AIM

The aim of this study was to define the role of endorectal ultrasound in the evaluation of transphincteric fistula-in-ano treated with a seton.

METHODS

Fifty-one patients affected by complex fistula-in-ano and treated with the application of a drain seton at the Second Unit of General Surgery of the University of Cagliari were recruited for the study. Clinical and ultrasonographic (US) evaluation, with transanal scans, were performed in each case before operation. Intraoperative demonstration of a transphincteric track was an indication for a partial fistulotomy with the application of a seton, tied up loosely around the external sphincter. If clinical and US evaluation, during follow-up, revealed a good drainage of the fistula by the seton and its superficialization, definitive fistulotomy was performed.

RESULTS

Endoanal US had an 88.2% accuracy. Sclerosis around the seton was observed in 9 patients (17.6%); in other 9 cases a surgical toilette of the track was necessary because of the bad drainage carried out by the seton. Definitive fistulotomy was performed in 35 patients, whilst 16 are still bearer of the seton. After a mean follow-up of 39.5 months, 1 recurrence (2.9%) has occurred. Functional results were satisfactory: 55.9% of the patients has a perfect continence and 88.2% has a Wexner's incontinence score of up to 5.

CONCLUSIONS

At skilled institutions, endoanal ultrasound allows to optimize the therapy of transphincteric fistula-in-ano treated with a seton and contribute to obtain good results in terms of recurrence and functional outcomes.