Comparison of preoperative examination findings and endoanal ultrasonography results with operation findings in perianal fistula disease

Abstract

Purpose: The aim of the current study was to compare the preoperative examination findings, endoanal ultrasonography results, and operative findings in patients diagnosed with perianal fistula. Materials and Methods: A prospective study was conducted between 2021 and 2022 on patients who underwent surgical treatment for perianal fistula. The patients were recorded and classified according to the Park classification by the surgeon performing the operation. Subsequently, a surgeon with 10 years of endoanal ultrasonography experience reclassified the patients and recorded the findings (Ultrasonographic Evaluation - USE). The surgery was performed by a different surgeon who was blind to the USE results and the final diagnosis was recorded (Evaluation Under Anesthesia - EAU). The preoperative examination findings, endoanal ultrasonography findings, and operative findings were compared postoperatively. Results: The study included 60 patients, with 52 being male and 8 being female, and a mean age of 44.2 ± 12.6 years. The patients were classified as low transsphincteric (TSF), intersphincteric (ISF), and high TSF at ratios of 40%, 33.3%, and 26.7%, respectively (24, 20, and 16 patients, respectively). Endoanal ultrasonography found that 30%, 35%, and 21.7% of patients had low TSF, ISF, and high TSF, respectively (18, 21, and 13 patients, respectively), while postoperatively, 45%, 33%, and 21.7% of patients were classified as low TSF, ISF, and high TSF, respectively (27, 20, and 13 patients, respectively). The ISF rate in preoperative examination findings was significantly higher than in postoperative diagnoses, with intermediate coherence between the two diagnoses (κ: 0.462). The rates of low and high TSF were found to be significantly higher in ultrasonography findings than in postoperative diagnoses, with high coherence between the two (κ: 0.701). Conclusion: Endoanal ultrasonography is important for mapping, especially for transsphincteric fistulas, in the surgical treatment of perianal fistulas.