Anorectal Diagnostic Overview

11-25-093.11.2010 © 2009© 2010 AnorectalAnorectal ManometryManometry OverviewOverview

•• MeasurementMeasurement ofof pressurespressures andand thethe annotationannotation ofof rectalrectal sensationsensation throughoutthroughout thethe rectumrectum andand analanal canalcanal toto determine:determine: – Neural and physiological mechanisms for continence present – Neural and physiological mechanisms for present – Pre-surgical evaluation – Anal pain PatientPatient GroupsGroups •• AdultAdult – – Chronic

•• PediatricPediatric – Hirschsprung’s screening – Encopresis FecalFecal IncontinenceIncontinence

Inability to defer the elimination FecalFecal IncontinenceIncontinence DemographicsDemographics

•• Prevalence increases with age

•• 7 % of population has chronic soiling – Equal prevalence in older males & females

•• 1 % of population has gross incontinence – Elderly people have 5 times greater prevalence than young – Women are twice as likely to have gross incontinence as men – 10-16% of women > 64 YOA have gross incontinence IncontinenceIncontinence DemographicsDemographics

•• Females > 45 YOA are 8 times as likely to have gross fecal incontinence as males of equal age

•• Females > 65 YOA are 12 times as likely to have gross fecal incontinence as younger females

•• Over 30% of women reporting urinary incontinence also report fecal incontinence PrimaryPrimary PhysiologicPhysiologic FactorsFactors

• Pudendal damage

• Injury during child birth

• Injury secondary to straining to defecate

• Muscle atrophy with age

• Rectal injury due to radiation, colorectal surgery

• Diabetic neuropathy FecalFecal IncontinenceIncontinence ImpactImpact

• Primary factor triggering nursing home admission

• 45% of nursing home patients are incontinent

• Linked with skin breakdown & infection ChronicChronic ConstipationConstipation

Inability to effectively eliminate ChronicChronic ConstipationConstipation DemographicsDemographics

•• 2 % of the adult population

•• Prevalence increases with age

•• Highest incidence in older females

•• 10 times as prevalent as fecal incontinence PrimaryPrimary AnatomicAnatomic ComponentsComponents

•• RectumRectum (rectal(rectal vault)vault)

•• PuborectalisPuborectalis musclemuscle

•• AnalAnal canalcanal musclesmuscles PuborectalisPuborectalis SlingSling MuscleMuscle

Contracted puborectalis Relaxed puborectalis prevents defecation allows defecation MuscleMuscle ControlControl TypesTypes

•• InvoluntaryInvoluntary

•• VoluntaryVoluntary InvoluntaryInvoluntary MuscleMuscle Internal Anal

Provides 75 % of pressure VoluntaryVoluntary MuscleMuscle

Provides 25 % of anal canal pressure Involuntary/VoluntaryInvoluntary/Voluntary MuscleMuscle Puborectalis

Contracted Relaxed TheThe ContinenceContinence SequenceSequence • Stool fills & distends rectal vault

• Puborectalis & relax (involuntary)

• Urge sensation perceived

• External sphincter & puborectalis contracted (voluntary)

• Conscience avoidance of increasing abdominal pressure

• wall expands to accommodate stool

• Sensation subsides, temporarily CriticalCritical FactorFactor 11

Rectal Angulation CriticalCritical FactorFactor 22

Contraction Contraction

Effective Outlet Obstruction WhatWhat CanCan GoGo Wrong?Wrong? • Rectal filing not perceived, no warning of impending doom – External sphincter not contracted – No avoidance of abdominal pressure increases

• Weak puborectalis muscle – Poor rectal angulation

• Weak sphincter muscles – Ineffective outlet obstruction

• Damaged / asymmetrical sphincter muscles – Ineffective outlet obstruction TheThe DefecationDefecation SequenceSequence

• Stool fills & distends rectal vault

• Puborectalis & internal anal sphincter relax (involuntary)

• Urge sensation perceived, toilet accessed

• Puborectalis & external sphincter relaxed (voluntary)

• Abdominal oblique & diaphragm muscle contractions increase intra- abdominal pressure

• Rectum contractions

• Defecation happens… CriticalCritical FactorFactor 11

No Rectal Angulation CriticalCritical FactorFactor 22

High Rectal Pressure

Low Canal Pressure Low Canal Pressure

Incompetent Outlet Obstruction WhatWhat CanCan GoGo Wrong?Wrong?

•• External sphincter not relaxed (paradoxically contracted)

•• Abdominal muscles not contracted, weakly contracted

•• Puborectalis not relaxed, paradoxically contracted – Poor rectal angulation TheThe TestingTesting ToolsTools •• – Rectal vault sensation & compliance – Anal canal strength, symmetry & control

•• EMG – Puborectalis control

•• Latency Testing (PNTL) – Motor nerve health to puborectalis & anal canal AnorectalAnorectal ManometryManometry TestingTesting

•• Anal canal muscles – Strength – Length – Symmetry (damaged?)

•• Sensory nerve function

•• Patient control of continence & defecation sequences AnorectalAnorectal MotilityMotility OverviewOverview

•• AnorectalAnorectal manometrymanometry consistconsist ofof severalseveral studiesstudies (sequences)(sequences) whichwhich cancan include:include: – Resting Study – Squeeze Study – RAIR Study – Sensation Study – Push Maneuvar – Compliance Study

RestingResting StudyStudy

•• RestingResting pressurepressure –– MeasuresMeasures thethe pressurepressure throughoutthroughout thethe analanal canalcanal exertedexerted byby thethe puborectalispuborectalis muscle,muscle, internalinternal analanal sphincter,sphincter, andand externalexternal analanal sphinctersphincter duringduring periodsperiods ofof rest.rest. –– TheThe majoritymajority ofof thethe tonictonic pressurepressure isis fromfrom IASIAS (80%)(80%) –– Normal:Normal: 5050--100100 mmHgmmHg RestingResting StudyStudy RestingResting StudyStudy

•• SphincterSphincter lengthlength – Measures the length in cm of the anal sphincter from where the pressure rises off baseline to where the pressure drops to baseline as the catheter is pulled through the sphincter. – Normal male: 3.5 cm – Normal female: 2.5-3 cm RestingResting StudyStudy

Length RestingResting StudyStudy

•• SymmetrySymmetry –– AA multidirectionalmultidirectional cathetercatheter providesprovides aa 360360 degreedegree displaydisplay ofof thethe analanal sphinctersphincter toto determinedetermine presencepresence ofof defectdefect inin thethe restingresting state.state. RestingResting StudyStudy RestingResting StudyStudy

What did we learn? ••Competency of anal sphincter (disrupted or weak IAS) – Low resting pressure • Incontinence – Asymmetry • Incontinence – Short • May be seen in pts. with surgical or traumatic injuries • May contribute to incontinence ••High pressure – May be smooth or striated muscle spasm • Anal pain • Fissure Squeeze Study

• Measures the increase in sphincter pressure with a voluntary squeeze – Puborectalis muscle and external anal sphincter contributes to the squeeze pressure – Continence success dependent on voluntary effort to overcome RAIR and increased intra-rectal pressure SqueezeSqueeze StudyStudy

•• SqueezeSqueeze PressurePressure – Increase in pressure over resting pressure with a voluntary squeeze • Double basal • normal: 50-100 mmHg •• MaximumMaximum VoluntaryVoluntary SqueezeSqueeze PressurePressure – Increase in pressure over rectal pressure with a voluntary squeeze • normal: >100 mmHg Squeeze Study

• Symmetry – Multidirectional pressure sensors plot a 4 quadrant display to determine a defect during a voluntary squeeze

SqueezeSqueeze StudyStudy

•• WhatWhat dodo wewe learn?learn? – Weak voluntary squeeze • Weak EAS from either muscular or neural damage – Muscular sphincter damage – Neurological damage of the motor pathways – Poorly compliant patient ™ -Incontinence – Early fatigue • Possible pudendal nerve damage – Incontinence – Asymmetry • Sphincter defect – Incontinence SqueezeSqueeze StudyStudy

•• WhatWhat dodo wewe learn?learn? –– HighHigh squeezesqueeze pressurespressures •• Possible males with chronic pelvic pains RAIRRAIR StudyStudy

•• DeterminesDetermines ifif thethe internalinternal analanal sphinctersphincter pressurepressure isis inhibitedinhibited inin responseresponse toto rectalrectal distensiondistension –– Normal:Normal: inhibitioninhibition ofof pressurepressure withwith rectalrectal volumesvolumes >20>20 mlml RAIR Study

• Internal anal sphincter relaxation in response to rectal distension – Volume incremental RAIRRAIR StudyStudy

•• WhatWhat dodo wewe learn?learn? – A screen for Hirschsprung’s disease • RAIR present then functioning myenteric plexus and the absence of Hirschsprung’s • No inhibition of IAS – Hirschsprung’s – Mega rectum – Tonically contracted EAS – Diminished rectal sensation • Incontinence • Mega rectum – Failure of EAS to contract • Fecal incontinence PushPush StudyStudy

•• AssessAssess puborectalispuborectalis andand externalexternal analanal sphinctersphincter responseresponse toto pushingpushing asas inin anan attemptattempt toto defecate.defecate. PushingPushing resultsresults inin abd.abd. compression,compression, perinealperineal descentdescent andand analanal relaxation.relaxation. –– Normal:Normal: decreasedecrease pressurepressure •• The pressure should not increase which indicates a paradoxical response Push Study

• Normal strain response

Increase intrarectal pressure

Decrease in EAS pressure Push Study

• Abnormal strain response

Increase in EAS pressure

PushPush StudyStudy

•• WhatWhat dodo wewe learnlearn –– ScreenScreen forfor functionalfunctional outletoutlet obstructionobstruction (FOO)(FOO) –– ParadoxicalParadoxical responseresponse •• FOO, , dyssynergia •• Symptoms of – inability to pass stool – Excessive straining – Incomplete evacuation