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.