Biofeedback rectal evacuation

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TheEffectsofBiofeedbackonRectalSensationandDistalColonicMotilityinPatientsWithDisordersofRectalEvacuationEvidenceofanInhibitoryRectocolonicReflexinHumans?RolandM.H.G.Mollen,M.D.,BeatriceSalvioli,M.D.,MichaelCamilleri,M.D.,DuaneBurton,LouisJ.Kost,SidneyF.Phillips,M.D.,andJohnH.Pemberton,M.D.GastroenterologyResearchUnitandSectionofColorectalSurgery,MayoClinic,Rochester,Minnesota

OBJECTIVE:Abnormalitiesofdescendingcolonmotilityre-portedinasubsetofpatientswithrectalevacuationdisor-dersareconsistentwitharectocolonicinhibitoryreflex.Ouraimsweretoevaluatedistalcolonmotorfunctionandrectalsensationinsuchpatientsandassesseffectsofbiofeedback(BF)trainingonthesefunctions.METHODS:Sevenpatients(fivewomen,twomen;meanage36yr)withrectalevacuationdisorderswerestudiedbeforeandafter10-daysbiofeedbacktraining;sixhealthyvolun-teers(fivewomen,oneman;meanage30yr)werestudiedonce.Coloniccompliance,motility,sensationthresholds,andperceptionscoresduringstandardizedrectaldistentionsweremeasuredusingtwobarostat-manometryassembliesinsertedintothecleansedcolonwiththeaidofflexiblesigmoidoscopy.RESULTS:Sigmoidcompliance,fasting,andpostprandialmotilityindex,andperceptionthresholdsweresimilarincontrolsandpatientsbeforeandafterbiofeedbacktraining.Postprandialsigmoidtonetended(pϭ0.09)tobelowerinpatientsthancontrols;afterbiofeedback,postprandialtonewascomparabletothatincontrols.Rectalurgencyscoresat24mmHgdistentionweregreaterinpatientsthanincon-trols(pϭ0.02forboth).Afterbiofeedback,thereweretrendsforlowerperceptionsofurgencytodefecate(7.6Ϯ1.1cmpre-vs5.3Ϯ1.5post-;pϭ0.04)at24mmHg;conversely,gassensationat12mmHgwashigher(1.2Ϯ0.5cmpre-vs3.3Ϯ0.6post-;pϭ0.05).CONCLUSIONS:Normalizationofrectalevacuationandpostprandialsigmoidtoneinpatientswithevacuationdis-ordersbybiofeedbacktrainingsupportsthepresenceofarectocolonicinhibitoryreflex.Effectofbiofeedbackonrec-talsensationinthesepatientsrequiresfurtherstudy.(AmJGastroenterol1999;94:751–756.©1999byAm.Coll.ofGastroenterology)INTRODUCTIONOutletobstructionstodefecation,alsotermedevacuationdisorders,arefrequentlyunrecognizedcausesofconstipa-tioninpatientsreferredtogastroenterologyclinics(1–3).Evacuationdisordersrefertoaconstellationofconfusingtermsintheliteraturesuchasanismus,pelvicfloordysfunc-tion,paradoxicalpuborectaliscontraction,puborectalisdys-synergia,andspasticpelvicfloorsyndrome.Inapreviousstudy,weobservedthatasubsetofpatientswithobstructiontodefecationhadanabnormalmotorfunc-tion(e.g.,toneandphasiccontractility)oftheleftcolon(4);themechanismforthisabnormalityincolonicmotorfunc-tionisunclear.Theobservationledtothehypothesisthatthecolonicmotordysfunctionrepresentsareflexinhibitionduetostimulationoftherectumbyretainedstoolorgaswithinthefunctionallyobstructedrectum.Ifthishypothesisiscorrect,itwouldbeanticipatedthatrestorationofnormalevacuationwouldresultinnormalizationofcolonicmotil-ity.However,analternativehypothesisfortheimpairedpostprandialcolonictonemightbeadisturbanceofneuro-muscularfunction.Infact,Grotzetal.(5)havereportedadecreasedrectalwallcontractilityinresponsetofeeding,acholinergicagonistandasmoothmusclerelaxantinpatientswithchronicconstipation.Ifthealternativehypothesisiscorrect,restorationofnormalevacuationwouldnotaltercolonicmotilityortone.Theaimofthestudywastocomparemotorfunctionofthesigmoidcolonandrectumandrectalsensationinagroupofpatientswithrectalevacuationdisordersandhealthycontrols,andtodeterminetheeffectsofbiofeedback(BF)trainingonthesefunctions.Werecruitedadifferentsetofpatientsfromthosereportedinourearlierstudy(4),andcompareddatafromthepatientstothoseofhealthycontrolsstudiedononeoccasion.

MATERIALSANDMETHODSPatientsandControlsSevenpatients(fivewomen,twomen;meanage,36yr)werestudiedbeforeandaftercompletionofthe10-dayMayoClinicintensiveprogramofbiofeedbackretrainingforoutletobstructiontodefecation.Thisprogramincorpo-ratespsychologicalconsultationandrehabilitation,anddi-

THEAMERICANJOURNALOFGASTROENTEROLOGYVol.94,No.3,1999©1999byAm.Coll.ofGastroenterologyISSN0002-9270/99/$20.00PublishedbyElsevierScienceInc.PIIS0002-9270(99)00002-7etaryadvice,apartfromthefour1-hbiofeedbacksessionsperdaywithasinglephysicaltherapistassignedtoeachpatient.Wedefinedevacuationdisorderastheneedtostrainexcessivelytopassbowelmovementsandasensationofincompleteevacuationatleastaquarterofthetime.Symp-tomswerepresentforatՆ1yr.Colonictransitstudieswereperformedaspartoftheclinicalevaluation.Patientswithclinicallysuspectedevacuationdisorderswereincludedinthestudywhenatleastoneofthethreefollowingtestswereabnormal:failuretoexpela50-mlballoonintheleftlateralpositiondespiteadditionof200gofweight;failureoftherectoanalangletoincreasebymorethan15°duringstrainingtodefecateduringbariumdefecog-raphyorscintigraphicmeasurement;restinganalcanalpres-suresofϾ120cmwater[average(6)].Improvementinevacuationfollowingpelvicfloorandanalsphincterretrainingwasdemonstratedbytheabilitytospontaneouslyexpeltherectalballoon(nϭ6)orimprove-mentinanalsphinctertoneatrest(patient3).Apriori,weconsideredsuchimprovementwasessentialtotestthestudyhypothesesthatabnormalmotilityofthecolonwasduetoreflexrectocolonicinhibitionbythepoorlyevacuatingrec-tum.Exclusioncriteriawere:Ͻ18yrofage,previouscolonicresection,extrinsicneurologicdisorder,evidenceofcolonicorrectalstricture,useofmotility-alteringmedicationswithin48hofthestudy,andevidenceofdilatedcolonormegarectumonradiographs.Wealsostudiedsixhealthyvolunteers(fivefemale,onemale;meanage,30yr)toobtaindataforcomparisonwiththeprebiofeedbackstudiesofpatientswithevacuationdis-orders.Inclusioncriteriaforhealthycontrolswere:Ն18yr,nopreviousabdominalorpelvicsurgery(otherthanappen-dectomy),andnohistoryofconstipationordiarrhea.ThestudieswereapprovedbytheMayoClinicInstitutionalReviewBoard,andwritteninformedconsentwasobtainedfromallparticipants.Allwomenofchildbearingpotentialhadanegative␤-HCGpregnancytestwithin48hofeachintubatedstudy.RectalandColonicMotilityandSensationDuringthedaybeforethestudy,patientsandvolunteersingested1Lofasolutionofpolyethyleneglycolandelec-trolytes(OCL,AbbottLaboratories,Chicago,IL)andotherliquidsuntiltheirfecaleffluentconsistedofclearliquid.Thenextday,aftera12-hfastandwiththepatientintheleftlateraldecubitusposition,flexiblesigmoidoscopywasper-formedwithoutsedationandasoft-tipped,Teflon-coatedguidewire(Microvasive,HobbsMedical,StaffordSprings,CT)wasinsertedintothetransversecolon.Theendoscopewaswithdrawn,andacombinedmanometry-barostatassem-blywasadvancedintothelowerdescendingcolonoverthesoft-tipped,Teflon-coatedguidewirewiththeaidoffluo-roscopy.Themanometer-barostat,adaptedfromoneusedinrecentstudies(7),hadsideholes5cmproximaland5–25cm(separatedby5-cmintervals)distaltothebarostatbal-loonforpneumohydraulicperfusionmanometry(8).Theballoonwasahighlycompliantpolyethylenebag,10cminlength(HeftyBaggies,MobilChemical,Pittsford,NY),tiedatbothendstometalringsincorporatedinthedevice;theballoonwaslocatedinthesigmoid-descendingcolonjunc-tion.Anotherballoonmountedonacatheterwasinsertedintotherectumwithitslowermargin5cmproximaltotheanalverge.Asimilarguidewirewaspassedthroughthecenterofthecathetertopreventkinkingduringinsertion.Afterflu-oroscopicconfirmationofthepositionofthecatheters,theguidewireswereremovedandthetwocatheterswerecon-nectedtoseparatebarostats(rigidpistontype,G&JElec-tronics,Toronto,Ontario,Canada).Becauseballoonvol-umesinabdominalvisceraareposition-dependent(9,10)andareinfluencedbytheweightofadjacentorgans,weconductedthestudieswithsubjectsontheirrightsideduringtheentiredurationofthestudyandmaintainedaconstantoperatingpressureinthebarostatically-controlledballoons.Beforethemeasurements,weperformedaconditioningdistentionofthecolonicorrectalsegmentsinordertoensurethatsubsequentestimatesofcomplianceandsensa-tionwerereproducible,ashadbeendemonstratedinrectumbyHammeretal.(11)andinthestomachbyAhluwaliaetal.(12).Aftertransientinflationofthebarostatbagtoavolumeof350mlintherectumandcolontoensuretheunfoldingofthebag,itwasdeflatedandcompletelyreinflatedwith1-mmHgincrementsofpressure.Theoperatingpressurewasdefinedas2mmHgabovetheminimaldistentionpressure(MDP),atwhichrespiratoryexcursionswereclearlyre-cordedfromthebarostatvolumetracing.Ifrespiratoryvari-ationswerenotobvious,weclampedthepressurewhenthevolumeoftheairinthebagwas25ml.