Abstract
PURPOSE: The aim of the present study was to define endosonographic criteria for an internal opening of fistulain-ano. METHODS: 118 patients with a diagnosis of fistula-in-ano and a control group of 201 cases underwent endosonography in an outpatient setting. Confirmation of an internal opening was performed by intraoperative procedures. RESULTS: Of the 139 cases of fistula-in-ano, the internal opening of 130 cases was confirmed. Analysis of endosonographic findings of the confirmed cases revealed that 122 cases showed positive findings for predictive location of an internal opening, and 8 cases demonstrated negative findings. Fifty-seven cases showed an appearance of a root-like budding formed by the intersphincteric tract that contacts the internal sphincter, classified as Criterion I. Fifty cases demonstrated the appearance of a root-like budding with an internal sphincteric defect, classified as Criterion II. Fifteen cases showed a subepithelial breach connecting to the intersphincteric tract through an internal sphincteric defect, classified as Criterion III. Using the combination of these three criteria, the accuracy was as follows: sensitivity, 94 percent; specificity, 87 percent; positive predictive value, 81 percent; negative predictive value, 96 percent. CONCLUSION: These combined criteria would be of particular help in performing preoperative location of an internal opening with endosonography.
Similar content being viewed by others
References
Garcia-Aguilar J, Belmonte C, Wong WD, Goldberg SM, Madoff RD. Anal fistula surgery: factors associated with recurrence and incontinence. Dis Colon Rectum 1996;39:723–9.
Law PJ, Talbot RW, Bartram CI, Northover JM. Anal endosonography in the evaluation of perianal sepsis and fistula-in-ano. Br J Surg 1989;76:752–5.
Deen KI, Williams JG, Hutchinson R, Keighley MR, Kumar D. Fistula in ano: endoanal ultrasonographic assessment assists decision making for surgery. Gut 1994;35:391–4.
Choen S, Burnett S, Bartram CI, Nicholls RJ. Comparison between anal endosonography and digital examination in the evaluation of anal fistulae. Br J Surg 1991;78:445–7.
Parks AG. Pathogenesis and treatment of fistula-in-ano. Br Med J 1961;1:463–9.
Parks AG, Gordon PH, Hardcastle JD. A classification of fistula-in-ano. Br J Surg 1976;63:1–12.
Cirocco WC, Reilly JC. Challenging the predictive accuracy of Goodsall's rule for anal fistulas. Dis Colon Rectum 1992;35:537–42.
Tjandra JJ, Milsom JW, Stolfi VM,et al. Endoluminal ultrasound defines anatomy of the anal canal and pelvic floor. Dis Colon Rectum 1992;35:465–70.
Bartram CI, Burnett SJ. Atlas of anal endosonography. Oxford, Butterworth-Heinemann, 1991:64–5.
Cheong DM, Nogueras JJ, Wexner SD, Jagelman DG. Anal endosonography for recurrent anal fistulas: image enhancement with hydrogen peroxide. Dis Colon Rectum 1993;36:1158–60.
Bartram CI, Frudinger A. Handbook of anal endosonography. Bristol, Pennsylvania: Wrightson Biomedical Publishing, 1997:26–7.
Author information
Authors and Affiliations
Additional information
Read at the meeting of The American Society of Colon and Rectal Surgeons, San Antonio, Texas, May 2 to 7, 1998.
About this article
Cite this article
Cho, DY. Endosonographic criteria for an internal opening of fistula-in-ano. Dis Colon Rectum 42, 515–518 (1999). https://doi.org/10.1007/BF02234179
Issue Date:
DOI: https://doi.org/10.1007/BF02234179