Multiple scale of complexity for anorectal fistulas

Background: Anorectal fistulas are common and difficult to manage. Objective: To create a scale of complexity through the identification, description of medical history, clinical and ultrasonographic findings. To reduce the rate of recurrence and complications in fistulas is the treatment goal. Patient's inherent traits increase the complexity of anorectal fistulas with the risks of incontinence, delayed healing, infections, and requiring difficult surgeries. The aim of this study was to create a scale of complexity through identification, description of medical history, and clinical and ultrasonography (USG) findings. Patients and Methods: Retrospective study of a prospectively maintained database conducted at two Venezuelan hospitals. All patients who underwent anorectal USG examination at our institutions between 2010 and 2017 were investigated and included in the numerical scoring system, which categorizes the risk of fistula into simple, intermediate, and complex. The Chi-square test of the Statistical Program of Social Sciences (SPSS) was used to establish the significance level, P < 0.005. One thousand one hundred and seventy-three patients were evaluated, and perianal fistula was identified in 989 patients. Results: Of the 232 intersphincteric fistulas, 75.86% were simple, 22.41% were intermediate, and 1.72% were complex. Of the 295 lower transsphincteric fistulas, 51.19% were simple, 42.71% intermediate, and 6.10% were complex. Of the 327 high transsphincteric fistulas, 17.74% were simple, 59.94% were intermediate, and 22.32% were complex. Of the 48 extrasphincteric fistulas, 66.67% were intermediate, and 33.33% were complex. Finally, of the 18 suprasphincteric fistulas, 50% were intermediate and 50% were complex. Conclusions: The complexity of the fistula may not be obvious in routine thorough clinical evaluation, requiring complementary studies. Using the scale avoids excluding factors that indicate complexity, with a statistically significant difference with the classification based exclusively on tracts. Limitation: The limitation of this study is that it is a retrospective single medical group study.