Anorectal Physiology Tests current place in clinical practice

1
Ano-rectal Physiology Testscurrent place in
clinical practice

• Bruce D George
• John Radcliffe Hospital
• Oxford

2
The purpose of anorectal physiology tests

• Research anatomy/physiology
• Research disease pathophysiology
• Routine clinical practice

3
IAS smooth muscle Autonomic/local
neural control
EAS skeletal muscle Voluntary/reflex
control Pudendal nerve
Anatomy revision
4
Rectal sensation distension indistinct ?wall
?pelvic floor pelvic parasympathetic
Anal canal sensation precise sampling
reflex pudendal nerve S234
5
Normal Continence
The ability to perceive, to retain and to
evacuate bowel contents at socially convenient
times
6
Factors contributing to normal bowel function
Colonic transit
CNS co-ordination
Sensation
Mechanical barrier
Ability to evacuate
7
Anorectal physiology tests

• Anal canal pressures
• Resting IAS
• Squeeze EAS
• Sensation
• Anal
• rectal
• Nerves
• Pudendal nerve
• Ultrasound

8
Routine clinical practice

• Faecal incontinence
• Constipation
• Prior to surgery which may damage sphincter
  mechanism
• Fistula
• Fissures
• Ileoanal pouch

9
Faecal incontinence

• To detect structural defects in internal or
  external sphincter
• To detect evidence of global pelvic floor failure
• To detect the normal sphincter mechanism

10
History
Severity gas, liquids, solids effect on
quality of life Other symptoms gastrointestinal
(constipation), gynaecological, urological,
Possible causes obstetric, local surgery, back,
neurological
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Examination
General Abdominal Inspection at rest soiling,
excoriation, scars, patulous,
guttering squeeze straining perineal
descent Rectal examination Proctoscopy and
sigmoidoscopy
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Structural defects
Anal stretch
Thin internal anal sphincter
Anterior obstetric defect
13
Selection of Patient for Sphincter Repair

• Ideal patient
• isolated sphincter defect
• normal sensation, evacuation, pelvic floor
  function
• normal CNS
• severe incontinence

• Wrong patient
• generalised weakness of pelvic floor
• pelvic nerve damage
• inability to evacuate
• mild symptoms

14
Global pelvic floor failure

• Associated gynaecological prolapse/urinary
  incontinence
• Perineal descent
• Low pressures
• Impaired sensation
• Prolonged PNTML

15
Faecal incontinence with normal ano-rectal
physiology and ultrasound

• Difficult problem
• Recheck history and examination
• Additional tests
• MRI of lumbosacral spine
• MRI of pelvis
• Ambulatory colonic/rectal motility

16
Constipation

• Part of investigation of severe intractable
  constipation
• In combination with colonic transit studies,
  proctography
• Detect very rare adult Hirschprungs disease or
  internal sphincter hypertrophy
• Detection of associated psychological issues

17
Prior to anal fistula surgery

18
Influence of anal ultrasound on management of
anal fistula

• 38 consecutive patients undergoing EUA
• All pre-op physiology and ultrasound
• Surgeon blinded to results at time of EUA
• Surgeon shown results in theatre
• Surgical management affected in 7 (29 of
  fistulae)
• 2 occult sphincter defect
• 3 reclassification of fistula
• 2 identification of fistula
• Colorectal Disease 2002 4 118-22.

19
Prior to anal fissure surgery

• Lateral internal sphincterotomy
• Gold standard after failed GTN/botulinum
• 1 to 30 risk of incontinence

20

GTN/Botulinum 1st line therapy

Persistent symptomatic fissure
Female/previous anal surgery
Male/no anal surgery
Physiology ultrasound
defect
Lateral internal sphincterotomy
No defect
Persistent medical therapy/ Conservative surgery
21
Effects of policy of physiology and ultrasound
prior to internal sphincterotomy

• Trend towards non-sphincter cutting management
• Repeated use of botulinum
• Combination therapy GTN, botulinum, diltiazem
• Fissurectomy botulinum
• Advancement flap
• Truly informed consent

22
Anorectal physiology after internal sphincterotomy

To investigate incontinence

To investigate persistent fissure
23
Evolution of ano-rectal physiology and ultrasound

• Anatomy and physiology
• Clinical research
• Routine clinical practice
• Incontinence
• Constipation
• Fistula, fissure.