Garg scoring system to predict long-term healing in cryptoglandular anal fistulas: a prospective validation study

Abstract

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.

Keywords: Fecal incontinence; Magnetic resonance imaging; Rectal fistula; Recurrence.

Fig. 1.

A 52-year-old male patient was operated for right-sided high transsphincteric abscess with supralevator extension. The fistula healed completely on clinical examination at postoperative 3 months with no symptoms or signs. Magnetic resonance imaging (MRI) done at that time showed healed tracts with weighted score of 0 (as per Garg scoring system). The patient is asymptomatic 22 months after surgery. (A) Axial section (schematic diagram). (B) Coronal section (schematic diagram). (C) Preoperative axial T2-weighted MRI. (D) Sketch of Fig. 1C highlighting transsphincteric abscess in green. (E) Preoperative axial short tau inversion recovery (STIR) MRI. (F) Preoperative coronal STIR MRI. (G) Postoperative 3-month axial T2-weighted MRI. (H) Sketch of Fig. 1G. (I) Postoperative 3-month axial STIR MRI. (J) Postoperative 3-month coronal STIR MRI. Arrows indicate fistula location.

Fig. 2.

A 45-year-old male patient was operated for right-sided high transsphincteric horseshoe fistula. The fistula healed completely on clinical examination at postoperative 3 months with no symptoms or signs. However, magnetic resonance imaging (MRI) done at that time showed a residual intersphincteric tract with weighted score of 9 (as per Garg scoring system). The patient was informed about the possibility of recurrence. The patient presented again 20 months after the operation with a large posterior horseshoe abscess. (A) Axial section (schematic diagram). (B) Coronal section (schematic diagram). (C) Preoperative axial T2-weighted MRI showing posterior horseshoe fistula tract. (D) Sketch of Fig. 2C highlighting posterior horseshoe fistula tract in green. (E) Preoperative axial short tau inversion recovery (STIR) MRI showing posterior horseshoe fistula tract. (F) Postoperative 3-month axial T2-weighted MRI showing residual intersphincteric fistula tract. (G) Sketch of Fig. 3F showing residual intersphincteric fistula tract in green. (H) Postoperative 3-month axial STIR MRI showing residual intersphincteric fistula tract. (I) Postoperative 20-month axial T2-weighted MRI showing large posterior horseshoe abscess. (J) Sketch of Fig. 2I showing large posterior horseshoe abscess in green. (K) Postoperative 20-month axial STIR MRI showing large posterior horseshoe abscess. Arrows indicate fistula location.

Fig. 3.

A 33-year-old male patient was operated for a right posterior small intersphincteric abscess and fistula. Magnetic resonance imaging (MRI) done at 3 months after surgery showed a residual intersphincteric tract with weighted score of 10 (as per Garg scoring system). The patient was followed up. At postoperative 12 months, the fistula healed completely clinically as well as on MRI. (A) Axial section (schematic diagram). (B) Coronal section (schematic diagram). (C) Preoperative axial short tau inversion recovery (STIR) MRI showing right posterior intersphincteric fistula. (D) Postoperative 3-month axial STIR MRI showing residual intersphincteric fistula tract. (E) Postoperative 12-month axial STIR MRI showing complete fistula healing. Arrows indicate fistula location.