effect of modification of shock-wave delivery on stone fragmentation talic rf & rabah dm college...

Effect of modification of Effect of modification of shock-wave delivery on stone shock-wave delivery on stone

fragmentationfragmentation

Talic RF & Rabah DMTalic RF & Rabah DM

College of Medicine & king Khalid university hospitalCollege of Medicine & king Khalid university hospitalKing Saud UniversityKing Saud UniversityRiyadh, Saudi ArabiaRiyadh, Saudi Arabia

First generation LithotriptorFirst generation Lithotriptor

High success rateHigh success rate

Minimally invasiveMinimally invasive

Second & 3Second & 3rdrd generation lithotriptors generation lithotriptors

User convenienceUser convenience Reduced anesthesia requirmentsReduced anesthesia requirments Multi-functionalityMulti-functionality Results?Results?

Recent publications evaluating Recent publications evaluating different SWL of renal calculidifferent SWL of renal calculi

StudyStudy YearYear LithotriptorLithotriptor Stone Stone freefree)%( )%(

Retreatment Retreatment raterate)%( )%(

Cope et alCope et al 19911991 Wolf PiezolithWolf Piezolith 7575 5151

Mykulak et alMykulak et al 19921992 TherasonicTherasonic 5656 2121

CassCass 19951995 Dornier HM3Dornier HM3 6363 66

Coz et alCoz et al 20002000 Modulith SL-20Modulith SL-20 8787 2121

Lalak et alLalak et al 20022002 Dornier CompactDornier Compact 6363 NDND

Johnson et alJohnson et al 20032003 Dornier Doli SDornier Doli S 7474 66

Stone clearance is the most Stone clearance is the most important aspect for patients important aspect for patients

receiving SWL for urinary calculireceiving SWL for urinary calculi

Kouriefs et al. Ann R Col Surg Eng 2004Kouriefs et al. Ann R Col Surg Eng 2004

Improving SWL resultsImproving SWL results

Patient selectionPatient selection Prognostic variablesPrognostic variables Modification of SW deliveryModification of SW delivery

– Shock-wave rateShock-wave rate– Shock-wave pulse sequencing Shock-wave pulse sequencing – Stone targetingStone targeting– Dose escalation in SW deliveryDose escalation in SW delivery

Modification of SW treatment strategyModification of SW treatment strategy– Chemolytic pretreatmentChemolytic pretreatment– Synchronus bilateral stone SWLSynchronus bilateral stone SWL

Pressure-wave-form at the focusPressure-wave-form at the focus

Leading shock-waveLeading shock-wave (compressive force)(compressive force)– Dynamic fractureDynamic fracture– Cavitational erosionCavitational erosion

Tensile waveTensile wave

Modification of Shock WaveModification of Shock Wave delivery & Strategy delivery & Strategy

Shock-Wave Rate ModificationShock-Wave Rate Modification

Shock-wave pulse sequencing Shock-wave pulse sequencing

Stone targetingStone targeting

Dose escalation in SW deliveryDose escalation in SW delivery

Chemolytic pretreatmentChemolytic pretreatment

Shock-wave rate modificationShock-wave rate modification

FAST RATE


SLOW RATE


Electrohydrolic lithotriptor/Ceramic spheresElectrohydrolic lithotriptor/Ceramic spheres

– 0.4-s interval = few large fragments0.4-s interval = few large fragments

– 2.0-s interval = many small fragments2.0-s interval = many small fragments

Wiskell & Kinn. Br J Urol 1995


Econolith 2000/118 Ceramic stonesEconolith 2000/118 Ceramic stones

– 15,20,22 KV at 30,60,120 &150 sw/min15,20,22 KV at 30,60,120 &150 sw/min

– Improved fragmentation at ↑ KV and slow rateImproved fragmentation at ↑ KV and slow rate

Greenstein & Matzkin. Urology 1999


Dornier MFL 5000/ 12 solid stadandarised Dornier MFL 5000/ 12 solid stadandarised spherical blaster stonesspherical blaster stones

More SW needed at 20 KV to fragment stonesMore SW needed at 20 KV to fragment stones

at 117 sw/min compared to 60 or 80 sw/minat 117 sw/min compared to 60 or 80 sw/min

Weir et al. J endourol 2000


EDAP piezoelectric lithotriptor/ Human EDAP piezoelectric lithotriptor/ Human kidney stoneskidney stones

– 3000 SW at frequencies of 1.25,2.5,5 & 10/sec.3000 SW at frequencies of 1.25,2.5,5 & 10/sec.– Better fragmentation with SLOWER frequencies Better fragmentation with SLOWER frequencies

Vallancien et al. Eur Urol 1989


In-vivo studyIn-vivo study Artificial stones in pig kidneys/ PCNLArtificial stones in pig kidneys/ PCNL

– Stone fragmentation significantly improved at Stone fragmentation significantly improved at

SW rate of 30/min compared with 120/min.SW rate of 30/min compared with 120/min.

Paterson et al. J Urol 2002


First clinical study (prospective radomized)First clinical study (prospective radomized) 114 patients with ureteric stones114 patients with ureteric stones Piezoelectric lithotriptor at a rate of 60 or Piezoelectric lithotriptor at a rate of 60 or

240240 Success rate was reduced for lower ureteral Success rate was reduced for lower ureteral

stones and unchanged for upper ureteral stones and unchanged for upper ureteral stones with the slower ratesstones with the slower rates

Roberts et al. J endourol 1999


To determine the effect of To determine the effect of SWL RATESWL RATE on the treatment outcome of patients on the treatment outcome of patients

with renal and ureteric stoneswith renal and ureteric stones

Shock-wave rate modificationShock-wave rate modification Patients & MethodsPatients & Methods

A Prospective Randomized TrialA Prospective Randomized Trial Inclusion Criteria:Inclusion Criteria:

Stones Stones SingleSingle

Radio-opaqueRadio-opaque

Renal or uretericRenal or ureteric

Not more than 30mmNot more than 30mm

Exclusion CriteriaExclusion Criteria Bleeding disordersBleeding disorders Distal obstructionDistal obstruction Uncontrolled UTIUncontrolled UTI


FOLLOW UPFOLLOW UP At 3 month visitAt 3 month visit KUB ±IVU/USKUB ±IVU/US Success: completely stone freeSuccess: completely stone free clinically insignificant gravel < 2mmclinically insignificant gravel < 2mm Statistics: Univariate AnalysisStatistics: Univariate Analysis chi-squarechi-square

Fisher’s Exact testFisher’s Exact test Mann-Whiney testMann-Whiney test

Multivariate AnalysisMultivariate Analysis

150 patients150 patientsSlow rate = 71 patientsSlow rate = 71 patientsFast rate = 79 patientsFast rate = 79 patients

SexSex 108 (72%) Male 108 (72%) Male 42 (28%) Female42 (28%) Female

AgeAge 42.1±13.4 years 42.1±13.4 yearsSlow: 41.8±14.8 yearsSlow: 41.8±14.8 yearsFast: 42.3±12.1 yearsFast: 42.3±12.1 years

((P=NSP=NS))

0

10

20

30

40

50

60

Slow rate Fast rate

Male Female

No

of p

atie

nts

(P=NS)

SEX

Results

Shock-wave rate modification


Stone sizeStone size:: – 11.98 ± 6.0 mm11.98 ± 6.0 mm

– Range = (5-30)Range = (5-30)

Slow rate: 12.4 ± 5.9Slow rate: 12.4 ± 5.9 Fast rate: 11.6 ± 6.3Fast rate: 11.6 ± 6.3

((P=NSP=NS))

0

5

10

15

20

25

30

35

40

Slow rate Fast rate

Right Left(P=NS)

No

of p

atie

nts

Side

Results


0

1000

2000

3000

4000

5000

6000

7000

8000

Slow rate Fast rate

Total SW

5794±3384 7438±4519(P=0.005)

Results


0102030405060708090

100

Slow rate Fast rate

Treatment time

96.5±56,4 61.9±37.6(P=0.000)

Results


ResultsResults Success rateSuccess rate

Entire group of patients: Entire group of patients: 141/150 141/150 ))94%94%((

Slow rate group: 70/71 (Slow rate group: 70/71 (98.5%98.5%)) Fast rate group: 71/79 (Fast rate group: 71/79 (89.8%89.8%))

((PP= 0.025)= 0.025)


VARIABLEVARIABLE SIGNIFICANCESIGNIFICANCE

))P valueP value((

SWL rateSWL rate 0.0250.025

Stone LengthStone Length 0.0000.000

Session numberSession number 0.0010.001

Total ShocksTotal Shocks 0.0120.012

Success Rate


CONCLUSIONSCONCLUSIONS

Shock Wave Lithotripsy Shock Wave Lithotripsy raterate has an has an independent significant impact on the independent significant impact on the successsuccess rate after rate after SWLSWL Treatment Treatment

The The EnhancedEnhanced success rate with success rate with slow slow SWLSWL rate treatment is achieved with rate treatment is achieved with Less Less

number of shock wavesnumber of shock waves


Results are better at a Results are better at a SW rate of 60/min.SW rate of 60/min.

Especially in patients Especially in patients with larger stones with larger stones (namely those who (namely those who have worse outcome have worse outcome classically)classically)

Pace et al. J Urol 2005


Efficacy of Slow shock wave rate is Efficacy of Slow shock wave rate is establishedestablished

Enhanced Safety and reduced renal tissue Enhanced Safety and reduced renal tissue injury → Awaits further studies.injury → Awaits further studies.


Shock-wave rateShock-wave rate

Shock-wave pulse sequencingShock-wave pulse sequencingSynchronus twin-pulse techniqueSynchronus twin-pulse techniqueSequential twin – pulse – deliverySequential twin – pulse – delivery




SW Pulse sequencing modificationSW Pulse sequencing modification

Synchronus twin-pulse techniqueSynchronus twin-pulse technique

The best angle The best angle between the 2 shock between the 2 shock tubes was 90tubes was 90oo

Enhanced stone Enhanced stone dissintegration with the dissintegration with the use of 2 energy use of 2 energy sourcessources

Sheir et al. J Endourol 2001


Synchronus twin-pulse techniqueSynchronus twin-pulse technique

Gross & histologic examination Gross & histologic examination of porcine kidneys showed of porcine kidneys showed renal damage when treated renal damage when treated with 2 shock tubes compared with 2 shock tubes compared to conventional under the table to conventional under the table single tube.single tube.

Sheir et al. Urology 2003

26%

34%

SF at 14/7

40%

Redo- All SF in 1/12

At 1/12

Sheir et al. BJU 2005

)Awaiting prospective randomized studies(

Clinical study


Sequential twin – pulse – delivery Sequential twin – pulse – delivery

HM3 pulse followed, at HM3 pulse followed, at carefuly timed close interval, carefuly timed close interval, by an auxilliary sw from by an auxilliary sw from (PEA) pizeo- electric annular (PEA) pizeo- electric annular

array. array. ↓↓ (Intensify the collapse of SW (Intensify the collapse of SW

induced bubles at stone induced bubles at stone surfac)surfac)

Zhou et al. J Urol 2004Zhou et al. J Urol 2004


Sequential twin – pulse – delivery Sequential twin – pulse – delivery 20 KV HM3 pulse 20 KV HM3 pulse

(500-600ms interval) (500-600ms interval) 4KV PEA pulse4KV PEA pulse

1500 SW to cylindical 1500 SW to cylindical Bego stone phantomsBego stone phantoms

Vessel phantom to Vessel phantom to mimic renal injurymimic renal injury– Consistent rupture after Consistent rupture after

30 SW at 20KV with 30 SW at 20KV with original HM3original HM3

– No Vessel rupture after No Vessel rupture after 200 SW with combined 200 SW with combined HM3/PEAHM3/PEA

Zhou et al. J Urol 2004Zhou et al. J Urol 200470

75

80

85

90

95

100Efficiency

HM3 HM3/PEA

81.3%

95.2%



Shock-wave pulse sequencingShock-wave pulse sequencing Synchronus twin-pulse techniqueSynchronus twin-pulse technique Sequential twin – pulse – deliverySequential twin – pulse – delivery

STONE TARGETINGSTONE TARGETING



Effect of stone motionEffect of stone motion

Ventilatory motion )50mm(Ventilatory motion )50mm( Focal zone of most Focal zone of most

lithotriptors )4-15mm(lithotriptors )4-15mm(

In-vitro study:In-vitro study: Motorized positionerMotorized positioner Storz Modulith SLXStorz Modulith SLX Gypsum cement stonesGypsum cement stones

Motion > 20mmMotion > 20mm

)75% of SW missed the stone()75% of SW missed the stone(

0

10

20

30

40

50

60

70

80

75% 50%

No motion 10mm motion

Fragmentation

Cleveland at al. J Endo urol 2004

Effect of stone motionEffect of stone motion

Solution:Solution: ? Stone Tracking Device? Stone Tracking Device ? Gating Device? Gating Device

– Stops the shock wave that will miss the stoneStops the shock wave that will miss the stone– Decrease injury and maintain stone Decrease injury and maintain stone

comminution efficiency comminution efficiency



Shock-wave pulse sequencingShock-wave pulse sequencing Synchronus twin-pulse techniqueSynchronus twin-pulse technique Sequential twin – pulse – deliverySequential twin – pulse – delivery


DOSE ESCALATION in SW DELIVERYDOSE ESCALATION in SW DELIVERY



In-vitro studyHM3 Lithotriptor

Begostone phantoms

500 SW at 18 KV500 SW at 20 Kv500 SW at 22 KV

CE* = 88.7%

500 SW at 22 KV500 SW at 20 Kv500 SW at 18 KV

CE * = 81.2%

1500 SW20 Kv

CE = 83.5%

* P significant

Zhou et al. J Urol 2004

CHEMOLYTIC PRE-TREATMENTCHEMOLYTIC PRE-TREATMENT

Altering the chemical environment of the Altering the chemical environment of the fluid surrounding stones, it is possible to fluid surrounding stones, it is possible to

decrease the surface energy and the decrease the surface energy and the concomitant fracture strength of renal calculi concomitant fracture strength of renal calculi

Akers SR et al. J Urol 1987

CHEMOLYTIC PRE-TREATMENTCHEMOLYTIC PRE-TREATMENT

In vitro evidence concludes that wave In vitro evidence concludes that wave speed, wave impedance, dynamic speed, wave impedance, dynamic

mechanical properties and micro hardness mechanical properties and micro hardness of EDTA treated calcium oxalate stones of EDTA treated calcium oxalate stones

and Tromethamine treated uric acid stones and Tromethamine treated uric acid stones were found to decrease compared to were found to decrease compared to

untreated (synthetic urine) control groupsuntreated (synthetic urine) control groups

Heimbach D et al. J Urol. 2004


Progress in basic research of SWL allowed Progress in basic research of SWL allowed urologists to start implementing their better urologists to start implementing their better understanding of the mechanisms involved understanding of the mechanisms involved in stone comminution and tissue injury into in stone comminution and tissue injury into clinical practice. clinical practice.

Slowing the shock wave rate was shown in Slowing the shock wave rate was shown in prospective randomized clinical trials to prospective randomized clinical trials to enhance patients stone free rates enhance patients stone free rates


In vivo and clinical work is needed to further In vivo and clinical work is needed to further evaluate the beneficial effects seen in, in evaluate the beneficial effects seen in, in vitro studies, with sequential twin pulse vitro studies, with sequential twin pulse

delivery and with dose escalation in SWL on delivery and with dose escalation in SWL on stone comminution while simultaneously stone comminution while simultaneously

decreasing side effects. decreasing side effects.


This future work may well pave the way for This future work may well pave the way for new designs and modifications of existing new designs and modifications of existing

lithotriptors that will ultimately enhance lithotriptors that will ultimately enhance current stone free rates and minimize tissue current stone free rates and minimize tissue

injury.injury.

Thank You

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effect of modification of shock-wave delivery on stone fragmentation talic rf & rabah dm college...

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