FISTULAS
Educational Objectives
| The goal of this program is to improve the management and repair of fistulas and abscesses. After hearing and
assimilating this program, the clinician will be better able to:
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 | 1. Choose the best imaging study for identifying cryptoglandular fistulas.
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| 2. List the treatment options for cryptoglandular fistulas and determine when each is appropriate.
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| 3. Identify the factors associated with successful repair of advancement flaps.
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| 4. Discuss the findings of a recent consensus conference on the use of bioprosthetic plugs.
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| 5. Describe the options for repairing simple rectovaginal fistulas if the patient does not have a sphincter defect.
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Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the
planning committee to disclose relevant financial relationships within the past 12 months that might create any personal
conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes
quality in health care and not a proprietary business or commercial interest. For this program, the following has been
disclosed: Dr. Ellis has a research grant from Cook Surgical. Drs. Fry and Lowry and the planning committee reported
nothing to disclose.
Acknowledgements
Drs. Ellis, Fry, and Lowry were recorded at the 19th Annual International Colorectal Disease Symposium, held February
14-16, 2008, in Fort Lauderdale, FL, and sponsored by the Cleveland Clinic Florida. The Audio-Digest Foundation
thanks the speakers and the Cleveland Clinic Florida for their cooperation in the production of this program.
| CHANGING PARADIGMS IN THE MANAGEMENT OF ANAL ABSCESS AND FISTULA —Robert D. Fry,
MD, Emile and Roland de Hellebranth Professor of Surgery, and Chief, Division of Colon and Rectal Surgery, University
of Pennsylvania School of Medicine, Philadelphia
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| Location of glands: intersphincteric, transsphincteric, suprasphincteric, and extrasphincteric (usually results from
perforation of suprasphincteric fistula)
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| Imaging: ultrasonography (US)—preferred modality, but identifies internal opening in only one-third of cases, and
depth of view limited to 2 cm beyond probe; cannot distinguish between supralevator and high infralevator fistulas;
however, has established role in anal fistula evaluation; anal fistulography—performed by inserting water-soluble
contrast into external opening; seldom used today because sphincter may not be visible due to
inadequate tract filling; computed tomography (CT)—least useful imaging study; cannot distinguish between
scar tissue and septic tracts; magnetic resonance imaging (MRI)—gold standard for evaluating anatomy of complex
anal fistulas, although depth of field limited to 2-3 cm from coil; pelvic phased-array coil more accurate
for extensive sepsis or supralevator extensions; study of choice for patients with history of previous fistulotomies
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| Goodsall’s rule: fistula with external opening anterior to a transverse line bisecting anus will follow radial course
to dentate line (wrong in 50% of cases); posterior opening curves posteriorly to communicate with anal crypt
in posterior midline
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| Treatment: options include none (noncutting seton), conversion to cutting seton, laying open of fistula in ano, injection
of fibrin glue, endorectal advancement flap, or anal fistula plug; immediate fistulotomy—associated with
lower recurrence rate than simple incision and drainage; perform only when internal opening found and fistula
simple; recurrence rate ≈50% after incision and drainage, but reduced to 83% when primary fistulotomy performed
at time of abscess drainage (however, also trend toward higher risk for incontinence); reasons for recurrences
after fistulotomy include misdiagnosis (fistula actually complex), presence of horseshoe extensions, no
identification of lateral location of internal opening, and previous fistula surgery; surgeon’s expertise perhaps most
important determinant of success; risk for recurrence—lowest with intersphincteric and transsphincteric fistulas;
approximately one-third of suprasphincteric and extrasphincteric fistulas recur; correct operation cannot be performed
unless internal opening found; reasons for fistula persistence—errors of omission (failure to identify internal
opening); errors of commission (excessive probing of internal opening, converting suprasphincteric fistula into
transsphincteric fistula); unusual infections (actinomycoses); granulomatous disease (Crohn’s disease [CD] or tuberculosis);
cancer or radiation therapy; foreign bodies (eg, fishbone stuck in crypt); fistulectomy—rarely indicated;
associated with high rate of incontinence; marsupialization—some evidence that it decreases wound healing
time; in general, recurrences associated with inadequate opening of postanal space
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| Seton: loose seton—flexible foreign body (eg, suture material, wire, rubber band) that provides drainage and allows
mature tract to form; may be part of staged fistulotomy that leaves other options open; allows long-term drainage;
cutting seton—analogous to pulling piano wire through block of ice and allowing ice to freeze in one piece behind
wire; similarly, sphincter closes as seton drawn forward
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| Advancement flap procedures: transanal flaps associated with ≈70% success rate; complications include mucosal
ectropion, leading to seepage (disturbance of continence observed in ≈21% of cases, due to ectropion or deformity
of anal canal; overall failure rate ≈30%; types of flaps include island, V-Y advancement, and canal sphincter
advancement
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| Fibrin glue: recent reports put success rates at 22%-30%; persistent inflammation on MRI good predictor of recurrence
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| Fibrin plug: indications include transsphincteric fistulas (ideal indication), anovaginal fistulas (although shorter
tract decreases odds of success), intersphincteric fistulas if continence threatened; CD; extrasphincteric fistulas;
contraindications—uncomplicated intrasphinteric fistulas, pouch vaginal fistulas, rectovaginal fistulas,
persistent sepsis (likely cause of most recurrences; eliminate before treating fistula), and inability to identify
external and internal openings; overall success rate 50% to 60%
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| Fistulas associated with CD: risk higher with more distal disease (eg, 20%-30% with small bowel disease, 80%-
90% with rectal disease); lower disease also associated with lower chances of treatment success; indwelling setons
or mushroom catheters better at controlling sepsis and allowing disease to “burn out”; dissolution of rectal mucosa
contraindication for use of seton
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| ADVANCEMENT FLAP FOR ANAL FISTULAS: ENSURING SUCCESS —Ann C. Lowry, MD, Adjunct Professor
of Surgery, University of Minnesota Medical School, Minneapolis
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| Benefits of advancement flaps: close fistula with little or no alteration in continence because sphincter muscle
not disturbed
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| Techniques: standard endorectal advancement flap; endorectal advancement flap with core fistulectomy; anocutaneous
(island) anoplasty
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| Principles: adequate mobilization necessary to avoid tension; base should be 2 to 3 times wider than apex to ensure
adequate vascular supply; internal sphincter should be closed
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| Standard flap: flap consists of mucosa and submucosa; internal sphincter mobilized on both sides, then closed over
internal opening; opening trimmed, and flap brought down and sutured into place
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| Endorectal advancement flap with core fistulectomy: principles similar to those of standard flap, with excision
of epithelialized tract; tract cored out, starting at external opening; average success rate of advancement flap
alone ≈70%; similar with core fistulectomy
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| Anocutaneous flap: proponents prefer not to mobilize rectal wall; flap raised, with external base wide enough for
adequate blood supply; internal opening debrided and closed; opening removed from flap, and flap then sutured
into place; published success rates range from 80% to 97%
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| Predictors of success: use of setons, permitting infection or induration to resolve before procedure; previous seton
placement associated with higher rates of healing; number of previous repairs correlates inversely with success
(one previous repair does not appear to reduce chances of success); closure of internal sphincter
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| Negative predictive factors: CD; rectovaginal fistula; male sex; previous repairs; large fistulas; use of fibrin glue
along with flap; cigarette smoking
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| Ideal patient: nonsmoker with intact sphincter muscle, no history of inflammatory bowel disease (IBD), and ≤1
previous repair with advancement flap; however, optimal technique not yet identified; predictors of success
uncertain
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| FISTULA PLUGS: TECHNIQUE AND BEST PRACTICES —C. Neal Ellis, MD, Associate Professor of Surgery,
General Surgery Residency Program Director, and Director of Surgical Research, University of South Alabama College
of Medicine, Mobile
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| Bioprosthetic plug: available since 2005; obliterates anal fistulas, while preserving sphincter integrity without precluding
other options; short learning curve; plug failure not thought to be associated with morbidity
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| Findings of consensus conference on use of bioprosthetic plug: not indicated for routine intersphincteric fistulas;
expected success rate, 60% to 70%; plug placement technique critical; start with mature fistula tract with
no induration or acute inflammation (achieve by placing noncutting seton for >6 wk); do not enlarge tract (debridement
acceptable); povidone-iodine (Betadine) not recommended, as it may keep fibroblasts from infiltrating
plug; plug should be snug but not so tight that it compresses blood supply to surrounding tissue;
suture plug securely into fistula tract, using large portions of internal sphincter (rectal pressure ≤100 cm
H2 O); plugs that come out during first postsurgical week should be considered technical failures; do not suture
in distal aspect of plug; leave tract open for good drainage around plug; severely restrict patient activity
(nothing more strenuous than slow walking) for ≥2 wk; tract drainage continues for some time after plug
placement; procedure not failure without purulent drainage, recurrent abscess, or drainage persisting >12
wk
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| Speaker’s results with plug: 63 patients, including 60 with draining seton for ≥6 wk; 35 smoked cigarettes; of 75
plugs placed, 54 (72%) worked; fistulas healed with first plug in 51 of 63 patients; 3 more healed with repeat
plugs; of 21 plug failures, 1 due to technical errors, 1 to persistent fistula, and 4 to recurrent fistulas; of plug failures,
3 in patients with posterior midline fistulas, 4 in patients who smoked, and 2 in patients who had CD; median
time to late recurrence, 7 mo; on univariate analysis, plug failure associated with male sex, having posterior
fistula or recurrent fistula due to previous plug failure, or being cigarette smoker
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| Findings of other recently published studies or abstracts: aggregate success rate 60%, with average follow-up of
5 mo
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| Conclusions: bioprosthetic plugs successful in most patients; failure associated with fistula recurrence or previous
plug failure, as well as posterior fistula, male sex, and cigarette smoking; if first plug fails, do not put in second one
unless initial failure due to late fistula recurrence or technical error; more research needed to understand why first
plugs sometimes fail
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| RECTOVAGINAL FISTULAS: AN ALGORITHM FOR SUCCESS —Dr. Lowry
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| Simple fistulas: low, small, and typically caused by infection or trauma (often, obstetric injury); evaluation should
focus on continence; significant incidence of occult sphincter injury
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| Decision tree: first determine whether defect present
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| If patient has sphincter defect: repair using sphincteroplasty with 2-layer closure (90%-100% success rate), or
perineal proctotomy (consists of fistulotomy plus serial closure of rectal and vaginal muscles; continence rates
seldom reported)
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| If patient does not have sphincter defect: endorectal advancement flap most likely choice; success rates ≈50%;
avoid premature repairs
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| Conservative alternatives: fibrin glue (results disappointing); fistula plug (limited data with rectovaginal fistulas
show poor results)
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| If repair unsuccessful: reevaluate patient; confirm presence of fistula; assess surrounding tissue for unrecognized
IBD or sepsis; identify cause of failure whenever possible; evaluate sphincter
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| Causes of advancement flap failure: infection; fecal impaction; diarrhea; technical failure; undiagnosed IBD
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| Impact of previous repairs: success rates of first and second repairs roughly equivalent, but success “drops considerably”
after that (reasonable to repeat flap if first one fails, or to try vaginal repair); consider other options
if third repair fails (bring in other tissue); interposition of biologics—can be done via transperineal or intersphinteric
technique
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| Tissue interposition: bulbocavernosus procedure—start with transperineal dissection; mobilize portion of labial
fat, pass it through subcutaneous tunnel, and lay it over rectal- and under vaginal-side closure, then close
wounds over small suction drain; success rates up to 100% reported in small studies; gracilis procedure—more
appropriate for higher fistulas; rectus abdominis—another choice for higher fistulas; requires mobilization of
rectus muscle, which is passed down abdominally between rectum and vagina; small studies show success
rates good; transabdominal repair—another option for high fistulas, as is resection with coloanal anastomosis;
Bricker anastomosis—bowel divided at sigmoid, opened, and sewed down over opening of fistula; stoma created;
after healing, proximal bowel brought down and sewed to apex of loop
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| Conclusion: be aware of options; evaluate patient carefully; “if at first you don’t succeed, keep trying”
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Suggested Reading
Champagne BJ et al: Efficacy of anal fistula plug in closure of cryptoglandular fistulas: long-term follow-up. Dis
Colon Rectum 49:1817, 2006; Cirocco WC, Reilly JC: Challenging the predictive accuracy of Goodsall’s rule for
anal fistulas. Dis Colon Rectum 35:537, 1992; Corman ML et al: The surgisis® AFPTM anal fistula plug: report of
a consensus conference. Colorectal Disease 10:17, 2007; Ellis CN, Clark S: Effect of tobacco smoking on advancement
flap repair of complex anal fistulas. Dis Colon Rectum 50:459, 2007; Ellis CN, Clark S: Fibrin glue as an adjunct
to flap repair of anal fistulas: a randomized, controlled study. Dis Colon Rectum 49:1736, 2006; Ellis CN:
Bioprosthetic plugs for complex anal fistulas: an early experience. J Surg Educ 64:36, 2007; Schwandner O et al:
Initial experience on efficacy in closure of cryptoglandular and Crohn’s transphincteric fistulas by the use of the anal
fistula plug. Int J Colorectal Dis 23:319, 2008; Tyler KM et al Successful sphincter-sparing surgery for all anal fistulas.
Dis Colon Rectum 50:1535, 2007; van der Hagen SJ et al: Long-term outcome following mucosal advancement
flap for high perianal fistulas and fistulotomy for low perianal fistulas: recurrent perianal fistulas: failure of
treatment or recurrent patient disease? Int J Colorectal Dis 21:784, 2006; van der Hagen SJ et al: Staged mucosal
advancement flap for the treatment of complex anal fistulas: pretreatment with noncutting Setons and in case of recurrent
multiple abscesses a diverting stoma. Colorectal Dis 7:513, 2005; Williams JG et al: The treatment of anal fistula:
ACPGBI position statement. Colorectal Disease 9(Suppl 4):18, 2007.
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