Risk of fistula development following drainage of ano-rectal abscess : bacteriological study

الملخص EN

Background : Anorectal sepsis is a common surgical disorder.

The majority of anorectal suppurative disease results from infection of anal gland (Cryptoglandular), and usually due to a mixture of fecal and / or cutaneous flora.

Drainage alone result in cure of 50 % of patients, the other 50 % develop an anal fistula with persistent symptoms of local infection .If only skin pathogens are cultured from an anorectal abscess, there is a decreased incidence of fistula formation.

Objectives : to find out the correlation between different types of bacteria as a causative agent of anorectal abscess and the future risk of fistula-in-ano development.

Methods : During the period from July 2004 till October 129.2007 patients admitted to Al- Diwaniya teaching hospital for surgical management of anorectal abscess, three anatomical variant of anorectal abscess were encountered which assessed bacteriologicaly by aspirating pus from the abscess at the time of surgery, which was subjected to an aerobic and anaerobic cultures.

Each individual patient was followed up for 6 months after the initial episode for development of fistula in ano, or recurrent abscess.

Results : showed that the perianal abscess was the most common abscess encountered 62.8 %, followed by ischiorectal type 30.2 %, with the sub mucous variety was the least common 7 %.

Out of 129, 76 patients develop fistula 58.9 %, with higher proportion in the ischiorectal variant.

It was found that Bacteroides spp.

and Escherichia coli (Gut derived bacterial flora) were a predominant isolate in those who developed fistula which were significantly higher than in the non-fistula group.

In contrast, Staphylococci and Streptococci were the predominant isolate in the non-fistula group in significantly higher rate than fistula group.

Conclusion : careful bacteriological assessment of pus obtained from an anorectic abscess may provide a good indication of future development of fistula in an which may affect subsequent management.