Anal fistula can be a challenging condition to manage, with complex fistulas presenting even greater difficulties. The primary concerns in treating this condition are a risk of damage to the anal sphincters, which can compromise fecal continence, and refractoriness to treatment, as evidenced by a high recurrence rate. Furthermore, the treatment of complex anal fistula involves several additional challenges. Satisfactory solutions to many of these obstacles remain elusive, and no consensus has been established regarding the available treatment options. In summary, complex anal fistula has no established gold-standard treatment, and the quest for effective therapies continues. This review discusses and highlights groundbreaking advances in the management of complex anal fistula over the past decade.

Anal fistulas, especially complex and high fistulas, are difficult to manage. The transanal opening of the intersphincteric space (TROPIS) procedure was first described in 2017, and a high success rate of over 90% was reported in high complex fistulas. Since then, more studies and even a meta-analysis have corroborated the high efficacy of this procedure in high fistulas. Conventionally, the main focus was to close the internal (primary) opening for the fistula to heal. However, most complex fistulas have a component of the fistula tract in the intersphincteric plane. This component is like an abscess (sepsis) in a closed space (2 muscle layers). It is a well-known fact that in the presence of sepsis, healing by secondary intention leads to better results than attempting to heal by primary intention. Therefore, TROPIS is the first procedure in which, instead of closing the internal opening, the opening is widened by laying open the fistula tract in the intersphincteric plane so that healing can occur by secondary intention. Although the drainage of high intersphincteric abscesses through the transanal route was described 5 decades ago, the routine utilization of TROPIS for the definitive management of high complex fistulas was first described in 2017. The external anal sphincter (EAS) is completely spared in TROPIS, as the fistula tract on either side of the EAS is managed separately—inner (medial) to the EAS by laying open the intersphincteric space and outer (lateral) to the EAS by curettage or excision.

Purpose: Complex anal fistulas can recur after clinical healing, even after a long interval which leads to significant anxiety. Also, ascertaining the efficacy of any new treatment procedure becomes difficult and takes several years. We prospectively analyzed the validity of Garg scoring system (GSS) to predict long-term fistula healing. Methods: In patients operated for cryptoglandular anal fistulas, magnetic resonance imaging was performed preoperatively and at 3 months postoperatively to assess fistula healing. Scores as per the GSS were calculated for each patient at 3 months postoperatively and correlated with long-term healing to check the accuracy of the scoring system. Results: Fifty-seven patients were enrolled, but 50 were finally included (7 were excluded). These 50 patients (age, 41.2±12.4 years; 46 men) were followed up for 12 to 20 months (median, 17 months). Forty-seven patients (94.0%) had complex fistulas, 28 (56.0%) had recurrent fistulas, 48 (96.0%) had multiple tracts, 20 (40.0%) had horseshoe tracts, 15 (32.0%) had associated abscesses, 5 (10.0%) were suprasphincteric, and 8 (16.0%) were supralevator fistulas. The GSS could accurately predict long-term healing (high positive predictive value, 31 of 31 [100%]) but was not very accurate in predicting nonhealing (negative predictive value, 15 of 19 [78.9%]). The sensitivity in predicting healing was 31 of 35 (88.6%). Conclusion GSS accurately predicts long-term fistula with a high positive predictive value (100%) but is less accurate in predicting nonhealing. This scoring system can help allay anxiety in patients and facilitate the early validation of innovative procedures for anal fistulas.