Rev. Bras. Anestesiol. vol.65 número4

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REVISTA

BRASILEIRA

DE

ANESTESIOLOGIA

OfficialPublicationoftheBrazilianSocietyofAnesthesiology

www.sba.com.br

REVIEW

ARTICLE

Analgesic

efficacy

of

the

ultrasound-guided

blockade

of

the

transversus

abdominis

plane

---

a

systematic

review

Javier

Ripollés

a,∗

,

Sandra

Marma˜

na

Mezquita

b

,

Alfredo

Abad

c

,

José

Calvo

a

a_Service_of_{Anesthesiology}_and_Reanimation,_Hospital_{Universitario}_Infanta_Leonor,_Madrid,_Spain

b_Service_of_{Anesthesiology}_and_Reanimation,_Hospital_{Universitario}_Moisés_Broggi,_Sant_Joan_Despí,_Barcelona,_Spain

c_Service_of_{Anesthesiology}_and_Reanimation,_Hospital_{Universitario}_La_Paz,_Madrid,_Spain

Received23July2013;accepted31October2013 Availableonline25October2014

KEYWORDS

TAPblock; Transversus abdominisplane; Ultrasoundguided; Sistematicreview

Abstract

Background: Thetransverseabdominalplanblockadeisablockofabdominalwallthathas

diff-usedrapidlyintheclinicalpracticeaspartofamultimodalanalgesiaforabdominalsurgery.

The performanceoftheultrasound-guided techniquehasallowed thelowering ofpotential

complications, aswell as new approachesthat were carried out according to the

descrip-tions,andtheprospectivestudieswouldmakeitpossibletoutilizethetransverseabdominal

planblockadeindifferentsurgicalinterventions;however,theresultsobtainedinrandomized

clinicaltrialsareinconsistent.

Objectives: Toprepareasystematicreviewaimingtodeterminetheefficacyofthe

ultrasound-guidedtransverseabdominalplanblockadefordifferentsurgicalinterventions,aswellasthe

indicationsaccordingtotheapproachesandtheirinfluences.

Methods:Tworesearchapproaches,onemanual,andtheotherinPubmedreturned28

ran-domizedclinicaltrialswhereinterventionwithultrasound-guidedtransverseabdominalplan

blockadeswasperformedtocomparetheanalgesicefficacyincontrasttoanothertechniquein

adults,publishedbetween2007andOctober2013,inEnglishorSpanish,withJadadscore>1,

accordingtotheinclusioncriteriaforthisreview.Theauthorsanalyzedindependentlyallthe

randomizedclinicaltrials.

Conclusions: Thetransverseabdominalplanblockadeshavebeenshowntobeaneffective

tech-niqueincolorectalsurgery,cesareansection,cholecystectomy,hysterectomy,appendectomy,

donornephrectomy,retropubicprostatectomy,andbariatricsurgery.However,thedatafound

inrandomizedclinicaltrialarenotconclusive,andasaresult,itisnecessarytodevelopnew

andwelldesignedrandomizedclinicaltrial,withenoughstatisticalpowertocomparedifferent

approaches,drugs,doses,andvolumesforthesameintervention,aimingtoanswerthecurrent

questionsandtheireffectsinthehabitualclinicalpractice.

reserved.

∗_{Corresponding}_author.

E-mails:ripo542@gmail.com,ripo542@hotmail.com(J.Ripollés).

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PALAVRAS-CHAVE

BloqueioTAP; Planotransversodo abdome;

Ecoguiada;

Revisãosistemática

Eficáciaanalgésicadobloqueioecoguiadodoplanotransversodoabdome---revisão sistemática

Resumo

Justificativa:Obloqueiodoplanotransversoabdominal(TAP)éumbloqueiodaparede

abdom-inalquesedifundiurapidamente napráticaclínicacomo partedeanalgesiamultimodalem

cirurgiaabdominal.Atécnicaecoguiadapermitiureduziraspossíveiscomplicac¸ões,assimcomo

asnovasabordagens,que,deacordocomasdescric¸õesfeitaseosestudosprospectivos,

per-mitiramusaroTAPemváriosprocedimentoscirúrgicos;noentanto,osresultadosobtidosem

ensaiosclínicosrandomizados(ECR)sãoinconsistentes.

Objetivos: Revisão sistemáticapara determinar aeficácia analgésica do TAPecoguiado em

diversosprocedimentoscirúrgicos,assimcomodeterminarasindicac¸õesdeacordocom

abor-dagensesuainfluência.

Métodos: FoifeitaumapesquisanoPubMedeoutralivreeforamencontrados28ECRemque

intervenc¸ãocomoTAPecoguiadoerafeitaesecomparavasuaeficáciaanalgésicacomoutra

técnicaemhumanosadultos,publicadosentre2007eoutubrode2013comescoredeJadad

>1,eminglêsouespanhol,deacordocomoscritériosdeinclusãoparaestarevisão.Todosos

ECRforamanalisadosdeformaindependentepelosautores.

Conclusões:OTAPmostrouserumatécnicaeficazemcirurgiacolorretal,cesárea,

colecistec-tomia,histerectomia,apendicectomia,nefrectomiaemdoador,prostatectomiaretropúbicae

cirurgiabariátrica.Noentanto,osdadosencontradosnosECRsãoinconclusivos,demodoque

maisECRbemdesenhadossãonecessáriosecompoderestatísticosuficientenacomparac¸ãode

diferentesabordagens,drogas,dosesevolumesparaumamesmaintervenc¸ão,afimderesolver

ostemasdaatualidadeeseuimpactonapráticaclínicahabitual.

direitosreservados.

Introduction

Theblockofthetransversusabdominisplane(TAP)hadbeen firstdescribed asa blockof the abdominalwallbased on anatomical references to introduce local anesthetic (LA) inthe TAPthroughthePetittriangle byloss ofresistance technique.1_In₂₀₀₇_the_first_description_of_the ultrasound-guidedTAPappeared,2_and_its_use_has_become_popular_since theninhighandlowabdominalsurgeries,althoughithasnot beenfullyintegratedintheregularclinicalpractice.3 _The apparitionoftheultrasound-guidedtechniquehasallowed the reduction of block failure risk, unacceptably high in theanatomicaltechnique4_as_well_as_reduction_of_possible complicationsassociatedwiththistechnique5 _even_though they have been described6 _but _probably _{underestimated} becauseofpublicationbias.

Theuseofultrasonographyhasallowedthedevelopment ofnewapproaches, likethesubcostal, theposterior,7 _the obliquesubcostal,8 _or _combinations _like _the _dual _TAP9 _in whichthepossibilitiesofTAPhavebeenincreased.However, currently there is no recommendation for the use of the ultrasound-guidedTAPincomparisontotheclassicTAP10_due toalackofrandomizedclinicaltrials(RCTs)thattestboth techniques.11

Potentially,theinjectionofLAatthislevelprovides anal-gesia in the skin, muscles and parietal peritoneum from T7toL1, onceit blocksthe afferentneuronal endingsof theabdominalwalls.However,currentlythereisa contro-versy inthe specialized literaturein relation tothe level ofdistributionof the localanesthetic withasingle injec-tion, since some studies demonstrate an extension from

T7 to L112 _and _others, _an _extension _from _T10 _to _L1.13 The greatestextensiondemonstratedwiththe ultrasound-guided technique is T7 with oblique subcostal TAP, T9 with the classic mid-axillary approach, and paravertebral extension from T4 to L1 with the posterior approach.14 Thereby, themid-axillaryTAPshouldbeusedfor infraum-bilical surgeries, the subcostal for periumbilical, and the oblique subcostal in supraumbilical incisions between T7 and T9.15 _In _fact, _the _RCTs _are _poorly _correlated _to _the expectedextensionandnotalwaysconclusive.Considering studies of contrastdistribution15 _it _is _possible _to_suppose thatthediffusionoftheinjectedsubstancewillvary accord-ingtotheapproach,withdifferentresultsthatmayaffect theanalgesia.Thecurrentliteratureshowsthatnotallthe blockades are equal, and that the approach significantly alterstheblockade’s pharmacodynamicsandtheresultant analgesia characteristics. Currently, it is recognized that themoreposteriorapproaches,inotherwords,the instal-lation of the needle closer to the traditional approach, based on non-ultrasound-guided original, gives rise to a wider analgesia in terms of dermatomes and the tempo-ral block probably due to the block of the sympathetic ganglia in the thoracic paravertebral space.16 _The _more anterior approaches provide an analgesia in the abdom-inal wall in line with the pharmacokinetics of the LA used.

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in prospective studies in liver transplantation45 _and _in prostatectomy.46

ItisimportanttonotethatinspiteofTAPproviding anal-gesiaintheskin,subcutaneousandparietalperitoneum,it should bealways executed asan extra component in the multimodalanalgesia,becauseitisnoteffectiveinthe con-trolofvisceralpain.47,48

Due to the fact that diverse techniques and interven-tions in which the ultrasound-guided TAP has been used, itsindicationsarenotdetermined.49 _The _objective_of _this reviewistodeterminetheefficacyoftheultrasound-guided TAPfordifferentsurgicalinterventionsinthoseRCTswhere ultrasound-guidedTAPhasbeen executed, andtoobserve howit affectsthe analgesia.It alsoinvestigates the indi-cations according to the approaches, their influence, the influenceofTAPduration,andthedoseandtypeoftheused LA,inadditiontocomplicationsandtheassessment,orits lack,oftheblockade’ssensitivelevel.

Methods

A systematic review about the analgesic efficacy of the ultrasound-guided TAPis performed according to the rec-ommendationestablishedbyPreferredReportingItemsfor SystematicreviewsandMeta-Analysis(PRISMA).50

The authors searched in the US National Library of Medicine database (MEDLINE) for the terms «TAP block», «Transversus Abdominal Plane Block», «Transversus Abdo-minis Plane Block», «Bloqueo del Plano Transverso del Abdomen» and «Bloqueo TAP», as well as manually. The searchwasrestricted toprospectiveRCTinhumans, pub-lishedbetweenJanuary2007andOctober 2013,inEnglish or Spanish. The found RCTs were evaluated in order to identifythoseinwhichultrasound-guidedTAPiscompared to another analgesic modality in adult patient. The RCTs withJadadscore<251 ₍_Fig.₁₎_were_not_included._The_RCTs selectedforthesystematicreviewweretheonesinwhichan interventionisperformedwithultrasound-guidedTAPsthat comparetheanalgesicefficacyinrelationtoanother tech-niqueinadulthumans,publishedbetween2007andOctober 2013,inEnglishorSpanish,withJadadscore>1.Thereare RCTsinwhichtheanalgesicefficacyisevaluatedaccording totheapproachbasedonreferencesorattendedbya sur-geon.However,inthisreview,theauthorslimitedthesearch toRCTwithultrasound-guidedTAPsincetheyconsiderthat currentlythistechniqueshouldbethetechniqueofelection, becauseof the diminution of blockfailure, the avoidable complications with the ultrasound-guided technique, and thegreaterpossiblevarietyofapproaches.

Two independent investigators (J. Ripollés and S. Marma˜na)reviewedeacharticleinordertodeterminethe

eligible ones. The investigators have extracted the data independentlybymeansoftablesmadeforthispurposeand solved discrepancies before analyzing the results. Demo-graphic data, which included author,year of publication, participant,intervention,outcomes,designandJadadscore wereextracted fromthe included RCT (Table 1). Forthe analysisoftheanalgesicefficacy,thedataextractedwere: painscoreatrestandinearlyandlatemovement,earlyand lateconsumptionofanalgesic(bymeansof<12hasearlyand >12h aslate),timeuntilrescue analgesia,and secondary effectsofopioids:postoperativenauseaandvomit(PONV), sedationanditching(Table2).Ananalysisofthetechnique usedfortheTAPwasperformed,including:typeofsurgery, typeof block, duration, laterality of the block, the nee-dle used, drug, doses and volume utilized, supplemental analgesiaadministered,identificationofsensitiveleveland complicationsassociatedwiththeTAP(Table3).Theuseof mid-axillaryapproachisassumedinthosetrialsinwhichit hasnotbeenspecified.

TheprobabilityofmethodologicalbiasofeachRCTwas independentlyevaluatedbytwoauthors,adoptingtheJadad score.

Results

Thirty-oneRCTswereobtained,whichalignedwiththe inclu-sioncriteriaforthesystematicreview,17---44_A,_D,_C,_including 2193patients.TheflowdiagramoftheselectionoftheRCT isshowninFig.2.

The RCTswere dividedintosubgroupsaccordingtothe typeofthesurgeryinwhichTAPwasusedforitsanalysis: colorectal,17,18 _cesarean,19---28 _{cholecystectomy,}28---33 hyste-rectomy,34---37 _inguinal _{herniorrhaphy,}38---40 _{appendectomy,}41 nephrectomy,42,43_bariatric,44,45_gastrectomy46 _and retropu-bicprostatectomy.47 _Of_the_articles_included, _93.5%_had_a goodqualityaccordingtoJadadscore.

ThecharacteristicsoftheRCTincludedinthesystematic reviewareshowninTable1.

Interventionandsurgery

Theultrasound-guided TAPincolorectalsurgerywas eval-uated in 2 RCTs,17,18 _in _which _the _TAP _was _compared _to TAP vs. epidural anesthesia17 _and _TAP _vs. _placebo _TAP18_; inthefirstcase,itisspecifiedforhighabdominalsurgery, whereasinthesecondRCT,ananalysisofsubgroupsis per-formed distinguishing in left(supraumbilical incision) and right (infraumbilical incision). In the first RCT,17 _a sub-costalpostoperativeapproachisutilized,andnodifferences were found between visual analog scale (VAS) score for painat rest or in movement in the first 72h withTAP or

Does the study describe itself as randomized? Yes = 1 point; No = 0 points

Is the method utilized for producing the sequence of randomization described? and Is this method appropriate? Yes = 1 point; No = 0 points; the method is not appropriate = - 1 point

Does the study describe itself as double-blind? Yes = 1 point; No = 0 points

Is the blinding method described? and Is this method appropriate? Yes = 1 point; No = 0 points; the method is not appropriate = - 1 point Is there a description of withdrawals and dropouts?

Yes = 1 point; No = 0 points This questionnaire returns a punctuation in a scale that goes from 0 to 5, so that the higher punctuation means that the evaluated RCT has a better methodological quality. Rigorous 5 points; low quality < 3 points.

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et

Table1 PICOs(Patient,Intervention,Comparison,Outcome).

Surgery

Author,year

N Intervention Comparison Outcome Design JadadScore

C.colorectal

Nirajetal.,201117 ₆₂ _Bilateral_TAP_with_catheter

inhighabdominalsurgery

TAPvs.epidural VASpainscoreatrestandin movementinthefirst72h

Randomizeddouble-blind trial

5

Walteretal., 201318

68 BilateralTAPinc.colorectal TAPvs.noTAP Consumptionofopioidsin thefirst24h

5

Cesarean Belavyetal., 200919

57 BilateralTAPincesarean withspinalanesthesia

TAPvs.placebo TAP

Consumptionofopioidsin thefirst24h

Randomizedblindtrial 5

Costelloetal., 200920

96 BilateralTAPincesarean withspinalanesthesiawith ITM

TAPvs.placebo TAP

VASpainscoreatrestandin movementinthefirst24h

5

Baajetal.,201021 ₄₀ _Bilateral_TAP_in_cesarean withspinalanesthesia

TAPvs.placebo TAP

3

Kanazietal., 201022

57 ITMincesarean TAPvs.

ITM+placeboTAP

Timeuntiltheopioidrescue Randomizeddouble-blind trial

4

Loaneetal.,201223 ₆₆ _Bilateral_TAP_in_cesarean underspinalanesthesia

TAPvs.

ITM+placeboTAP

5

Tanetal.,201224 ₄₀ _Bilateral_TAP_in_cesarean withgeneralanesthesia

TAPvs.placebo TAP

5

Bollagetal., 201225

90 BilateralTAPwithclonidine incesareanwithspinal anesthesia

clonidineTAPvs. TAPvs.placebo TAP

Hyperalgesiaindexofthe woundfollowingTAP

5

Eslamianetal., 201226

50 BilateralTAPincesarean withgeneralanesthesia

TAPvs.noTAP VASpainscoreatrestandin movementinthefirst24h

5

Cánovasetal., 201327

90 BilateralTAPincesarean withspinalanesthesia

TAPvs.placebo TAPvs.

ITM+placeboTAP

5

Leeetal.,201328 ₅₁ _Bilateral_TAP_in_cesarean withspinalanesthesiawith ITM

TAPvs.placebo TAP

VASpainscoreinmovement inthefirst48h

5

Cholecystectomy El-Dawlatlyetal., 200929

42 BilateralTAPinlaparoscopic cholecystectomy

TAPvs.noTAP Consumptionofopioidsin thefirst24h

3

Raetal.,201030 ₅₄ _Bilateral_TAP_in_laparoscopic cholecystectomy

TAPvs.placebo TAP

Numericalandverbalpain scoreinthefirst24h

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abdominal

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259

Table1(Continued)

Surgery

Author,year

Petersenetal.,

201231

TAPvs.placebo TAP

VASpainscoreinmovement inthefirst24h

5

Ortizetal.,201232 ₈₀ _Bilateral_TAP_in_laparoscopic cholecystectomy

TAPvs.infiltration VASpainscoreinthefirst 24h

Tolchardetal., 201233

TAPvs.infiltration Consumptionofopioidsin thefirst24h

ReductionofVAS

5

Gynecological Griffithsetal., 201034

65 BilateralTAPinoncologic gynecologicalsurgery

TAPvs.placebo Consumptionofopioidsin thefirst24h

ReductionofVAS

5

Atimetal.,201135 ₅₅ _Bilateral_TAP_in hysterectomy

TAPvs.TAP placebovs.local infiltration

2

DeOliveiraetal., 201136

75 BilateralTAPin gynecologicalc. laparoscopic

TAPvs.placebo TAP

QoR-40satisfactionscore Randomizeddouble-blind trial

5

Kaneetal.,201237 ₅₆ _Bilateral_TAP_in

laparoscopichysterectomy

TAPvs.noTAP SatisfactionscoreQoR-40 Randomizedblindtrial 3

H.inguinal Avelineetal., 201138

275 UnilateralTAPininguinal herniorrhaphy

TAPvs.b. ileoinguinal-ileohipogastric

LópezGonzález etal.,201339

TAPvs.infiltration VASpainscoreatrestand immovementinthefirst 24h

Petersenetal., 201340

TAPvs.Placebo TAPvs.

IIB+infiltrationLA

5

Appendectomy

Nirajetal.,200941 ₅₂ _Unilateral_TAP_in_open appendectomy

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Surgery

Author,year

Nephrectomy

Hosgoodetal.,

201242

46 TAPindonornephrectomy TAPvs.placebo TAP

Consumptionofopioidsin thefirst48handVASpain score

5

Parikhetal., 201343

60 TAPindonornephrectomy TAPvs.placebo TAP

5

Bariatric

Sinhaetal.,201344 ₁₀₀ _TAP_in_bariatric_surgery (laparoscopicY-Roux anastomosis)

TAPvs.placebo TAP

5

Albrechtetal., 201345

70 TAPinbariatricsurgerywith localinfiltrationLA

5

Gastrectomy

Wuetal.,201346 ₉₀ _TAP_in_radical_gastrectomy _TAP_vs._epidural vs.nointervention

Consumptionofopioidsin thefirst24handVASpain score

5

Elkassabanyetal., 201347

52 BilateralTAPinretropubic radicalprostatectomy

TAPvs.placebo TAP

VASpainscoreand consumptionofopioidsin thefirst24h

5

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abdominal

plan

blockade

261

Table2 Analgesicefficacy.

Author,year N Groups(n) Painscore

---atrest

Painscore

---inmovement

Consumption

ofanalgesics

Opioid

rescuetime

Adverseeffects

relatedtoopioids

Conclusions

Early Late Early Late Early Late NVPO Itching Sedation

Nirajetal.,

201117

62 1--- TAPn27 2--- TAPn31

NA − NA NA Thereisnodifference

betweenVASscorein restandduring movementsinthe first72hwithTAPor epidural

Walteretal., 201318

68 1--- TAPn33 2--- NoTAPn 35

NA NA TAPreducesaround

33%themean consumptionof opioidsinthefirst 24h(20mg);p<0.05 Belavyetal.,

200919

57 1--- TAPn23 2--- placebo TAPn24

NA + − TAPreducesthe

meanconsumptionof opioidsinthefirst 24h(13.5mg); p<0.05 Costelloetal.,

200920

96 1---TAPn47 2---placebo TAPn49

ND No NA NA NA TAPdoesnotreduce

theVASscoreinthe first24h

Baajetal., 201021

+ + + + NA NA + NA NA TAPreducesthe

meanconsumptionof opioidsinthefirst 24h(25.89mgvs. 62mg;p<0.05) Kanazietal.,

201022

57 1--- ITMn28 2---TAPn29

− − NA − + + TAPextendsaround

50%(TAP8h,MIT4h) thetimesincethe firstopioidrescue (p<0.05) Loaneetal.,

201223

66 1--- TAPn33 2

---ITM+placebo TAPn33

− − − − NA + + TAPincreasesthe

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et

---atrest

Painscore

---inmovement

Consumption

ofanalgesics

Opioid

rescuetime

Adverseeffects

relatedtoopioids

Conclusions

Tanetal.,

201224

NA NA TAPreducesthe

meanconsumptionof opioidsinthefirst 24h(12.3mgvs. 31.4mg;p<0.01) Bollagetal.,

201225

90 1---TAP placebon30 2---TAPn25 3---TAP clonidinen 26

− − + + NA NA NA NA Toaddclonidineto

TAPwithbupivacaine doesnotimprovethe injurieshyperalgesia rate,anditdoesnot improvetheVAS scoreatrestandin movement

50 1---TAPn23 2---NoTAPn 25

+ + + + + + NA NA NA TAPreducestheVAS

scoreatrestandin movement,aswellas theconsumptionof opioidsinthefirst 24h(50mgtramadol vs.150mgtramadol; p=0.0001)

Cánovasetal., 201327

90 1

---ITM+placebo TAPn30 2---placebo TAP 3---TAP

+ + + + + + + + + TAPreducestheVAS

scoreatrest,12/24h (p<0.05),andin movement(p≤0.02)

Leeetal., 201328

+ + + + TAPreducesthepain

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of

ultrasound-guided

transverse

abdominal

plan

blockade

263

---atrest

Painscore

---inmovement

Consumption

ofanalgesics

Opioid

rescuetime

Adverseeffects

relatedtoopioids

Conclusions

El-Dawlatly etal.,200929

42 1--- TAPn21 2--- NoTAPn 21

NA NA NA NA + + NA NA NA NA TAPreducesthe

intraoperative consumptionof sufentanyl(p<0.01), andalsoreducesthe consumptionof morphineinthefirst 24h(12.3mg; p<0.05) Raetal.,

201030

54 1--- TAP0.5% n18 2--- TAP 0.25%n18 3---NoTAP

+ + + + + + NA NA NA + TAP0.25%andTAP

0.5%reduce

verbal-numericalpain scoreinthefirst24h (p<0.001).Thereare nodifferences betweenTAP0.25% andTAP0.5%.TAP reducesthe consumptionof intraoperative remifentanylandalso reducesthe

consumptionof analgesicsin postoperative (p<0.001).Thereare nodifferences betweenTAP0.25% andTAP0.5% Petersenetal.,

201231

+ + + NA NA TAPreducestheVAS

painscorein movement,

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---atrest

Painscore

---inmovement

Consumption

ofanalgesics

Opioid

rescuetime

Adverseeffects

relatedtoopioids

Conclusions

Ortizetal.,

201232

80 1---TAPn39 2---local infiltrationn 35

NA NA NA NA NA TAPdoesnotreduce

theVASscoreinthe first24h

+ NA + NA − NA NA NA NA TAPreducesVASin

thefirst8h(p<0.01) TAPreducesthe consumptionof opioidsinthefirst8h (9.2mgvs.16.8mg; p<0.01)

Griffithsetal., 201034

NA TAPdoesnotreduce

theconsumptionof opioidsinthefirst 24h.TAPdoesnot reduceVASinthefirst 2postoperative hours.

Atimetal., 201135

55 1---TAPn18 2---placebo TAPn18 3---local infiltrationn 19

+ + + + + NA NA TAPandinfiltration

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of

ultrasound-guided

transverse

abdominal

plan

blockade

265

---atrest

Painscore

---inmovement

Consumption

ofanalgesics

Opioid

rescuetime

Adverseeffects

relatedtoopioids

Conclusions

DeOliveira

etal.,201136

75 1--- TAP 0.25%n23 2--- TAP0.5% n24 3--- placebo TAPn23

+ + + + + + NA NA NA NA TAPimprovesthe

QoR-40satisfaction score;averageof16 ropivacaine0.5%and 17ropivacaine0.25% vs.saline(p<0.05). Thereareno differencesbetween ropivacaine0.5%vs. ropivacaine0.25% Kaneetal.,

201237

56 1--- TAPn28 2--- NoTAPn 28

NA NA NA TAPdoesnotreduce theQoR-40scoreor VASscale.Itdoesnot reduceorincrease theconsumptionof opioids

Avelineetal., 201138

275 1---TAPn132 2---IHBn139

+ + + + NA NA NA NA TAPreducesthepain

scoreatearly (average11vs.15; p=0.04)andlate (average29vs.33; p=0.013)rest.TAP reducesthemean consumptionof opioidsinthefirst 24h;p=0.03 LópezGonzález

etal.,201339

+ + a _Significant

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---atrest

Painscore

---inmovement

Consumption

ofanalgesics

Opioid

rescuetime

Adverseeffects

relatedtoopioids

Conclusions

Petersenetal.,

201340

90 1---TAPn30 2--- Infiltra-tion/IIB30 3---placebo TAPn30

− − − TAPdoesnotreduce

thepainscoreatrest orinmovementin thefirst24h

Nirajetal., 200941

52 1---TAPn25 2---NoTAPn 26

+ + + + NA + NA NA TAPreducesthe

meanconsumptionof opioidsinthefirst 24h(28mgvs.50mg; p<0.002)

Hosgoodetal., 201242

+ + + + + + + NA TAPreducesthe

meanconsumptionof opioidsinthefirst24 postoperativehours (12.4mgvs.21.6mg; p=0.015).Thereisno significantdifference inthecumulative consumptionof opioidsinthefirst 48h

Parikhetal., 201343

+ + + + + NA TAPreducesthe

meanconsumptionof opioidsinthefirst 24h

(103.8±32.18mgvs. 235.8±47.5mg) Sinhaetal.,

201344

+ + + + + + NA + TAPreducesthe

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of

ultrasound-guided

transverse

abdominal

plan

blockade

267

---atrest

Painscore

---inmovement

Consumption

ofanalgesics

Opioid

rescuetime

Adverseeffects

relatedtoopioids

Conclusions

Albrechtetal.,

201345

70 1--- TAPn25 2--- NoTAPn 28

Thereareno differencesbetween theconsumptionof opioidsTAPand controlinthefirst4 postoperativehours (32.2mgvs.35.6mg; p=0.41)

Wuetal., 201346

90 1--- TAPn29 2--- Epidural n27

3--- Controln 26

−/+ −/+ NA TAPisbetterthan

generalanesthesia regardingthe consumptionof opioidsinthefirst 24h.Epiduralis betterthanTAP regardingthe consumptionof opioidsinthefirst 24h

Elkassabany etal.,201347

+ − + − + − + − NA NA TAPreducesthe

meanconsumptionof opioidsinthefirst 24h(22.1mgvs. 45.5mg,)

IHB,iliohypogastricblock;IIB,ilioinguinalblock;VAS,visualanalogscale;ITM,intrathecalmorphine;NA,notavailable;TAP,transverseabdominisplan;+,favorabletoTAP;−,favorable tocomparator.

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Author,year Typeof

block

Technique Time Needle Anesthetic

usedby

injection

Complications Sensitivelevel

oftheblock

Block duration

Additional analgesia

Conclusions

Nirajetal.,

201117

Bilateral Subcostal Postoperative 16G80mm 1mgkg−1 bupivacaine 0.375%

No No NA Paracetamol

1g Tramadol 50---100mg

Therearenodifferences betweenVASpainscore atrestorinmovement inthefirst72h,withTAP orepidural

Walteretal., 201318

Bilateral ND Preoperative ND 40ml. Levobupiva-caine 2mgkg−1 (maximum 150mg)

1g

TAPreducesin33%the meanconsumptionof opioidsinthefirst24h (20mg),p<0.05

Belavyetal., 200919

Bilateral Mid-axillary Postoperative 20G150mm 20ml ropivacaine 0.5%

1g Diclofenac 100mg

TAPreducesthemean consumptionofopioids inthefirst24h (13.5mg),p<0.05 Costelloetal.,

200920

No No No Ketorolac

30mg Paracetamol 1.3grectal

TAPdoesnotreduceVAS scoreinthefirst24h

Baajetal., 201021

Bilateral Mid-axillary Preoperative 20G100mm 20ml bupivacaine 0.25%

No No NA No TAPreducesthemean

consumptionofopioids inthefirst24h, (25.89mgvs.62mg; p<0.05)

Kanazietal., 201022

Bilateral Mid-axillary Postoperative 21G100mm 20ml levobupiva-caine 0.375+ adrenaline

1g Diclofenac 100mg

TAPextends50%(TAP 8h,MIT4h)ofthetime untilthefirstopioid rescue,p<0.05

Loaneetal., 201223

Bilateral Mid-axillary Postoperative 22G80mm Ropivacaine 1.5mgkg−1 maximum 20ml

No No NA Naproxen

500mg Paracetamol 1g

TAPincreasesthemean consumptionofopioids inthefirst24h,(7.5mg vs.2.7mg;p=0.03) Tanetal.,

201224

Bilateral Mid-axillary Postoperative 22G70mm 20ml levobupiva-caine 0.25%

No No NA Morphine

chloride 0.15mgkg−1

(15)

of

ultrasound-guided

transverse

abdominal

plan

blockade

269

Author,year Typeof

block

usedby

injection

oftheblock

Block duration

Conclusions

Bollagetal.,

201225

Bilateral Mid-axillary Postoperative 20G 20ml ropivacaine 0.375%

1g Diclofenac 75mg Tramadol

ToaddclonidinetoTAP withbupivacainedoes notimprovethewound hyperalgesiarate,andit doesnotimprovethe VASscoreatrestandin movement

Bilateral Mid-axillary Postoperative 22G50mm 15ml bupivacaine 0.25%

No No NA Diclofenac

100mg

TAPreducestheVAS scoreatrestandin movement,aswellas theconsumptionof opioidsinthefirst24h (50mgtramadolvs. 150mgtramadol; p=0.0001) Cánovasetal.,

201327

Bilateral Mid-axillary Postoperative 20G 20ml levobupiva-caine 0.5%

No No NA Morphine

chloride

TAPreducesVASatrest, 12/24h(p<0.05),andin movement(p≤0.02)

Leeetal., 201328

1g Ketorolac 50mg Morphine chloride

TAPreducesthepain scoreatrestandin movementinthefirst2 postoperativehours(0.5 and1.9vs.2.8and4.9; p<0.001)

El-Dawlatly etal.,200929

Bilateral Mid-axillary Preoperative 21G90mm 15ml bupivacaine 0.5

No No NA NA TAPreducesthe

(16)

J.

Ripollés

et

Author,year Typeof

block

usedby

injection

oftheblock

Block duration

Conclusions

Raetal.,

201030

Bilateral Mid-axillary Preoperative 22G50mm 15ml bupivacaine 0.25%o 15ml bupivacaine 0.5%

No No NA Ketorolac

30mg Fentanyl

TAP0.25%andTAP0.5% reducethe

verbal-numericalpain scoreinthefirst24h (p<0.001).Thereareno differencesbetweenTAP 0.25%andTAP0.5%.TAP reducestheconsumption ofintraoperative remifentanylaswellas theuseofpostoperative analgesics(p<0.001). Therearenodifferences betweenTAP0.25%and TAP0.5%

L.Petersen etal.,201231

Bilateral Mid-axillary Preoperative 22G80mm 20ml ropivacaine 0.5%

No No 24h Paracetamol

1g Ibuprofen 600mg Morphine chloride

TAPreducestheVASpain scoremovement, calculatedasthearea underthecurveinthe first24h(26mmvs. 34mm;p=0.04) Ortizetal.,

201232

Bilateral Mid-axillary Preoperative 21G100mm 15ml bupivacaine 0>,5%

No No NA Ketorolac

30mg

TAPdoesnotreducethe VASscoreinthefirst24h

Bilateral Subcostal Preoperative 22G100mm Bupivacaine 1mgkg−1 (average 22ml)

No No NA Codeine TAPreducesVASinthe

first8h(p<0.01) TAPreducesthe consumptionofopioids inthefirst8h,(9.2mg vs.16.8mg;p<0.01) Griffithsetal.,

201034

Bilateral Mid-axillary Postoperative 90mm 20ml ropivacaine 0.5%

1g, parecoxib 40mg

(17)

of

ultrasound-guided

transverse

abdominal

plan

blockade

271

Author,year Typeof

block

usedby

injection

oftheblock

Block duration

Conclusions

Atimetal.,

201135

Bilateral Medial armpit

Preoperative 20G100mm 20ml bupivacaine 0.25%

No No NA Diclofenac

75mg Tramadol 0.5mgkg−1

TAPandinfiltration reducethepainscoreat restandinmovementat thehours1,2,4,6,24 (p<0.0001).TAPreduces thepainscoreatrest andinmovementatthe hours6and24regarding theinfiltration

(p<0.001) DeOliveira

etal.,201136

Bilateral Mid-axillary Preoperative 21G90mm 15ml ropivacaine 0.25%o0.5%

No No NA Ketorolac

30mg

TAPimprovestheQoR-40 satisfactionscore; average16ropivacaine 0.5%and17ropivacaine 0.25%vs.saline; p<0.05.Thereareno differencesbetween ropivacaine0.5%vs. ropivacaine0.25% Kaneetal.,

201237

Bilateral NA Postoperative NA 20ml ropivacaine 0.5%+ adrenaline

No No NA NA TAPdoesnotreduce

QoR-40scoreorVAS score.Itdoesnotreduce orincreasethe

consumptionofopioids Avelineetal.,

201138

Unilateral Mid-axillary Preoperative 22G 1.5mgkg−1 levobupiva-caine 0.5%

1g Ketoprofen 100mg

(18)

J.

Ripollés

et

Author,year Typeof

block

usedby

injection

oftheblock

Block duration

Conclusions

LópezGonzález

etal.,201339

Unilateral Mid-axillary Preoperative NA 30ml bupivacaine 0.25%

No No NA Paracetamol1g

Dexketoprofen 50mg

Morphinechloride

Significantdifferences werenotdetectedinVAS painscorebetweenat restandinmovement. TAPreducesthemean consumptionofopioids inthefirst24h(0.3mg vs.1.05mg;p<0.05) Petersenetal.,

201340

Unilateral Mid-axillary Preoperative 22G80mm 25ml ropivacaine 0.75%

No No NA Ketebidona TAPdoesnotreducethe painscaleatrestorin movementinthefirst 24h

Nirajetal., 200941

Unilateral Mid-axillary Postoperative 23G60mm 20ml ropivacaine 0.5%

Diclofenac50mg

TAPreducesthemean consumptionofopioids inthefirst24h(28mg vs.50mg;p<0.002) Hosgoodetal.,

201242

Unilateral Mid-axillary Preoperative 22G 20ml ropivacaine 0.375%

Morphinechloride

TAPreducesthemean consumptionofopioids inthefirst6

postoperativehours (12.4mgvs.21.6mg; p=0.015).Thereisno significantdifferencein thecumulative consumptionofopioids inthefirst48h Parikhetal.,

201343

Unilateral Mid-axillary Postoperative 18Gtohuy 25ml bupivacaine 0.375%

No No NA Diclofenac

1.5mgkg−1 Tramadol

TAPreducesthemean consumptionofopioids inthefirst24h (103.8±32.18mgvs. 235.8±47.5mg) Sinhaetal.,

201344

Bilateral Modified mid-axillary

Postoperative NA 20ml ropivacaine 0.375%

No No No NA TAPreducesthemean

(19)

of

ultrasound-guided

transverse

abdominal

plan

blockade

273

Author,year Typeof

block

Technique Time Needle Anestheticusedby

injection

oftheblock

Block duration

Conclusions

Albrechtetal.,

201345

Bilateral Oblique subcostal

Preoperative 22G80mm 30mlbupivacaine 0.25%+adrenaline

No No No Paracetamol

1g Oxycodone 5---10mg

Therearenodifferences intheconsumptionof opioidsbetweenTAPand controlinthefirst24 postoperativehours (32.2mgvs.35.6mg; p=0.41)

Wuetal., 201346

Bilateral Oblique subcostal

Preoperative ND 20mlropivacaine 0.375%

No No No Morphine

chloride

TAPisbetterthan generalanesthesia regardingthe

consumptionofopioids inthefirst24h.Epidural isbetterthanTAP regardingthe

consumptionofopioids inthefirst24h Elkassabany

etal.,201347

Bilateral Mid-axillary Postoperative22G 20mlbupivacaine 0.5%

No No No Morphine

chloride

TAPreducesthemean consumptionofopioids inthefirst24h(22.1mg vs.45.5mg)

(20)

Transversus abdominal plane block TAP block

Citations in Pubmed 478

208 articles analyzed

270 articles excluded (no human, no English, no Spanish)

129 articles excluded (no RCT, randomized, blind) 56 RCT articles

for analysis

25 RCT included for systematic review Manual search 6

RCT included

31 RCT included for systematic review

26 articles excluded They do not fulfill the inclusion

criteria (adult, ecoguided, analgesic efficacy, Jadad > 2) Transversus abdominal plane block

Identification

Search

Elegibility

Included

Figure2 Flowdiagramoftheselectionofthearticlesincluded.

epidural.Inthe second RCT,18 _a_preoperative _mid-axillary approach was performed and a reduction of 33% in the meanconsumptionofopioidswasobservedinthefirst24h (20mg)(p<0.05),mainlyduetotheinfraumbilicalsurgery, althoughtheconsumptionofopioidsinthefirst24hinthe supraumbilical-surgerysubgroup also decreased. Decrease ofPONV, sedation or itching wasobserved in noneof the cases.

The ultrasound-guided TAP in cesarean was evaluated in 10 RCTs. Among those, cesarean with spinal anesthe-sia was evaluated in 8 RCTs19---23,25,27_; _of _which ₄20,22,23,27 comparedTAP vs. spinal morphine (ITM),2 comparedvs. placebo TAP,19,21 _and _in _one _the _addition _of _clonidine _in TAPvs. TAP vs. placebo TAP,26 _and_recently _the _analgesic effectTAPincesareanwithspinalanesthesiawithITMwas evaluated.28

In 2 RCTs, TAP with cesarean was compared to gen-eralanesthesia.24,26 _In_all_cases,_the_block_was_carried_out afterthecesarean,throughbilateralmid-axillaryapproach;

thesensitive level neithertheduration oftheblock were altered.19---28

(21)

thegroupC,at12h1.9±1.1,andat24h2.3±1.2(p<0.05). Wheninmovement,theanalgesiawasbetterinthegroupC (p≤0.02).Thetimeuntiltheanalgesicrescuewasinferior inthe groupB:in thegroupA,9.3±4.9 (p=0.02in com-parisontothegroupC);inthegroupB,2±1.8(p<0.001in comparisontothegroupC);andinthegroupC,13.2±2.1h. Theconsumptionofopioidsinthefirst24hwas:inthegroup B38±5,inthegroupA,10±2(p<0.05),andinthegroup C,5±2(p<0.001).Theincidenceofnauseawassuperiorin thegroupB(36.6%),andtheitchingwasgreateringroupA (36.6%).

Bollagetal.25_studied_the_effect_of_the_addition_of cloni-dineandropivacaineintheexecutionoftheTAPinpatients undergoing cesarean under spinal anesthesia with ITM to measure wound hyperalgesia. There were no differences betweenITM,ITMwithTAPandITMwithTAPandclonidine. NodifferencesintheconsumptionofopioidsorinVASwere found.

In the RCTs that compared TAP vs. placebo TAP in cesareanwithspinalanesthesiawithoutITM,Belavyetal.19 foundadecreaseintheconsumptionofopioidsinthefirst 24h (18mg vs. 13.5mg; p<0.05) and in the timefor the firstopioidrescue(2h vs.3h;p=0.019). However,no sig-nificantdifferencesinVASatrestormovementwerefound, aswellasfortheincidenceofsecondaryeffectsofopioids. Baajetal.21_demonstrated_a_significant_reduction_in_the con-sumption of opioidsin the first 24h (25.89mg vs. 62mg; p>0.05), aswell asa lessening of 25% in theVAS at rest andinmovementforthefirst24h,andadecreaseinPONV. Theseresults,however,werenotsignificant.

Leeetal.28_demonstrated_that_the_execution_of_bilateral TAPinpatientsscheduledtocesareanwithspinalanesthesia withITM lessens significantly the painscore at rest or in movementwithinthefirst2hafterthesurgery(0.5and1.9 vs.2.8and4.9;p<0.001).Italsodecreasestheconsumption of analgesics(0vs. 25%;p=0.01).However,nosignificant differences were found in reducing the painscore in the first24horinPONV.

IntheRCTthatcompareTAPvs.placeboTAPincesarean undergeneral anesthesia, Tanetal.24 _concluded_that _the TAPreducesthemeanconsumptionofopioidsinthefirst24h (12.3mg vs. 31.4mg; p<0.01). In addition, nosignificant differenceswerefoundintheVASatrestorinmovementor intheapparitionofsecondaryeffectsofopioids. Eslamian etal.26 _demonstrated_a_decrease_in_the_VAS_at_rest _and_in movement,areductionintheconsumptionofopioidsinthe first24h(50mgvs.250mg;p=0.001)andanincreaseforthe opioidrescue(210minvs.30min;p=0.0001);theincidence ofsecondaryeffectsofopioidswasnotevaluated.

The ultrasound-guided bilateral TAP in laparoscopic cholecystectomywasstudied in 5RCTs,29---33 _among_whose placebo wascompared within 3,29,30 _and_no _intervention in one28_; _and _in ₂ _of _the _RCTs _to _the _LA _infiltration _in laparoscopicwounds.32,33 _In_all_the_cases,_it_was_executed bilaterally and after the operation. In four cases,29,32 _a mid-axillary approach was used, and in one, subcostal.33 In the RCT where TAP is comparedto placebo TAP or no intervention,29---31_El-Dawlatly_et_al.29_compared_the_effect_of theTAPinlaparoscopiccholecystectomyvs.nointervention and demonstrated a lower consumption of intraoperative opioids(8.6mcg vs.23mcg;p<0.01),and of morphinein thefirst24h(10.5mgvs.22.8mg;p<0.05).NeitherVASnor

secondaryeffectsofopioidswereevaluated.Raetal.30 com-paredTAPwithbupivacaine0.25%vs.TAPwithbupivacaine 0.5%vs.placeboTAP,demonstratingthatTAP,atboth con-centrationsincomparisonwithplaceboreducedthenumeric verbalpainscoreinthefirst24h(p<0.001),regardlessthe bupivacainedosesof 0.25%and0.5%. Theconsumption of intraoperativeopioidsand analgesicsin thepostoperative periodwaslowerinthegroups withTAPwithbupivacaine (p<0.001),withnoinfluencefromdifferentLA concentra-tions used. The control group presented higher sedation scorein thepostoperative period in comparison withthe groupofTAPplusbupivacaine0.5%.Petersenetal.,31_when comparingTAPvs.placeboTAPfoundareductionforVASin movement (calculatedasan areaunderthe curve)in the first24h (26mm vs. 34mm; p=0.04); aswell asa lower consumption of opioidsin the first 2 postoperative hours (7.5mgvs. 5mg; p<0.001).There werenodifferences in PONVor in sedation between the twogroups. In theRCT thatcompareTAPvs.LAinfiltrationinlaparoscopicwounds inthelaparoscopiccholecystectomy,31,32_Ortiz_et_al.32 per-formedamid-axillaryapproachanddidnotfinddifferences in the VAS, in the consumption of analgesics in the first 24h,andinPONV.However,recentlyTolchardetal.,33_from asubcostalapproach,demonstratedthatthe TAPlowered the early VAS in movement (8h; p<0.01) as well as the consumptionofopioidsinthefirst8h(9.2mgvs.16.8mg; p<0.01).Thesecondaryeffectsofopioidswerenot evalu-ated.

(22)

terectomy.

The use of ultrasound-guided TAP in inguinal hernior-rhaphywithgeneral anesthesiawasstudiedin 3 RCT38---40_; in the 3 it wasperformed in unilateral, mid-axillary, and preoperative. Aveline et al.38 _compared _TAP _vs. ilioin-guinal/iliohypogastricblock demonstrating, withina large series of 275 patients, that the TAP decreased the pain scoreat early(average11 vs.15; p=0.04)andlate (aver-age29vs.33;p=0.013)rest,andthemeanconsumptionof opioidsinthefirst24h(p=0.03).RecentlyLópez-González etal.39_compared_TAP_vs._LA_local_infiltration_finding_no sig-nificantdifferencesinVASpainscoreatrestorinmovement. Althoughthemeanconsumptionofopioidsdecreasedinthe first24h(0.3mgvs.1.05mg;p<0.05),evenwithoutclinical relevance,thedifferenceislowerandtherewereno differ-encesinthesecondaryeffectsofopioids.Petersenetal.40 comparetheuseofTAPvs.placeboTAPandvs.ilioinguinal blockattendedbyasurgeonfortheinfiltrationofsurgical wound,demonstratingthattheexecutionofTAPininguinal herniorrhaphybringsnobenefitstotheanalgesiaobtained fromparacetamolandibuprofen.

Nirajet al.41 _demonstrated _that _the_TAPs _diminish _the mean consumption of opioids in the first 24h (28mg vs. 50mg;p<0.002),theVASatrestorinmovementinthefirst 24handPONVwhenitiscomparedtointravenousanalgesia inpatients thatunderwentopen appendectomy,andhave notfoundcomplicationsassociatedwiththeTAP.41

Two RCTs compared TAP vs. placebo in donor nephrectomy.42,43 _In _both_RCTs_a _lower_mean_consumption ofopioidsinthefirst24h(12.4mgvs.21.6mg;p=0.015in the first6h42 _and _103.8_±_32.18_mg _vs. _235.8_±_47.5_mg _in thefirst 24h)43 _as_well _as _a _lower_{postoperative} _VAS _was demonstrated. In none there were differences in PONV, sedationoritching.

The ultrasound-guided TAP in laparoscopic bariatric surgerywasevaluatedin2RCTs.44,45 _Sinha_et_al.44 demon-strated theutility of bilateral TAP vs. placebo by usinga modification of the classical mid-axillary approach in the reduction of opioids consumption in the first 24h (8mg vs. 48mg; p=0.000), and in VAS at rest or movement in the first 24h, as well as all for the secondary effects of opioids. However,Albrecht et al.45_, _comparing_TAP _vs. no TAP in patients receiving LA infiltration, did not find anybenefits in theexecution of TAPby obliquesubcostal approach.

Wuetal.46_compared_the_preoperative_oblique_subcostal bilateral TAP in radical gastrectomy to thoracic epidural andnointervention(generalanesthesia), findingthatTAP is superiorto thegeneral anesthesiafor the consumption ofopioidsinthefirst24h,butinferiortothoracicepidural inthisconsumption. TAPdidnotdiminish VASin compari-sontogeneralanesthesia, aswell astheepiduraldidnot diminishVASincomparisontotheTAP.Wuetal.46_conclude thattheepiduralis superiortotheTAPinradical gastrec-tomy.

Recently, the bilateral mid-axillary TAP7 _in retropu-bicradicalprostatectomy hasbeenused,demonstratinga diminutionin the consumption of opioidsin the first 24h (22.1mgvs.45.5mg;p<0.05),aswellasanincreaseinthe timeuntilthefirstopioidrescue(p=0.001)andalowerearly

Twenty-eightRCTswerefoundwheremid-axillaryapproach wascarriedout,18---44,47_one_subcostal,17_and₂_RCTs_in_which theobliquesubcostalapproachwasexecuted.44,46

The blockade was carried out preoperatively in 15,18,21,28---32,34,35,37,38,40,43,44 _and _{postoperatively} _in 1617,19,20,22---27,34,37,40---43,47_;_obtaining_favorable_results_in₁₁_of the15RCTscarriedoutpreoperatively,18,21,29---31,33,35,36,38,39,42 and in 11 of the 16 RCTs in those carried out postoperatively.19,24---27,40---43,47 _However, _none _of _the _RCTs compared the preoperative vs. postoperative TAP or differentapproachesforthesameintervention.

Drugs,volumeanddoses

SeveralLAsandtheirconcentrationswereusedinTAP: bupi-vacainein10(0.25%in421,30,35,39_;_0.375%_in₂17,43_;_and_5%_in 426,29,30_and₁_mg_kg−1_in_one33₎_{levobupivacaine}_in₅_(0.25%_in one24_;_0.375%_in_one22_;_0.5%_in₂28,38_and₂_mg_kg−1_in_one)18_; andropivacainein15(0.25%in236,45_;_0.375%_in₆20,25,42---46_; 0.5%in520,36,37,39---41_;_0.75%_in_one28_;_and₁_mg_kg−1_in_one23_). Adrenalinewasaddedin3,22,37,45_and_clonidine_in_one.25_Only in 2 therewas a comparison for different concentrations ofLA.30,36_In_none_of_them_the_use_of_different_volumes_or differentLAforthesameinterventionwerecompared.

Sensitivelevel,durationoftheblockand

complications

None oftheRCTsreviewedanalyzed thesensitivelevel of theblockoritsduration.Innoneofthecasescomplications werereported.17---47

Discussion

The execution of the ultrasound-guided TAP in colorec-tal surgery demonstratedits usefulnessfor surgerieswith infraumbilical incision by mid-axillary approach.18 Mean-while, in surgery with supraumbilical incision, despite reducingtheconsumptionofopioidsinthefirst24h,itdid notshowthesameperformancesignificantlybymid-axillary approach when compared to placebo,18 _or _by _subcostal approachwhenitiscomparedtoepiduralanesthesia.17_The epiduralanesthesiawillcontinuetobethe‘‘goldstandard’’ or technique of election for this intervention until more evidencewithTAPisavailable.

(23)

concen-ofthelevobupivacaine.IntheRCTscarriedoutbyCanovas etal.27_{complications}_related_to_the_TAP_were_not_reported, althoughitisimportanttorememberthatgestationbringsa highervascularizationthatincreasestherisktoreachtoxic concentrationsofLA,52_and_the_possibility_of_transference_of theLAtothebreastmilkhastobetakenintoaccount.53,54

In case of cesarean withspinal anesthesiawithout ITM theexecutionoftheTAPdemonstratedupto60%of reduc-tionintheconsumptionofopioids.21 _However,_a_lower_VAS orPONV,itchingorsedationwasnotobtained,therebythe executionoftheTAPcouldbeindicatedforthosecasesof hypersensitivitytoopioid,historyofPONV,orpossibilityof transferenceofopiatetobreastmilk.55_In_case_of_cesarean withgeneralanesthesia,theexecutionofthebilateralTAP demonstratesreductionintheconsumptionofopioids24,26_; althoughthereductioninVASisnotconclusive,itimproved inoneRCT,24_and_no_differences_were_found_in_another26_;_it equallyoccurswiththeapparitionof secondaryeffectsof opioids.IntheRCTexecutedbyTanetal.24_{levobupivacaine} 0.25%wasused,andinthatcarriedoutbyEslamianetal.,26 bupivacaineat0.25%.

The execution of bilateral TAP is a valid alternative in patients undergoing cesarean without ITM, since it decreases theconsumptionof opioidsandtheirsecondary effects.Theseconclusionsarenotsimilartothoseobtained inrecentmeta-analysiswhereultrasound-guidedTAPisnot specified.52,56 _However,_in _those_cesareans_in _which_spinal anesthesiawithITM iscarriedout,itdidnotdemonstrate tobebeneficial,40_considering_the_scarce_clinical_relevance of pain reduction only within the first 2 postoperative hours.

The execution of bilateral mid-axillary TAPfor laparo-scopic cholecystectomy demonstrated that it reduces the postoperative consumption of opioids,30,31 _the intraoper-ative consumption of opioids30,31 _and _VAS30---33 _when _it _is comparedtoplaceboTAPornointervention.However, com-pared with LA infiltration, it obtains just the decreasing of the consumption of opioids and VAS when a subcostal approachis performed.32,33 _Ra _et_al.30 _demonstrated _that in the execution of TAP there are no differences with bupivacaine0.25% orbupivacaine 0.5%.The infiltrationof laparoscopic wounds aftercholecystectomy is an habitual practice, although it had good results with mid-axillary TAP when TAP vs. placebo TAP or no intervention are compared.29---31_When_it_is_compared_to_LA_{infiltration,}_results arenotobtained,32 _so_that_the_execution_of_TAP_may_be_a validoptionincaseofimpossibilityoflocalLAinfiltration, orasawayofreducingtheconsumptionofintraoperative analgesics. Withthe subcostalapproach, theVAS and the consumption ofopioidsareimproved,33 _so_that _in_case _of executionofTAPincholecystectomy,thisapproachshould beelected. MoreRCTsarerequiredin ordertodetermine theoptimaldoseandvolumeinthisintervention.

The studiescarriedoutingynecologicalproceduresare very heterogeneous. The execution of preoperative mid-axillary TAP demonstrated to be useful and superior to the local LA infiltration in total abdominal hysterectomy withPfannenstielincision35_and_in_outpatient_{gynecological} procedures,36_despite_not_having_demonstrated_to_be effec-tivein laparoscopic hysterectomy37 _or _in _a_{heterogeneous} groupofprocedureswithmid-laparotomy.34 _Given_the het-erogeneity ofthe RCTsin thegynecological interventions,

newRCTsareneeded,eventhoughithasbeendemonstrated tobeeffectiveintotalabdominalhysterectomy.35

The execution of TAP in inguinal herniorrhaphy is contradictory,38---40 _since _that, _although _Aveline _et _al.38 have demonstrated it was superior to the ilioin-guinal/iliohypogastricblockwhencomparedtoplacebo,no benefits in the diminution in the pain score are found.40 ThereisagradeofevidenceIA,recommendationAforthe executionofblocksof abdominalwall/localLAinfiltration foringuinalherniorrhaphy.57_Due_to_the_scarse_clinical rele-vancethatitdemonstratedwhencomparedtothelocalLA infiltration,39,40_currently_it_is_not_permitted_to_recommend itsusefortheintervention,thelocalLAinfiltrationbeinga techniqueofchoice.

The mid-axillary TAP demonstrated to be useful when compared to placebo in patients undergoing laparo-scopic bariatric surgery where local LA infiltration is not executed44_. _However, _it _is _not _the _same _for _patients whoreceive infiltrationoflaparoscopic wounds45 _although promisingobliquesubcostalapproachisused8,14 _that_could beduetothepreincisionalexecutionofblockinafull-length intervention,ortothelackofbenefitfortheadditionofTAP tothelocalLAinfiltration.TheresultsoftheTAP,whenthey arecomparedtotheinfiltrationwithLA,arenotconclusive, demonstratingtobesuperiorinsomeRCTs33,35,39_and_not_in others32 _and_having_similar_results _to_those_of _Albrecht _et al45_when_TAP_vs._no_TAP_is_compared_in_patients_that_receive localLAinfiltration.58

Theunilateralmid-axillaryTAPdemonstratedtoprovide appropriate analgesia in patients submitted to open appendectomy.40

Recently, Hosgood et al.42 _and _Parikh _et _al.43 demon-strated the efficacy of the mid-axillary TAP in donor nephrectomy.Wuetal.46 _conclude_that_the_epidural tech-niqueissuperiortoasingle-doseTAPviaobliquesubcostal in radical gastrectomy; however, probably the use of cathetersinTAPwouldimprovetheresults,asNirajetal.17 suggest and in studies carried out in renal and hepato-biliary surgery, not finding differences between TAP with catheterandepiduralanesthesia.TrialscarriedoutwithTAP attendedbysurgeon,in supraumbilicalcolorectalsurgery9 andultrasound-guided18_,_demonstrated_its_efficacy _so_that thedebateabouttheappropriateapproachforeach inter-ventionstillremains,andtheTAPcouldbeausefuloptionif itsefficacywasdemonstratedintheseinterventions,mainly those in programs of accelerated recovery where epidu-ralanesthesia,consideredasthe‘‘goldstandard’’forthis intervention,isavoided.17

Due tothe fact thatonly in retropubic radical prosta-tectomytheTAPwasevaluated,47_despite_the_good_results obtained,moreRCTsareneededinordertoconfirmthese resultsandtheirclinicalbenefits.

Limitations

ThebibliographicresearchwaslimitedtoMEDLINE-Pubmed and to a manual driven one, aiming to comprise all the RCTspublished, sothat there maybe published RCTsnot evaluated.

(24)

approachesthattheultrasound-guidedtechniquepermits, althoughthemultipleRCTsexecutedwithattendedTAPor TAPbasedonreferencesshouldbeequallyconsideredbythe interesttothetechnique.

Conclusions

The execution of bilateral mid-axillary TAP is indicated in patients undergoing cesarean without ITM19---21,24---26_; _in cholecystectomybysubcostalTAP,33 _or _mid-axillary_where theinfiltration is impossible, or as away of reducingthe consumption of postoperative opioids; in total abdomi-nal hysterectomy by bilateral mid-axillary TAP35_; _in _open appendectomy by unilateral mid-axillary TAP40_; _in _donor nephrectomy,mid-axillaryTAP.42,43_However,_there_are con-troversies in the use of oblique subcostal TAP in radical gastrectomy,17,46_in_the_use_of_bilateral_mid-axillary_in colo-rectalsurgery18 _and_in _retropubic_radical_{prostatectomy,}47 becauseofthelimitationoftheRCTanalyzed.

It is not possible to recommend its use in inguinal herniorrhaphy.40

Thereisaconsiderabledebateaboutthebestapproach foreachtypeofintervention59_since_that_despite_the demon-strationof metamericextension describedby Lee etal.14 andCarneyetal.,15 _the_data_found_in_RCT_are_not conclu-sive or concordant. New well-designed RCTs with enough statistical power tosolve the current questionsand their consequencesinthehabitualclinicalpracticearerequired. The lack of RCTsthat compare the pre- or postoperative execution of TAP in the same surgical intervention ren-dersit impossible torecommend the appropriatetime to theexecution ofthe block.In comparingTAP with differ-entconcentrations,30,36_it_was_demonstrated_that_there_are nobenefitsinusingahigherdose,andgiventhepotential toxiceffects of LAin the TAP and the possible overcom-ingoftheirtoxicdose,asdemonstratedbyGriffithsetal.60 withdosesofropivacainehabituallyused,itisnecessaryto studytheeffectiveminimumdosestodecreasethepossible deleteriouseffectsoftheLA.

The use of catheters in the abdominaltransverse plan couldincrease theanalgesicefficacy oftheblock,aswell astheuseofnewLA,liketherecentlyapprovedliposomal bupivacaine(EXPAREL), whichcouldincrease theduration oftheblock,althoughtherearenotrialsabout thesafety ofthisnewdruginperipheralblocks.Ultimately,inthe exe-cutionofnewRCTsitwouldbeconvenienttodeterminethe sensitiveleveloftheblock,aswellasitsdurationandthe plasmaticconcentrationsreachedwithdifferent concentra-tionsandvolumesofLA,inordertodeterminetheoptimal doseofLAforeachintervention.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

Acknowledgements

Theauthorswouldliketoacknowledgethestaffofthe Pro-fessional Library of Hospital Universitario Infanta Leonor Madridfortheinestimablecollaboration.

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