1. 27/06/13 Dept. of Surgery
Benign Anorectal: Abscess and
Fistula
Rakesh Kumar Gupta, MS
2. Benign Anorectal: Abscess and
Fistula
Anorectal abscess and fistula-in-ano represent different stages of
the same disease
the abscess represents the acute inflammatory event
the fistula represents the chronic process
3. Benign Anorectal: Abscess and
Fistula
Diagnosis and treatment requires in-depth understanding of
anorectal anatomy and spaces
4. Anorectal Suppuration
Epidemiology
Anorectal abscesses (“Acute phase”)
100,000 cases per year
Age range 20-60, 2:1 ratio M:F
30% recurrence rate*
Anorectal fistula (“Chronic phase”)
25-40% of abscesses lead to fistula**
10-20% recurrence rate
* Shrum RC. Dis Colon Rectum 1959; 2:469–472, **Shouler PJ et al . Int J Colorect Did 1986,1:113-5
5. 80% are submucosal, 8% extend to internal sphincter, 8% to the
conjoined longitudinal muscle, 2% intersphincteric, 1% penetrate
internal sphincter
At the dentate line, the ducts of the anal glands empty into anal crypts
90% of anorectal abscess result fromcrytogladularinfection
13. Abscess - Treatment
Exam under anesthesia for pain out of proportion to exam
Incision and drainage - trim edges to prevent coaptation
I&D of supralevator abscess:
depends on location - intersphincteric origin then divide
internal sphincter and drain into rectum; if arises from
ischianal abscess can be drained through perineal skin
15. Abscess - Treatment
Catheter drainage: stab incision to drain pus, mushroom catheter
in cavity to drain pus
make stab incision as close as possible to anus
size and length of catheter should correspond to abscess cavity
16. Short distance fromanus – feel forsoft spot
Place drain and trim– avoids packing
Follow up in 7-10 days to remove drain
18. Abscess - Treatment
Primary fistulotomy
may be easier to identify tract
eliminates source of infection
decreases recurrence/need for reoperation
Downsides: false passage formation with acute inflammation, 30-
50% of those with abscess likely won’t develop a fistula, need for
anesthesia vs. local for I & D
19. Incision and drainage of perianal abscess with or without
treatment of anal fistula. Cochrane Database Syst Rev. 2010 Jul 7;
(7):CD006827.
CONCLUSIONS: The published evidence shows fistula surgery with
abscess drainage
Significantly reduces recurrence or persistence of abscess/fistula, or
the need for repeat surgery.
No statistically significant evidence of incontinence following fistula
surgery with abscess drainage.
Intervention may be recommended in carefully selected patients.
20. Abscess - Antibiotics
Little or no role
Antibiotics? Culture?
Indications:
Immunosuppression
Valvular heart dz
Prosthetic devices
Sepsis or Extensive cellulitis
Crohn’s dz
Sitz Baths
21. Abscess - Complications
Recurrence
recurrence in as many as 89% of pts
Extra-anal causes
should be evaluated for recurrent disease (hidradenitis
suppurativa, Crohn’s)
Incontinence
iatrogenic (superficial external sphincter), inappropriate wound
care (excessive scarring from prolonged packing)
22. Abscess - Complications
Can result in necrotizing anorectal infection (rare)
Resuscitation, IV abx, wide debridement to healthy tissue
Need for colostomy debatable - recommended if sphincter muscle
is grossly infected, immunocompromised, rectal or colonic
involvement/perforation
Reexamination under anesthesia
HBO - 100% O2 at 3atm over 2 hrs - promote leukocyte phagocytic
function and fibroblast proliferation
24. Anal Infection and Hematologic
Diseases
Anorectal suppuration with acute leukemia with mortality 45-78%
Neutrophil count <500 with 11% incidence of anorectal abscess
Most important prognostic factor - # days of neutropenia
Presenting symptoms: fever, pain, urinary retention
Antibiotics vs I & D if fluctuance, sepsis, or progression of soft
tissue infection after antibiotics trial
25. Anal Infection & HIV
HIV+ pts have increased risk of perianal sepsis
Can be associated with in situ neoplasia
Surgery + antibiotics 2/2 immunosuppression
make incison site small bc pts at risk for poor wound healing
30. Intersphincteric Fistula-in-ano
Most common type of fistula - 70%
Results from perianal abscess
Variations:
simple low tract
high tract with rectal opening or blind tract
extrarectal extension
pelvic disease tracking
32. Transsphincteric Fistula
Approx 23% fistulas
Results from ischioanal absecesses
Rectovaginal fistula is a form of transsphincteric fistula
Operative mgt with setons if sphincter preservation in question
34. Suprasphincteric Fistula
5% of fistulas
Result from supralevator abscesses
Tract arises from intersphincteric abscess, travels above
puborectalis, then downward lateral to external sphincters in
ischioanal space
36. Extrasphincteric Fistula
2% of fistulas - rarest form
From rectum above the levators, through them, to the perianal skin
Trauma, foreign body, Crohn’s carcinoma
Most common cause is iatrogenic from probing during fistulotomy
surgery
37. Evaluationof AnalFistula
An accurate preoperative assessment of the anatomy of an anal fistula
is very important.
Five essential points of a clinical examination of an anal fistula :
(1) location of the internal opening.
(2) location of the external opening.
(3) location of the primary track .
(4) location of any secondary track.
(5) determination of the presence or absence of underlying disease .
38. Fistula-in-ano: Physical
Examination
Goodsall’s rule:
transverse line across the perineum -
posterior external openings have internal openings in the
posterior midline
anterior external openings have tract radially toward the nearest
crypt
greater distance from anal margin with more variability
more accurate rule for posterior fistulas
39.
40. Fistula Description
Clock description
Does the anus tell time?
Relies on description of patient’s position: supine,
lateral, prone and relative landmarks
Anatomic description: more consistent
Pubic bone defines anterior
Coccyx define posterior
Right and left
*If terms be incorrect, then statements do not accord with facts; and when
statements and facts do not accord, then business is not properly executed.”
43. High Fistulas Have High Internal Openings (opening of the duct at
the crypt, is always at the level of the pectinate line)
Internal Opening is Not Always Present
Fistulas with Multiple Openings are Tuberculus in Origin
Every Fistula Requires an MRI/Endoanal USG
Which is the Best Surgery for Fistula in Ano?
Controversies in Fistula in Ano
45. Investigations
Additional tools available in case of difficulty.
Do not replace a good clinical examination to diagnose the type &
extent of fistula.
Not necessary to investigate every case of fistula even the complex
ones can be diagnosed fairly accurately by a good clinical
examination.
MRI & Endoanal ultrasound both give comparable
Delineating the tracts by intra-operative dye study may be more
helpful than the above investigations.
Fistulograms have a very limited role in the diagnosis of fistula in
ano
48. TREATMENT
The objective is to cure with lowest possible recurrence
rate and minimal, if any, alteration in continence, shortest
period.
The principles are:
Control sepsis
EUA
Laying open abscesses and secondary tracts
Adequate drainage – seton insertion
.
49. Define anatomy
Openings and tracts
Internal and External (Identification of the primary opening)
Single –v- multiple
Extensions / Horseshoe (Side tracts should be sought )
Relation to sphincter complex
High –v- Low (Relationship to puborectalis)
Exclude co-existent disease
51. Fistula-in-ano: Treatment
Identification of internal opening
passage of probe
injection of dye, methylene blue, or hydrogen peroxide
following granulation in fistula tract
noting puckering of crypt with traction on fistula tract
52. Fistulotomy/fistulectomy
Lay-open technique (fistulotomy) : identification of tract with
unroofing tract, useful for 85-95% of primary fistulae .
Appropriate for simple interspincteric and low transsphincteric
Curettage is performed to remove granulation tissue.
Marsupialization of the edges to improve healing times.
53. Surgical Options – Fistulotomy
Fistula tract identified with probe
Extent of external sphincter
involvement assessed
Tract and muscle divided
Secondary tracts laid open
+/- marsupialisation wound
56. Surgical Options – Fistulectomy
• Core out tract
• Direct visualisation of secondary
tracts
• Sphincter repair +/- advancement flap
57. Fistula-in-ano: Operative
Management
Seton - placement of non-absorbable suture material in fistula tract
Indications for setons:
Promote fibrosis around fistula tract that encircles entire sphincter
mechanism
Mark the site of fistula in massive anorectal sepsis
Anterior high transsphincteric fistulas in women
HIV pts with poor wound healing and high transsphincteric fistulas
Crohn’s
Any time continence is questioned
58. Surgical Options – Cutting Seton
Lay open external tract
Draining seton replaced with cutting
seton
1/0 Prolene suture
Tied tight around sphincter complex
Simultaneous slow cutting and repair
of sphincter
May require re-tightening
60. Fistula-in-ano: Operative
Management
High-transphincteric fistulas can be treated with combination lay-
open technique and seton placement - division of internal sphincter
to level of external opening and then seton placement
Cutting setons can convert high fistulas to low fistulas
Second-stage fistulotomy ~ 8 wks later
61. Fistula-in-ano: Operative
Management
Suprasphincteric fistula - tract involves external sphincter and
puborectalis -
can manage with division of internal sphincter and superficial
external sphincter with seton around remaining ES
or internal sphincterotomy, seton, opening of fistula tracts
without division of external sphincter
62. Fistula-in-ano: Operative
Management
Anorectal Advancement Flap
internal opening closed with absorbable suture, full-thickness flap
of rectal mucosa/submucosa/IAS raised - adv 1 cm beyond
internal opening
base of the flap should be twice the width of the apex
pros: reduction in healing time, reduced pain, little potential
damage to sphincters, lack of deformity to anal canal
poor outcomes in Crohn’s, pts on steroids, smokers, o/w success
reported in up to 90% of pts
65. Fistula-in-ano: Operative
Management
Fibrin Glue - used in conjuntion with AAF or alone
technique: internal and external openings identified, tract curetted,
fistula tract injected through connector from external opening until
glue visible in internal opening, slowly withdrawn
can be repeated several times without compromising continence
66. Fistula-in-ano: Operative
Management
Fibrin Glue - Followup:
short-term follow-up with good success 70-80%
longer follow-up with success falling to 60% and even 14% in pts with
complex anal fistulas
69. Fistula-in-ano: Operative
Management
Bioprosthetic fistula plug made from surgisis
Technique - identification of internal and external opening with
placement of plug over probe using suture similar to seton placement
Plug secured at primary opening using absorbable suture
70. Fistula-in-ano: Operative
Management
Technique works best with long tracts without active inflammation or
sepsis
Short-term follow up (3months) with higher success rate for Crohn’s
fistulas when compared to fibrin glue
Long-term follow up - high failure rate
75. Crohn’s and Anal Fistulas
The most common perianal manifestation and occur in 6-34% Crohn’s
pts - pts with colonic Crohn’s with higher incidence, rectal Crohn’s
with 100% fistula formation
Conservative approach to treatment as 38% heal without surgery
76. Crohn’s and Anal Fistulas
Medications for treatment: cipro/flagyl, immunomodulators
(steroids, 6MP, azathioprine, infliximab)
6-MP and azathioprine only effective in 1/3 pts with fistulizing
Crohn’s
Infliximab associated with 62% reduction
Combination 6MP and infliximab may prolong effect of treatment
Selective seton placement with infliximab + maintenance med with
healing in 67%
77. Crohn’s and Anal Fistulas
Operative intervention: seton placement, rectal advancement flap if
rectal-sparing, poss fibrin glue/plug
Avoid cutting sphincter - incontinence reported in pts with Crohn’s
proctitis even without anal surgery
78. ACPGBI FIAT Trial
Fistula Plug
Insertion
Surgeon’s
Preference
EUA: transsphincteric
fistula ≥ 1/3 of sphincter
complex
Insertion of draining seton
RANDOMISE
MRI fistulography
Advancement
Flap
Cutting Seton Fistulotomy LIFT
79. ACPGB&I FIAT
Primary end-points
Faecal incontinence QoL
Generic QoL
Secondary end-points
Healing – 12 months
Complications
Faecal incontinence
Re-interventions
Health resource utilisation
Cost effectiveness
Patient identification
EUA & draining seton
Eligibility &
Consent
Randomisation
1:1 plug –v- surgeon’s
preference
6-week FU
6-monthFU
12-month FU
+ MRI scan
Surgisis® fistula
plug
Surgeon’s preference
(fistulotomy, seton, advancement
flap, LIFT)
MRI scan
Surgery
(6-weeks post seton insertion)
Diseases of Colon and Rectum Journal (Feb 2009) - increased risk of fistula formation with age < 40 , decreased risk in DM pts , not affected by gender, smoking history, perioperative antibiotics or HIV status
Perianal - most common (45%), suppuration travels inferiorly in intersphincteric space from anal gland Ischioanal - penetrate through external sphincter Horseshoe abscess - B/L extension of ischioanal abscess into deep postanal space Supralevator- MUST rule out intraabdominal pathology
Cryptoglandular etiology - infected anal crypt gland (obstructed by debris - feces or traumatized tissue) stasis and overgrowth of enteric bacteria; suppurative fluid follows path of least resistance and travels to where gland terminates LGV - proctocolitis + inguinal bubos (enlarged, tender lymph nodes with hemorrhagic necrosis) Crohn’s, diverticulitis, appendicitis - more commonly cause supralevator abscesses
Pain worse with movement/pressure (sneezing, coughing, bearing down), better with drainage Exam - depends on LOCATION, supralevator abscesses - mass adjacent to rectal ampulla, may present with urinary retention DRE - critical with intersphincteric and supralevator (may have NO findings on external exam)
Pain worse with movement/pressure (sneezing, coughing, bearing down), better with drainage Exam - depends on LOCATION, supralevator abscesses - mass adjacent to rectal ampulla, may present with urinary retention DRE - critical with intersphincteric and supralevator (may have NO findings on external exam)
Low intersphincteric abscesses should be treated by de-roofing of the abscess and division of the internal sphincter up to a level of the dentate line. High intersphincteric abscesses are relatively frequent and mostly require staged surgery with a temporary mushroom (de Pezzer) catheter. Accurate anatomical ultrasound localization and proper drainage become important to avoid recurrences or extrasphincteric fistulas.
BACKGROUND: The perianal abscess is a common surgical problem. A third of perianal abscesses may manifest a fistula-in-ano which increases the risk of abscess recurrence requiring repeat surgical drainage. Treating the fistula at the same time as incision and drainage of the abscess may reduce the likelihood of recurrent abscess and the need for repeat surgery. However, this could affect sphincter function in some patients who may not have later developed a fistula-in-ano. OBJECTIVES: We aimed to review the available randomised controlled trial evidence comparing incision and drainage of perianal abscess with or without fistula treatment. SEARCH STRATEGY: Randomised trials were identified from MEDLINE, EMBASE, the Cochrane Library, and reference lists of published papers and reviews. SELECTION CRITERIA: Trials comparing outcome after fistula surgery with drainage of perianal abscess compared with drainage alone were included in the review. DATA COLLECTION AND ANALYSIS: The primary outcomes were recurrent or persistent abscess/fistula which may require repeat surgery and short-term and long-term incontinence. Secondary outcomes were duration of hospitalisation, duration of wound healing, postoperative pain, quality of life scores. For dichotomous variables, relative risks and their confidence intervals were calculated. MAIN RESULTS: We identified six trials, involving 479 subjects, comparing incision and drainage of perianal abscess alone versus incision and drainage with fistula treatment. Metaanalysis showed a significant reduction in recurrence, persistent abscess/fistula or repeat surgery in favour of fistula surgery at the time of abscess incision and drainage (RR=0.13, 95% Confidence Interval of RR = 0.07-0.24). Transient manometric reduction in anal sphincter pressures, without clinical incontinence, may occur after treatment of low fistulae with abscess drainage. Incontinence at one year following drainage with fistula surgery was not statistically significant (pooled RR 3.06, 95% Confidence Interval 0.7-13.45) with heterogeneity demonstrable between the trials (Chi(2) =5.39,df=3, p=0.14, I(2) =44.4%). AUTHORS' CONCLUSIONS: The published evidence shows fistula surgery with abscess drainage significantly reduces recurrence or persistence of abscess/fistula, or the need for repeat surgery. There was no statistically significant evidence of incontinence following fistula surgery with abscess drainage. This intervention may be recommended in carefully selected patients.
Recommendations of American Society of Colon and Rectal Surgeons I&D - with cruciate or elliptical incision; if cruciate excise redundant skin Abscesses requiring OR - recurrent abscesses, complex abscesses (horseshoe), supralevator and intersphincteric Antibiotics - only indicated in pts with immunosuppression (e.g. DM, leukemia/CA, HIV, malnourished), prosthetic device (valvular, intravascular, joint), valvular heart dz, ?Crohn’s dz (Cipro/Flagyl), ?history of MRSA Prophylactic fistulotomy - NOT recommended b/c high frequency of anorectal dysfxn (e.g. incontinence); only reserved for pts with horseshoe abscesses or refractory symptoms DCR study (1991) - Significantly decreased in recurrence rate and persistence rate (40% vs 3%) but more likely to have anal dysfxn (40% vs 21%) Sitz baths (or hand-held shower) - TID x15min and after BMs
IMPORTANT to identify anatomy and determine if there is sphincter involvement b/c increased risk of incomplete healing, fistula recurrence and sphincter injury if fistula anatomy is incorrectly delineated or an occult abscess missed EUS - sometimes methylene blue is also used Others usually only done with recurrent or complicated fistula (e.g. h/o rectal surgery, crohn’s disase) MRI - need anorectal coil TRUS pitfall - focal length of the 7-MHz U/S probe is not sufficiently deep to image beyond the external sphincter or puborectalis Fistulogram - can’t visualize sphincter muscles CT - poor resolution for fistula tracts Study - Buchanan et al, cohort of 108 patients with recurrent fistulae using digital examination, endoanal ultrasound, and MRI on each patient; Digital examination correctly identified 61% of tracks compared with 81% of tracks by endoanal ultrasound and 90% by MRI.
