brief summary about fistula in ano

1. Fistula in ano
Mohammed alhinai

2. Fistula in ano : pathological track lined by epithelium which connect two
epithelium surface ( connect the lumen of anal canal or rectum with the external
perianal surface.
Causes
Primary :
- Anorectal abscess
( most common)
secondary :
- Crohn disease (could cause multiple opening )
- Anorectal carcinoma
- Iatrogenic causes
- Lymphogranuloma venereum
- Rectal foreign bodies
- Actinomycosis
- Tuberculosis (could cause multiple opening )
• Lymphogranuloma venereum ( chronic infection in the lymphatic system caused by Chlamydia
trachomatis, and can cause inflammatory perirectal masses)
• Radiation proctitis (pelvic radiation can develop bleeding, rectal pain, and fistulas)
• Rectal foreign bodies rare cause ( by anorectal mucosal laceration is the most common complication
from anal insertion of a foreign body and can result in an abscess and fistula formation )
• Actinomycosis (cause a simple fistula-in-ano or an inflamed perirectal mass in immunocompromised
individuals)
• Tuberculosis ( rarly occur in immunocomprised and and in population with high incidence of
tuberculosis ).

3. Externally into
perianal skin
Internally into anal
canal or rectum
Mucus and stool force through the
fistulous lead to stop healing of
fistula by granulation tissue.
pathogenesis

4. Clinical features:
• Age : occur during adult age – rarely in children.
• Symptoms :
- Most common symptoms is watery or purulent discharge from external fistula.
- intermittent rectal pain if pus collect in fistula aggravated by defecation, sitting and
activity.
- intermittent and malodorous perianal drainage and pruritus
- Can occasion be bloodstained.
• Physical examination :
- Position of fistula : external opening may be visualized, or palpated as induration
just below the skin if the external opening is incomplete or blind.
- Tenderness
- Discharge
- Rectal examination : internal opening may felt as area of induration or small nodule
below the mucosa. If felt, try to decide as below or above anorectal junction ( low
level or high level ).

5. Goodsall’s rule :
It help to identify the location of internal opening of fistula by draw
transverse line through the centre of anus :
1- if the external opening of fistula anterior to the line : the track will be in
straight line toward the internal opening.
2- if external opening posterior to line : the track will curve as horseshoe
manner to open into midline of posterior anal canal

6. Classification of anal fistula:
• Its important as affect the surgical management and to know the risk of
continence of anal sphincter.

8. • Then another classification divide the location of internal opening
according to ano-rectal ring ( where the puborectalis muscle sling fuse
with external sphincter) :
• 1- low fistula in ano : below the ano-rectal ring which at this level can be
laid open the fistula without significant of impairment of continence.
• 2- high fistula in ano : laying the open of fistula would divide the ano-
rectal ring and affect the patient continence.

9. Differential diagnosis:
• Anal abscess
• Anal fissure
• Anal ulcer or sores.
Diagnosis
Clinical diagnosis
(usually)
Imaging studies :
- MRI helpful for diagnostic
evaluation of recurrent
fistula and exclude other
causes
- MRI best imaging to know
the route of fistula.
- Fistulography and CT scan
may help in some cases
Endoscopic evaluation :
- Including proctoscopy or
sigmoidoscopy or
colonoscopy.
- helpful for diagnostic
evaluation of recurrent
fistula and exclude other
causes

10. Management:
• Overall goal of surgery :
- Eradicate the fistula
- Preserve anal sphincteric function.
- Prevent recurrence.
The surgical management of fistula depend on
Location of fistula in relation
to external anal sphincter
Amount of sphincter complex
involved with fistula tract.
According for that, fistula divide into :
Simple fistula :
- minimal involvement of
external sphincter muscle
- low fistula in ano according to
location
complex fistula :
- involving more than 30 percent of the external
sphincter.
- High fistula in ano
- Women with anterior fistulas
- Fistulas with multiple tracts
- Recurrent fistulas
- Fistula caused by secondary causes.

11. • Simple fistula :
1- fistulotomy :
- open the fistula tract in its entirety and promote healing of incision. ( for lower
fistula ).
- Patients should be observed for a minimum of six months following the procedure
before determining a treatment failure or success.
- complication of a fistulotomy is incontinence from procedure-related damage to
the external anal sphincter.
- Recurrence rates for an anorectal fistula are low.
2- fibrin sealant:
- mixture of fibrinogen, thrombin, and calcium ions form a clot that is injected into
the fistula tract and within 10 to 60 seconds the fistula is potentially sealed.
- The main benefit of fibrin glue is sphincter preservation.
- Recurrence is low but higher compare to fistulotomy.

12. • Complex fistula :
Multiple procedures use, commonly :
1- fistulotomy and setons (higher fistula) :
- A cutting seton is a reactive suture or elastic that is placed through the
fistula tract and tightened at regular intervals
- A noncutting or draining seton is a seton that is placed primarily for
drainage.
- two most important complications of a fistulotomy with a cutting seton are
recurrence and incontinence.

13. Anal fissure

14. Fissure in ano:
• anal fissure is a tear in the anoderm distal to the dentate line.
Causes of anal
fissure
Primary secondary
- Passage of hard stool
- Constipation
- Prolonged diarrhea
- Vaginal delivery
- Anal sex
- Previous anal surgical procedure.
- Inflammatory bowel disease
( crohn’s disease )
- Granulomatous disease
( extrapulmonary tuberculosis-
sarcoidosis )
- Malignancy
- Communicable disease ( HIV
infection – syphilis- chlamydia)

16. Pathogenesis:
prolong repeated cycle lead to chronic anal fissure.
Fissure
Pain
Spasm of
internal
sphincter
Constipation
with ( other
causes)
- Spasm pull the edge of fissure
lead to impair healing
- Prolong spasm lead to reduce
blood supply causing ischemic

17. Location of anal fissure :
Location of anal
fissure
Posterior ( most
common as fixed
with coccyx bone )
Anterior ( less
common)
Lateral
- Most common caused
by primary causes.
- Usually caused by trauma
or secondary causes.
- Indicate serious condition
and require to know
underlying cause.
- Colonoscopy and biopsy
required.

18. Anal fissure
Acute anal
fissure
Chronic
anal fissure
Clinical feature :
- Less intense pain
- Small amount of bright
rectal bleeding
- Perianal pruritus or skin
irritation
- Tearing pain increase by
passage of bowel
movement
- Small amount of bright
rectal bleeding
- Perianal pruritus or skin
irritation

19. Anal fissure
Acute anal
fissure
Chronic
anal fissure
Physical examination :
- Pale with raised edges
- External skin tag at distal
end of fissure (sentinel pile)
- Hypertrophied anal papillae
at proximal end.
- Fresh laceration like paper
cut.
Digital rectal examination and anoscopy contraindicated
as increase the pain.

20. Diagnosis :
- clinical diagnosis based on history and physical
examination.
- Lateral anal fissure need to evaluate further to
know the underlying causes.

21. Management :