extracorporeal shock wave lithotripsy (eswl)
TRANSCRIPT
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