Background
Although anal fistula are encountered commonly in surgical practice and have been studied extensively, some complex forms still continue to represent a difficult surgical challenge for many surgeons. The corner stone and the main aim of treatment for an anal fistula is to permanently eliminate abscess formation and achieve healing at the same time preserving anal function and continence. Therefore, precise preoperative assessment of perianal fistulae is crucial to achieving optimal surgical results.
Patients and methods
In this prospective comparative study, 60 patients were enrolled during the period from December 2012 to June 2014. Endoanal ultrasonography (EAUS) (two-dimensional/three-dimensional) with or without H O enhancement was used for the preoperative assessment of perianal fistulae and abscesses, and the degree of accuracy and its agreement with the surgical findings were estimated. Primary fistulous tract and its relation to the sphincter complex, side tracts, internal opening, and any associated sepsis were determined by EAUS; the reviewers were blinded to the findings of the assessment.
Results
In classification of the primary tract, there was agreement between EAUS and surgical findings in 47 of the 60 (78.3%) patients. In terms of the presence of an internal opening, the corresponding figures were 53 (88%) cases. In assessment of the secondary (side) tracts by EAUS, 55 (91.7%) patients were diagnosed accurately. In terms of the diagnosis of the presence or absence of abscess cavity or collection in the cases, EAUS diagnosed 53 (88.3%) patients accurately.
Conclusion
EAUS with its recent innovations of three-dimensional technique and H O enhancement is an excellent modality when planning for fistula surgery, especially with experienced and well-trained operators.