Perianal fistula

Colorectal

Clinicals - History

Fact Explanation
History of an perianal abscess A fistula is an abnormal connection between two epithelial surfaces. An anal fistula is a tract which usually communicates an infected anal gland to a secondary opening in perianal skin, which is lined with granulation tissue. Cryptoglandular disease
(anorectal abscesses ) is responsible for 90% of fistula-in-ano. Anorectal abscesses represent the acute presentation of cryptoglandular disease, while fistulae are the chronic evolution of the same process.
There is usually a History of an anorectal abscess that was either drained spontaneously or surgically. He/ she may remember of a discharge, pain, swelling in the perianal area.
History of an perianal abscess
A fistula is an abnormal connection between two epithelial surfaces. An anal fistula is a tract which usually communicates an infected anal gland to a secondary opening in perianal skin, which is lined with granulation tissue. Cryptoglandular disease
(anorectal abscesses ) is responsible for 90% of fistula-in-ano. Anorectal abscesses represent the acute presentation of cryptoglandular disease, while fistulae are the chronic evolution of the same process.
There is usually a History of an anorectal abscess that was either drained spontaneously or surgically. He/ she may remember of a discharge, pain, swelling in the perianal area.
Discharge The abscess usually discharge pus. This is usually foul smelling yellowish with streaks of blood. The discharge may occur continuously or intermittently. Discharge
The abscess usually discharge pus. This is usually foul smelling yellowish with streaks of blood. The discharge may occur continuously or intermittently.
Perianal pain If the discharge is intermittent, the patient may have increased pain and pressure prior to recurrent drainage, which gives relief. Perianal pain
If the discharge is intermittent, the patient may have increased pain and pressure prior to recurrent drainage, which gives relief.
Nonspecific symptoms Other symptoms include bleeding, soreness, pruritis or Skin excoriation (perianal dermatitis). Nonspecific symptoms
Other symptoms include bleeding, soreness, pruritis or Skin excoriation (perianal dermatitis).
Past history of similar events Sometimes perianal fistulas recurs. Patient may give a history of similar event in the past. Most of the patients with perianal fistula have a underlying disease conditions such as Crohn’s disease. Past history of similar events
Sometimes perianal fistulas recurs. Patient may give a history of similar event in the past. Most of the patients with perianal fistula have a underlying disease conditions such as Crohn’s disease.
Risk factors While the Cryptoglandular disease accounts for the most of the perianal fistulae, other less common causes of fistulae are Crohn’s disease, trauma, anal fissures, carcinoma, radiation therapy, tuberculosis, and chlamydial infections. Males in their 30s -40s are more predisposed than females. Risk factors
While the Cryptoglandular disease accounts for the most of the perianal fistulae, other less common causes of fistulae are Crohn’s disease, trauma, anal fissures, carcinoma, radiation therapy, tuberculosis, and chlamydial infections. Males in their 30s -40s are more predisposed than females.

Clinicals - Examination

Fact Explanation
External opening of the fistula The external opening can be seen as an elevation of granulation tissue in the perianal area, usually within 3cm distance from the anal verge. Spontaneous discharge of the pus can be observed. Or else this may be elicited on the digital rectal examination, as the pus discharges outside through that opening. Rarely several openings may be seen. External opening of the fistula
The external opening can be seen as an elevation of granulation tissue in the perianal area, usually within 3cm distance from the anal verge. Spontaneous discharge of the pus can be observed. Or else this may be elicited on the digital rectal examination, as the pus discharges outside through that opening. Rarely several openings may be seen.
Fistula tract Patient is usually in pain. So he/ she may not allow to perform further examinations. If it is allowed, digital rectal examination will permit to palpate a fibrous tract or cord that runs beneath the skin. It is the sinus tract that extends from the external opening to the abscess. According to the Goodsall rule, if the external opening lies anterior to a plane which is transversely passing through the center of the anus, a straight radial course will be followed by the fistula to the dentate line. If the external opening locates posterior to this line, the fistula tract will follow a curved course to the posterior midline. Thus Goodsall's rule gives a general idea of the course of the fistula tract, that can be confirmed by the examination. Rarely, specially when the external opening is located more than 3cm from the anal verge, this rule becomes unreliable. Inability to palpate the fistula tract implies a deeper course
and therefore higher transsphincteric fistula.
Fistula tract
Patient is usually in pain. So he/ she may not allow to perform further examinations. If it is allowed, digital rectal examination will permit to palpate a fibrous tract or cord that runs beneath the skin. It is the sinus tract that extends from the external opening to the abscess. According to the Goodsall rule, if the external opening lies anterior to a plane which is transversely passing through the center of the anus, a straight radial course will be followed by the fistula to the dentate line. If the external opening locates posterior to this line, the fistula tract will follow a curved course to the posterior midline. Thus Goodsall's rule gives a general idea of the course of the fistula tract, that can be confirmed by the examination. Rarely, specially when the external opening is located more than 3cm from the anal verge, this rule becomes unreliable. Inability to palpate the fistula tract implies a deeper course
and therefore higher transsphincteric fistula.
Internal opening Internal openings may be felt during the digital rectal examination as indurated nodules or pits that correspond to enlarged papilla, leading to a thickened tract. Internal opening
Internal openings may be felt during the digital rectal examination as indurated nodules or pits that correspond to enlarged papilla, leading to a thickened tract.
Old surgical scars Scar from earlier procedures may be appreciated as well as chronic skin changes such as thickened and redness from persistent drainage. Old surgical scars
Scar from earlier procedures may be appreciated as well as chronic skin changes such as thickened and redness from persistent drainage.
Anoscopic examination This examination allows visualization of the dentate line for possible identification of internal
openings before surgery, as well as identification of other pathology such as Crohn’s disease or
carcinoma.
Anoscopic examination
This examination allows visualization of the dentate line for possible identification of internal
openings before surgery, as well as identification of other pathology such as Crohn’s disease or
carcinoma.

Investigations - Diagnosis

Fact Explanation
Fistulography Fistulography involves cannulation of the external opening with injection of water soluble contrast
It may be useful for evaluation of recurrent or complex fistulae. Its use has been generally discouraged because of risk of septicemia and poor visualization of anatomic landmarks. This study has been substituted by other imaging techniques.
Fistulography
Fistulography involves cannulation of the external opening with injection of water soluble contrast
It may be useful for evaluation of recurrent or complex fistulae. Its use has been generally discouraged because of risk of septicemia and poor visualization of anatomic landmarks. This study has been substituted by other imaging techniques.
Endoanal Ultrasound Ultrasonography helps in identification of the fistula tract in relation to the internal and external sphincters, to determine if the fistula is simple or complex and to define the location of the internal opening. The injection of hydrogen peroxide into the fistula opening during ultrasound improves
identification of fistulae and their internal openings by making them hyper instead of hypoechoic.
Endoanal Ultrasound
Ultrasonography helps in identification of the fistula tract in relation to the internal and external sphincters, to determine if the fistula is simple or complex and to define the location of the internal opening. The injection of hydrogen peroxide into the fistula opening during ultrasound improves
identification of fistulae and their internal openings by making them hyper instead of hypoechoic.
MRI scan This is becoming the study of choice in evaluating complex and recurrent fistulae. Accurate classification with MRI is possible than with 2-D ultrasound. But it is best reserved for the cases where ultrasound has already failed in identifying the fistula and internal opening. MRI scan
This is becoming the study of choice in evaluating complex and recurrent fistulae. Accurate classification with MRI is possible than with 2-D ultrasound. But it is best reserved for the cases where ultrasound has already failed in identifying the fistula and internal opening.
Anal Manometry Pressure evaluation of the sphincter mechanism is helpful in patients with a decreased tone This can be observed during the preoperative evaluation, in patients with a history of previous fistulotomy and patients with a history of obstetrical trauma. Anal Manometry
Pressure evaluation of the sphincter mechanism is helpful in patients with a decreased tone This can be observed during the preoperative evaluation, in patients with a history of previous fistulotomy and patients with a history of obstetrical trauma.

Management - Specific

Fact Explanation
Watchful waiting For an uncomplicated or asymptomaticcase, drainage seton can be left in place long-term to prevent problems. This is the safest option although it does not definitively cure the fistula. Draining setons will keep the fistulous tract open, allowing for abscess drainage and tract maturation, therefore facilitating a future fistulotomy or other advanced fistula closure technique. Watchful waiting
For an uncomplicated or asymptomaticcase, drainage seton can be left in place long-term to prevent problems. This is the safest option although it does not definitively cure the fistula. Draining setons will keep the fistulous tract open, allowing for abscess drainage and tract maturation, therefore facilitating a future fistulotomy or other advanced fistula closure technique.
Fistulotomy A probe is passed gently through the tract. Then an incision is made over the probe by a scalpel or electrocautery opening the tract. The edges of the tract are excised completely. Once open, the fistulous tract should be cleaned with a curette to remove any granulation tissue. At the completion of the procedure, light packing tape may be placed in the fistula tract. This option leaves behind a scar, and depending on the position of the fistula in relation to the sphincter muscle, can cause problems with incontinence. Fistulotomy is not suitable for fistulas that cross the entire anal sphincter. Fistulotomy
A probe is passed gently through the tract. Then an incision is made over the probe by a scalpel or electrocautery opening the tract. The edges of the tract are excised completely. Once open, the fistulous tract should be cleaned with a curette to remove any granulation tissue. At the completion of the procedure, light packing tape may be placed in the fistula tract. This option leaves behind a scar, and depending on the position of the fistula in relation to the sphincter muscle, can cause problems with incontinence. Fistulotomy is not suitable for fistulas that cross the entire anal sphincter.
Seton Placement A cutting seton gradually cuts through the sphincter muscle via pressure necrosis, with fibrosis behind the seton, preventing sphincter retraction and incontinence. Care must be taken to not advance the seton too quickly, as the patient will experience a tremendous amount of pain as well as suffer a complication of sphincter division. Seton Placement
A cutting seton gradually cuts through the sphincter muscle via pressure necrosis, with fibrosis behind the seton, preventing sphincter retraction and incontinence. Care must be taken to not advance the seton too quickly, as the patient will experience a tremendous amount of pain as well as suffer a complication of sphincter division.
Fibrin Glue Fibrin glue may be used as an alternative means of occluding the fistulous tract. When applied to the fistula tract, the fibrin clot seals the tract and stimulates migration, proliferation, and activation of fibroblasts. Fibrin Glue
Fibrin glue may be used as an alternative means of occluding the fistulous tract. When applied to the fistula tract, the fibrin clot seals the tract and stimulates migration, proliferation, and activation of fibroblasts.
Anal Fistula Plug This fistula plug made from lyophilized porcine intestinal collagen is designed to occlude the fistula tract from the internal to the external opening.
The plug provides a scaffold for the ingrowth of native tissue.
Anal Fistula Plug
This fistula plug made from lyophilized porcine intestinal collagen is designed to occlude the fistula tract from the internal to the external opening.
The plug provides a scaffold for the ingrowth of native tissue.
Endorectal flaps This treatment modality consists of removal and patching of the internal opening with a muscular–mucosal flap of rectal wall. In patients with chronic high fistula a mucosal advancement flap is used. Endorectal flaps
This treatment modality consists of removal and patching of the internal opening with a muscular–mucosal flap of rectal wall. In patients with chronic high fistula a mucosal advancement flap is used.
Ligation of the intersphincteric fistula tract (LIFT) LIFT technique is the novel modified approach through the intersphincteric plane. LIFT procedure is based on secure closure of the internal opening and removal of infected cryptoglandular tissue through the intersphincteric approach. Ligation of the intersphincteric fistula tract (LIFT)
LIFT technique is the novel modified approach through the intersphincteric plane. LIFT procedure is based on secure closure of the internal opening and removal of infected cryptoglandular tissue through the intersphincteric approach.

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