Extra-corporal Shockwave Lithotripsy- for Urolithiasis

Dr. Chan Shu Yin EddieDr. Chan Shu Yin EddieUrology Division, Department of Urology Division, Department of SurgerySurgeryPYNEHPYNEH

Agenda

History and basic principle of ESWL

Challenges and Complications of ESWL

Take home messages

ESWLESWL

Easy, simple, thing thatnothing need to learn

REALLY???REALLY???

History of ESWL

1951 SW for treatment of brain tumours 1971 in-vitro disintegration of kidney stones 1974 in-vivo trials 10/1983 1st ESWL machine HM3 installed 1984 FDA approval 1991 1st 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-free 15% additional Rx OBS 17% stone-free 21% 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

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