighted in excess of 2 pounds…weigh as little as 2 ounces today. The last 15 years of lithotriptor technology have been a disappointment.” Dr. J. Lingeman

ESWL – Challenges When to use ESWL? Management of post-ESWL complications

Case 1 Good case for ESWL? BMI = 49

Ureteric Stone Rate of spontaneous passage ESWL is unnecessary for small uncomplicated ureteric stones ≤ 5mm 5 – 10 mm % proximal ureteric 29 – 98 %10 – 53 % % distal ureteric 71 – 98 %25 – 53 %

Case 2

ESWL vs. Observation: Outcome for small asymptomatic calyceal stone <15mm 228 patients  200 available for FU, mean 2.2 yr (1-5 yr) SWL 28% stone-free15% additional Rx OBS17% stone-free21% additional Rx p = 0.06 p=0.27 No difference in outcome Bristol Urological Institutes, BJU 2001;87,1-8

ESWL - Complications Complications of anaesthesia or sedation / antibiotics 1% clinical significant haematoma 5-25% pain due to stone fragments passage 2-6% stone obstruction – steinstrasse Hypertension – unknown long-term effects

Perinephric Haematoma

Occurrence  Radiologically 20-25%  Clinical significant - < 1%  Risk factors HT Uncontrolled coagulopathy NSAID Obesity UTI Bilateral treatment Lithotriptor model – larger peak pressure and smaller focal zone

Case 3

Case 4 50 years old lady Small lower pole renal stone presented with mild loin discomfort ESWL was offered

50 years old lady Small lower pole renal stone presented with mild loin discomfort ESWL was offered Developed high fever with septic shock after ESWL Need ICU care

50 years old lady Small lower pole renal stone presented with mild loin discomfort ESWL was offered Developed high fever with septic shock after ESWL Need ICU care Treated with PCN insertion and antibiotics

Take Home messages Stone management can be difficult. ESWL should not be considered as a treatment modality in isolation and must not be abused. Complications of ESWL are not very common but may lead to major morbidity. Complications can be silent and delayed in picking up