Sinuses / fistulas : Causes and Treatment

October 16, 2012 | By | Reply More

Sinuses / fistulas : Causes and Treatment

A sinus is a blind epithelial track, lined by granulation tissue that extends from a free surface into the tissues, e.g. pilonidal sinus

A fistula is an abnormal communication between two epithelial surfaces. It is lined by granulation tissue and colonized by bacteria. E.g. fistula-in-ano, pancreaticocutaneous, colovesical, vesicovaginal

  • Specific disease, e.g. Crohn’s.
  • Abscess formation and spontaneous drainage, e.g. diverticular abscess discharging into vagina with fistula formation.
  • Penetrating wounds.
  • latrogenic (e.g. anastomotic leak discharging via wound).
  • Neoplastic.
Persistence of a fistula is due to the following
  • Presence of foreign material, e.g. suture/bone in a sinus.
  • Distal obstruction of the viscus of origin.
  • Continuing active sepsis, e.g. TB, actinomycosis.
  • Epithelialization of the track.
  • Chronic inflammation, e.g. Crohn’s.
  • Malignancy in the track.


Establish the extent by sinography/fistulogram. MRI scan often helpful.
Principles of sinus treatment
  • Ensure adequate drainage—laying it open and removing granulations.
  • Remove septic material, foreign bodies.
  • Biopsy sinus wall if concern over underlying diagnosis.
  • Loose packs may be used to help drainage.
Principles of fistula treatment
  • Treat any sepsis, fluid imbalances, and poor nutrition if associated.
  • Ensure good drainage to prevent fistula extension.
  • Identify the anatomy—use EUA or imaging if required.
  • Biopsy the fistula if concern over underlying diagnosis.
  • Definitive treatment requires:
    • excision of the organ of origin or closure of the site of origin;
    • removal of the chronic fistula track and surrounding inflamed tissue;
    • closure of ‘recipient’ organ if internal or drainage of external site if to skin.

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Category: Pathology, Surgery

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