extracorporeal shock wave lithotripsy (eswl)

DONE BY : MUSTAFA KHALIL IBRAHIM TBILISI STATE MEDICAL UNIVERSITY

4th year, 1st semester, 2nd group

Extracorporeal shock wave lithotripsy (ESWL(

ESWLMachi

neBod

y

Stone

What is ESWL ?

Crystallization of minerals inside urine, which act as the nidus for more sedimentation and finally the formation of a stone within the kidney.

Renal Stone (Nephrolithiasis)

Calcium-containing stone

Calcium OxalateCalcium PhosphateUric acid stone Cysteine stones

Types of Kidney Stones

NO symptomPain: sudden or severe painnausea, vomitingRenal colicFrequent and painful urination,

hematuriaUrinary tract infection: Block the

urinary tract

Signs and Symptoms of renal stone

Plain X-ray

CTUltrasound Diagnosis

Intravenous Urogram

ESWLPercutaneous nephrolithotomy UreteroscopyOpen surgery

Treatments

Use focusing Shock Waves to breakdowna stone into small pieces.

Shock waves are acoustic pulses.

Pass through better in water and solid butnot in air.

Introduce in 1980 by Dornier which is a supersonic aircraft company

What is ESWL ?

Contra-indication

Indication

Relevant coagulation problems Lung tissue in shock wave path Tumors in shock wave area Aneurysms Polyarthritis (difficult to

positioning) Active pyelonephritis Pregnancy

• Stones of less than 2 cm in the kidney

• Or • less than 1 cm in the ureter.

1) A shockwave generator (electromagnetic generator)

2) A focusing system3) A coupling system4) An imaging/localization units

basic Components of lithotripsymachine

Provide a air-free contactIn the propagation and

transmission of a wave, energy is lost at interfaces with differing densities.

A coupling system is needed to minimize the dissipation of energy of a shockwave as it traverses the skin surface

Coupling system

Transcranial magnetic stimulation

Dornier

Coupling system

Fluoroscopy Ultrasound

Imaging units

ESWLprocedures

1) find out the location of stone2) Fasting3) Take the blood pressure4) Check the cardiac physical exam 5) Pre-medication (pain relief)6) Check LMP for female patients7) Brief the details of the treatment to the

patient

Preparation

Lie the patient on the table (Supineoblique or prone(

Procedures

1)Compare with the previous KUB image

2)Using, iliac crest and the spine as landmark

3)Move the patient in the mid level of the

removable broad

: KUB Kidneys, , ureters and bladder-x ray

(localization )Procedures

4)Remove the broad5)Apply gel to the coupling cushion6)Move the coupling cushion to treatment position7) Increase the coupling pressure and touchthe patient skin8) Apply soft pad or sand bag on the opposite side of thepatient (immobilize the patient)

10)Screening in PA view11)Move the table to locate the stone in the center12)Screening in CC view13)Adjust the height of the

table to locate the stone in center

14)Instruct to the patient15)Call doctor to confirm the

position andstart the treatment

Select the suitable parameters1)Power of shockwave (start from low energylevel to high energy level)

2)The frequency of shockwave (ECG gated for patients with cardiac pacemakers or those with arrhythmias who regularly take anti-arrythmic drugs3)Total energy of shockwave

(Renal stone < Ureteric stone(

High energy level + high frequency = shorter

treatment time Low energy level + low frequency

=longer treatment time

During the treatment

Monitor the patient conditione.g. Blood pressure, heart rate, painAny abnormality => Stop shock wave!

Monitor the position and the progress ofstone Move far away from the center => Stopshock wave and make adjustment!

Before ESWL

After ESWL

Patient is being observed for at least anhour in Day ward.

Follow up 2 weeks later with X-ray (KUB)

Remaining Stone => ESWL againOther treatment

Post Treatment

HematomasRisk of hemorrhageHyperventilation

tetanyBlockage of urinary

tract

The higher the total energy, the

higher risk

Complications

Disadvantages AdvantagesMay require repeat

proceduresNot suitable for all

types of stonesCause

complicationsPainful

Non-invasiveSafeNo General

anesthesiaShort treatment

timeConvenience

1) Presentation powerpoint by Beatrice Pang and Connie Li, 2011

2) Dornier Medtech. Operating Manual of Dornier Gemini. 2012

3) JS Rodman et al. No more kidney stones. 20074) SWH Chan et al.A report on randomly sampled

questionnaire survey about renal stone disease in Hong Kong. HK Med J. 2008

5) B Sturtevant et al. Fracture mechanics model of stone comminution in ESWL and implications for tissue damage. Phys Med Biol. 2000

6) W Eisenmenger.The mechanisms of stone fragmentation in ESWL.Ultrasound in Med. & Biol. 2001

7) http://zh.wikipedia.org/w/index.php?title=Image:KUB_stone.j pg&variant=zh-tw

8) http://www.medison.ru/uzi/img/p287.jpg9) http://www.mwstone.com/STONES/equipment.htm10) http://www.tms-uro.com/eng/physicians/swl/1a_vision_dev

ice.htm11) http://www.dornier.com/EMEA/clinical-

solutions/urology/kidney-stones/12) http://emedicine.medscape.com/artic

le/444554-overview

Reference