Menno E.Sluijter Consultant Center for Pain Medicine Swiss ... · §A method to reduce oxidative...
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www.pain-nottwil.ch Mode of Action and Parameters of Pulsed Radiofrequency Menno E.Sluijter Consultant Center for Pain Medicine Swiss Paraplegic Center Nottwil, Switzerland
Transcript of Menno E.Sluijter Consultant Center for Pain Medicine Swiss ... · §A method to reduce oxidative...
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ModeofActionandParametersofPulsedRadiofrequency
MennoE.SluijterConsultantCenterforPainMedicineSwissParaplegicCenterNottwil,Switzerland
www.pain-nottwil.ch
TypesofPulsedRadiofrequency
§ ClassicalPRF§ Saferalternativeofthermolesions§ Target:Afferentchain§ Application:invasive
§ immunoPRF§ Amethodtoreduceoxidativestressandinflammationbothinpainfulandinnon-painfulconditions
§ Target:T-cellsandothereffectorcellsoftheInnateImmuneSystem
§ Application:transcutaneous
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ClassicalPRF
§ ClassicalPRF§ Saferalternativeofthermolesions§ Target:Afferentchain§ Application:invasive§ Physics
§ Currentupto250mA§ Activeelectrodesurface0.05+11.3=11.35mm2 (5mmtip)§ Efieldsupto200.000V/m
§ Parameters§ Arbitrarilysetat2*20msec/secand35Vin1997
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ClassicalPRFWhatwentwrong?
§ “Moreisbetter”:Voltageincreasedto45V
§ Consequences§ Temperaturemeasurement§ Tissuedamagereports
§ Assumedtobeathermaleffect§ Thisiswrong.ItisEfielddamage
§ Correctionofparametersimpossible§ Lackofknowledgeaboutmechanism
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PRFquestionsregardingtiptemperature
measurement
1. IsraisingMTTfunctionalinPRF?nottothisreferent’sknowledge
2. DoweneedMTTmeasurementbecausewedon’twanttoreducethedutyloadof40msec/sec?
No.STPcurrentprovidesbetterresultssofar
3. IsmeasuringMTTreliable?No,itisnot
4. IssteeringthegeneratoroutputonMTTsafe?No,itisveryriskyinover-perfusedtissue
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ClassicalPRFRe:Temperaturemeasurement
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2005:INTRA-ARTICULARPRFDrAlexandreTeixeira
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PRFvsHEATRF
• HEATRF PRF§ Indication nociceptive pain inflammation
§ Modeofactionablation anti-inflammation
§ Target afferentnerve tobeadjusted
§ Effectonfocus none improvementProtectiveheatshockproteins?
Epigeneticanchoring?
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INFLAMMATION
§ OxidativeStress§ Overproductionoffreeradicals§ Superfast§ Nomemory§ Noself-sustainingcycles§ +++depressingeffectonreactivityofT-cells
§ Inflammation§ Intricateprocessinvolvingmanyenzymesandcytokines§ Timeconstantfromshorttoverylong§ Manyself-sustainingcycles§ AlsodepressingT-cellsbutin(sub-)chronicstage
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PULSEDRADIOFREQUENCYhypothesisonthemodeofaction
§ PhysiologicalrangePRFEfields(40– 250V/m)areresponsiblefortheeffect
§ Reductionofoxidativestressandinflammation§ Longertermeffectiscausedby
§ Persistentdownwardtrendofinflammation§ Possiblyprotectiveoxidativestressproteins(hsp’s?)§ Possiblyepigeneticchanges
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CLASSICALPRFphysiologicalEfieldsduringinvasivePRF
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Consequencesforparameters
§ Wecaneasilydowithsmallerdutyloads§ STP-likeloads(15msec/sec)areOK§ Thiswillfurtherreducetissuedamage
§ Wecanaffordusing40Vorevenless§ Thehighfieldsnearthetiphavenofunction
§ Theyprobablycausethepost-proceduraldiscomfort§ Theareaofthephysiologicalfieldsismorethansufficient
§ MoreisNOTbetter§ Recommendation:40V– STPcurrent– 8-10min
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Consequencesfortechnique
§ Gowherethecytokinesare§ Realizethefollowing:
§ Youarenottreatinganerveunlessthereisinflammationaroundit
§ TheDRGisoftensecondarilyinvolved
§ Considerusingabluntneedle§ Sharptipshaveaveryhighimpedanceandthismovesthe“healingarea”backwardstowhereitisprobablynotneeded.
§ Usesensorystimulationtomakesurethatyouareatasafedistance
§ Ifapatientstillhaspainat4-weekcheckup,waitlonger§ Theanti-inflammatoryphasemaylastupto3months
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CARPALTUNNELSYNDROMEanatomy
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PRFOFTHEMEDIALBRANCHanalternativeapproach
TECHNIQUE INITIATED BY DR PIETRO SCHIANCHI, LUGANO
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ClassicalPRFGowherethecytokinesare!
§ Mpatient54yo§ Clinically:L5radicularsyndrome§ MRI:HNPL4/5.L3/4andL5/S1:normal§ DiagnosticL5nerveblock:+++positive
§ Treatment§ PRFDRGL5
§ 4wkresult:noimprovement
§ Treatment#2§ IntradiscalL4/5:negativedisc.Notreatment.§ IntradiscalL3/4:+++positivedisc.PRF.
§ 4wkresult:OK
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ClassicalPRFMini-intradiscalprocedure
§ Enterintothediscwithnormaltechnique§ Dosensorystimulation(50Hz)
§ Aresponsebelow1.8Vindicatesinflammation
§ Ifdiscispositive,doPRF§ 40V§ 10minutes§ STPcurrent
§ OMIT:§ Provocation§ Discography
§ Themorphologyhasnorelevance
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Consequencesforyourattitude
§ STOPYOURPAVLOVREFLEX
§ THISISNOTABLATION
