Transcript Anorectal physiological assessment - Welcome

Anorectal physiological
assessment
Perineal trauma study day
13th November 2007
Mrs. Kirsty Cattle MRCS
Research Registrar
Faecal incontinence
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Causes of incontinence
Stool factors
 Stool delivery
 Rectum – storage organ
 Anal sphincters
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Anatomical
 Innervation
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Miscellaneous
www.aafp.org/afp/20010615/2391_f1.jpg
Anorectal physiology
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Manometry
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Rectal sensation
PNTML
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Including anorectal inhibitory reflex
Pudendal nerve terminal motor latency
Endoanal ultrasound
Manometry
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Resting pressure
Reflects internal anal sphincter function
 Normal: > 45 cm H2O, usually ~ 70 cm H2O
 Difference between maximum resting anal pressure
and rectal pressure
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Pressure (cm H2O)
Maximum
resting pressure
Distance from anal verge (cm)
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Squeeze pressure
Reflects external anal sphincter function
 Normal in women: ~ 70 cm H2O
 The “best squeeze” is documented as the maximum
squeeze pressure, i.e. the biggest increase generated
from resting anal pressure
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Pressure (cm H2O)
Maximum
squeeze
pressure
Distance from anal verge (cm)
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Anorectal inhibitory reflex
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Reflex relaxation of the internal anal sphincter when
the distal rectum is distended
Inflation of balloon in rectum
with 20-30 ml air
Rectal balloon deflated
Pressure (cm H2O)
Time
Rectal sensation
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Normal values:
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First sensation 40 – 50 ml
Call to stool 80 – 100 ml
Urgency 120 – 150 ml
Pudendal nerve studies
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Measurement of conduction speed in terminal
pudendal nerve
Transrectal technique: Stimulate nerve near ischial
spines, measure time taken to produce twitch of
external anal sphincter
 Normal range < 2.2 ms
 Statistically different between incontinent patients
and controls, but may be normal in incontinent
patients
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http://www.emory.edu/ANATOMY/AnatomyManual/88.jpg
http://med.stanford.edu/interactiveimages/anatomyweb/media/PL/M/0006/035.gif
http://www.alpinebiomed.com/modules/
cms/UserFiles/Image/accessories/StMar
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Ultrasound
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10 MHz rotating probe
Clear visualisation of
sphincters
Delineation of simple
fistulae
http://radiology.rsnajnls.org/cgi/content/figsonly/224/2/417
http://radiology.rsnajnls.org/cgi/content/figsonly/224/2/417
http://www.thieme-connect.com/bilder/roefo/200112/ro1203-4
Other assessments
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Barium enema/Colonoscopy
Defaecating proctogram
Summary
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Anorectal physiology studies provide us with:
Function and anatomy of sphincters
 Assessment of sensation
 Estimation of pudendal nerve function
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Use:
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Treatment options, including planning of surgery
Thank you
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Any questions?