Embed Size (px)
Citation preview
www.pain-nottwil.ch
ModeofActionandParametersofPulsedRadiofrequency
MennoE.SluijterConsultantCenterforPainMedicineSwissParaplegicCenterNottwil,Switzerland
www.pain-nottwil.ch
TypesofPulsedRadiofrequency
§ ClassicalPRF§ Saferalternativeofthermolesions§ Target:Afferentchain§ Application:invasive
§ immunoPRF§ Amethodtoreduceoxidativestressandinflammationbothinpainfulandinnon-painfulconditions
§ Target:T-cellsandothereffectorcellsoftheInnateImmuneSystem
§ Application:transcutaneous
www.pain-nottwil.ch
ClassicalPRF
§ ClassicalPRF§ Saferalternativeofthermolesions§ Target:Afferentchain§ Application:invasive§ Physics
§ Currentupto250mA§ Activeelectrodesurface0.05+11.3=11.35mm2 (5mmtip)§ Efieldsupto200.000V/m
§ Parameters§ Arbitrarilysetat2*20msec/secand35Vin1997
www.pain-nottwil.ch
ClassicalPRFWhatwentwrong?
§ “Moreisbetter”:Voltageincreasedto45V
§ Consequences§ Temperaturemeasurement§ Tissuedamagereports
§ Assumedtobeathermaleffect§ Thisiswrong.ItisEfielddamage
§ Correctionofparametersimpossible§ Lackofknowledgeaboutmechanism
www.pain-nottwil.ch
PRFquestionsregardingtiptemperature
measurement
1. IsraisingMTTfunctionalinPRF?nottothisreferent’sknowledge
2. DoweneedMTTmeasurementbecausewedon’twanttoreducethedutyloadof40msec/sec?
No.STPcurrentprovidesbetterresultssofar
3. IsmeasuringMTTreliable?No,itisnot
4. IssteeringthegeneratoroutputonMTTsafe?No,itisveryriskyinover-perfusedtissue
www.pain-nottwil.ch
ClassicalPRFRe:Temperaturemeasurement
www.pain-nottwil.ch
2005:INTRA-ARTICULARPRFDrAlexandreTeixeira
www.pain-nottwil.ch
PRFvsHEATRF
• HEATRF PRF§ Indication nociceptive pain inflammation
§ Modeofactionablation anti-inflammation
§ Target afferentnerve tobeadjusted
§ Effectonfocus none improvementProtectiveheatshockproteins?
Epigeneticanchoring?
www.pain-nottwil.ch
INFLAMMATION
§ OxidativeStress§ Overproductionoffreeradicals§ Superfast§ Nomemory§ Noself-sustainingcycles§ +++depressingeffectonreactivityofT-cells
§ Inflammation§ Intricateprocessinvolvingmanyenzymesandcytokines§ Timeconstantfromshorttoverylong§ Manyself-sustainingcycles§ AlsodepressingT-cellsbutin(sub-)chronicstage
www.pain-nottwil.ch
PULSEDRADIOFREQUENCYhypothesisonthemodeofaction
§ PhysiologicalrangePRFEfields(40– 250V/m)areresponsiblefortheeffect
§ Reductionofoxidativestressandinflammation§ Longertermeffectiscausedby
§ Persistentdownwardtrendofinflammation§ Possiblyprotectiveoxidativestressproteins(hsp’s?)§ Possiblyepigeneticchanges
www.pain-nottwil.ch
CLASSICALPRFphysiologicalEfieldsduringinvasivePRF
www.pain-nottwil.ch
Consequencesforparameters
§ Wecaneasilydowithsmallerdutyloads§ STP-likeloads(15msec/sec)areOK§ Thiswillfurtherreducetissuedamage
§ Wecanaffordusing40Vorevenless§ Thehighfieldsnearthetiphavenofunction
§ Theyprobablycausethepost-proceduraldiscomfort§ Theareaofthephysiologicalfieldsismorethansufficient
§ MoreisNOTbetter§ Recommendation:40V– STPcurrent– 8-10min
www.pain-nottwil.ch
Consequencesfortechnique
§ Gowherethecytokinesare§ Realizethefollowing:
§ Youarenottreatinganerveunlessthereisinflammationaroundit
§ TheDRGisoftensecondarilyinvolved
§ Considerusingabluntneedle§ Sharptipshaveaveryhighimpedanceandthismovesthe“healingarea”backwardstowhereitisprobablynotneeded.
§ Usesensorystimulationtomakesurethatyouareatasafedistance
§ Ifapatientstillhaspainat4-weekcheckup,waitlonger§ Theanti-inflammatoryphasemaylastupto3months
www.pain-nottwil.ch
CARPALTUNNELSYNDROMEanatomy
www.pain-nottwil.ch
PRFOFTHEMEDIALBRANCHanalternativeapproach
TECHNIQUE INITIATED BY DR PIETRO SCHIANCHI, LUGANO
www.pain-nottwil.ch
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
www.pain-nottwil.ch
ClassicalPRFMini-intradiscalprocedure
§ Enterintothediscwithnormaltechnique§ Dosensorystimulation(50Hz)
§ Aresponsebelow1.8Vindicatesinflammation
§ Ifdiscispositive,doPRF§ 40V§ 10minutes§ STPcurrent
§ OMIT:§ Provocation§ Discography
§ Themorphologyhasnorelevance
www.pain-nottwil.ch
Consequencesforyourattitude
§ STOPYOURPAVLOVREFLEX
§ THISISNOTABLATION
