the best surgical treatment for fistula-in-ano dr john wong pyneh
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The Best Surgical Treatment for Fistula-in-ano
Dr John WongPYNEH
EtiologyCryptoglandular theoryTraumaForeign body IatrogenicMalignancyCrohn’s diseaseTuberculosisHIV
J.G.Williams et al. Colorectal Disease 2007
Classification Park’s classification (1976)
J.G.Williams et al. Colorectal Disease 2007
Goodsall’s rule
49%
90%
J.G.Williams et al. Colorectal Disease 2007
Investigation
Investigation Indications:
Complex fistula Impaired sphincter function Suspicious of secondary cause
Investigation Anatomy
Endoanal Ultrasound, MRI Physiology
Anorectal manometry Cause
Inflammatory marker, colonoscopy, rectal biopsy
Endoanal Ultrasound High accuracy (93%) to identify the
internal opening Injection of hydrogen peroxide can
increase the detection rate
ANZ J. Surg. 2005; 75: 64-72
J.G.Williams et al. Colorectal Disease 2007
Endoanal Ultrasound Disadvantage:
Pain and discomfort Operator dependent Limit field ~2cm from probe
Limited use for trans-sphincteric or more complex FIA!
MRI Gold standard Multi-planar image Show the fistula system in relation to the
underlying anatomy High sensitivity
Primary track: 86% Secondary track: 91% Horseshoe extesion 97%
ANZ J. Surg. 2005; 75: 64-72
J.G.Williams et al. Colorectal Disease 2007
Treatment
Principles of management To drain abscess To deal with the secondary track if any Definitive treatment of the primary track
Fistulotomy Lay-opening of the fistula
track from external opening to internal opening
Inter-sphincteric fistula Recurrence rate 0-21% Disturbance in continence:
0 to 82% Extent of external sphincter
division: <30%
J.G.Williams et al. Colorectal Disease 2007
Fistulectomy Excision of the entire fistula track Low lying fistula
No advantage in both recurrence and incontinence rate compared with fistulotomy
High lying fistula ‘Core out’ technique + internal
sphincterotomy
Surgical intervention for anorectal fistula. The Cochrane Collaboration 2010
Fistulectomy + Internal Sphincterotomy
SetonLoose seton
Achieve drainage of the fistula track Allow any secondary track to heal As part of staged fistulotomy
J.G.Williams et al. Colorectal Disease 2007
Staged fistulotomy
Low recurrence rate Significant rate in incontinence
Major incontinence rate up to 42%
J.G.Williams et al. Colorectal Disease 2007
SetonTight (cutting) seton
Commonly used in high transphincteric fistula
Divide the muscle slowly to produce a gradual fistulotomy
J.G.Williams et al. Colorectal Disease 2007
J.G.Williams et al. Colorectal Disease 2007
Fibrin Glue Fibrin clot to seal the
track Stimulate the migration,
proliferation and activation of the fibroblasts
Sphincter-sparing method
A.I. Malik & R.L. Nelson; Colorectal Disease 2008
Fibrin Glue High recurrence rate Long term healing rate(~14% - 60%)
A.I. Malik & R.L. Nelson; Colorectal Disease 2008
Anal Fistula Plug Sphincter-sparing method Bioprosthetic plug Internal opening must be identified
Anal Fistula Plug Controversial results from different centre
P. Garg et al. Colorectal Disease 2010
HYS Cheung et al. Surgical Practice 2009
PYNEH 11 5 45%
Advancement Flap + core out fistulectomy Sphincter-sparing method Pre-op bowel prep and antibiotics cover Internal opening must be identified
Advancement Flap + core out fistulectomy
Low long term success rate High recurrence due to:
Small flap Excessive tension
J.G.Williams et al. Colorectal Disease 2007
LIFT Ligation of Intersphincteric Fistula Tract Rojanasakul in 2007
LIFT Short term success rate was
encouraging (~57-94%) Long term result still unknown
Arch Surg. 2011;146(9):1011-1016
Conclusion No single best treatment for FIA Treatment for FIA must be individualized
Types of the fistula Premorbid sphincter function
Recommendation Inter-sphincteric fistula (High / low
lying, with or without internal opening)
Fistulotomy
Recommendation Extra-sphincteric fistula
Usually associated with an underlying cause
Treat the underlying cause Drain any sepsis Never disrupt or explore the sphincter
Thank you!
Exception for Goodsall’s rule- Horseshoe fistula - Long track that extend to the anterior
quadrant of the anal canal- Crohn’s disease- Iatrogenic
Fistulogram Accuracy ~16-50% only Difficult to relate the track to the sphincter
anatomy The acute track are just column of
granulation tissue without a lumen Need external opening Painful
Fistulotomy in acute anorectal sepsis Pros:
decrease the rate of recurrent anorectal sepsis
Cons: increase risk of impair continence Some individuals would have unnecessary
surgery Fisulotomy should be performed when
internal opening can be found and the fistula is submucosal or intersphincteric (low lying)
J.G.Williams et al. Colorectal Disease 2007
Radiofrequency fistulotomy Use of radio-wave as energy source Less bleeding Less pain Quicker recovery No difference in recurrence and
incontinence rate
Surgical intervention for anorectal fistula. The Cochrane Collaboration 2010
Fistulotomy with marsupialization Suturing the edge of the track to its
base Less bleeding Shorter healing time No difference in recurrence and
incontinence rate
Surgical intervention for anorectal fistula. The Cochrane Collaboration 2010
Fistulotomy vs Fistulectomy
No difference in recurrence and incontinence rate
A.I. Malik & R.L. Nelson; Colorectal Disease 2008
Chemical setonCoated with layers of latex and
plant extractsStrong alkaline outer layerCut through tissue at a rate of
1cm every 6 daysMore painfulEvidence on recurrence and
healing rate remain inconclusive
A.I. Malik & R.L. Nelson; Colorectal Disease 2008
Anal fistula plugBetter outcome in :
Deep trans-sphincteric fistula Long track fistula Narrow-gauge fistula
Advancement Flap Contra-indications:
Presence of proctitis Undrained sepsis Malignant / radiation related fistula Stricture of the anorectum Severe sphincter defect Severe peripheral scaring due to previous
surgery
J.G.Williams et al. Colorectal Disease 2007
FIA with Crohn’s disease Medical treatment, eg. Anti TNF-alpha
Infliximab Emergency treatment
Incision and drainage of the fistula Stabilization
Insertion of seton to optimize drainage and medical therpay
J.G.Williams et al. Colorectal Disease 2007
Incontinence scale Flatus, mucus, liguid, solid stool The Cleveland Clinic (Wexner)
Incontinence Score sum of 5 parameters is on a scale from 0
(=absent) to 4 (daily) frequency of incontinence to gas, liquid, solid, of need to wear pad, and of lifestyle changes.