·         abscess – a cavity filled with pus, it is bordered by fibrin and has no lining of its own

-          the source of fistulas and abscesses in the periproctal and anal area are infections of the anal glands (the orifices of the Morgagni crypts, which easily store infectious agents), from which the inflammation spreads to the surrounding connective tissue, thus abscesses can form:

-          submucous

-          intersphincteric (high, low)

-          transsphincteric

-          ischiorectal

-          pelvirectal

-          subcutaneous (marginal, perianal) – most common

·         fistulas either originate from the rectum or anal landscape (caused by perforation or incision of periproctal tubers, or in Crohn's disease) or from other organs (urethra, prostate, female genitalia), they can be:

-          complete (external adn internal orifice – usually in Morgagni crypts)

-          incomplete (external or internal fistulas)

Based on the course of fistula, according to Park, fistulas are divided into:

-          intrasphincteric (submucous, subcutaneous)

-          intersphincteric (70 % of all) – from the internal sphincter and thence to the perineum. Fistulotomy is sufficient as a therapy, because the overflow of the internal sphincter does not affect continence. It is left to heal per secundam.

-          transsphincteric – through both sphincters to the ischiorectal fossa and then to the perineum. Fistulotomy can be performed in low type of the fistula if the patient has good sphincter function preoperatively. For high type and anterior, and especially in women who are more prone to incontinence, the Seton ligature is preferred.

-          extrasfincteric (only 1%) – beginning above the sphincters, passing over the levator and away from the anus, it opens onto the perineum. They don't have to have an internal orifice. If they have, the treatment is to resect the affected section of bowel laparotomically.

-          Goodsall's rule applies to the course of fistulas - if the external orifice is before the line horizontally dividing the anal opening into anterior and posterior parts, the course of the fistula is straight, if the external orifice of the fistula is after this line, its course is arcuate

-          complete fistulas can have several external orifices, the internal one is usually one

-          abscess is an acute manifestation of inflammation, fistula is a chronic manifestation, with retention of pus in the fistula an exacerbation of the abscess occurs

-          in so called atypical fistulas there is no internal orifice in the area of the crypts - it occurs during injuries, m. Crohn's, venereal diseases - some fistulas are extrasphincteric, pelvirectal (from pelvic inflammatory processes) and rectovaginal (rectovaginal, -vesical, -urethral, -prostatic)

clinical manifestations and diagnosis of perirectal and anal abscesses

-          local pressure and pain in the periproctal area, pain intensifies after defecation, in superficial abscesses the skin over them is red and swollen, painful fluctuation on touch, muscle contraction due to pain, inability to sit

-          overall, there may be a septic condition with high temperatures, shivering, especially in deep abscesses

-          imaging modalities of importance are ultrasound (external or endorectal) and CT or diagnostic puncture of the abscess under general anaesthesia

clinical manifestations and diagnosis of perirectal and anal fistulas

-          internal fistulas empty into the rectum, clinically they may never manifest at all

-          external fistulas secrete pus or stool (eczema, pruritus), retention of pus leads to abscess formation (pain, temperature), fistula running under the skin can be palpated as a rigid strip, probing is possible at different depths

-          the internal orifice can be identified by methylene blue injection, the course of the fistula can be visualized by contrast fluid injection under X-ray (fistulography)

treatment of fistulas

1.)   fistulotomy – discise on the probe after finding the internal orifice, watch out for m. puborectalis, excochleation of the base,

hemostasis, healing per secundam. Contraindication is m. Crohn. An alternative is Seton.

2.)   fistulectomy – excision of the entire fistula wall, healing per secundam

3.)   Hippocratic elastic ligature (SETON) - in transsphincteric fistulas when there is a risk of continence disorders

4.)  partial fistulectomy and endoanal flap - Seton's alternative for high transsphincteric fistulas. Ectomy is performed from the external orifice to the sphincter, only excochleation is performed deeper. The inner orifice is sutured and covered with a mucosal flap

5.)  fibrin glue (commercial or individually manufactured by the blood bank)

6.)  fistulaplug - bioprosthesis from lyophilized porcine intestinal mucosa