Rev. Bras. Anestesiol. vol.67 número1

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REVISTA

BRASILEIRA

DE

ANESTESIOLOGIA

PublicaçãoOficialdaSociedadeBrasileiradeAnestesiologia

www.sba.com.br

SCIENTIFIC

ARTICLE

Comparison

of

transforaminal

and

interlaminar

epidural

steroid

injections

for

the

treatment

of

chronic

lumbar

pain

Serbülent

Gökhan

Beyaz

SakaryaUniversityFacultyofMedicine,DepartmentofAnesthesiologyandPainMedicine,Sakarya,Turkey

Received21May2015;accepted22June2015 Availableonline19March2016

KEYWORDS

Transforaminal; Interlaminar; Lowbackpain; Spinalinjection; Complication

Abstract

Studydesign:Across-sectionalstudy.

Objective: We compared the 12 month outcomesof fluoroscopically guided transforaminal

epiduralsteroidinjectionswithinterlaminarepiduralsteroidinjectionsforthetreatmentof chroniclumbarspinalpain.Chroniclowerbackpainisamultifactorialdisorderwithmany pos-sibleetiologies.Thelifetimeprevalenceofspinalpainisreportedly65---80%intheneckand lowerback.Epiduralinjectionofcorticosteroidsisacommonlyusedinterventionformanaging chronicspinalpain.

Methods:Patientswhodidnotbenefitfromprevioustreatmentswereincludedinthisstudy.

Injectionswere performedaccordingtomagneticresonanceimagingfindings atthenearest leveloflumbarpathology;173patientsreceivedinterlaminarepiduralsteroidinjectionsand126 patientsreceivedtransforaminalepiduralsteroidinjections.Allofthepatientswereregularly followed upfor12 monthsusing averbalnumericratingscale. Magneticresonanceimaging findings,complications,verbalnumericratingscale,andsatisfactionscoreswererecorded.

Results:Lumbardiskpathologywasthemostfrequentlyencounteredproblem.The

interlami-narepiduralsteroidinjectionswerepreferredattheL4---L5intervertebrallevel.Verbalnumeric ratingscalescoressignificantlydecreasedduringthe12-monthperiodcomparedtobasalscores (p<0.001).Significantdifferencesbetweenthetwogroupsaccordingtoverbalnumericrating scaleandsatisfactionscoreswerenotobserved(p>0.05).Therewerenomajorcomplications; however,theinterlaminarepiduralsteroidinjectionsgrouphad22(12.7%)minorcomplications, andthetransforaminalepiduralsteroidinjectionsgrouphad12(9.5%)minorcomplications.

Conclusions: Thisstudyshowedthatinterlaminarepiduralsteroidinjectionscanbeaseffective

astransforaminalepiduralsteroidinjectionswhenperformedatthenearestleveloflumbar pathologyusingfluoroscopyin12-monthintervals.

E-mail:[email protected]

http://dx.doi.org/10.1016/j.bjane.2015.06.003

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PALAVRAS-CHAVE

Transforaminal; Interlaminar; Dorlombar; Injec¸ãoespinhal; Complicac¸ão

Comparac¸ãodastécnicastransforaminaleinterlaminardeinjec¸õesepiduraisde esteroidesparaotratamentodedorlombarcrônica

Resumo

Desenhodoestudo:Estudotransversal.

Objetivo:Comparamososdesfechosde12mesesdeinjec¸õesperiduraisdeesteroidesusandoa

técnicatransforaminal(IPETF)guiadaporfluoroscopiacomasinjeçõesperiduraisdeesteroides usandoatécnicainterlaminar(IPEIL)paraotratamentodadorlombarcrônica.Adorlombar crônicaéumadoençamultifatorialcommuitasetiologiaspossíveis.Relata-sequeaprevalência dedornacolunaduranteavidaéde65%-80%nopescoçoeparteinferiordascostas.Ainjeção periduraldecorticosteroideséumaintervençãocomumenteusadaparacontrolaradorcrônica dacolunavertebral.

Métodos: Pacientesquenão obtiveram benefíciodetratamentosanteriores foramincluídos

nesteestudo.AsinjeçõesforamrealizadasdeacordocomosachadosemRessonânciaMagnética (RM)aonívelmaispróximodapatologialombar;173pacientesreceberamIPEILe126pacientes receberamIPETF.Todosospacientesforamacompanhadosregularmentepor12meses,usando umaescalanuméricaverbal(ENV)paraaclassificação.AchadosemRM,complicações,escores ENVeíndicesdesatisfaçãoforamregistrados.

Resultados: Patologiaemdiscolombarfoioproblemamaisfrequentementeencontrado.IPEIL

foipreferidoaonívelintervertebraldeL4-L5.OsescoresdaENVdiminuíramsignificativamente duranteoperíodode12 mesesemcomparaçãocomosvaloresbasais(p<0,001).Nãohouve diferençassignificativasentreosdoisgruposdeacordocomaENVeosíndicesdesatisfação (p>0,05).Nãohouvegrandescomplicações,mashouvecomplicaçõesmenoresem22(12,7%) nogrupoIPEILe12(9,5%)nogrupoIPETF.

Conclusões:EsteestudomostrouqueIPEILpodesertãoeficazcomoIPETFquandorealizadas

aonívelmaispróximodapatologialombarusandoafluoroscopiaemintervalosde12meses. ©2016SociedadeBrasileiradeAnestesiologia.PublicadoporElsevierEditoraLtda.Este ´eum artigoOpen Accesssobumalicenc¸aCCBY-NC-ND( http://creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Lowerbackpainwithorwithoutlowerlimbpainisthemost commonproblemamongacuteandchronicpaindisorders, andhassignificantimplications.1---3_Chronic_lower_back_pain

isamultifactorialdisorderwithmanypossibleetiologies.4,5

Thelifetimeprevalenceofspinalpainisreportedly65---80% intheneckandlowerback.6_Kuslich_et_al.7_identified

inter-vertebraldiscs,facetjoints,ligaments,fascia,muscles,and nerverootduraasthetissuescapableoftransmittingpain inthelowerback.

Intervertebral disk herniation, spinal stenosis, inter-vertebral disk degeneration without disk herniation, degenerativespondylolisthesiswithstenosis,andpost lum-barsurgerysyndromearethemost commondiagnosesfor lowerbackandlegsymptoms.1

Disk-related pain is caused by disk degeneration, disk herniation,orbiochemicaleffectsincludinginflammation. Degeneration of thehuman intervertebral diskis a major clinicalproblemandtheleadingcauseofpainanddisability, resultinginsignificanthealthcare-relatedcosts.The degen-erativeprocessin intervertebraldiscsis associatedwitha seriesofbiochemicalandmorphologicalchangesthat com-bine toalter the biomechanical properties of the motion segment.Diskdegenerationwithorwithoutdiskherniation canleadtolowerbackpain.8

Generally, the etiology of lumbar spinal pain includes not only mechanical neural compression, but also vascu-larcompromise,inflammation,andbiochemicalandneural mechanisms.Neurotoxicityhasalsobeenattributedtomany agentsincludingphospholipaseA2andtumornecrosisfactor, whichmayplayessentialrolesinintervertebraldisk-induced nerverootdamage.9,10

Epidural injection of corticosteroids is one of the most commonly used interventions for managing chronic spinalpain.1---5,11,12_However,_clinical_data_regarding_epidural

steroidapplicationsinTurkeywerenotavailable.Currently, epiduralinjectionsarefrequentlyperformedinterventions in the United States, and over 1 million epidural steroid injectionsareperformedannuallyworldwide.1,2,11

Oftheseveralapproachesavailabletoaccessthelumbar epiduralspace, thelumbar interlaminarapproachis com-monlyused,followedbylumbartransforaminalandcaudal epiduralsteroidinjections.3,6 _Increasing_emphasis _is_being

placedonfluoroscopicallyguided,target-specificinjections toimprove treatmentoutcomes; therefore,modern study designs focus on fluoroscopically guided transforaminal injectiontechniques,whichhavethetheoreticaladvantage ofdeliveringtheinjectatetothesiteofthepathologyinthe anteriorepiduralspace.13

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injections(TFESI),bothfluoroscopicallyguided,overa 12-monthperiodoftreatmentforchroniclumbarspinalpain.

Methods

This a cross-sectional study was approved by the Faculty of Medicine’s Ethics Committee of Sakarya University (no 2012/45); 364patients, treatedby epiduralsteroid injec-tions for chronic lumbar pain, were evaluated. All of the studypatientswereinformedregardinginterventions, and writteninformedconsentwasobtained.

Thecriteriaforthestudyincludedaminimumof6months lowerbackpain,unilateralorbilaterallegpainsymptoms, andnopositiveresponsestomedicalorphysicaltherapies. Medical therapies included non steroidal anti inflamma-tory drugs, andin somecases, opioids. Physicaltherapies includedinitialbedrestandpassivephysiotherapy,followed byanextension-basedexerciseprogramandlight,and iso-metriccorestrengtheningifpainwasnotrelievedafter 2 weeksofmedicaltherapies.Patientlumbarspinal patholo-gies were clinically examined. An experienced radiologist confirmedthepathologiesusingmagneticresonanceimaging (MRI).Exclusioncriteriaforthestudyincludedpatientswho refusedinterventions,didnotreceivelumbarsurgery,were pregnant,hadanycontraindicationstointerventions (coag-ulopathy,sepsis,or allergytodrugsor contrastmaterial), received lumbar spinal interventions in other clinics, had previouslyundergonelumbarsurgery,andhadneurological deficitsorcaudaequinasyndrome.

All of the patients were examined, and imaging stud-ies were reviewed prior to injection by the author. The choice ofwhether touse thetransforaminal or the inter-laminarapproachwasdeterminedbythefirstauthorinno predeterminedorder.TFESIwasperformed ifpatientshad radicularpainandpositiveMRIfindingsat oneortwo lev-els.Similarly,ILESIwasperformedifpatientshadradicular pain,lowerbackpain,andMRIfindingsatoneortwolevels. Atthetimeoftheprocedures,theauthorhadnopersonal preferenceforeitherapproach.

Alloftheinjectionswereperformedinasimilarmanner. Routinehemograms,biochemical,andcoagulation parame-ters wereevaluatedtoconfirm thattheywere withinthe normalrange,afterwhich thepatients weretakentothe operatingroom.Alloftheinjectionswereperformedbyone anesthesiologist,and6---8hoffastingwaspreferredonthe injectionday. Alloftheprocedureswereperformedunder C-arm fluoroscopic guidance. Initial anteroposterior (AP) imageswereobtainedtoidentifythelevelandinterlaminar spacein a pronepositionwitha10cmhigh pillow placed under the abdomen. On the fluoroscopic table, standard anesthesia monitoring (noninvasive blood pressure, pulse oxymeter,ECG)wasperformed,and0.9%NaClwasstarted intravenously.Theinjectionareawascleanedwithan anti-septiciodine-basedsolution,andanesthetizedwith0.5mL 2%prilocaineinjectedintotheskinandsubcutaneoustissue; 1---2mgmidazolamand25---50␮gfentanylwereadministered forconscioussedation.

FortheTLESIapproach,a20gaugebluntcurvedneedle (Epimed®_,_Johnstown,_NY,_USA)_was_used._The_target_point

wasaccessedbythesubpedicularsafetriangle14,15_approach

in theobliqueposition. Inall ofthe TLESIapplications, a

mixtureof80mgtriamcinoloneacetonidein0.25% bupiva-caine was used.After placing the needle into the target point, 0.5---2mL nonionic contrast material (Iomeron 300, Patheon,ItaliaS.p.A.)wasinjectedtodeterminewhether vascularleakageorintrathecaldistributionoccurred.After theaccurate anteriorepidural flow pattern wasobserved onoblique,anteroposterior,andlateralimages,4mLofthe mixturewas injected if TLESIwas performed for asingle level.IfTLESIwasperformedformorethanonelevel,2mL ofthe mixtureper each levelwasinjected, but thetotal steroiddosewasmaintainedconstant;forexample,atotal of8mLof80mgtriamcinoloneacetonidein0.25% bupiva-cainemixturewasadministeredforalllevels.Inthecaseof vascularleakage,theneedlesitewasslightlyrepositioned andrecontrolled bycontrastmaterial. Ifvascular leakage persisted,theprocedurewascanceledforthatlevel.Ifthe interventionwas performed for morethan one level, the erroneousinjectionoftheresidualmixtureintothe subse-quentlevelwasavoidedbyflushingtheneedlewithsterile isotonicaftereachlevel.

FortheILESIapproach,an18gauge,3½-in.or5in.Tuohy needlewasadvanceddirectly perpendiculartotheskin in a posterior toanterior direction, with use of the loss-of-resistancetoairtechniquetoidentifytheepiduralspace.In caseswhen traditionalmethods failedtoreachthe epidu-ral space,the parasagittalapproach waspreferred.After negativeaspirationforcerebrospinalfluidandblood,2mL nonioniccontrast material wasinjected todocument the appropriatecontrastspreadintotheepiduralspace.Next, acombinationof8mLof80mgtriamcinoloneacetonidewith 3mL0.25%bupivacainewasinjectedintheepiduralspace. Aftertheintervention,thepatientsrestedonthetable for5min,andwerethentransportedtotherecoveryroom where they stayed 2h if complications did not develop. Thecomplicationsthatoccurredduringtheprocedurewere recorded.The patientswereaskedtosit,stand,andwalk before rating their pain using the Verbal Numerical Rat-ingScale(VNRS,0-10scale).Allofthedataobtainedwere recordedonthe patient’scharts. The patients discharged fromthe hospitalwereasked toimmediatelyrefertoour painclinicifanunexpectedsituationoccurred.Onthe con-troldays(1,3,6,9,and12monthsafterinjection),patients wereinterviewedatthehospital,andprobabletherapeutic effects,VNRS,andcomplicationswererecorded.Moreover, age,gender,andMRIfindingswererecordedonthepatient’s charts for post-interventional evaluations. ModifiedNorth

Table 1 Modified North American Spine Society Patient SatisfactoryScore.

Score

Bad Nochangeofcomplaints;evenworse. Moderate EpiduralsteroidhelpedmebutIwon’tlet

thisprocedureagain.

Good MostofthecomplaintsarerelievedandI wouldagainletthisprocedureifmy complaintsreappear.

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AmericanSpineSociety(NASS)patientsatisfactionscorewas recordedusinga4pointscale(Table1).

Statisticalanalysis

Alldata were analyzed usingthe statistical package SPSS version 15.0 for Windows. Kolmogorov---Smirnov test was usedtodetermineifthedemographicdataweredistributed normally.Chi-Squaretestwasusedtocomparethe satisfac-tionscoresandcomplicationsbetweenthegroups.Repeated measurements ANOVA parametric test for repeated mea-surementsanalysiswasusedtoevaluatetheimprovements inVNRSscoresbeforeandaftertheprocedure.Independent samplet-testanalysiswasperformedfordifferencesinpain reductionbetweenthetwogroups.Datawerepresentedas means±standarddeviation(SD).

Results

Inthe present study,364 patientswere enrolledbetween April 2013 and October 2014 for epidural injections. Of these,23patientsdidnotcometothehospital,1refused interventionontheoperationtable,6couldnotbereached by telephone, and 36 had a previous history of lumbar surgery. The number of patients with complete data was 299. The distribution of these patients according to the month was 299 (100%), 238 (79.6%), 211 (70.6%), 171 (57.2%),and114(38.1%),respectively.

A total of 299 patients received 485 interventions. The patients were divided into two groups according to the steroid injection approach used. The transforaminal approachgroup(theTFESIgroup)consistedof126patients with266 injectionsincludingrepeatedinjections,andthe interlaminarapproachgroup(theILESIgroup)consistedof 173patients with219 injectionsincludingrepeated injec-tions.Theaverageagewas54.66(11.69)years(range23---85 years).Demographicdatarevealednosignificantdifferences betweenthegroups(Table2).

WhenMRIimageswereevaluated,numerouspathologies were detected, such as disk herniation, spinal degen-eration, spondilolisthesis, facet hypertrophy, and spinal stenosis.Diskpathologiesweredividedinto4types;namely, bulging, protrusion, extrudation, and sequestration. The most affected level was L4---L5 (Table 3). Bulging was the most common pathology, and no sequestration was

Table2 Demographicfeaturesofgroups.

ILESI(n=173) TFESI(n=126) pa

Years 58.08(13.49) 51.45(12.50) 0.001 GenderM/F 50/123 41/85 0.623 Weight 69.38(10.25) 66.48(11.84) 0.527 Height 161(8.7) 164(11.6) 0.376 Numberof

injections

173 219 0.001

Painduration, years

2.2 1.9 0.172

ILESI, interlaminar epidural steroid injections; TFESI, trans-foraminalepiduralsteroidinjections.

a_Chi-square_test.

Table3 TheMRIfindingsof299patientstheLESI.

ILESI,n(%) TFESI,n(%) pa

L1-L2 0.526

Bulging 10(71.4) 10(55.5) Protrusion 4(28.6) 8(44.5) Extrusion 0 0

L2-L3 0.445

Bulging 27(71.05) 29(60.41) Protrusion 11(28.95) 18(37.51) Extrusion 0 1(2.08)

L3-L4 0.234

Bulging 48(71.64) 44(58.66) Protrusion 18(28.36) 28(37.33) Extrusion 1(1.49) 3(4.01)

L4-L5 0.085

L5-S1 0.200

Dataarepresentedasn(%).LESI,lumbarepiduralsteroid injec-tion.

a _Chi-square_test.

detected;144patientshadonlydiskpathologies.Inaddition todiskpathologies,64patientshaddegenerativechanges, 125 patients had diffuse degeneration, 73 patients had spinalstenosesofvarioustypes,and27patientshadfacet jointhypertrophy.

L4---L5 was the most injected level in both groups (Table4).Theaveragepre-injectionVNRSscoreintheILESI group was7.8 (1.9)and intheTFESI group was7.6(2.2). Thepost-injectionVNRSscoresinbothgroupsat1,3,6,9, and12monthsalsodecreased(p<0.001,Fig.1).Although theVNRSscoresgraduallyincreasedafterthefirstmonth, nosignificantdifferencecouldbedetected.TheVNRSand satisfactionscoreswerenotsignificantlydifferentbetween thegroups(p>0.05forbothscores).

Nocatastrophic complications wereobserved in either the ILESI or TFESI group. The ILESI group had 22 (12.7%) minor complications, and the TFESI group had 12 (9.5%) minorcomplications (Table5). Duringthetherapy period,

12

10

*

* * * *

8

6

VNRS ₄

2

0

0 1 3

Month

6 9 12

ILESI TFESI

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Table4 Repeatedinjectionsforlumbarepiduralsteroidinjections.

Singleinjection Firstrepeated injections

Secondrepeated injections

Totalinjections

TFESI

Onelevel 26/26 16/32 --- 42/58

Twolevel 70/140 11/44 4/24 85/208

ILESI

Onelevel 130/130 40/80 3/9 173/219

Dataarepresentedaspatientnumber/injectionnumber.

ILESI,interlaminarepiduralsteroidinjections;TFESI,transforaminalepiduralsteroidinjections.

Table5 DistributionofcomplicationsforILESIandTFESI.

ILESI(n=173) TFESI(n=126)

Duralpuncture 4(2.31%) 3(2.38%)a

Postdural puncture headache

1(0.57%)

---Subduralblock 3(1.73%) 3(1.59%) Transient

increasedpain

3(1.73%) 3(2.38%)

Transient paresthesia

8(4.62%) 3(2.38%)

Hiccup 1(0.57%) ---Menstrual

irregularities

1(0.57%)

---Vasovagalreaction 1(0.57%) ---Total 22(12.7%) 12(9.5%)

ILESI, interlaminar lumbar epidural steroid injection; TFESI, transforaminalepiduralsteroidinjection.

Dataaregivenn(%).

a _The_contrast_agent_were_intrathecal_spread_in_three_patients

whoduralpuncture.

threepatientsintheILESIgroup(1.73%)andeightpatients intheTFESIgroup(6.35%)underwentlumbarsurgery.

Discussion

This study was conducted to evaluate and compare

the effects of two different lumbar steroid injection approaches.Thelengthofthestudyperiodwas12months, and the study population included chronic lumbar pain patients.

Pre-procedural analysis of patient information did not show any significant difference in symptom duration betweenthetwogroups.TheaverageageintheILESIgroup wassignificantlyhigherthanthat intheTFESI group. Pre-intervention VNRS scores in the ILESI group were higher thanthoseintheTFESIgroup,althoughwithoutstatistical significance. In terms of comparableparameters, the MRI findings were not significantly different between the two groups(Table3).

Atthe12monthfollow-up,theVNRSscoressignificantly decreasedafterepiduralsteroidinjectionsinbothgroups. Thisdecreasewasreflectedclinicallyasincreased satisfac-tion scores. Most of the patients (85.1%) improved after

injection,andexpressedimprovedwell-being.However,the symptomsworsenedin13.9%ofthepatientswhoratedtheir conditionasbad.

Inanotherrecentstudy,interlaminarinjectionprovided superiorpainreliefinupto92%ofpatients,whereas trans-foraminal injection provided pain relief in up to 90.5% of patients; however, in 9.5% of patients the condition worsened after TFESI, indicating that both steroid injec-tions largely provided pain relief.16 _The _decreased _VNRS

scores in the TFESI group were not significantly differ-ent from the ILESI group. High satisfaction scores could beexplainedbytheinjectatematerialbeingadministered close to the pathology sites. Conversely, the ILESI group consistedofolderpatientswithmulti-levelpathologiesand morecomplexconditions,whichmighthavecontributedto thedifferences.

Thecurrentstudyisimportantbecausebothgroupshad similarly high satisfactionscores (85.1%), which might be duetoeffective fluoroscopyorinjectionsiteproximity.In 2002,Wangetal.17 _conducted_a_study_on₆₉_patients_with

symptomatic lumbar diskhernia. On follow-ups after the epiduralsteroidinjections,radicularpainwasdecreasedfor 20---27months,andsurgicalinterventionwasavoidedduring thisperiod.

In 2007, Acherman et al.18 _conducted _a _study _on ₉₀

patients comparing the transforaminal, interlaminar, and caudal approaches, and concluded that the transforami-nalapproachwasthemosteffective.However,theresults weresimilarinallthreegroups(TFESI,ILESI,caudal epidu-ral steroid injection groups). Each group consisted of 30 patients;13patientsintheTFESIgroupand12intheILESI group were not satisfied and only 1 patient experienced improvement.ThepathologysitelevelinILESIwasthesame forallpatients,whichmighthavecausedthedifferences.

Inthecurrentstudy,therewerenosignificantdifferences betweenTFESIandILESIlevelsasshownintheTable5.

In 2006, Schaufele et al.13 _conducted _a _study _on ₂₀

patientscomparingthetwoapproachesofepiduralsteroid injections, and concluded the TFESI was more effective. However,significant limitationsexisted in theirstudy;the populationnumberwasverysmall(n=20),andtheageof patientswasunknown. The similaritytothis studyis that theyinjectedthesteroidatthesameleveloflumbar pathol-ogy.In2004,Butterman19_compared_surgery_with_ILESI_using

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painfor6weeksbeforesurgery.In1995,areviewbyKoes et al.20 _examined _eight _randomized _trials _that _evaluated

the effectiveness of ILESI on disk herniation, sciatica, or radiculopathyinthelumbarspine.Oftheeightrandomized trialsevaluating lumbar radiculitis, five were positive for short-termrelief,whereasonlyonestudywaspositivefor long-termrelief.In2003,Boswelletal.4 _conducted_a

sys-tematicreviewofILESIpatients,andshowedanabsenceof long-termside-effects.

These results are supported by two randomized con-trolled studies,21,22,5 _but _Karppinen _et _al.21 _reported _less

positive outcomes. Thus, numerous studies on TFESI and ILESIhavebeenpublished,whichindicatepositiveor neg-ative results with over 6 months of efficacy. Recently, TFESIprovidedmoreefficientresults,butILESIstudieswere conductedas randomizedcontrolled studies usinga blind techniqueforsinglelevelinjections.InanILESIstudyusing theblindtechnique,thesuccessratewas70%,meaningthat 30%23_of_the_patients_were_not_satisfied._However_in_the

cur-rent study,fluoroscopy wasused in both TFESI andILESI. Inaddition,ILESIwasperformed attheclosest sitetothe pathology.Our resultsshowed thatTFESI hadmuchlower scoresthanILESI,becausethepatientswereolderandtheir pathologiesweremulti-leveled.

Hopwood and Abram24 _described ₃₃ _factors _associated

withthesuccessrateoflumbarepiduralsteroidinjections, andsuggested thatall factors shouldbeconsidered when treatingchroniclumbarpainpatientswithepiduralsteroids. However,theexperienceofthepersonperformingthe pro-cedureremainsaveryimportantfactorthatinfluencesthe success/satisfactionrate.2

InareviewbyParretal.1_evaluating_disk_herniation_and

radiculitis, none of the randomized ILESI trialswere per-formedunderfluoroscopy.Amongvariousreviews,epidural steroidinjectionswerenotperformedunderfluoroscopyin anyof thepublished,randomizedcontrolledstudies.1,3,4,20

Recently,authorstendedtopreferTFESIunderfluoroscopy, becausethedrugwasdirectly administeredtotheprecise pathologysitelevel.

Fewer complications were encountered in the TFESI groupthantheILESIgroup(9.5%and12.7%,respectively), andmajorcomplicationsrequiringhospitalizationwerenot observed.When performingTFESI,theduralmaybe punc-tureddespiteappropriateneedleplacement.Subduraland intrathecalspreadofcontrastisrarelyobservedwith trans-foraminalinjections,andthuscanbeeasilyoverlooked.In theTFESIgroup,sixpatientshadduralpunctureduringan intervention,but none of thepatients had complainedof headaches.However, in theILESI group, only one patient had dural puncture, and was treated with an epidural bloodpatch.Accidentalduralpuncturesmayleadtospinal headaches.15 _A _particularly _concerning _complication _of _a

duralpunctureistheinstillationofanestheticintothe sub-duralspace,whichmayleadtoasubduralneuralblockade. Priorreportshavesuggestedanincidenceof0.82%for sub-dural injections during interlaminar epidural injections.25

To recognize a potential dural puncture, interventionists need to distinguish the intrathecal, subdural, and epidu-ralcontrastflowpatterns.Goodmanetal.26_reported_dural

puncturecomplicationsduringtheTFESI,particularlyduring thesubduralinjection,whichisprobablyunder-reportedby practitioners.

Thestrengthofthisstudywasthatthesameperson per-formedalloftheinterventionsunderfluoroscopyguidance, and the study population waslarge. However,limitations including selection bias, recall bias,and incomplete data sets existed. Patients were not randomized for inclusion in this study, because group heterogeneity was the most importantlimitationinthisstudy.Assessingglobaland back-specificfunctioninadditiontoVNRSscoreswouldbeabetter methodforqualifying anydifferencesinclinicaloutcomes betweenILESIandTFESI.

Advanced age may cause increased multiple-level pathologies that aggravatelumbar spinal pain.After a 12 monthfollow-up,weconcludedthatILESIcanbeaseffective asTFESIifperformedunderfluoroscopyattheclosestlevel tothelumbarpathology.Nevertheless,furtherrandomized studiescomparingthetwoapproachesperformedunder flu-oroscopyattheclosestleveltothelumbarpathologiesare necessary.

Conflicts

of

interest

Theauthordeclaresnoconflictsofinterest.

Acknowledgments

Alloftheauthorscriticallyrevisedthemanuscriptfor impor-tantintellectualcontentandapprovedthefinalmanuscript. Thisstudyhadnosponsorandnoexternalfunding.

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