Current Management Current Management of Fistula-in-anoof Fistula-in-ano

Dr. Leung Tak Lun CaniceDr. Leung Tak Lun CaniceDepartment of SurgeryDepartment of SurgeryNorth District HospitalNorth District Hospital

Case PresentationCase Presentation

M/47M/47 Hx of perianal abscessHx of perianal abscess On and off On and off perianalperianal discharge discharge P/EP/E

FIA with external opening at 4 oc FIA with external opening at 4 oc position, 3cm from anal vergeposition, 3cm from anal verge

Internal opening at 4 oc, above deInternal opening at 4 oc, above dentate linentate line

EUA and Rigid sigmoidoscopyEUA and Rigid sigmoidoscopy Transpincteric FIA with ext. opening Transpincteric FIA with ext. opening

at 4 ocat 4 oc Internal opening at 4 oc, above dentInternal opening at 4 oc, above dent

ate lineate line External tract at left ischorectal foExternal tract at left ischorectal fo

ssa excisedssa excised Seton inserted Seton inserted Plan for tightening of seton in 4/52 Plan for tightening of seton in 4/52

At 2At 2ndnd operation operation Seton already broken and lostSeton already broken and lost Basically healed fistulaBasically healed fistula Curettage of granulation tissue Curettage of granulation tissue

donedone

Recurrence!!Recurrence!!

4 months later4 months later c/o persistent dischargec/o persistent discharge MRI offeredMRI offered

MRI finding -> transphincteric tyMRI finding -> transphincteric type of FIA with bifurcation tract npe of FIA with bifurcation tract near the anus and ending at 5 anear the anus and ending at 5 and 7 o’clock positiond 7 o’clock position

ReoperationReoperation

Intra-op findingIntra-op finding Transphincteric FIA with external Transphincteric FIA with external

opening at 4 oc opening at 4 oc Internal opening at 4cm from anal Internal opening at 4cm from anal

verge just below level of levator anverge just below level of levator ani but at the top of internal sphinteri but at the top of internal sphinter

Curettage of the track done and Curettage of the track done and seton inserted againseton inserted again

Follow upFollow up

Well and no dischargeWell and no discharge

Etiology Etiology

Pre-existing abscessPre-existing abscess Anal gland theoryAnal gland theory

Anal glands 8 or more in numberAnal glands 8 or more in number Form small abscess at interspincteric plane when infectForm small abscess at interspincteric plane when infect

eded Other causes include congenital, pelvic sepsis, trauma, hidradenitis suOther causes include congenital, pelvic sepsis, trauma, hidradenitis su

ppurativa, haemorrhoid, iatrogenic, inflammatory bowel disease, TB, mppurativa, haemorrhoid, iatrogenic, inflammatory bowel disease, TB, maligancyaligancy

Parks ClassificationParks Classification

Clinical presentationClinical presentation

Anal discharge preceded by epiAnal discharge preceded by episode of pain and perianal swellisode of pain and perianal swellingng

Repeated episode of perianal seRepeated episode of perianal sepsispsis

Clinical assessmentClinical assessment

History History Physical examination Physical examination

Palpation of the perineum Palpation of the perineum Digital examinationDigital examination

Clinical assessmentClinical assessment

EUAEUA Light GALight GA Palpation Palpation Methylene blue, hydrogen Methylene blue, hydrogen

peroxide injectionperoxide injection probingprobing

Imaging modalityImaging modality

FistulogramFistulogram Endoanal ultrasoundEndoanal ultrasound MRI MRI

FistulographyFistulography

DisappointingDisappointing Accuracy 16% onlyAccuracy 16% only Difficult to relate the track to the Difficult to relate the track to the

sphincter and levator anisphincter and levator ani The acute track are just column The acute track are just column

of inflamed granulation tissue of inflamed granulation tissue without a lumen without a lumen

Endoanal ultrasoundEndoanal ultrasound

High accuracy (93%) of predicting High accuracy (93%) of predicting the site of internal opening of an anal the site of internal opening of an anal fistulafistula

Overall concordance for type of Overall concordance for type of fistula is 82% fistula is 82%

Colorectal Colorectal Disease, 4, 436-440Disease, 4, 436-440

Hydrogen peroxide improve the Hydrogen peroxide improve the concordance with type of fistula concordance with type of fistula from 80% to 89%from 80% to 89%

Colorectal Disease, 4, 436-440Colorectal Disease, 4, 436-440

Endoanal ultrasoundEndoanal ultrasound

MRIMRI

Advantage of MRI Advantage of MRI Multiplanar imaging Multiplanar imaging High soft tissue differentiation to High soft tissue differentiation to

show the track system in relation show the track system in relation to the underlying anatomy in a to the underlying anatomy in a projection relevant to surgical projection relevant to surgical explorationexploration

MRIMRI

Concordance rate with surgical Concordance rate with surgical exploration of 86% to 88% in exploration of 86% to 88% in initial reportsinitial reports

Currently Currently Up to 100% sensitivity for primary Up to 100% sensitivity for primary

tracttract 96% for abscess96% for abscess 100% for horse extension100% for horse extension 96% for internal opening96% for internal opening

Axial / Coronal viewAxial / Coronal view

T1 axial T2 axialT1 axial T2 axial

T1 coronal T2 coronalT1 coronal T2 coronal

Gadolinium enhancement with fat Gadolinium enhancement with fat suppression – axial view suppression – axial view

Gadolinium enhancement with fat Gadolinium enhancement with fat suppression – coronal view suppression – coronal view

Role of Imaging Role of Imaging

FIA has significant recurrence FIA has significant recurrence rate up to 25%rate up to 25% Due to part of the track system not Due to part of the track system not

being recognised at surgerybeing recognised at surgery Inadequate drainage of sepsisInadequate drainage of sepsis False communication found by False communication found by

injudicious probinginjudicious probing

Radiology can demonstrate Radiology can demonstrate clinically undetected sepsis, can clinically undetected sepsis, can guide initial surgery and reveal guide initial surgery and reveal the site of residual sepsisthe site of residual sepsis

In one prospective study of MRI In one prospective study of MRI in primary fistula (in primary fistula (BJS 2002BJS 2002)) 30 patients30 patients MRI led to further exploration in 2 MRI led to further exploration in 2

casescases 1 patient require further surgery at 1 patient require further surgery at

a median FU of 12 monthsa median FU of 12 months

Other prospective study (Other prospective study (Lancet Lancet 2002; 360: 1661-2)2002; 360: 1661-2) 71 patients71 patients Agreement between MRI and surgery Agreement between MRI and surgery

in 25 cases -> 12% recurrencein 25 cases -> 12% recurrence MRI led to further surgery in 15 cases MRI led to further surgery in 15 cases

-> 13.3% recurrence-> 13.3% recurrence Disagreement in 31 cases but no Disagreement in 31 cases but no

further surgery undertaken -> 51.6% further surgery undertaken -> 51.6% recurrence recurrence

Recurrence rate for individual Recurrence rate for individual surgeons who always, surgeons who always, sometimes or never acted on sometimes or never acted on the discrepant MRI finding were the discrepant MRI finding were 16%, 30%, 57% respectively16%, 30%, 57% respectively

Treatment outcomeTreatment outcome

Low FIALow FIA

Low FIALow FIA

Fibrin glue Fibrin glue injectioninjection

The EndThe End