Fistula-in-Ano
It is a track lined by granulation tissue which connects peri-anal skin superficially to anal canal; anorectum or rectum deeply. It usually occurs in a pre existing anorectal abscess which burst spontaneously.
Fistula-in-ano can be:
- Cryptoglandular—90%
- Non-cryptoglandular (other causes)—10%.
Classification:
- Low level fistulas—these open into the anal canal below the internal ring.
- High level fistulas—these open into the anal canal at or above the internal ring.
- Intersphincteric fistula.
- Transphincteric fistula.
- Supralevator fistula
- Extrasphincteric fistula.
- Simple fistula without extensions.
- Complex fistula with extensions.
- Single external opening.
Multiple external openings which are often seen in-:
Tuberculosis, Ulcerative colitis, Crohn’s disease lymphogranuloma venereum (LGV), Hidradenitis Suppurativa, Actinomycosis.
Principles of Management:
Identify the cause cryptoglandular or other:-
- Delineate exactly the fistula anatomy— MRI/EUS.
- Identify relation of fistula to anal sphincter.
- Drain all sites of infection.
- Eradicate track and secondary extensions.
- Preserve anal continence function.
The primary objectives are to eradicate the tract and drain all associated sites of infection while simultaneously preserving anal continence.
Surgeries:
- FILAC – Fistula laser closure of fistulous track.
- DLPL- Distal laser proximal ligation
- Laying open the fistula—
fistulotomy with curetting - Fistulectomy
- Fistulectomy with primary repair
- Fistulectomy with primary repair
- Fistulectomy with secondary repair
- LIFT technique (Ligation of intersphincteric fistula track)
- Seton technique (Latin-seta—a bristle)
- Colostomy—lay open,
fistulectomy, later closure of colostomy—for high type. - VAAFT procedure (Video assisted ablation of fistulous track.
