A Novel MRI and Clinical-Based Scoring System to Assess Post-Surgery Healing and to Predict Long-Term Healing in Cryptoglandular Anal Fistulas

Abstract

Background Anal fistulas cause great uncertainty and anxiety in patients and surgeons alike. This is largely because of the inability to accurately confirm postoperative fistula healing, especially long-term healing. There is no scoring system available that can objectively assess cryptoglandular anal fistulas for postoperative healing and can also accurately predict long-term healing. Methods Several parameters that could indicate anal fistula healing were assessed. Out of these, six parameters (four MRI-based and two clinical) were finalized, and a weighted score was given to each parameter. A novel scoring system (NSS) was developed. A minimum possible score (zero) indicated complete healing whereas the maximum weighted score (n = 20) indicated confirmed non-healing. Scoring was done with postoperative MRI (at least 3 months post-surgery), then compared with the actual healing status, and subsequently correlated with the final long-term clinical outcome. Results The NSS was validated in 183 operated cryptoglandular fistula-in-ano patients over a 3-year period in whom 283 MRIs (preoperative plus postoperative) were performed. The postoperative follow-up was 12–48 months (median-30 months). The NSS was found to have a very high positive predictive value (98.2%) and moderately high negative predictive value (83.7%) for long-term fistula healing. Additionally, its sensitivity and specificity in predicting healing were 93.9% and 94.7%, respectively. Conclusion Thus, this new scoring system is highly accurate and would be a useful tool for surgeons and radiologists managing anal fistulas. By objectivizing the assessment of postoperative healing, it can both ease and streamline management. Moreover, reliable prediction of recurrence-free long-term healing will greatly allay the apprehensions associated with this dreaded disease.

Anal Fistula of Crypto-Glandular Etiology: A Review of the Literature with a Step-by-Step Approach for Diagnosis and Surgical Management

“…Advances in MRI imaging, allow the identification of factors affecting of healing after surgery and in combination with clinical parameters the risk of recurrence may be calculated; recently a new scoring system to predict recurrences was performed 3 months after surgery, based in 4 MRI variables and 2 clinical variables: In MRI the healing or not of the internal opening, of the inter-sphincteric fistulous tract, of external tract in ischiorectal fossa and the presence/lack of a new abscess in inter-sphincteric space postoperatively, are considered risk factors for recurrence. In fact on clinical examination, the passage or not of flatus from any external opening and the discharge or not of liquid excretions intraanally or via an external opening are important factors to estimate the risk of recurrence [11] .…”

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

“…This was the first scoring system described for cryptoglandular anal fistulas. However, that was a retrospective study [5]. The validity of the new scoring system (GSS) is evaluated prospectively in this study.…”

“…A fistula that may appear clinically well healed (cessation of all pus discharge and absence of any swelling or pain in the perianal region) can still recur months and even years after surgery [4]. This causes a lot of anxiety and frustration in patients' minds as even a clinical cure provides little reassurance, and the fear of recurrence looms large for several years [5]. Another problem with unpredictability is that it becomes quite difficult to ascertain the efficacy of any procedure utilized for anal fistulas [4].…”

“…Garg et al [5] proposed a new scoring system (Garg scoring system [GSS]) which was shown to be effective in predicting longterm healing in cryptoglandular anal fistulas with a positive predictive value (PPV) of 98.2%. This was the first scoring system described for cryptoglandular anal fistulas.…”

“…Total weighted score of < 8 indicates healing; total weighted score of ≥ 8 indicates non-healing. Reused from Garg et al[5] according to the Creative Commons License of Dovepress' open access publishing.…”